Nuclear translocation of the Hsp70/Hsp90 organizing protein mSTI1 is regulated by cell cycle kinases
- Longshaw, Victoria M, Chapple, J Paul, Cheetham, Michael E, Blatch, Gregory L
- Authors: Longshaw, Victoria M , Chapple, J Paul , Cheetham, Michael E , Blatch, Gregory L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6488 , http://hdl.handle.net/10962/d1006271 , https://dx.doi.org/10.1242/jcs.00905
- Description: The co-chaperone murine stress-inducible protein 1 (mSTI1), an Hsp70/Hsp90 organizing protein (Hop) homologue, mediates the assembly of the Hsp70/Hsp90 chaperone heterocomplex. The mSTI1 protein can be phosphorylated in vitro by cell cycle kinases proximal to a putative nuclear localization signal (NLS), which substantiated a predicted casein kinase II (CKII)-cdc2 kinase-NLS (CcN) motif at position 180-239 and suggested that mSTI1 might move between the cytoplasm and the nucleus under certain cell cycle conditions. The mechanism responsible for the cellular localization of mSTI1 was probed using NIH3T3 fibroblasts to investigate the localization of endogenous mSTI1 and enhanced green fluorescent protein (EGFP)-tagged mSTI1 mutants. Localization studies on cell lines stably expressing NLS(mSTI1)-EGFP and EGFP demonstrated that the NLS(mSTI1) was able to promote a nuclear localization of EGFP. The mSTI1 protein was exclusively cytoplasmic in most cells under normal conditions but was present in the nucleus of a subpopulation of cells and accumulated in the nucleus following inhibition of nuclear export (leptomycin B treatment). G1/S-phase arrest (using hydroxyurea) and inhibition of cdc2 kinase (using olomoucine) but not inhibition of casein kinase II (using 5,6-dichlorobenzimidazole riboside), increased the proportion of cells with endogenous mSTI1 nuclear staining. mSTI1-EGFP behaved identically to endogenous mSTI1. The functional importance of key residues was tested using modified mSTI1-EGFP proteins. Inactivation and phosphorylation mimicking of potential phosphorylation sites in mSTI1 altered the nuclear translocation. Mimicking of phosphorylation at the mSTI1 CKII phosphorylation site (S189E) promoted nuclear localization of mSTI1-EGFP. Mimicking phosphorylation at the cdc2 kinase phosphorylation site (T198E) promoted cytoplasmic localization of mSTI1-EGFP at the G1/S-phase transition,whereas removal of this site (T198A) promoted the nuclear localization of mSTI1-EGFP under the same conditions. These data provide the first evidence of nuclear import and export of a major Hsp70/Hsp90 co-chaperone and the regulation of this nuclear-cytoplasmic shuttling by cell cycle status and cell cycle kinases.
- Full Text:
- Date Issued: 2004
Nuclear translocation of the Hsp70/Hsp90 organizing protein mSTI1 is regulated by cell cycle kinases
- Authors: Longshaw, Victoria M , Chapple, J Paul , Cheetham, Michael E , Blatch, Gregory L
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6488 , http://hdl.handle.net/10962/d1006271 , https://dx.doi.org/10.1242/jcs.00905
- Description: The co-chaperone murine stress-inducible protein 1 (mSTI1), an Hsp70/Hsp90 organizing protein (Hop) homologue, mediates the assembly of the Hsp70/Hsp90 chaperone heterocomplex. The mSTI1 protein can be phosphorylated in vitro by cell cycle kinases proximal to a putative nuclear localization signal (NLS), which substantiated a predicted casein kinase II (CKII)-cdc2 kinase-NLS (CcN) motif at position 180-239 and suggested that mSTI1 might move between the cytoplasm and the nucleus under certain cell cycle conditions. The mechanism responsible for the cellular localization of mSTI1 was probed using NIH3T3 fibroblasts to investigate the localization of endogenous mSTI1 and enhanced green fluorescent protein (EGFP)-tagged mSTI1 mutants. Localization studies on cell lines stably expressing NLS(mSTI1)-EGFP and EGFP demonstrated that the NLS(mSTI1) was able to promote a nuclear localization of EGFP. The mSTI1 protein was exclusively cytoplasmic in most cells under normal conditions but was present in the nucleus of a subpopulation of cells and accumulated in the nucleus following inhibition of nuclear export (leptomycin B treatment). G1/S-phase arrest (using hydroxyurea) and inhibition of cdc2 kinase (using olomoucine) but not inhibition of casein kinase II (using 5,6-dichlorobenzimidazole riboside), increased the proportion of cells with endogenous mSTI1 nuclear staining. mSTI1-EGFP behaved identically to endogenous mSTI1. The functional importance of key residues was tested using modified mSTI1-EGFP proteins. Inactivation and phosphorylation mimicking of potential phosphorylation sites in mSTI1 altered the nuclear translocation. Mimicking of phosphorylation at the mSTI1 CKII phosphorylation site (S189E) promoted nuclear localization of mSTI1-EGFP. Mimicking phosphorylation at the cdc2 kinase phosphorylation site (T198E) promoted cytoplasmic localization of mSTI1-EGFP at the G1/S-phase transition,whereas removal of this site (T198A) promoted the nuclear localization of mSTI1-EGFP under the same conditions. These data provide the first evidence of nuclear import and export of a major Hsp70/Hsp90 co-chaperone and the regulation of this nuclear-cytoplasmic shuttling by cell cycle status and cell cycle kinases.
- Full Text:
- Date Issued: 2004
Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective
- Edkins, Adrienne L, Price, John T, Pockley, A Graham, Blatch, Gregory L
- Authors: Edkins, Adrienne L , Price, John T , Pockley, A Graham , Blatch, Gregory L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164332 , vital:41109 , DOI: 10.1098/rstb.2016.0521
- Description: Many heat shock proteins (HSPs) are essential to survival as a consequence of their role as molecular chaperones, and play a critical role in maintaining cellular proteostasis by integrating the fundamental processes of protein folding and degradation. HSPs are arguably among the most prominent classes of proteins that have been broadly linked to many human disorders, with changes in their expression profile and/or intracellular/extracellular location now being described as contributing to the pathogenesis of a number of different diseases. Although the concept was initially controversial, it is now widely accepted that HSPs have additional biological functions over and above their role in proteostasis (so-called ‘protein moonlighting’).
- Full Text:
- Date Issued: 2017
- Authors: Edkins, Adrienne L , Price, John T , Pockley, A Graham , Blatch, Gregory L
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164332 , vital:41109 , DOI: 10.1098/rstb.2016.0521
- Description: Many heat shock proteins (HSPs) are essential to survival as a consequence of their role as molecular chaperones, and play a critical role in maintaining cellular proteostasis by integrating the fundamental processes of protein folding and degradation. HSPs are arguably among the most prominent classes of proteins that have been broadly linked to many human disorders, with changes in their expression profile and/or intracellular/extracellular location now being described as contributing to the pathogenesis of a number of different diseases. Although the concept was initially controversial, it is now widely accepted that HSPs have additional biological functions over and above their role in proteostasis (so-called ‘protein moonlighting’).
- Full Text:
- Date Issued: 2017
STIP1/HOP regulates the actin cytoskeleton through interactions with actin and changes in actin-binding proteins cofilin and profilin:
- Beckley, Samantha Joy, Hunter, Morgan C, Kituyi, Sarah N, Wingate, Ianthe, Chakraborty, Abantika, Schwarz, Kelly, Makhubu, Matodzi P, Rousseau, Robert P, Ruck, Duncan K, de la Mare, Jo-Anne, Blatch, Gregory L, Edkins, Adrienne L
- Authors: Beckley, Samantha Joy , Hunter, Morgan C , Kituyi, Sarah N , Wingate, Ianthe , Chakraborty, Abantika , Schwarz, Kelly , Makhubu, Matodzi P , Rousseau, Robert P , Ruck, Duncan K , de la Mare, Jo-Anne , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165373 , vital:41238 , https://doi.org/10.3390/ijms21093152
- Description: Cell migration plays a vital role in both health and disease. It is driven by reorganization of the actin cytoskeleton, which is regulated by actin-binding proteins cofilin and profilin. Stress-inducible phosphoprotein 1 (STIP1) is a well-described co-chaperone of the Hsp90 chaperone system, and our findings identify a potential regulatory role of STIP1 in actin dynamics. We show that STIP1 can be isolated in complex with actin and Hsp90 from HEK293T cells and directly interacts with actin in vitro via the C-terminal TPR2AB-DP2 domain of STIP1, potentially due to a region spanning two putative actin-binding motifs. We found that STIP1 could stimulate the in vitro ATPase activity of actin, suggesting a potential role in the modulation of F-actin formation. Interestingly, while STIP1 depletion in HEK293T cells had no major effect on total actin levels, it led to increased nuclear accumulation of actin, disorganization of F-actin structures, and an increase and decrease in cofilin and profilin levels, respectively. This study suggests that STIP1 regulates the cytoskeleton by interacting with actin, or via regulating the ratio of proteins known to affect actin dynamics.
- Full Text:
- Date Issued: 2020
- Authors: Beckley, Samantha Joy , Hunter, Morgan C , Kituyi, Sarah N , Wingate, Ianthe , Chakraborty, Abantika , Schwarz, Kelly , Makhubu, Matodzi P , Rousseau, Robert P , Ruck, Duncan K , de la Mare, Jo-Anne , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165373 , vital:41238 , https://doi.org/10.3390/ijms21093152
- Description: Cell migration plays a vital role in both health and disease. It is driven by reorganization of the actin cytoskeleton, which is regulated by actin-binding proteins cofilin and profilin. Stress-inducible phosphoprotein 1 (STIP1) is a well-described co-chaperone of the Hsp90 chaperone system, and our findings identify a potential regulatory role of STIP1 in actin dynamics. We show that STIP1 can be isolated in complex with actin and Hsp90 from HEK293T cells and directly interacts with actin in vitro via the C-terminal TPR2AB-DP2 domain of STIP1, potentially due to a region spanning two putative actin-binding motifs. We found that STIP1 could stimulate the in vitro ATPase activity of actin, suggesting a potential role in the modulation of F-actin formation. Interestingly, while STIP1 depletion in HEK293T cells had no major effect on total actin levels, it led to increased nuclear accumulation of actin, disorganization of F-actin structures, and an increase and decrease in cofilin and profilin levels, respectively. This study suggests that STIP1 regulates the cytoskeleton by interacting with actin, or via regulating the ratio of proteins known to affect actin dynamics.
- Full Text:
- Date Issued: 2020
The TPR2B domain of the Hsp70/Hsp90 organizing protein (Hop) may contribute towards its dimerization
- Longshaw, Victoria M, Stephens, Linda L, Daniel, Sheril, Blatch, Gregory L
- Authors: Longshaw, Victoria M , Stephens, Linda L , Daniel, Sheril , Blatch, Gregory L
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6481 , http://hdl.handle.net/10962/d1006253 , http://dx.doi.org/10.2174/092986609787848162
- Description: The role of the TPR2B domain of Hop is as yet unknown. We have shown here by site directed mutagenesis and size exclusion chromatography for the first time that the TPR1 and TPR2B domains of Hop independently dimerized, and that the dimerization of TPR2B was not dependent on its predicted two-carboxylate clamp residues. Furthermore, our data indicated that the dimerization of Hop and its domains was not disrupted in the presence of Hsp70 and Hsp90 peptides.
- Full Text:
- Date Issued: 2009
The TPR2B domain of the Hsp70/Hsp90 organizing protein (Hop) may contribute towards its dimerization
- Authors: Longshaw, Victoria M , Stephens, Linda L , Daniel, Sheril , Blatch, Gregory L
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6481 , http://hdl.handle.net/10962/d1006253 , http://dx.doi.org/10.2174/092986609787848162
- Description: The role of the TPR2B domain of Hop is as yet unknown. We have shown here by site directed mutagenesis and size exclusion chromatography for the first time that the TPR1 and TPR2B domains of Hop independently dimerized, and that the dimerization of TPR2B was not dependent on its predicted two-carboxylate clamp residues. Furthermore, our data indicated that the dimerization of Hop and its domains was not disrupted in the presence of Hsp70 and Hsp90 peptides.
- Full Text:
- Date Issued: 2009
Not all J domains are created equal: implications for the specificity of Hsp40-Hsp70 interactions
- Hennessy, Fritha, Nicoll, Willam S, Zimmerman, Richard, Cheetham, Michael E, Blatch, Gregory L
- Authors: Hennessy, Fritha , Nicoll, Willam S , Zimmerman, Richard , Cheetham, Michael E , Blatch, Gregory L
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6487 , http://hdl.handle.net/10962/d1006270 , http://dx.doi.org/10.1110/ps.051406805
- Description: Heat shock protein 40s (Hsp40s) and heat shock protein 70s (Hsp70s) form chaperone partnerships that are key components of cellular chaperone networks involved in facilitating the correct folding of a broad range of client proteins. While the Hsp40 family of proteins is highly diverse with multiple forms occurring in any particular cell or compartment, all its members are characterized by a J domain that directs their interaction with a partner Hsp70. Specific Hsp40-Hsp70 chaperone partnerships have been identified that are dedicated to the correct folding of distinct subsets of client proteins. The elucidation of the mechanism by which these specific Hsp40-Hsp70 partnerships are formed will greatly enhance our understanding of the way in which chaperone pathways are integrated into finely regulated protein folding networks. From in silico analyses, domain swapping and rational protein engineering experiments, evidence has accumulated that indicates that J domains contain key specificity determinants. This review will critically discuss the current understanding of the structural features of J domains that determine the specificity of interaction between Hsp40 proteins and their partner Hsp70s. We also propose a model in which the J domain is able to integrate specificity and chaperone activity.
- Full Text:
- Date Issued: 2005
- Authors: Hennessy, Fritha , Nicoll, Willam S , Zimmerman, Richard , Cheetham, Michael E , Blatch, Gregory L
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6487 , http://hdl.handle.net/10962/d1006270 , http://dx.doi.org/10.1110/ps.051406805
- Description: Heat shock protein 40s (Hsp40s) and heat shock protein 70s (Hsp70s) form chaperone partnerships that are key components of cellular chaperone networks involved in facilitating the correct folding of a broad range of client proteins. While the Hsp40 family of proteins is highly diverse with multiple forms occurring in any particular cell or compartment, all its members are characterized by a J domain that directs their interaction with a partner Hsp70. Specific Hsp40-Hsp70 chaperone partnerships have been identified that are dedicated to the correct folding of distinct subsets of client proteins. The elucidation of the mechanism by which these specific Hsp40-Hsp70 partnerships are formed will greatly enhance our understanding of the way in which chaperone pathways are integrated into finely regulated protein folding networks. From in silico analyses, domain swapping and rational protein engineering experiments, evidence has accumulated that indicates that J domains contain key specificity determinants. This review will critically discuss the current understanding of the structural features of J domains that determine the specificity of interaction between Hsp40 proteins and their partner Hsp70s. We also propose a model in which the J domain is able to integrate specificity and chaperone activity.
- Full Text:
- Date Issued: 2005
Hsp70/Hsp90 organising protein (hop): beyond interactions with chaperones and prion proteins
- Baindur-Hudson, Swati, Edkins, Adrienne L, Blatch, Gregory L
- Authors: Baindur-Hudson, Swati , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/164852 , vital:41178 , ISBN 978-3-319-11730-0 , DOI: 10.1007/978-3-319-11731-7_3
- Description: The Hsp70/Hsp90 organising protein (Hop), also known as stress-inducible protein 1 (STI1), has received considerable attention for diverse cellular functions in both healthy and diseased states. There is extensive evidence that intracellular Hop is a co-chaperone of the major chaperones Hsp70 and Hsp90, playing an important role in the productive folding of Hsp90 client proteins. Consequently, Hop is implicated in a number of key signalling pathways, including aberrant pathways leading to cancer. However, Hop is also secreted and it is now well established that Hop also serves as a receptor for the prion protein, PrPC.
- Full Text:
- Date Issued: 2015
- Authors: Baindur-Hudson, Swati , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2015
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/164852 , vital:41178 , ISBN 978-3-319-11730-0 , DOI: 10.1007/978-3-319-11731-7_3
- Description: The Hsp70/Hsp90 organising protein (Hop), also known as stress-inducible protein 1 (STI1), has received considerable attention for diverse cellular functions in both healthy and diseased states. There is extensive evidence that intracellular Hop is a co-chaperone of the major chaperones Hsp70 and Hsp90, playing an important role in the productive folding of Hsp90 client proteins. Consequently, Hop is implicated in a number of key signalling pathways, including aberrant pathways leading to cancer. However, Hop is also secreted and it is now well established that Hop also serves as a receptor for the prion protein, PrPC.
- Full Text:
- Date Issued: 2015
HOP expression is regulated by p53 and RAS and characteristic of a cancer gene signature
- Mattison, Stacey A, Blatch, Gregory L, Edkins, Adrienne L
- Authors: Mattison, Stacey A , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66278 , vital:28928 , https://doi.org/10.1007/s12192-016-0755-8
- Description: publisher version , The Hsp70/Hsp90 organising protein (HOP) is a co-chaperone essential for client protein transfer from Hsp70 to Hsp90 within the Hsp90 chaperone machine. Although HOP is upregulated in various cancers, there is limited information from in vitro studies on how HOP expression is regulated in cancer. The main objective of this study was to identify the HOP promoter and investigate its activity in cancerous cells. Bioinformatic analysis of the -2500 to +16 bp region of the HOP gene identified a large CpG island and a range of putative cis-elements. Many of the cis-elements were potentially bound by transcription factors which are activated by oncogenic pathways. Luciferase reporter assays demonstrated that the upstream region of the HOP gene contains an active promoter in vitro. Truncation of this region suggested that the core HOP promoter region was -855 to +16 bp. HOP promoter activity was highest in Hs578T, HEK293T and SV40- transformed MEF1 cell lines which expressed mutant or inactive p53. In a mutant p53 background, expression of wild-type p53 led to a reduction in promoter activity, while inhibition of wild-type p53 in HeLa cells increased HOP promoter activity. Additionally, in Hs578T and HEK293T cell lines containing inactive p53, expression of HRAS increased HOP promoter activity. However, HRAS activation of the HOP promoter was inhibited by p53 overexpression. These findings suggest for the first time that HOP expression in cancer may be regulated by both RAS activation and p53 inhibition. Taken together, these data suggest that HOP may be part of the cancer gene signature induced by a combination of mutant p53 and mutated RAS that is associated with cellular transformation.
- Full Text: false
- Date Issued: 2018
- Authors: Mattison, Stacey A , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66278 , vital:28928 , https://doi.org/10.1007/s12192-016-0755-8
- Description: publisher version , The Hsp70/Hsp90 organising protein (HOP) is a co-chaperone essential for client protein transfer from Hsp70 to Hsp90 within the Hsp90 chaperone machine. Although HOP is upregulated in various cancers, there is limited information from in vitro studies on how HOP expression is regulated in cancer. The main objective of this study was to identify the HOP promoter and investigate its activity in cancerous cells. Bioinformatic analysis of the -2500 to +16 bp region of the HOP gene identified a large CpG island and a range of putative cis-elements. Many of the cis-elements were potentially bound by transcription factors which are activated by oncogenic pathways. Luciferase reporter assays demonstrated that the upstream region of the HOP gene contains an active promoter in vitro. Truncation of this region suggested that the core HOP promoter region was -855 to +16 bp. HOP promoter activity was highest in Hs578T, HEK293T and SV40- transformed MEF1 cell lines which expressed mutant or inactive p53. In a mutant p53 background, expression of wild-type p53 led to a reduction in promoter activity, while inhibition of wild-type p53 in HeLa cells increased HOP promoter activity. Additionally, in Hs578T and HEK293T cell lines containing inactive p53, expression of HRAS increased HOP promoter activity. However, HRAS activation of the HOP promoter was inhibited by p53 overexpression. These findings suggest for the first time that HOP expression in cancer may be regulated by both RAS activation and p53 inhibition. Taken together, these data suggest that HOP may be part of the cancer gene signature induced by a combination of mutant p53 and mutated RAS that is associated with cellular transformation.
- Full Text: false
- Date Issued: 2018
The ataxia protein sacsin is a functional co-chaperone that protects against polyglutamine-expanded ataxin-1
- Parfitt, David A, Michael, Gregory J, Vermeulen, Esmeralda G M, Prodromou, Natalia V, Webb, Tom R, Gallo, Jean-Marc, Cheetham, Michael E, Nicoll, William S, Blatch, Gregory L, Chapple, J Paul
- Authors: Parfitt, David A , Michael, Gregory J , Vermeulen, Esmeralda G M , Prodromou, Natalia V , Webb, Tom R , Gallo, Jean-Marc , Cheetham, Michael E , Nicoll, William S , Blatch, Gregory L , Chapple, J Paul
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6485 , http://hdl.handle.net/10962/d1006262 , http://hmg.oxfordjournals.org/content/18/9/1556
- Description: An extensive protein–protein interaction network has been identified between proteins implicated in inherited ataxias. The protein sacsin, which is mutated in the early-onset neurodegenerative disease autosomal recessive spastic ataxia of Charlevoix-Saguenay, is a node in this interactome. Here, we have established the neuronal expression of sacsin and functionally characterized domains of the 4579 amino acid protein. Sacsin is most highly expressed in large neurons, particularly within brain motor systems, including cerebellar Purkinje cells. Its subcellular localization in SH-SY5Y neuroblastoma cells was predominantly cytoplasmic with a mitochondrial component. We identified a putative ubiquitin-like (UbL) domain at the N-terminus of sacsin and demonstrated an interaction with the proteasome. Furthermore, sacsin contains a predicted J-domain, the defining feature of DnaJ/Hsp40 proteins. Using a bacterial complementation assay, the sacsin J-domain was demonstrated to be functional. The presence of both UbL and J-domains in sacsin suggests that it may integrate the ubiquitin–proteasome system and Hsp70 function to a specific cellular role. The Hsp70 chaperone machinery is an important component of the cellular response towards aggregation prone mutant proteins that are associated with neurodegenerative diseases. We therefore investigated the effects of siRNA-mediated sacsin knockdown on polyglutamine-expanded ataxin-1. Importantly, SACS siRNA did not affect cell viability with GFP-ataxin-1[30Q], but enhanced the toxicity of GFP-ataxin- 1[82Q], suggesting that sacsin is protective against mutant ataxin-1. Thus, sacsin is an ataxia protein and a regulator of the Hsp70 chaperone machinery that is implicated in the processing of other ataxialinked proteins.
- Full Text:
- Date Issued: 2009
- Authors: Parfitt, David A , Michael, Gregory J , Vermeulen, Esmeralda G M , Prodromou, Natalia V , Webb, Tom R , Gallo, Jean-Marc , Cheetham, Michael E , Nicoll, William S , Blatch, Gregory L , Chapple, J Paul
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6485 , http://hdl.handle.net/10962/d1006262 , http://hmg.oxfordjournals.org/content/18/9/1556
- Description: An extensive protein–protein interaction network has been identified between proteins implicated in inherited ataxias. The protein sacsin, which is mutated in the early-onset neurodegenerative disease autosomal recessive spastic ataxia of Charlevoix-Saguenay, is a node in this interactome. Here, we have established the neuronal expression of sacsin and functionally characterized domains of the 4579 amino acid protein. Sacsin is most highly expressed in large neurons, particularly within brain motor systems, including cerebellar Purkinje cells. Its subcellular localization in SH-SY5Y neuroblastoma cells was predominantly cytoplasmic with a mitochondrial component. We identified a putative ubiquitin-like (UbL) domain at the N-terminus of sacsin and demonstrated an interaction with the proteasome. Furthermore, sacsin contains a predicted J-domain, the defining feature of DnaJ/Hsp40 proteins. Using a bacterial complementation assay, the sacsin J-domain was demonstrated to be functional. The presence of both UbL and J-domains in sacsin suggests that it may integrate the ubiquitin–proteasome system and Hsp70 function to a specific cellular role. The Hsp70 chaperone machinery is an important component of the cellular response towards aggregation prone mutant proteins that are associated with neurodegenerative diseases. We therefore investigated the effects of siRNA-mediated sacsin knockdown on polyglutamine-expanded ataxin-1. Importantly, SACS siRNA did not affect cell viability with GFP-ataxin-1[30Q], but enhanced the toxicity of GFP-ataxin- 1[82Q], suggesting that sacsin is protective against mutant ataxin-1. Thus, sacsin is an ataxia protein and a regulator of the Hsp70 chaperone machinery that is implicated in the processing of other ataxialinked proteins.
- Full Text:
- Date Issued: 2009
The complex immunological and inflammatory network of adipose tissue in obesity
- Apostolopoulos, Vasso, De Courten, Maximilian P J, Stojanovska, Lily, Blatch, Gregory L, Tangalakis, Kathy, De Courten, Barbora
- Authors: Apostolopoulos, Vasso , De Courten, Maximilian P J , Stojanovska, Lily , Blatch, Gregory L , Tangalakis, Kathy , De Courten, Barbora
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66120 , vital:28905 , https://doi.org/10.1002/mnfr.201500272
- Description: publisher version , A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low‐grade inflammation which is characterized by activation and infiltration of pro‐inflammatory immune cells and a dysregulated production of high levels of pro‐inflammatory cytokines. This pro‐inflammatory milieu contributes to insulin resistance, type‐2 diabetes, cardiovascular disease, and other related co‐morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity‐related diseases.
- Full Text: false
- Date Issued: 2016
- Authors: Apostolopoulos, Vasso , De Courten, Maximilian P J , Stojanovska, Lily , Blatch, Gregory L , Tangalakis, Kathy , De Courten, Barbora
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66120 , vital:28905 , https://doi.org/10.1002/mnfr.201500272
- Description: publisher version , A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low‐grade inflammation which is characterized by activation and infiltration of pro‐inflammatory immune cells and a dysregulated production of high levels of pro‐inflammatory cytokines. This pro‐inflammatory milieu contributes to insulin resistance, type‐2 diabetes, cardiovascular disease, and other related co‐morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity‐related diseases.
- Full Text: false
- Date Issued: 2016
Nuclear translocation of the phosphoprotein Hop (Hsp70/Hsp90 organizing protein) occurs under heat shock, and its proposed nuclear localization signal is involved in Hsp90 binding
- Daniel, Sheril, Bradley, Graeme, Longshaw, Victoria M, Söti, Csaba, Csermely, Peter, Blatch, Gregory L
- Authors: Daniel, Sheril , Bradley, Graeme , Longshaw, Victoria M , Söti, Csaba , Csermely, Peter , Blatch, Gregory L
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6472 , http://hdl.handle.net/10962/d1005951 , http://dx.doi.org/10.1016/j.bbamcr.2008.01.014
- Description: The Hsp70–Hsp90 complex is implicated in the folding and regulation of numerous signaling proteins, and Hop, the Hsp70–Hsp90 Organizing Protein, facilitates the association of this multichaperone machinery. Phosphatase treatment of mouse cell extracts reduced the number of Hop isoforms compared to untreated extracts, providing the first direct evidence that Hop was phosphorylated in vivo. Furthermore, surface plasmon resonance (SPR) spectroscopy showed that a cdc2 kinase phosphorylation mimic of Hop had reduced affinity for Hsp90 binding. Hop was predominantly cytoplasmic, but translocated to the nucleus in response to heat shock. A putative bipartite nuclear localization signal (NLS) has been identified within the Hsp90-binding domain of Hop. Although substitution of residues within the major arm of this proposed NLS abolished Hop–Hsp90 interaction as determined by SPR, this was not sufficient to prevent the nuclear accumulation of Hop under leptomycin-B treatment and heat shock conditions. These results showed for the first time that the subcellular localization of Hop was stress regulated and that the major arm of the putative NLS was not directly important for nuclear translocation but was critical for Hop–Hsp90 association in vitro. We propose a model in which the association of Hop with Hsp90 and the phosphorylated status of Hop both play a role in the mechanism of nucleo-cytoplasmic shuttling of Hop.
- Full Text:
- Date Issued: 2008
- Authors: Daniel, Sheril , Bradley, Graeme , Longshaw, Victoria M , Söti, Csaba , Csermely, Peter , Blatch, Gregory L
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6472 , http://hdl.handle.net/10962/d1005951 , http://dx.doi.org/10.1016/j.bbamcr.2008.01.014
- Description: The Hsp70–Hsp90 complex is implicated in the folding and regulation of numerous signaling proteins, and Hop, the Hsp70–Hsp90 Organizing Protein, facilitates the association of this multichaperone machinery. Phosphatase treatment of mouse cell extracts reduced the number of Hop isoforms compared to untreated extracts, providing the first direct evidence that Hop was phosphorylated in vivo. Furthermore, surface plasmon resonance (SPR) spectroscopy showed that a cdc2 kinase phosphorylation mimic of Hop had reduced affinity for Hsp90 binding. Hop was predominantly cytoplasmic, but translocated to the nucleus in response to heat shock. A putative bipartite nuclear localization signal (NLS) has been identified within the Hsp90-binding domain of Hop. Although substitution of residues within the major arm of this proposed NLS abolished Hop–Hsp90 interaction as determined by SPR, this was not sufficient to prevent the nuclear accumulation of Hop under leptomycin-B treatment and heat shock conditions. These results showed for the first time that the subcellular localization of Hop was stress regulated and that the major arm of the putative NLS was not directly important for nuclear translocation but was critical for Hop–Hsp90 association in vitro. We propose a model in which the association of Hop with Hsp90 and the phosphorylated status of Hop both play a role in the mechanism of nucleo-cytoplasmic shuttling of Hop.
- Full Text:
- Date Issued: 2008
Plasmodium falciparum Hep1 is required to prevent the self aggregation of PfHsp70-3
- Nyakundi, David O, Vuko, Loyiso A M, Bentley, Stephen J, Hoppe, Heinrich C, Blatch, Gregory L, Boshoff, Aileen
- Authors: Nyakundi, David O , Vuko, Loyiso A M , Bentley, Stephen J , Hoppe, Heinrich C , Blatch, Gregory L , Boshoff, Aileen
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66109 , vital:28903 , https://doi.org/10.1371/journal.pone.0156446
- Description: publisher version , The majority of mitochondrial proteins are encoded in the nucleus and need to be imported from the cytosol into the mitochondria, and molecular chaperones play a key role in the efficient translocation and proper folding of these proteins in the matrix. One such molecular chaperone is the eukaryotic mitochondrial heat shock protein 70 (Hsp70); however, it is prone to self-aggregation and requires the presence of an essential zinc-finger protein, Hsp70-escort protein 1 (Hep1), to maintain its structure and function. PfHsp70-3, the only Hsp70 predicted to localize in the mitochondria of P. falciparum, may also rely on a Hep1 orthologue to prevent self-aggregation. In this study, we identified a putative Hep1 orthologue in P. falciparum and co-expression of PfHsp70-3 and PfHep1 enhanced the solubility of PfHsp70-3. PfHep1 suppressed the thermally induced aggregation of PfHsp70-3 but not the aggregation of malate dehydrogenase or citrate synthase, thus showing specificity for PfHsp70-3. Zinc ions were indeed essential for maintaining the function of PfHep1, as EDTA chelation abrogated its abilities to suppress the aggregation of PfHsp70-3. Soluble and functional PfHsp70-3, acquired by co-expression with PfHep-1, will facilitate the biochemical characterisation of this particular Hsp70 protein and its evaluation as a drug target for the treatment of malaria. , This work was funded by grants from the National Research Foundation (NRF); grant number 87663 and Deutsche Forschungsgemeinschaft (DFG); grant number LI 402/14-1. D.O.N. is the recipient of academic development and training funds from Mwenge Catholic University, Moshi, Tanzania. S.J.B. is the recipient of an NRF Doctoral Innovation Scholarship.
- Full Text:
- Date Issued: 2016
- Authors: Nyakundi, David O , Vuko, Loyiso A M , Bentley, Stephen J , Hoppe, Heinrich C , Blatch, Gregory L , Boshoff, Aileen
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66109 , vital:28903 , https://doi.org/10.1371/journal.pone.0156446
- Description: publisher version , The majority of mitochondrial proteins are encoded in the nucleus and need to be imported from the cytosol into the mitochondria, and molecular chaperones play a key role in the efficient translocation and proper folding of these proteins in the matrix. One such molecular chaperone is the eukaryotic mitochondrial heat shock protein 70 (Hsp70); however, it is prone to self-aggregation and requires the presence of an essential zinc-finger protein, Hsp70-escort protein 1 (Hep1), to maintain its structure and function. PfHsp70-3, the only Hsp70 predicted to localize in the mitochondria of P. falciparum, may also rely on a Hep1 orthologue to prevent self-aggregation. In this study, we identified a putative Hep1 orthologue in P. falciparum and co-expression of PfHsp70-3 and PfHep1 enhanced the solubility of PfHsp70-3. PfHep1 suppressed the thermally induced aggregation of PfHsp70-3 but not the aggregation of malate dehydrogenase or citrate synthase, thus showing specificity for PfHsp70-3. Zinc ions were indeed essential for maintaining the function of PfHep1, as EDTA chelation abrogated its abilities to suppress the aggregation of PfHsp70-3. Soluble and functional PfHsp70-3, acquired by co-expression with PfHep-1, will facilitate the biochemical characterisation of this particular Hsp70 protein and its evaluation as a drug target for the treatment of malaria. , This work was funded by grants from the National Research Foundation (NRF); grant number 87663 and Deutsche Forschungsgemeinschaft (DFG); grant number LI 402/14-1. D.O.N. is the recipient of academic development and training funds from Mwenge Catholic University, Moshi, Tanzania. S.J.B. is the recipient of an NRF Doctoral Innovation Scholarship.
- Full Text:
- Date Issued: 2016
Trypanosoma brucei J protein 2 is a stress inducible and essential Hsp40
- Ludewig, Michael H, Boshoff, Aileen, Horn, David, Blatch, Gregory L
- Authors: Ludewig, Michael H , Boshoff, Aileen , Horn, David , Blatch, Gregory L
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431798 , vital:72804 , xlink:href="https://doi.org/10.1016/j.biocel.2014.12.016"
- Description: Hsp40 proteins (also known as DnaJ or J proteins) serve as co-chaperones for Hsp70, but also display evidence of independent chaperone function. Furthermore, certain Hsp40s have been shown to be stress-inducible and essential. Trypanosomatids display a remarkable diversification of Hsp40 proteins, with numerous distinct Hsp40-like proteins encoded in the Trypanosoma brucei genome. This study investigated the role of one of the six T. brucei Type I Hsp40s, T. brucei J protein 2 (Tbj2). We found that Tbj2 was heat stress-inducible, and that knockdown using RNA interference resulted in a severe growth defect under normal growth temperatures. Furthermore, a green fluorescent protein (GFP)-Tbj2 fusion protein was found to be localized to the cytosol of T. brucei. Taken together, these data suggest that Tbj2 is not functionally equivalent to the other five Type I Hsp40s, and that it is an essential, cytosolic, and stress-inducible chaperone, potentially playing an important role in protein biogenesis in T. brucei.
- Full Text:
- Date Issued: 2015
- Authors: Ludewig, Michael H , Boshoff, Aileen , Horn, David , Blatch, Gregory L
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431798 , vital:72804 , xlink:href="https://doi.org/10.1016/j.biocel.2014.12.016"
- Description: Hsp40 proteins (also known as DnaJ or J proteins) serve as co-chaperones for Hsp70, but also display evidence of independent chaperone function. Furthermore, certain Hsp40s have been shown to be stress-inducible and essential. Trypanosomatids display a remarkable diversification of Hsp40 proteins, with numerous distinct Hsp40-like proteins encoded in the Trypanosoma brucei genome. This study investigated the role of one of the six T. brucei Type I Hsp40s, T. brucei J protein 2 (Tbj2). We found that Tbj2 was heat stress-inducible, and that knockdown using RNA interference resulted in a severe growth defect under normal growth temperatures. Furthermore, a green fluorescent protein (GFP)-Tbj2 fusion protein was found to be localized to the cytosol of T. brucei. Taken together, these data suggest that Tbj2 is not functionally equivalent to the other five Type I Hsp40s, and that it is an essential, cytosolic, and stress-inducible chaperone, potentially playing an important role in protein biogenesis in T. brucei.
- Full Text:
- Date Issued: 2015
PFB0595w is a Plasmodium falciparum J protein that co-localizes with PfHsp70-1 and can stimulate its in vitro ATP hydrolysis activity
- Njunge, James M, Mandal, Pradipta, Przyborski, Jude M, Boshoff, Aileen, Pesce, Eva-Rachele, Blatch, Gregory L
- Authors: Njunge, James M , Mandal, Pradipta , Przyborski, Jude M , Boshoff, Aileen , Pesce, Eva-Rachele , Blatch, Gregory L
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431739 , vital:72800 , xlink:href="https://doi.org/10.1016/j.biocel.2015.02.008"
- Description: Heat shock proteins, many of which function as molecular chaperones, play important roles in the lifecycle and pathogenesis of the malaria parasite, Plasmodium falciparum. The P. falciparum heat shock protein 70 (PfHsp70) family of chaperones is potentially regulated by a large complement of J proteins that localize to various intracellular compartments including the infected erythrocyte cytosol. While PfHsp70-1 has been shown to be an abundant cytosolic chaperone, its regulation by J proteins is poorly understood. In this study, we characterized the J protein PFB0595w, a homologue of the well-studied yeast cytosolic J protein, Sis1. PFB0595w, similarly to PfHsp70-1, was localized to the parasite cytosol and its expression was upregulated by heat shock. Additionally, recombinant PFB0595w was shown to be dimeric and to stimulate the in vitro ATPase activity of PfHsp70-1. Overall, the expression, localization and biochemical data for PFB0595w suggest that it may function as a cochaperone of PfHsp70-1, and advances current knowledge on the chaperone machinery of the parasite.
- Full Text:
- Date Issued: 2015
- Authors: Njunge, James M , Mandal, Pradipta , Przyborski, Jude M , Boshoff, Aileen , Pesce, Eva-Rachele , Blatch, Gregory L
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431739 , vital:72800 , xlink:href="https://doi.org/10.1016/j.biocel.2015.02.008"
- Description: Heat shock proteins, many of which function as molecular chaperones, play important roles in the lifecycle and pathogenesis of the malaria parasite, Plasmodium falciparum. The P. falciparum heat shock protein 70 (PfHsp70) family of chaperones is potentially regulated by a large complement of J proteins that localize to various intracellular compartments including the infected erythrocyte cytosol. While PfHsp70-1 has been shown to be an abundant cytosolic chaperone, its regulation by J proteins is poorly understood. In this study, we characterized the J protein PFB0595w, a homologue of the well-studied yeast cytosolic J protein, Sis1. PFB0595w, similarly to PfHsp70-1, was localized to the parasite cytosol and its expression was upregulated by heat shock. Additionally, recombinant PFB0595w was shown to be dimeric and to stimulate the in vitro ATPase activity of PfHsp70-1. Overall, the expression, localization and biochemical data for PFB0595w suggest that it may function as a cochaperone of PfHsp70-1, and advances current knowledge on the chaperone machinery of the parasite.
- Full Text:
- Date Issued: 2015
Sequence and domain conservation of the coelacanth Hsp40 and Hsp90 chaperones suggests conservation of function
- Tastan Bishop, Özlem, Edkins, Adrienne L, Blatch, Gregory L
- Authors: Tastan Bishop, Özlem , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126932 , vital:35936 , https://doi.10.1002/jez.b.22541
- Description: Molecular chaperones and their associated co‐chaperones play an important role in preserving and regulating the active conformational state of cellular proteins. The chaperone complement of the Indonesian Coelacanth, Latimeria menadoensis, was elucidated using transcriptomic sequences. Heat shock protein 90 (Hsp90) and heat shock protein 40 (Hsp40) chaperones, and associated cochaperones were focused on, and homologous human sequences were used to search the sequence databases. Coelacanth homologs of the cytosolic, mitochondrial and endoplasmic reticulum (ER) homologs of human Hsp90 were identified, as well as all of the major co‐chaperones of the cytosolic isoform. Most of the human Hsp40s were found to have coelacanth homologs, and the data suggested that all of the chaperone machinery for protein folding at the ribosome, protein translocation to cellular compartments such as the ER and protein degradation were conserved. Some interesting similarities and differences were identified when interrogating human, mouse, and zebrafish homologs. For example, DnaJB13 is predicted to be a non‐functional Hsp40 in humans, mouse, and zebrafish due to a corrupted histidine‐proline‐aspartic acid (HPD) motif, while the coelacanth homolog has an intact HPD. These and other comparisons enabled important functional and evolutionary questions to be posed for future experimental studies.
- Full Text:
- Date Issued: 2014
- Authors: Tastan Bishop, Özlem , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126932 , vital:35936 , https://doi.10.1002/jez.b.22541
- Description: Molecular chaperones and their associated co‐chaperones play an important role in preserving and regulating the active conformational state of cellular proteins. The chaperone complement of the Indonesian Coelacanth, Latimeria menadoensis, was elucidated using transcriptomic sequences. Heat shock protein 90 (Hsp90) and heat shock protein 40 (Hsp40) chaperones, and associated cochaperones were focused on, and homologous human sequences were used to search the sequence databases. Coelacanth homologs of the cytosolic, mitochondrial and endoplasmic reticulum (ER) homologs of human Hsp90 were identified, as well as all of the major co‐chaperones of the cytosolic isoform. Most of the human Hsp40s were found to have coelacanth homologs, and the data suggested that all of the chaperone machinery for protein folding at the ribosome, protein translocation to cellular compartments such as the ER and protein degradation were conserved. Some interesting similarities and differences were identified when interrogating human, mouse, and zebrafish homologs. For example, DnaJB13 is predicted to be a non‐functional Hsp40 in humans, mouse, and zebrafish due to a corrupted histidine‐proline‐aspartic acid (HPD) motif, while the coelacanth homolog has an intact HPD. These and other comparisons enabled important functional and evolutionary questions to be posed for future experimental studies.
- Full Text:
- Date Issued: 2014
Knockdown of Hop downregulates RhoC expression, and decreases pseudopodia formation and migration in cancer cell lines:
- Willmer, Tarryn, Contu, Lara, Blatch, Gregory L, Edkins, Adrienne L
- Authors: Willmer, Tarryn , Contu, Lara , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165196 , vital:41217 , DOI: 10.1016/j.canlet.2012.09.021
- Description: The Hsp90/Hsp70 organising protein (Hop) is a co-chaperone that mediates the interaction of Hsp90 and Hsp70 molecular chaperones during assembly of Hsp90 complexes in cells. Formation of Hsp90 complexes is a key intermediate step in the maturation and homeostasis of oncoproteins and several hormone receptors. In this paper, we demonstrate that knockdown of Hop decreased migration of Hs578T and MDA-MB-231 breast cancer cells. Hop was identified in isolated pseudopodia fractions; it colocalised with actin in lamellipodia, and co-sedimented with purified actin in vitro. Knockdown of Hop caused a decrease in the level of RhoC GTPase, and significantly inhibited pseudopodia formation in Hs578T cells. Our data suggest that Hop regulates directional cell migration by multiple unknown mechanisms.
- Full Text:
- Date Issued: 2013
- Authors: Willmer, Tarryn , Contu, Lara , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165196 , vital:41217 , DOI: 10.1016/j.canlet.2012.09.021
- Description: The Hsp90/Hsp70 organising protein (Hop) is a co-chaperone that mediates the interaction of Hsp90 and Hsp70 molecular chaperones during assembly of Hsp90 complexes in cells. Formation of Hsp90 complexes is a key intermediate step in the maturation and homeostasis of oncoproteins and several hormone receptors. In this paper, we demonstrate that knockdown of Hop decreased migration of Hs578T and MDA-MB-231 breast cancer cells. Hop was identified in isolated pseudopodia fractions; it colocalised with actin in lamellipodia, and co-sedimented with purified actin in vitro. Knockdown of Hop caused a decrease in the level of RhoC GTPase, and significantly inhibited pseudopodia formation in Hs578T cells. Our data suggest that Hop regulates directional cell migration by multiple unknown mechanisms.
- Full Text:
- Date Issued: 2013
The African coelacanth genome provides insights into tetrapod evolution:
- Amemiya, Chris T, Alföldi, Jessica, Lee, Alison P, Fan, Shaohua, Philippe, Herve´, MacCallum, Iain, Braasch, Ingo, Manousaki, Tereza, Schneider, Igor, Rohner, Nicolas, Organ, Chris, Chalopin, Domitille, Smith, Jeramiah J, Robinson, Mark, Dorrington, Rosemary A, Gerdol, Marco, Aken, Bronwen, Biscotti, Maria Assunta, Barucca, Marco, Baurain, Denis, Berlin, Aaron, Blatch, Gregory L, Buonocore, Francesco, Burmester, Thorsten, Campbell, Michael S, Canapa, Adriana, Cannon, John P, Christoffels, Alan, De Moro, Gianluca, Edkins, Adrienne L, Fan, Lin, Fausto, Anna Maria, Feiner, Nathalie, Forconi, Mariko, Gamieldien, Junaid, Gnerre, Sante, Gnirke, Andreas, Goldstone, Jared V, Haerty, Wilfried, Hahn, Mark E, Hesse, Uljana, Hoffmann, Steve, Johnson, Jeremy, Karchner, Sibel I, Kuraku, Shigehiro, Lara, Marcia, Levin, Joshua Z, Litman, Gary W, Mauceli, Evan, Miyake, Tsutomu, Mueller, M Gail, Nelson, David R, Nitsche, Anne, Olmo, Ettore, Ota, Tatsuya, Pallavicini, Alberto, Panji, Sumir, Picone, Barbara, Ponting, Chris P, Prohaska, Sonja J, Przybylski, Dariusz, Ratan Saha, Nil, Ravi, Vydianathan, Ribeiro, Filipe J, Sauka-Spengler, Tatjana, Scapigliati, Giuseppe, Searle, Stephen M J, Sharpe, Ted, Simakov, Oleg, Stadler, Peter F, Stegeman, John J, Sumiyama, Kenta, Tabbaa, Diana, Tafer, Hakim, Turner-Maier, Jason, van Heusden, Peter, White, Simon, Williams, Louise, Yandell, Mark, Brinkmann, Henner, Volff, Jean-Nicolas, Tabin, Clifford J, Shubin, Neil, Schartl, Manfred, Jaffe, David B, Postlethwait, John H, Venkatesh, Byrappa, Di Palma, Frederica, Lander, Eric S, Meyer, Axel, Lindblad-Toh, Kerstin
- Authors: Amemiya, Chris T , Alföldi, Jessica , Lee, Alison P , Fan, Shaohua , Philippe, Herve´ , MacCallum, Iain , Braasch, Ingo , Manousaki, Tereza , Schneider, Igor , Rohner, Nicolas , Organ, Chris , Chalopin, Domitille , Smith, Jeramiah J , Robinson, Mark , Dorrington, Rosemary A , Gerdol, Marco , Aken, Bronwen , Biscotti, Maria Assunta , Barucca, Marco , Baurain, Denis , Berlin, Aaron , Blatch, Gregory L , Buonocore, Francesco , Burmester, Thorsten , Campbell, Michael S , Canapa, Adriana , Cannon, John P , Christoffels, Alan , De Moro, Gianluca , Edkins, Adrienne L , Fan, Lin , Fausto, Anna Maria , Feiner, Nathalie , Forconi, Mariko , Gamieldien, Junaid , Gnerre, Sante , Gnirke, Andreas , Goldstone, Jared V , Haerty, Wilfried , Hahn, Mark E , Hesse, Uljana , Hoffmann, Steve , Johnson, Jeremy , Karchner, Sibel I , Kuraku, Shigehiro , Lara, Marcia , Levin, Joshua Z , Litman, Gary W , Mauceli, Evan , Miyake, Tsutomu , Mueller, M Gail , Nelson, David R , Nitsche, Anne , Olmo, Ettore , Ota, Tatsuya , Pallavicini, Alberto , Panji, Sumir , Picone, Barbara , Ponting, Chris P , Prohaska, Sonja J , Przybylski, Dariusz , Ratan Saha, Nil , Ravi, Vydianathan , Ribeiro, Filipe J , Sauka-Spengler, Tatjana , Scapigliati, Giuseppe , Searle, Stephen M J , Sharpe, Ted , Simakov, Oleg , Stadler, Peter F , Stegeman, John J , Sumiyama, Kenta , Tabbaa, Diana , Tafer, Hakim , Turner-Maier, Jason , van Heusden, Peter , White, Simon , Williams, Louise , Yandell, Mark , Brinkmann, Henner , Volff, Jean-Nicolas , Tabin, Clifford J , Shubin, Neil , Schartl, Manfred , Jaffe, David B , Postlethwait, John H , Venkatesh, Byrappa , Di Palma, Frederica , Lander, Eric S , Meyer, Axel , Lindblad-Toh, Kerstin
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165030 , vital:41202 , DOI: 10.1038/nature12027
- Description: The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage of lobe-finned fish was thought to have become extinct 70 million years ago. The modern coelacanth looks remarkably similar to many of its ancient relatives, and its evolutionary proximity to our own fish ancestors provides a glimpse of the fish that first walked on land. Here we report the genome sequence of the African coelacanth, Latimeria chalumnae. Through a phylogenomic analysis, we conclude that the lungfish, and not the coelacanth, is the closest living relative of tetrapods. Coelacanth protein-coding genes are significantly more slowly evolving than those of tetrapods, unlike other genomic features. Analyses of changes in genes and regulatory elements during the vertebrate adaptation to land highlight genes involved in immunity, nitrogen excretion and the development of fins, tail, ear, eye, brain and olfaction. Functional assays of enhancers involved in the fin-to-limb transition and in the emergence of extra-embryonic tissues show the importance of the coelacanth genome as a blueprint for understanding tetrapod evolution.
- Full Text:
- Date Issued: 2013
- Authors: Amemiya, Chris T , Alföldi, Jessica , Lee, Alison P , Fan, Shaohua , Philippe, Herve´ , MacCallum, Iain , Braasch, Ingo , Manousaki, Tereza , Schneider, Igor , Rohner, Nicolas , Organ, Chris , Chalopin, Domitille , Smith, Jeramiah J , Robinson, Mark , Dorrington, Rosemary A , Gerdol, Marco , Aken, Bronwen , Biscotti, Maria Assunta , Barucca, Marco , Baurain, Denis , Berlin, Aaron , Blatch, Gregory L , Buonocore, Francesco , Burmester, Thorsten , Campbell, Michael S , Canapa, Adriana , Cannon, John P , Christoffels, Alan , De Moro, Gianluca , Edkins, Adrienne L , Fan, Lin , Fausto, Anna Maria , Feiner, Nathalie , Forconi, Mariko , Gamieldien, Junaid , Gnerre, Sante , Gnirke, Andreas , Goldstone, Jared V , Haerty, Wilfried , Hahn, Mark E , Hesse, Uljana , Hoffmann, Steve , Johnson, Jeremy , Karchner, Sibel I , Kuraku, Shigehiro , Lara, Marcia , Levin, Joshua Z , Litman, Gary W , Mauceli, Evan , Miyake, Tsutomu , Mueller, M Gail , Nelson, David R , Nitsche, Anne , Olmo, Ettore , Ota, Tatsuya , Pallavicini, Alberto , Panji, Sumir , Picone, Barbara , Ponting, Chris P , Prohaska, Sonja J , Przybylski, Dariusz , Ratan Saha, Nil , Ravi, Vydianathan , Ribeiro, Filipe J , Sauka-Spengler, Tatjana , Scapigliati, Giuseppe , Searle, Stephen M J , Sharpe, Ted , Simakov, Oleg , Stadler, Peter F , Stegeman, John J , Sumiyama, Kenta , Tabbaa, Diana , Tafer, Hakim , Turner-Maier, Jason , van Heusden, Peter , White, Simon , Williams, Louise , Yandell, Mark , Brinkmann, Henner , Volff, Jean-Nicolas , Tabin, Clifford J , Shubin, Neil , Schartl, Manfred , Jaffe, David B , Postlethwait, John H , Venkatesh, Byrappa , Di Palma, Frederica , Lander, Eric S , Meyer, Axel , Lindblad-Toh, Kerstin
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165030 , vital:41202 , DOI: 10.1038/nature12027
- Description: The discovery of a living coelacanth specimen in 1938 was remarkable, as this lineage of lobe-finned fish was thought to have become extinct 70 million years ago. The modern coelacanth looks remarkably similar to many of its ancient relatives, and its evolutionary proximity to our own fish ancestors provides a glimpse of the fish that first walked on land. Here we report the genome sequence of the African coelacanth, Latimeria chalumnae. Through a phylogenomic analysis, we conclude that the lungfish, and not the coelacanth, is the closest living relative of tetrapods. Coelacanth protein-coding genes are significantly more slowly evolving than those of tetrapods, unlike other genomic features. Analyses of changes in genes and regulatory elements during the vertebrate adaptation to land highlight genes involved in immunity, nitrogen excretion and the development of fins, tail, ear, eye, brain and olfaction. Functional assays of enhancers involved in the fin-to-limb transition and in the emergence of extra-embryonic tissues show the importance of the coelacanth genome as a blueprint for understanding tetrapod evolution.
- Full Text:
- Date Issued: 2013
Targeting conserved pathways as a strategy for novel drug development: disabling the cellular stress response:
- Edkins, Adrienne L, Blatch, Gregory L
- Authors: Edkins, Adrienne L , Blatch, Gregory L
- Date: 2012
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/165129 , vital:41211 , ISBN 978-3-642-28174-7 , DOI: 10.1007/978-3-642-28175-4_4
- Description: The ability to respond to and cope with stress at a molecular level is essential for cell survival. The stress response is conserved across organisms by the expression of a group of molecular chaperones known as heat shock proteins (HSP). HSP are ubiquitous and highly conserved proteins that regulate cellular protein homeostasis and trafficking under physiological and stressful conditions, including diseases such as cancer and malaria. HSP are good drug targets for the treatment of human diseases, as the significant functional and structural data available suggest that they are essential for cell survival and that, despite conservation across species, there are biophysical and biochemical differences between HSP in normal and disease states that allow HSP to be selectively targeted. In this chapter, we review the international status of this area of research and highlight progress by us and other African researchers towards the characterisation and targeting of HSP from humans and parasites from Plasmodium and Trypanosoma as drug targets.
- Full Text:
- Date Issued: 2012
- Authors: Edkins, Adrienne L , Blatch, Gregory L
- Date: 2012
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/165129 , vital:41211 , ISBN 978-3-642-28174-7 , DOI: 10.1007/978-3-642-28175-4_4
- Description: The ability to respond to and cope with stress at a molecular level is essential for cell survival. The stress response is conserved across organisms by the expression of a group of molecular chaperones known as heat shock proteins (HSP). HSP are ubiquitous and highly conserved proteins that regulate cellular protein homeostasis and trafficking under physiological and stressful conditions, including diseases such as cancer and malaria. HSP are good drug targets for the treatment of human diseases, as the significant functional and structural data available suggest that they are essential for cell survival and that, despite conservation across species, there are biophysical and biochemical differences between HSP in normal and disease states that allow HSP to be selectively targeted. In this chapter, we review the international status of this area of research and highlight progress by us and other African researchers towards the characterisation and targeting of HSP from humans and parasites from Plasmodium and Trypanosoma as drug targets.
- Full Text:
- Date Issued: 2012
The networking of chaperones by co-chaperones: control of cellular protein homeostasis
- Edkins, Adrienne L, Blatch, Gregory L
- Authors: Edkins, Adrienne L , Blatch, Gregory L
- Date: 2014
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/165107 , vital:41209 , ISBN 978-3-319-11731-7
- Description: Co-chaperones are important mediators of the outcome of chaperone assisted protein homeostasis, which is a dynamic balance between the integrated processes of protein folding, degradation and translocation. The Networking of Chaperones by Co-chaperones describes how the function of the major molecular chaperones is regulated by a cohort of diverse non-client proteins, known as co-chaperones. The second edition includes the current status of the field and descriptions of a number of novel co-chaperones that have been recently identified. This new edition has a strong focus on the role of co-chaperones in human disease and as putative drug targets. The book will be a resource for both newcomers and established researchers in the field of cell stress and chaperones, as well as those interested in cross-cutting disciplines such as cellular networks and systems biology.
- Full Text:
- Date Issued: 2014
- Authors: Edkins, Adrienne L , Blatch, Gregory L
- Date: 2014
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/165107 , vital:41209 , ISBN 978-3-319-11731-7
- Description: Co-chaperones are important mediators of the outcome of chaperone assisted protein homeostasis, which is a dynamic balance between the integrated processes of protein folding, degradation and translocation. The Networking of Chaperones by Co-chaperones describes how the function of the major molecular chaperones is regulated by a cohort of diverse non-client proteins, known as co-chaperones. The second edition includes the current status of the field and descriptions of a number of novel co-chaperones that have been recently identified. This new edition has a strong focus on the role of co-chaperones in human disease and as putative drug targets. The book will be a resource for both newcomers and established researchers in the field of cell stress and chaperones, as well as those interested in cross-cutting disciplines such as cellular networks and systems biology.
- Full Text:
- Date Issued: 2014
Quinones and halogenated monoterpenes of algal origin show anti-proliferative effects against breast cancer cells in vitro:
- de la Mare, Jo-Anne, Lawson, Jessica C, Chiwakata, Maynard T, Beukes, Denzil R, Blatch, Gregory L, Edkins, Adrienne L
- Authors: de la Mare, Jo-Anne , Lawson, Jessica C , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165165 , vital:41214 , DOI: 10.1007/s10637-011-9788-0
- Description: Red and brown algae have been shown to produce a variety of compounds with chemotherapeutic potential. A recent report described the isolation of a range of novel polyhalogenated monoterpene compounds from the red algae Plocamium corallorhiza and Plocamium cornutum collected off the coast of South Africa, together with the previously described tetraprenylquinone, sargaquinoic acid (SQA), from the brown algae Sargassum heterophyllum. In our study, the algal compounds were screened for anti-proliferative activity against metastatic MDA-MB-231 breast cancer cells revealing that a number of compounds displayed anti-cancer activity with IC50 values in the micromolar range. A subset of the compounds was tested for differential toxicity in the MCF-7/MCF12A system and five of these, including sargaquinoic acid, were found to be at least three times more toxic to the breast cancer than the non-malignant cell line.
- Full Text:
- Date Issued: 2012
- Authors: de la Mare, Jo-Anne , Lawson, Jessica C , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165165 , vital:41214 , DOI: 10.1007/s10637-011-9788-0
- Description: Red and brown algae have been shown to produce a variety of compounds with chemotherapeutic potential. A recent report described the isolation of a range of novel polyhalogenated monoterpene compounds from the red algae Plocamium corallorhiza and Plocamium cornutum collected off the coast of South Africa, together with the previously described tetraprenylquinone, sargaquinoic acid (SQA), from the brown algae Sargassum heterophyllum. In our study, the algal compounds were screened for anti-proliferative activity against metastatic MDA-MB-231 breast cancer cells revealing that a number of compounds displayed anti-cancer activity with IC50 values in the micromolar range. A subset of the compounds was tested for differential toxicity in the MCF-7/MCF12A system and five of these, including sargaquinoic acid, were found to be at least three times more toxic to the breast cancer than the non-malignant cell line.
- Full Text:
- Date Issued: 2012
Assessment of potential anti-cancer stem cell activity of marine algal compounds using an in vitro mammosphere assay:
- de la Mare, Jo-Anne, Sterrenberg, Jason N, Sukhthankar, Mugdha G, Chiwakata, Maynard T, Beukes, Denzil R, Blatch, Gregory L, Edkins, Adrienne L
- Authors: de la Mare, Jo-Anne , Sterrenberg, Jason N , Sukhthankar, Mugdha G , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165184 , vital:41216 , DOI: 10.1186/1475-2867-13-39
- Description: The cancer stem cell (CSC) theory proposes that tumours arise from and are sustained by a subpopulation of cells with both cancer and stem cell properties. One of the key hallmarks of CSCs is the ability to grow anchorage-independently under serum-free culture conditions resulting in the formation of tumourspheres. It has further been reported that these cells are resistant to traditional chemotherapeutic agents.
- Full Text:
- Date Issued: 2013
- Authors: de la Mare, Jo-Anne , Sterrenberg, Jason N , Sukhthankar, Mugdha G , Chiwakata, Maynard T , Beukes, Denzil R , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2013
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165184 , vital:41216 , DOI: 10.1186/1475-2867-13-39
- Description: The cancer stem cell (CSC) theory proposes that tumours arise from and are sustained by a subpopulation of cells with both cancer and stem cell properties. One of the key hallmarks of CSCs is the ability to grow anchorage-independently under serum-free culture conditions resulting in the formation of tumourspheres. It has further been reported that these cells are resistant to traditional chemotherapeutic agents.
- Full Text:
- Date Issued: 2013