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Chae HB, Bae SB, Paeng SK, Wi SD, Thi Phan KA, Lee SY. S-nitrosylation switches the Arabidopsis redox sensor protein, QSOX1, from an oxidoreductase to a molecular chaperone under heat stress. Plant Physiol Biochem 2024; 206:108219. [PMID: 38048703 DOI: 10.1016/j.plaphy.2023.108219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 11/20/2023] [Indexed: 12/06/2023]
Abstract
The Arabidopsis quiescin sulfhydryl oxidase 1 (QSOX1) thiol-based redox sensor has been identified as a negative regulator of plant immunity. Here, we have found that small molecular weight proteins of QSOX1 were converted to high molecular weight (HMW) complexes upon exposure to heat stress and that this was accompanied by a switch in QSOX1 function from a thiol-reductase to a molecular chaperone. Plant treatment with S-nitrosoglutathione (GSNO), which causes nitrosylation of cysteine residues (S-nitrosylation), but not with H2O2, induced HMW QSOX1 complexes. Thus, functional switching of QSOX1 is induced by GSNO treatment. Accordingly, simultaneous treatment of plants with heat shock and GSNO led to a significant increase in QSOX1 chaperone activity by increasing its oligomerization. Consequently, transgenic Arabidopsis overexpressing QSOX1 (QSOX1OE) showed strong resistance to heat shock, whereas qsox1 knockout plants exhibited high sensitivity to heat stress. Plant treatment with GSNO under heat stress conditions increased their resistance to heat shock. We conclude that S-nitrosylation allows the thiol-based redox sensor, QSOX1, to respond to various external stresses in multiple ways.
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Affiliation(s)
- Ho Byoung Chae
- Division of Applied Life Sciences (BK21), PMBBRC, and Plant Biological Rhythm Research Center, Gyeongsang National University, Jinju, 52828, South Korea
| | - Su Bin Bae
- Division of Applied Life Sciences (BK21), PMBBRC, and Plant Biological Rhythm Research Center, Gyeongsang National University, Jinju, 52828, South Korea
| | - Seol Ki Paeng
- Division of Applied Life Sciences (BK21), PMBBRC, and Plant Biological Rhythm Research Center, Gyeongsang National University, Jinju, 52828, South Korea
| | - Seong Dong Wi
- Division of Applied Life Sciences (BK21), PMBBRC, and Plant Biological Rhythm Research Center, Gyeongsang National University, Jinju, 52828, South Korea
| | - Kieu Anh Thi Phan
- Division of Applied Life Sciences (BK21), PMBBRC, and Plant Biological Rhythm Research Center, Gyeongsang National University, Jinju, 52828, South Korea
| | - Sang Yeol Lee
- Division of Applied Life Sciences (BK21), PMBBRC, and Plant Biological Rhythm Research Center, Gyeongsang National University, Jinju, 52828, South Korea.
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Khaleghinejad SH, Shahsavani MB, Ghahramani M, Yousefi R. Investigating the role of double mutations R12C/P20R, and R12C/R69C on structure, chaperone-like activity, and amyloidogenic properties of human αB-crystallin. Int J Biol Macromol 2023; 242:124590. [PMID: 37116845 DOI: 10.1016/j.ijbiomac.2023.124590] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 04/08/2023] [Accepted: 04/21/2023] [Indexed: 04/30/2023]
Abstract
α-crystallin is a structurally essential small heat shock protein (sHSP) with a chaperone-like activity which maintains transparency of the lenticular tissues during a period of time that is as long as human life. α-crystallin is a multimeric protein consisting of αA and αB subunits, with 57 % homology. The CRYAB gene on chromosome 11 encodes human αB-crystallin (αB-Cry), which contains 175 amino acid residues. In the current study, the cataractogenic mutations R12C, P20R, R69C, and double mutations R12C/P20R and R12C/P20R were embedded into the human CRYAB gene. Following successful expression in the prokaryotic system and purification, a number of spectroscopic techniques, gel electrophoresis, dynamic light scattering (DLS), and transmission electron microscopy (TEM) were applied to assess the role of these mutations on the structure, amyloidogenicity, and biological function of human αB-Cry. The created mutations caused significant changes in the structure, and oligomeric state of human αB-Cry. These mutations, particularly R12C, R12C/P20R, and R12C/R69C, dramatically enhanced the tendency of this protein for the amyloid fibril formation and reduced its chaperone-like activity. Since double mutations R12C/P20R and R12C/P20R were able to intensely change the protein's structure and chaperone function, it can be suggested that they may play a destructive role in a cumulative manner. Our findings indicated that the simultaneous presence of two pathogenic mutations may have a cumulative destructive impacts on the structure and function of human αB-Cry and this observation is likely related to the disease severity of the mutated proteins.
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Affiliation(s)
- Seyed Hossein Khaleghinejad
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Mohammad Bagher Shahsavani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Maryam Ghahramani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran; Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran.
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Zhu D, Li S, Chen C, Wang S, Zhu J, Kong L, Luo J. Tubocapsenolide A targets C-terminal cysteine residues of HSP90 to exert the anti-tumor effect. Pharmacol Res 2021; 166:105523. [PMID: 33667688 DOI: 10.1016/j.phrs.2021.105523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/20/2021] [Accepted: 02/28/2021] [Indexed: 01/29/2023]
Abstract
Heat shock protein 90 (HSP90) is a chaperone protein that has been shown to regulate cancer progression. As a result, HSP90 has emerged as an attractive target for cancer therapy. Tubocapsenolide A (TA) is an anti-tumor component isolated from Tubocapsicum anomalum. Although the anti-tumor activity of TA was considered to be related to HSP90, the binding site and deep anti-tumor mechanisms still need to be elucidated. In this study, we found that TA is a covalent inhibitor of HSP90, which inhibits HSP90 ATPase activity without blocking ATP binding. Further studies indicated that TA targets the C-terminal Cys521 site, which led to HSP90 partial oligomerization and hindered its anti-aggregation and refolding activity. The damage of the chaperone activity disrupted the interaction between HSP90 and its cochaperone CDC37 as well as its client proteins, thereby inducing cell cycle arrest and apoptosis. Moreover, TA was found to have therapeutic effects on the xenograft tumor model by inducing the degradation of HSP90 client proteins. Together, our results identified HSP90 as the direct target of TA for mediating the anti-tumor activity. TA could serve as a lead compound for developing novel HSP90 C-terminal covalent inhibitors with binding site different from the ATP-binding domain.
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Affiliation(s)
- Dongrong Zhu
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China
| | - Shang Li
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China
| | - Chen Chen
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China
| | - Sibei Wang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China
| | - Jiangmin Zhu
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China
| | - Lingyi Kong
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.
| | - Jianguang Luo
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 210009, People's Republic of China.
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Padmanabha S, Vallikannan B. Fatty acids influence the efficacy of lutein in the modulation of α-crystallin chaperone function: Evidence from selenite induced cataract rat model. Biochem Biophys Res Commun 2020; 529:425-431. [PMID: 32703446 DOI: 10.1016/j.bbrc.2020.06.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 06/04/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Loss of α-crystallin chaperone function results in the lens protein aggregation leading to cataract. In this study, we evaluated the efficacy of micellar lutein with different fatty acids in modulating α-crystallin chaperone function under selenite cataract conditions. METHODS Cataract was induced in rat pups by giving sodium selenite (25 μM/kg body weight) by IP. Lutein [(L), 1.3 μmol/kg body weight)] was given day before and five days after selenite injection as a micelle with 7.5 mM linoleic acid (LA), or 7.5 mM eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) or 7.5 mM oleic acid (OA). Lens α-crystallins was purified, and its chaperone function and integrity was assessed. Cholesterol, calcium, calpain-2, procaspase-3, and expression of α-A and β-B1 crystallin in the lens of cataract and micellar lutein administered rats were evaluated. RESULTS Cataract induction significantly (p < 0.05) decreased lens α-crystallin chaperone function. Cataract rats had increased cholesterol and calcium level, increased the expression of calpain-2, and α-A and β-B1 crystallin, and reduced the pro-caspase-3 level in the lens. However, micellar lutein administration significantly (p < 0.05) protected client proteins from aggregation via the modulation of calcium-dependent calpain-2 protease activity. The chaperone function of lens α-crystallins in rats administered micellar lutein with EPA + DHA was found to be highest when compared to OA and LA. CONCLUSIONS Micellar lutein with unsaturated fatty acids beneficially modulates α-crystallin chaperone function. Among the fatty acids tested, micellar lutein with EPA + DHA exhibited superior effects, thereby offering a promising strategy for cataract management.
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Affiliation(s)
- Smitha Padmanabha
- Dept. of Biochemistry, CSIR-Central Food Technological Research Institute, Mysore, 570020, Karnataka, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Baskaran Vallikannan
- Dept. of Biochemistry, CSIR-Central Food Technological Research Institute, Mysore, 570020, Karnataka, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India.
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Ghahramani M, Yousefi R, Krivandin A, Muranov K, Kurganov B, Moosavi-Movahedi AA. Structural and functional characterization of D109H and R69C mutant versions of human αB-crystallin: The biochemical pathomechanism underlying cataract and myopathy development. Int J Biol Macromol 2019; 146:1142-1160. [PMID: 31678106 DOI: 10.1016/j.ijbiomac.2019.09.239] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/18/2019] [Accepted: 09/20/2019] [Indexed: 12/15/2022]
Abstract
In human αB-crystallin (αB-Cry), the highly conserved residues arginine 69 (R69) and aspartate 109 (D109) are located within a critical motif of α-crystallin domain (ACD), contributing to the subunit interactions and oligomeric assembly. Recently, two missense mutations (R69C and D109H) in human αB-Cry have been reported to cause congenital cataract and myopathy disorders. We used various spectroscopic techniques, dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), gel electrophoresis and transmission electron microscopy (TEM) to show how these mutations cause significant changes in structure, amyloidogenic feature and biological function of human αB-Cry. These pathogenic mutations resulted in the important alterations of the secondary, tertiary and oligomeric (quaternary) structures of human αB-Cry. The missense mutations were also capable to significantly increase the amyloidogenic propensity of human αB-Cry and to diminish the chaperone-like activity of this protein. The above mentioned changes were observed more noticeably after D109H mutation. The detrimental effects of D109H mutation may be due to the loss of salt bridge with R120 in the dimeric interface, flagging the anti-aggregation ability of αB-Cry chaperone. In conclusion, the R69C and D109H mutations displayed a significant damaging effect on the structure and chaperone function of human αB-Cry which could be considered as their biochemical pathomechanisms in development of congenital cataract and myopathy disorders.
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Affiliation(s)
- Maryam Ghahramani
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
| | - Reza Yousefi
- Protein Chemistry Laboratory (PCL), Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran.
| | - Alexey Krivandin
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin str. 4, Moscow 119991, Russia
| | - Konstantin Muranov
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin str. 4, Moscow 119991, Russia
| | - Boris Kurganov
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., Moscow 119071, Russia
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Dai J, Chen A, Zhu M, Qi X, Tang W, Liu M, Li D, Gu Q, Li J. Penicisulfuranol A, a novel C-terminal inhibitor disrupting molecular chaperone function of Hsp90 independent of ATP binding domain. Biochem Pharmacol 2019; 163:404-415. [PMID: 30857829 DOI: 10.1016/j.bcp.2019.03.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 03/07/2019] [Indexed: 12/30/2022]
Abstract
The goal of this study is to explore the mechanism of a heat shock protein 90 (Hsp90) C-terminal inhibitor, Penicisulfuranol A (PEN-A), for cancer therapy. PEN-A was produced by a mangrove endophytic fungus Penicillium janthinellum and had a new structure with a rare 3H-spiro [benzofuran-2, 2'-piperazine] ring system. PEN-A caused depletion of multiple Hsp90 client proteins without induction of heat shock protein 70 (Hsp70). Subsequently, it induced apoptosis and inhibited xerograph tumor growth of HCT116 cells in vitro and in vivo. Mechanism studies showed that PEN-A was bound to C-terminus of Hsp90 at the binding site different from ATP binding domain. Therefore, it inhibited dimerization of Hsp90 C-terminus, depolymerization of ADH protein by C-terminus of Hsp90, and interaction of co-chaperones with Hsp90. These inhibitory effects of PEN-A were similar to those of novobiocin, an inhibitor binding to interaction site for ATP of C-terminus of Hsp90. Furthermore, our study revealed that disulfide bond was essential moiety for inhibition activity of PEN-A on Hsp90. This suggested that PEN-A may be bound to cysteine residues near amino acid region which was responsible for dimerization of Hsp90. All results indicate that PEN-A is a novel C-terminal inhibitor of Hsp90 and worthy for further study in the future not only for drug development but also for unraveling the bioactivities of Hsp90.
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Affiliation(s)
- Jiajia Dai
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Ao Chen
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Meilin Zhu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Xin Qi
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Wei Tang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Ming Liu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China
| | - Dehai Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China
| | - Qianqun Gu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China
| | - Jing Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, PR China; Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Open Studio for Druggability Research of Marine Natural Products, Pilot National Laboratory for Marine Science and Technology (Qingdao), 1 Wenhai Road, Aoshanwei, Jimo, Qingdao 266237, PR China.
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Oliverio R, Nguyen P, Kdeiss B, Ord S, Daniels AJ, Nikolaidis N. Functional characterization of natural variants found on the major stress inducible 70-kDa heat shock gene, HSPA1A, in humans. Biochem Biophys Res Commun 2018; 506:799-804. [PMID: 30384997 DOI: 10.1016/j.bbrc.2018.10.148] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 10/23/2018] [Indexed: 10/28/2022]
Abstract
In this report, we investigated the effects of natural single nucleotide polymorphisms on the function of HSPA1A, the major stress-inducible Hsp70 gene in humans. We first established that all mutant proteins retain their ability to hydrolyze ATP, but three of them had a significantly lower rate of ATP hydrolysis as compared to the wild-type (WT) protein. We also used Isothermal Titration Calorimetry and found that although all mutants bind to protein substrate with dissociation constants similar to the WT protein, four of them had increased reaction entropies. We also tested whether these mutations affect the ability of HSPA1A to refold heat-denatured luciferase. These assays revealed that one mutation resulted in significantly lower levels while a second one resulted in higher levels of the refolded enzyme. We then determined whether the mutations affected the ability of HSPA1A to prevent apoptosis caused by poly-glutamine carrying huntingtin proteins. This assay determined that three of the mutations caused increased cell apoptosis as compared to the WT. Our results reveal that although none of these naturally occurring mutations exists on positions of known function, some alter the molecular chaperone activities of HSPA1A most probably by affecting the allosteric communication between its two major domains.
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Affiliation(s)
- Ryan Oliverio
- Department of Biological Science, Center for Applied Biotechnology Studies, and Center for Computational and Applied Mathematics, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, 92834-6850, USA
| | - Peter Nguyen
- Department of Biological Science, Center for Applied Biotechnology Studies, and Center for Computational and Applied Mathematics, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, 92834-6850, USA
| | - Brianna Kdeiss
- Department of Biological Science, Center for Applied Biotechnology Studies, and Center for Computational and Applied Mathematics, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, 92834-6850, USA
| | - Sara Ord
- Department of Biological Science, Center for Applied Biotechnology Studies, and Center for Computational and Applied Mathematics, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, 92834-6850, USA
| | - Amanda J Daniels
- Department of Biological Science, Center for Applied Biotechnology Studies, and Center for Computational and Applied Mathematics, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, 92834-6850, USA
| | - Nikolas Nikolaidis
- Department of Biological Science, Center for Applied Biotechnology Studies, and Center for Computational and Applied Mathematics, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, 92834-6850, USA.
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Preis W, Bestehorn A, Buchner J, Haslbeck M. An alternative splice variant of human αA-crystallin modulates the oligomer ensemble and the chaperone activity of α-crystallins. Cell Stress Chaperones 2017; 22:541-552. [PMID: 28214988 PMCID: PMC5465031 DOI: 10.1007/s12192-017-0772-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/31/2017] [Accepted: 02/01/2017] [Indexed: 01/26/2023] Open
Abstract
In humans, ten genes encode small heat shock proteins with lens αA-crystallin and αB-crystallin representing two of the most prominent members. The canonical isoforms of αA-crystallin and αB-crystallin collaborate in the eye lens to prevent irreversible protein aggregation and preserve visual acuity. α-Crystallins form large polydisperse homo-oligomers and hetero-oligomers and as part of the proteostasis system bind substrate proteins in non-native conformations, thereby stabilizing them. Here, we analyzed a previously uncharacterized, alternative splice variant (isoform 2) of human αA-crystallin with an exchanged N-terminal sequence. This variant shows the characteristic α-crystallin secondary structure, exists on its own predominantly in a monomer-dimer equilibrium, and displays only low chaperone activity. However, the variant is able to integrate into higher order oligomers of canonical αA-crystallin and αB-crystallin as well as their hetero-oligomer. The presence of the variant leads to the formation of new types of higher order hetero-oligomers with an overall decreased number of subunits and enhanced chaperone activity. Thus, alternative mRNA splicing of human αA-crystallin leads to an additional, formerly not characterized αA-crystallin species which is able to modulate the properties of the canonical ensemble of α-crystallin oligomers.
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Affiliation(s)
- Waldemar Preis
- Department Chemie, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Annika Bestehorn
- Department Chemie, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Johannes Buchner
- Department Chemie, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Martin Haslbeck
- Department Chemie, Center for Integrated Protein Science, Technische Universität München, Lichtenbergstrasse 4, 85748, Garching, Germany.
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Abstract
Abstract Intrinsically disordered regions (IDRs) of proteins fulfill important regulatory roles in most organisms. However, the proteins of certain endosymbiont and intracellular pathogenic bacteria with extremely reduced genomes contain disproportionately small amounts of IDRs, consisting almost entirely of folded domains. As their genomes co-evolving with their hosts have been reduced in unrelated lineages, the proteomes of these bacteria represent independently evolved minimal protein sets. We systematically analyzed structural disorder in a representative set of such minimal organisms to see which types of functionally relevant longer IDRs are invariably retained in them. We found that a few characteristic functions are consistently linked with conformational disorder: ribosomal proteins, key components of the protein production machinery, a central coordinator of DNA metabolism and certain housekeeping chaperones seem to strictly rely on structural disorder even in genome-reduced organisms. We propose that these functions correspond to the most essential and probably also the most ancient ones fulfilled by structural disorder in cellular organisms. Reviewers This article was reviewed by Michael Gromiha, Zoltan Gaspari and Sandor Pongor. Electronic supplementary material The online version of this article (doi:10.1186/s13062-016-0149-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rita Pancsa
- Structural Biology Research Center (SBRC), Flanders Institute for Biotechnology (VIB), Vrije Universiteit Brussel (VUB), 1050 Pleinlaan 2, Brussels, Belgium
| | - Peter Tompa
- Structural Biology Research Center (SBRC), Flanders Institute for Biotechnology (VIB), Vrije Universiteit Brussel (VUB), 1050 Pleinlaan 2, Brussels, Belgium. .,Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar Tudósok körútja 2., Budapest, Hungary.
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