1
|
Quel NG, Fernando de C Rodrigues L, Aragão AZB, Pinheiro GMS, Camacho RP, Souto DEP, Kubota LT, Barbosa LRS, Ramos CHI. Insights into the structure and function of the C-terminus of SGTs (small glutamine-rich TPR-containing proteins): A study of the Aedes aegypti homolog. Biochimie 2021; 187:131-143. [PMID: 34082040 DOI: 10.1016/j.biochi.2021.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/24/2021] [Accepted: 05/26/2021] [Indexed: 10/21/2022]
Abstract
SGTs (small glutamine-rich TPR-containing proteins) are dimeric proteins that belong to the class of co-chaperones characterized by the presence of TPR domains (containing tetratricopeptide repeats). Human (SGTA) and yeast (Sgt2) SGTs are characterized by three distinct domains: an N-terminal dimerization domain, a central TPR-domain important for binding to other proteins (chaperones included) and a C-terminal domain involved in hydrophobic interactions. Both these SGTs are involved in the cellular PQC (protein quality control) system, as they interact with chaperones and have functions that aid stress recovery. However, there are differences between them, such as structural features and binding specificities, that could be better understood if other orthologous proteins were studied. Therefore, we produced and characterized a putative SGT protein, designated AaSGT, from the mosquito Aedes aegypti, which is a vector of several diseases, such as dengue and Zika. The protein was produced as a folded dimer which was stable up to 40 °C and was capable of binding to AaHsp90 and fully protecting a model protein, α-synuclein, from aggregation. The conformation of AaSGT was investigated by biophysical tools and small angle X-ray scattering, which showed that the protein had an elongated conformation and that its C-terminal domain was mainly disordered. The results with a C-terminal deletion mutant supported these observations. Altogether, these results are consistent with those from other functional SGT proteins and add to the understanding of the PQC system in Aedes aegypti, an important aim that may help to develop inhibitory strategies against this vector of neglected diseases.
Collapse
Affiliation(s)
- Natália G Quel
- Institute of Chemistry, University of Campinas UNICAMP, Campinas SP, 13083-970 Brazil; National Institute of Science & Technology of Structural Biology and Bioimage (INCTBEB), Brazil
| | | | - Annelize Z B Aragão
- Institute of Chemistry, University of Campinas UNICAMP, Campinas SP, 13083-970 Brazil
| | - Glaucia M S Pinheiro
- Institute of Chemistry, University of Campinas UNICAMP, Campinas SP, 13083-970 Brazil
| | - Rafael P Camacho
- Institute of Chemistry, University of Campinas UNICAMP, Campinas SP, 13083-970 Brazil
| | - Denio E P Souto
- Department of Chemistry, Federal University of Paraná-UFPR, Curitiba PR, 81530-900, Brazil
| | - Lauro T Kubota
- Institute of Chemistry, University of Campinas UNICAMP, Campinas SP, 13083-970 Brazil; National Institute of Science & Technology of Bioanalytics (INCTBio), Brazil
| | - Leandro R S Barbosa
- Institute of Physics, University of São Paulo, São Paulo SP, 05508-090 Brazil; Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Carlos H I Ramos
- Institute of Chemistry, University of Campinas UNICAMP, Campinas SP, 13083-970 Brazil; National Institute of Science & Technology of Structural Biology and Bioimage (INCTBEB), Brazil.
| |
Collapse
|
2
|
Coto AL, Seraphim TV, Batista FA, Dores-Silva PR, Barranco ABF, Teixeira FR, Gava LM, Borges JC. Structural and functional studies of the Leishmania braziliensis SGT co-chaperone indicate that it shares structural features with HIP and can interact with both Hsp90 and Hsp70 with similar affinities. Int J Biol Macromol 2018; 118:693-706. [DOI: 10.1016/j.ijbiomac.2018.06.123] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/06/2018] [Accepted: 06/25/2018] [Indexed: 12/13/2022]
|
3
|
Krysztofinska EM, Evans NJ, Thapaliya A, Murray JW, Morgan RML, Martinez-Lumbreras S, Isaacson RL. Structure and Interactions of the TPR Domain of Sgt2 with Yeast Chaperones and Ybr137wp. Front Mol Biosci 2017; 4:68. [PMID: 29075633 PMCID: PMC5641545 DOI: 10.3389/fmolb.2017.00068] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 09/21/2017] [Indexed: 12/11/2022] Open
Abstract
Small glutamine-rich tetratricopeptide repeat-containing protein 2 (Sgt2) is a multi-module co-chaperone involved in several protein quality control pathways. The TPR domain of Sgt2 and several other proteins, including SGTA, Hop, and CHIP, is a highly conserved motif known to form transient complexes with molecular chaperones such as Hsp70 and Hsp90. In this work, we present the first high resolution crystal structures of Sgt2_TPR alone and in complex with a C-terminal peptide PTVEEVD from heat shock protein, Ssa1. Using nuclear magnetic resonance spectroscopy and isothermal titration calorimetry, we demonstrate that Sgt2_TPR interacts with peptides corresponding to the C-termini of Ssa1, Hsc82, and Ybr137wp with similar binding modes and affinities.
Collapse
Affiliation(s)
| | - Nicola J Evans
- Department of Chemistry, King's College London, London, United Kingdom
| | - Arjun Thapaliya
- Department of Chemistry, King's College London, London, United Kingdom
| | - James W Murray
- Department of Life Sciences, Imperial College London, South Kensington, United Kingdom
| | - Rhodri M L Morgan
- Department of Life Sciences, Imperial College London, South Kensington, United Kingdom
| | | | - Rivka L Isaacson
- Department of Chemistry, King's College London, London, United Kingdom
| |
Collapse
|
4
|
Thapaliya A, Nyathi Y, Martínez-Lumbreras S, Krysztofinska EM, Evans NJ, Terry IL, High S, Isaacson RL. SGTA interacts with the proteasomal ubiquitin receptor Rpn13 via a carboxylate clamp mechanism. Sci Rep 2016; 6:36622. [PMID: 27827410 PMCID: PMC5101480 DOI: 10.1038/srep36622] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/18/2016] [Indexed: 11/17/2022] Open
Abstract
The fate of secretory and membrane proteins that mislocalize to the cytosol is decided by a collaboration between cochaperone SGTA (small, glutamine-rich, tetratricopeptide repeat protein alpha) and the BAG6 complex, whose operation relies on multiple transient and subtly discriminated interactions with diverse binding partners. These include chaperones, membrane-targeting proteins and ubiquitination enzymes. Recently a direct interaction was discovered between SGTA and the proteasome, mediated by the intrinsic proteasomal ubiquitin receptor Rpn13. Here, we structurally and biophysically characterize this binding and identify a region of the Rpn13 C-terminal domain that is necessary and sufficient to facilitate it. We show that the contact occurs through a carboxylate clamp-mediated molecular recognition event with the TPR domain of SGTA, and provide evidence that the interaction can mediate the association of Rpn13 and SGTA in a cellular context.
Collapse
Affiliation(s)
- Arjun Thapaliya
- Department of Chemistry, King's College London, Britannia House, Trinity Street, London, SE1 1DB, U.K
| | - Yvonne Nyathi
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, U.K
| | | | - Ewelina M Krysztofinska
- Department of Chemistry, King's College London, Britannia House, Trinity Street, London, SE1 1DB, U.K
| | - Nicola J Evans
- Department of Chemistry, King's College London, Britannia House, Trinity Street, London, SE1 1DB, U.K
| | - Isabelle L Terry
- Department of Chemistry, King's College London, Britannia House, Trinity Street, London, SE1 1DB, U.K
| | - Stephen High
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, The Michael Smith Building, Oxford Road, Manchester, M13 9PT, U.K
| | - Rivka L Isaacson
- Department of Chemistry, King's College London, Britannia House, Trinity Street, London, SE1 1DB, U.K
| |
Collapse
|
5
|
Philp LK, Day TK, Butler MS, Laven-Law G, Jindal S, Hickey TE, Scher HI, Butler LM, Tilley WD. Small Glutamine-Rich Tetratricopeptide Repeat-Containing Protein Alpha (SGTA) Ablation Limits Offspring Viability and Growth in Mice. Sci Rep 2016; 6:28950. [PMID: 27358191 PMCID: PMC4928056 DOI: 10.1038/srep28950] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/07/2016] [Indexed: 01/26/2023] Open
Abstract
Small glutamine-rich tetratricopeptide repeat-containing protein α (SGTA) has been implicated as a co-chaperone and regulator of androgen and growth hormone receptor (AR, GHR) signalling. We investigated the functional consequences of partial and full Sgta ablation in vivo using Cre-lox Sgta-null mice. Sgta(+/-) breeders generated viable Sgta(-/-) offspring, but at less than Mendelian expectancy. Sgta(-/-) breeders were subfertile with small litters and higher neonatal death (P < 0.02). Body size was significantly and proportionately smaller in male and female Sgta(-/-) (vs WT, Sgta(+/-) P < 0.001) from d19. Serum IGF-1 levels were genotype- and sex-dependent. Food intake, muscle and bone mass and adiposity were unchanged in Sgta(-/-). Vital and sex organs had normal relative weight, morphology and histology, although certain androgen-sensitive measures such as penis and preputial size, and testis descent, were greater in Sgta(-/-). Expression of AR and its targets remained largely unchanged, although AR localisation was genotype- and tissue-dependent. Generally expression of other TPR-containing proteins was unchanged. In conclusion, this thorough investigation of SGTA-null mutation reports a mild phenotype of reduced body size. The model's full potential likely will be realised by genetic crosses with other models to interrogate the role of SGTA in the many diseases in which it has been implicated.
Collapse
Affiliation(s)
- Lisa K. Philp
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Tanya K. Day
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Miriam S. Butler
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Geraldine Laven-Law
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Shalini Jindal
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Theresa E. Hickey
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | | | - Lisa M. Butler
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
- Freemason’s Foundation Centre for Men’s Health, School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| | - Wayne D. Tilley
- Adelaide Prostate Cancer Research Centre and Dame Roma Mitchell Cancer Research Laboratories, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
- Freemason’s Foundation Centre for Men’s Health, School of Medicine, Faculty of Health Sciences, University of Adelaide, Adelaide, Australia
| |
Collapse
|
6
|
Borges JC, Seraphim TV, Dores-Silva PR, Barbosa LRS. A review of multi-domain and flexible molecular chaperones studies by small-angle X-ray scattering. Biophys Rev 2016; 8:107-120. [PMID: 28510050 PMCID: PMC5425780 DOI: 10.1007/s12551-016-0194-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 02/02/2016] [Indexed: 02/06/2023] Open
Abstract
Intrinsic flexibility is closely related to protein function, and a plethora of important regulatory proteins have been found to be flexible, multi-domain or even intrinsically disordered. On the one hand, understanding such systems depends on how these proteins behave in solution. On the other, small-angle X-ray scattering (SAXS) is a technique that fulfills the requirements to study protein structure and dynamics relatively quickly with few experimental limitations. Molecular chaperones from Hsp70 and Hsp90 families are multi-domain proteins containing flexible and/or disordered regions that play central roles in cellular proteostasis. Here, we review the structure and function of these proteins by SAXS. Our general approach includes the use of SAXS data to determine size and shape parameters, as well as protein shape reconstruction and their validation by using accessory biophysical tools. Some remarkable examples are presented that exemplify the potential of the SAXS technique. Protein structure can be determined in solution even at limiting protein concentrations (for example, human mortalin, a mitochondrial Hsp70 chaperone). The protein organization, flexibility and function (for example, the J-protein co-chaperones), oligomeric status, domain organization, and flexibility (for the Hsp90 chaperone and the Hip and Hep1 co-chaperones) may also be determined. Lastly, the shape, structural conservation, and protein dynamics (for the Hsp90 chaperone and both p23 and Aha1 co-chaperones) may be studied by SAXS. We believe this review will enhance the application of the SAXS technique to the study of the molecular chaperones.
Collapse
Affiliation(s)
- Júlio C Borges
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil.
| | - Thiago V Seraphim
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
| | - Paulo R Dores-Silva
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP, Brazil
| | | |
Collapse
|
7
|
Roberts JD, Thapaliya A, Martínez-Lumbreras S, Krysztofinska EM, Isaacson RL. Structural and Functional Insights into Small, Glutamine-Rich, Tetratricopeptide Repeat Protein Alpha. Front Mol Biosci 2015; 2:71. [PMID: 26734616 PMCID: PMC4683186 DOI: 10.3389/fmolb.2015.00071] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/29/2015] [Indexed: 11/21/2022] Open
Abstract
The small glutamine-rich, tetratricopeptide repeat-containing protein alpha (SGTA) is an emerging player in the quality control of secretory and membrane proteins mislocalized to the cytosol, with established roles in tail-anchored (TA) membrane protein biogenesis. SGTA consists of three structural domains with individual functions, an N-terminal dimerization domain that assists protein sorting pathways, a central tetratricopeptide repeat (TPR) domain that mediates interactions with heat-shock proteins, proteasomal, and hormonal receptors, and viral proteins, and a C-terminal glutamine rich region that binds hydrophobic substrates. SGTA has been linked to viral lifecycles and hormone receptor signaling, with implications in the pathogenesis of various disease states. Thus far, a range of biophysical techniques have been employed to characterize SGTA structure in some detail, and to investigate its interactions with binding partners in different biological contexts. A complete description of SGTA structure, together with further investigation into its function as a co-chaperone involved quality control, could provide us with useful insights into its role in maintaining cellular proteostasis, and broaden our understanding of mechanisms underlying associated pathologies. This review describes how some structural features of SGTA have been elucidated, and what this has uncovered about its cellular functions. A brief background on the structure and function of SGTA is given, highlighting its importance to biomedicine and related fields. The current level of knowledge and what remains to be understood about the structure and function of SGTA is summarized, discussing the potential direction of future research.
Collapse
|
8
|
Morgan RML, Pal M, Roe SM, Pearl LH, Prodromou C. Tah1 helix-swap dimerization prevents mixed Hsp90 co-chaperone complexes. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:1197-206. [PMID: 25945584 PMCID: PMC4427203 DOI: 10.1107/s1399004715004551] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 03/04/2015] [Indexed: 11/12/2022]
Abstract
Specific co-chaperone adaptors facilitate the recruitment of client proteins to the Hsp90 system. Tah1 binds the C-terminal conserved MEEVD motif of Hsp90, thus linking an eclectic set of client proteins to the R2TP complex for their assembly and regulation by Hsp90. Rather than the normal complement of seven α-helices seen in other tetratricopeptide repeat (TPR) domains, Tah1 unusually consists of the first five only. Consequently, the methionine of the MEEVD peptide remains exposed to solvent when bound by Tah1. In solution Tah1 appears to be predominantly monomeric, and recent structures have failed to explain how Tah1 appears to prevent the formation of mixed TPR domain-containing complexes such as Cpr6-(Hsp90)2-Tah1. To understand this further, the crystal structure of Tah1 in complex with the MEEVD peptide of Hsp90 was determined, which shows a helix swap involving the fifth α-helix between two adjacently bound Tah1 molecules. Dimerization of Tah1 restores the normal binding environment of the bound Hsp90 methionine residue by reconstituting a TPR binding site similar to that in seven-helix-containing TPR domain proteins. Dimerization also explains how other monomeric TPR-domain proteins are excluded from forming inappropriate mixed co-chaperone complexes.
Collapse
Affiliation(s)
- Rhodri M. L. Morgan
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, England
| | - Mohinder Pal
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, England
| | - S. Mark Roe
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, England
| | - Laurence H. Pearl
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, England
| | - Chrisostomos Prodromou
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, England
| |
Collapse
|
9
|
Hughes S, Wilkinson H, Gilbert SPR, Kishida M, Ding SS, Woollard A. The C. elegans TPR Containing Protein, TRD-1, Regulates Cell Fate Choice in the Developing Germ Line and Epidermis. PLoS One 2014; 9:e114998. [PMID: 25493563 PMCID: PMC4262444 DOI: 10.1371/journal.pone.0114998] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/17/2014] [Indexed: 02/07/2023] Open
Abstract
Correct cell fate choice is crucial in development. In post-embryonic development of the hermaphroditic Caenorhabitis elegans, distinct cell fates must be adopted in two diverse tissues. In the germline, stem cells adopt one of three possible fates: mitotic cell cycle, or gamete formation via meiosis, producing either sperm or oocytes. In the epidermis, the stem cell-like seam cells divide asymmetrically, with the daughters taking on either a proliferative (seam) or differentiated (hypodermal or neuronal) fate. We have isolated a novel conserved C. elegans tetratricopeptide repeat containing protein, TRD-1, which is essential for cell fate determination in both the germline and the developing epidermis and has homologs in other species, including humans (TTC27). We show that trd-1(RNAi) and mutant animals have fewer seam cells as a result of inappropriate differentiation towards the hypodermal fate. In the germline, trd-1 RNAi results in a strong masculinization phenotype, as well as defects in the mitosis to meiosis switch. Our data suggests that trd-1 acts downstream of tra-2 but upstream of fem-3 in the germline sex determination pathway, and exhibits a constellation of phenotypes in common with other Mog (masculinization of germline) mutants. Thus, trd-1 is a new player in both the somatic and germline cell fate determination machinery, suggestive of a novel molecular connection between the development of these two diverse tissues.
Collapse
Affiliation(s)
- Samantha Hughes
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Henry Wilkinson
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | | | - Marcia Kishida
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Siyu Serena Ding
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Alison Woollard
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
10
|
Structural and functional characterization of ybr137wp implicates its involvement in the targeting of tail-anchored proteins to membranes. Mol Cell Biol 2014; 34:4500-12. [PMID: 25288638 DOI: 10.1128/mcb.00697-14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nearly 5% of membrane proteins are guided to nuclear, endoplasmic reticulum (ER), mitochondrial, Golgi, or peroxisome membranes by their C-terminal transmembrane domain and are classified as tail-anchored (TA) membrane proteins. In Saccharomyces cerevisiae, the guided entry of TA protein (GET) pathway has been shown to function in the delivery of TA proteins to the ER. The sorting complex for this pathway is comprised of Sgt2, Get4, and Get5 and facilitates the loading of nascent tail-anchored proteins onto the Get3 ATPase. Multiple pulldown assays also indicated that Ybr137wp associates with this complex in vivo. Here, we report a 2.8-Å-resolution crystal structure for Ybr137wp from Saccharomyces cerevisiae. The protein is a decamer in the crystal and also in solution, as observed by size exclusion chromatography and analytical ultracentrifugation. In addition, isothermal titration calorimetry indicated that the C-terminal acidic motif of Ybr137wp interacts with the tetratricopeptide repeat (TPR) domain of Sgt2. Moreover, an in vivo study demonstrated that Ybr137wp is induced in yeast exiting the log phase and ameliorates the defect of TA protein delivery and cell viability derived by the impaired GET system under starvation conditions. Therefore, this study suggests a possible role for Ybr137wp related to targeting of tail-anchored proteins.
Collapse
|
11
|
Paul A, Garcia YA, Zierer B, Patwardhan C, Gutierrez O, Hildenbrand Z, Harris DC, Balsiger HA, Sivils JC, Johnson JL, Buchner J, Chadli A, Cox MB. The cochaperone SGTA (small glutamine-rich tetratricopeptide repeat-containing protein alpha) demonstrates regulatory specificity for the androgen, glucocorticoid, and progesterone receptors. J Biol Chem 2014; 289:15297-308. [PMID: 24753260 DOI: 10.1074/jbc.m113.535229] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Steroid hormone receptors are ligand-dependent transcription factors that require the ordered assembly of multichaperone complexes for transcriptional activity. Although heat shock protein (Hsp) 90 and Hsp70 are key players in this process, multiple Hsp70- and Hsp90-associated cochaperones associate with receptor-chaperone complexes to regulate receptor folding and activation. Small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) was recently characterized as an Hsp70 and Hsp90-associated cochaperone that specifically regulates androgen receptor activity. However, the specificity of SGTA for additional members of the steroid hormone receptor superfamily and the mechanism by which SGTA regulates receptor activity remain unclear. Here we report that SGTA associates with and specifically regulates the androgen, glucocorticoid, and progesterone receptors and has no effect on the mineralocorticoid and estrogen receptors in both yeast and mammalian cell-based reporter assays. In both systems, SGTA knockdown/deletion enhances receptor activity, whereas SGTA overexpression suppresses receptor activity. We demonstrate that SGTA binds directly to Hsp70 and Hsp90 in vitro with similar affinities yet predominately precipitates with Hsp70 from cell lysates, suggesting a role for SGTA in early, Hsp70-mediated folding. Furthermore, SGTA expression completely abrogates the regulation of receptor function by FKBP52 (52-kDa FK506-binding protein), which acts at a later stage of the chaperone cycle. Taken together, our data suggest a role for SGTA at distinct steps in the chaperone-dependent modulation of androgen, glucocorticoid, and progesterone receptor activity.
Collapse
Affiliation(s)
- Atanu Paul
- From the Border Biomedical Research Center and Department of Biological Sciences and
| | - Yenni A Garcia
- From the Border Biomedical Research Center and Department of Biological Sciences and
| | - Bettina Zierer
- the Center for Integrated Protein Science at the Department Chemie, Technische Universität München, Garching, Germany
| | - Chaitanya Patwardhan
- the Cancer Research Center, Georgia Regents University, Augusta, Georgia 30912, and
| | - Omar Gutierrez
- From the Border Biomedical Research Center and Department of Biological Sciences and
| | - Zacariah Hildenbrand
- the Department of Chemistry, University of Texas at El Paso, El Paso, Texas 79968
| | - Diondra C Harris
- From the Border Biomedical Research Center and Department of Biological Sciences and
| | - Heather A Balsiger
- From the Border Biomedical Research Center and Department of Biological Sciences and
| | - Jeffrey C Sivils
- From the Border Biomedical Research Center and Department of Biological Sciences and
| | - Jill L Johnson
- the Department of Biological Sciences, University of Idaho, Moscow, Idaho 83844
| | - Johannes Buchner
- the Center for Integrated Protein Science at the Department Chemie, Technische Universität München, Garching, Germany
| | - Ahmed Chadli
- the Cancer Research Center, Georgia Regents University, Augusta, Georgia 30912, and
| | - Marc B Cox
- From the Border Biomedical Research Center and Department of Biological Sciences and
| |
Collapse
|
12
|
Xue Q, Lv L, Wan C, Chen B, Li M, Ni T, Liu Y, Liu Y, Cong X, Zhou Y, Ni R, Mao G. Expression and clinical role of small glutamine-rich tetratricopeptide repeat (TPR)-containing protein alpha (SGTA) as a novel cell cycle protein in NSCLC. J Cancer Res Clin Oncol 2013; 139:1539-49. [PMID: 23857189 DOI: 10.1007/s00432-013-1474-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 07/04/2013] [Indexed: 11/24/2022]
Abstract
PURPOSE A small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) is a 35 kDa protein involved in a number of biological processes. However, the role of SGTA in non-small-cell lung cancer (NSCLC) tumorigenesis has never been elucidated. The purpose of this study was to determine whether SGTA could serve as a biomarker for stratification and prediction of prognosis in NSCLC. METHODS Small glutamine-rich tetratricopeptide repeat-containing protein alpha expression was evaluated by Western blot in 8 paired fresh lung cancer tissues and immunohistochemistry on 83 paraffin-embedded sections. The effect of SGTA was assessed by RNA interference in A549 cells. Serum starvation and refeeding, flow cytometry, CCK-8, and tunnel assays were performed. RESULTS Small glutamine-rich tetratricopeptide repeat-containing protein alpha was highly expressed in NSCLC and significantly correlated with NSCLC histological differentiation, clinical stage, and Ki-67. Multivariate analysis indicated that SGTA was an independent prognostic factor for NSCLC patients' survival. The present investigation demonstrated that suppression of SGTA expression resulted in a significant decline of proliferation in A549 cells. Besides, SGTA could abolish the toxicity of cisplatin in A549 cells. CONCLUSIONS These findings suggested that SGTA might play an important role in promoting the tumorigenesis of NSCLC, and thus be a promising therapeutic target to prevent NSCLC progression.
Collapse
Affiliation(s)
- Qun Xue
- Department of Cardiothoracic Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, 226001, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Up-regulation of SGTB is associated with neuronal apoptosis after neuroinflammation induced by lipopolysaccharide. J Mol Histol 2013; 44:507-18. [DOI: 10.1007/s10735-013-9517-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 06/03/2013] [Indexed: 10/26/2022]
|
14
|
Chartron JW, Gonzalez GM, Clemons WM. A structural model of the Sgt2 protein and its interactions with chaperones and the Get4/Get5 complex. J Biol Chem 2011; 286:34325-34. [PMID: 21832041 PMCID: PMC3190793 DOI: 10.1074/jbc.m111.277798] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 07/18/2011] [Indexed: 11/06/2022] Open
Abstract
The insertion of tail-anchored transmembrane (TA) proteins into the appropriate membrane is a post-translational event that requires stabilization of the transmembrane domain and targeting to the proper destination. Sgt2 is a heat-shock protein cognate (HSC) co-chaperone that preferentially binds endoplasmic reticulum-destined TA proteins and directs them to the GET pathway via Get4 and Get5. Here, we present the crystal structure from a fungal Sgt2 homolog of the tetratrico-repeat (TPR) domain and part of the linker that connects to the C-terminal domain. The linker extends into the two-carboxylate clamp of the TPR domain from a symmetry-related molecule mimicking the binding to HSCs. Based on this structure, we provide biochemical evidence that the Sgt2 TPR domain has the ability to directly bind multiple HSC family members. The structure allows us to propose features involved in this lower specificity relative to other TPR containing co-chaperones. We further show that a dimer of Sgt2 binds a single Get5 and use small angle x-ray scattering to characterize the domain arrangement of Sgt2 in solution. These results allow us to present a structural model of the Sgt2-Get4/Get5-HSC complex.
Collapse
Affiliation(s)
- Justin W. Chartron
- From the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - Grecia M. Gonzalez
- From the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| | - William M. Clemons
- From the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125
| |
Collapse
|
15
|
Hsp90 in non-mammalian metazoan model systems. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:712-21. [PMID: 21983200 DOI: 10.1016/j.bbamcr.2011.09.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 09/08/2011] [Accepted: 09/09/2011] [Indexed: 01/26/2023]
Abstract
The molecular chaperone Hsp90 has been discovered in the heat-shock response of the fruit fly more than 30years ago. Today, it is becoming clear that Hsp90 is in the middle of a regulatory system, participating in the modulation of many essential client proteins and signaling pathways. Exerting these activities, Hsp90 works together with about a dozen of cochaperones. Due to their organismal simplicity and the possibility to influence their genetics on a large scale, many studies have addressed the function of Hsp90 in several multicellular model systems. Defined pathways involving Hsp90 client proteins have been identified in the metazoan model systems of Caenorhabditis elegans, Drosophila melanogaster and the zebrafish Danio rerio. Here, we summarize the functions of Hsp90 during muscle maintenance, development of phenotypic traits and the involvement of Hsp90 in stress responses, all of which were largely uncovered using the model organisms covered in this review. These findings highlight the many specific and general actions of the Hsp90 chaperone machinery. This article is part of a Special Issue entitled: Heat Shock Protein 90 (HSP90).
Collapse
|
16
|
Ommen G, Chrobak M, Clos J. The co-chaperone SGT of Leishmania donovani is essential for the parasite's viability. Cell Stress Chaperones 2010; 15:443-55. [PMID: 19953351 PMCID: PMC3082645 DOI: 10.1007/s12192-009-0160-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 10/30/2009] [Accepted: 11/11/2009] [Indexed: 10/20/2022] Open
Abstract
Molecular chaperone proteins play a pivotal role in the protozoan parasite Leishmania donovani, controlling cell fate and ensuring intracellular survival. In higher eukaryotes, the so-called co-chaperone proteins are required for client protein recognition and proper function of chaperones, among them the small glutamine-rich tetratricopeptide repeat proteins (SGT) which interact with both HSP70 and HSP90 chaperones. An atypical SGT homolog is found in the L. donovani genome, encoding a protein lacking the C-terminal glutamine-rich region, normally typical for SGT family members. The gene is expressed constitutively during the life cycle and is essential for survival and/or growth of the parasites. LdSGT forms large, stable complexes that also include another putative co-chaperone, HSC70 interacting protein (HIP). The gene product forms cytoplasmic clusters, matching the subcellular distribution of HIP and partly that of the major cytoplasmic chaperones, HSP70 and HSP90, reflecting a direct molecular interaction with both chaperones.
Collapse
Affiliation(s)
- Gabi Ommen
- Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht St. 74, 20359 Hamburg, Germany
| | - Mareike Chrobak
- Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht St. 74, 20359 Hamburg, Germany
| | - Joachim Clos
- Bernhard Nocht Institute for Tropical Medicine, Bernhard Nocht St. 74, 20359 Hamburg, Germany
| |
Collapse
|
17
|
Survey of the year 2008: applications of isothermal titration calorimetry. J Mol Recognit 2010; 23:395-413. [DOI: 10.1002/jmr.1025] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
18
|
Gillan V, Maitland K, McCormack G, Him NAIIN, Devaney E. Functional genomics of hsp-90 in parasitic and free-living nematodes. Int J Parasitol 2009; 39:1071-81. [PMID: 19401205 PMCID: PMC2845815 DOI: 10.1016/j.ijpara.2009.02.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 02/12/2009] [Accepted: 02/16/2009] [Indexed: 01/06/2023]
Abstract
Heat shock protein 90 (Hsp-90) is a highly conserved essential protein in eukaryotes. Here we describe the molecular characterisation of hsp-90 from three nematodes, the free-living Caenorhabditis elegans (Ce) and the parasitic worms Brugia pahangi (Bp) and Haemonchus contortus (Hc). These molecules were functionally characterised by rescue of a Ce-daf-21 (hsp-90) null mutant. Our results show a gradient of rescue: the C. elegans endogenous gene provided full rescue of the daf-21 mutant, while Hc-hsp-90 provided partial rescue. In contrast, no rescue could be obtained using a variety of Bp-hsp-90 constructs, despite the fact that Bp-hsp-90 was transcribed and translated in the mutant worms. daf-21 RNA interference (RNAi) experiments were carried out to determine whether knock-down of the endogenous daf-21 mRNA in N2 worms could be complemented by expression of either parasite gene. However neither parasite gene could rescue the daf-21 (RNAi) phenotypes. These results indicate that factors other than the level of sequence identity are important for determining whether parasite genes can functionally complement in C. elegans.
Collapse
Affiliation(s)
- Victoria Gillan
- Parasitology Group, Division of Infection and Immunity, Institute of Comparative Medicine, Faculty of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK.
| | | | | | | | | |
Collapse
|
19
|
Dutta S, Tan YJ. Structural and functional characterization of human SGT and its interaction with Vpu of the human immunodeficiency virus type 1. Biochemistry 2008; 47:10123-31. [PMID: 18759457 DOI: 10.1021/bi800758a] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The small glutamine-rich tetratricopeptide repeat protein (SGT) belongs to a family of cochaperones that interacts with both Hsp70 and Hsp90 via the so-called TPR domain. Here, we present the crystal structure of the TPR domain of human SGT (SGT-TPR), which shows that it contains typical features found in the structures of other TPR domains. Previous studies show that full-length SGT can bind to both Vpu and Gag of human immunodeficiency virus type 1 (HIV-1) and the overexpression of SGT in cells reduces the efficiency of HIV-1 particle release. We show that SGT-TPR can bind Vpu and reduce the amount of HIV-1 p24, which is the viral capsid, secreted from cells transfected with the HIV-1 proviral construct, albeit at a lower efficiency than full-length SGT. This indicates that the TPR domain of SGT is sufficient for the inhibition of HIV-1 particle release but the N- and/or C-terminus also have some contributions. The SGT binding site in Vpu was also identified by using peptide array and confirmed by GST pull-down assay.
Collapse
Affiliation(s)
- Sujit Dutta
- Collaborative Antiviral Research Group, Cancer and Developmental Cell Biology Division, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, 61 Biopolis Drive, Singapore 138673
| | | |
Collapse
|