1
|
Singh MK, Shin Y, Ju S, Han S, Choe W, Yoon KS, Kim SS, Kang I. Heat Shock Response and Heat Shock Proteins: Current Understanding and Future Opportunities in Human Diseases. Int J Mol Sci 2024; 25:4209. [PMID: 38673794 PMCID: PMC11050489 DOI: 10.3390/ijms25084209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/03/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024] Open
Abstract
The heat shock response is an evolutionarily conserved mechanism that protects cells or organisms from the harmful effects of various stressors such as heat, chemicals toxins, UV radiation, and oxidizing agents. The heat shock response triggers the expression of a specific set of genes and proteins known as heat shock genes/proteins or molecular chaperones, including HSP100, HSP90, HSP70, HSP60, and small HSPs. Heat shock proteins (HSPs) play a crucial role in thermotolerance and aiding in protecting cells from harmful insults of stressors. HSPs are involved in essential cellular functions such as protein folding, eliminating misfolded proteins, apoptosis, and modulating cell signaling. The stress response to various environmental insults has been extensively studied in organisms from prokaryotes to higher organisms. The responses of organisms to various environmental stressors rely on the intensity and threshold of the stress stimuli, which vary among organisms and cellular contexts. Studies on heat shock proteins have primarily focused on HSP70, HSP90, HSP60, small HSPs, and ubiquitin, along with their applications in human biology. The current review highlighted a comprehensive mechanism of heat shock response and explores the function of heat shock proteins in stress management, as well as their potential as therapeutic agents and diagnostic markers for various diseases.
Collapse
Affiliation(s)
- Manish Kumar Singh
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; (M.K.S.); (Y.S.); (S.J.); (S.H.); (W.C.); (K.-S.Y.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Yoonhwa Shin
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; (M.K.S.); (Y.S.); (S.J.); (S.H.); (W.C.); (K.-S.Y.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Songhyun Ju
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; (M.K.S.); (Y.S.); (S.J.); (S.H.); (W.C.); (K.-S.Y.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Sunhee Han
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; (M.K.S.); (Y.S.); (S.J.); (S.H.); (W.C.); (K.-S.Y.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Wonchae Choe
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; (M.K.S.); (Y.S.); (S.J.); (S.H.); (W.C.); (K.-S.Y.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Kyung-Sik Yoon
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; (M.K.S.); (Y.S.); (S.J.); (S.H.); (W.C.); (K.-S.Y.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Sung Soo Kim
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; (M.K.S.); (Y.S.); (S.J.); (S.H.); (W.C.); (K.-S.Y.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Insug Kang
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 02447, Republic of Korea; (M.K.S.); (Y.S.); (S.J.); (S.H.); (W.C.); (K.-S.Y.)
- Biomedical Science Institute, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| |
Collapse
|
2
|
Cai E, Zeng R, Feng R, Zhang L, Li L, Jia H, Zheng W, Chen S, Yan M, Chang C. Discovery of N-Benzyl-4-(1-bromonaphthalen-2-yl)oxybutan-1-amine as a Potential Antifungal Agent against Sporidia Growth and Teliospore Germination of Sporisorium scitamineum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:3325-3333. [PMID: 38329286 DOI: 10.1021/acs.jafc.3c04589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The cultivation of sugar cane using perennial roots is the primary planting method, which is one of the reasons for the serious occurrence of sugar cane smut disease caused by the basidiomycetous fungus Sporisorium scitamineum in the sugar cane perennial root planting area. Consequently, it is crucial to eliminate pathogens from perennial sugar cane buds. In this study, we found that MAP kinase Hog1 is necessary for heat stress resistance. Subsequent investigations revealed a significant reduction in the expression of the heat shock protein 104-encoding gene, SsHSP104, in the ss1hog1Δ mutant. Additionally, the overexpression of SsHSP104 partially restored colony growth in the ss1hog1Δ strain following heat stress treatment, demonstrating the crucial role of SsHsp104 in SsHog1-mediated heat stress tolerance. Hence, we constructed the ss1hsp104:eGFP fusion strain in the wild type of S. scitamineum to identify small-molecule compounds that could inhibit the heat stress response, leading to the discovery of N-benzyl-4-(1-bromonaphthalen-2-yl)oxybutan-1-amine as a potential compound that targets the SsHog1 mediation SsHsp104 pathway during heat treatment. Furthermore, the combination of N-benzyl-4-(1-bromonaphthalen-2-yl)oxybutan-1-amine and warm water treatment (45 °C for 15 min) inhibits the growth of S. scitamineum and teliospore germination, thereby reducing the occurrence of sugar cane smut diseases and indicating its potential for eliminating pathogens from perennial sugar cane buds. In conclusion, these findings suggest that N-benzyl-4-(1-bromonaphthalen-2-yl)oxybutan-1-amine is promising as a targeted compound for the SsHog1-mediated SsHsp104 pathway and may enable the reduction of hot water treatment duration and/or temperature, thereby limiting the occurrence of sugar cane smut diseases caused by S. scitamineum.
Collapse
Affiliation(s)
- Enping Cai
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Rong Zeng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Ruqing Feng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Li Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Lei Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Huan Jia
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Wenqiang Zheng
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Shaofang Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| | - Meixin Yan
- Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530000, China
| | - Changqing Chang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China
- Guangdong Provincial Key Laboratory of Microbial Signals and Disease Control, Integrate Microbiology Research Center, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China
| |
Collapse
|
3
|
Chernova LS, Vishnyakov IE, Börner J, Bogachev MI, Thormann KM, Kayumov AR. The Functionality of IbpA from Acholeplasma laidlawii Is Governed by Dynamic Rearrangement of Its Globular-Fibrillar Quaternary Structure. Int J Mol Sci 2023; 24:15445. [PMID: 37895124 PMCID: PMC10607609 DOI: 10.3390/ijms242015445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/18/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023] Open
Abstract
Small heat shock proteins (sHSPs) represent a first line of stress defense in many bacteria. The primary function of these molecular chaperones involves preventing irreversible protein denaturation and aggregation. In Escherichia coli, fibrillar EcIbpA binds unfolded proteins and keeps them in a folding-competent state. Further, its structural homologue EcIbpB induces the transition of EcIbpA to globules, thereby facilitating the substrate transfer to the HSP70-HSP100 system for refolding. The phytopathogenic Acholeplasma laidlawii possesses only a single sHSP, AlIbpA. Here, we demonstrate non-trivial features of the function and regulation of the chaperone-like activity of AlIbpA according to its interaction with other components of the mycoplasma multi-chaperone network. Our results show that the efficiency of the A. laidlawii multi-chaperone system is driven with the ability of AlIbpA to form both globular and fibrillar structures, thus combining functions of both IbpA and IbpB when transferring the substrate proteins to the HSP70-HSP100 system. In contrast to EcIbpA and EcIbpB, AlIbpA appears as an sHSP, in which the competition between the N- and C-terminal domains regulates the shift of the protein quaternary structure between a fibrillar and globular form, thus representing a molecular mechanism of its functional regulation. While the C-terminus of AlIbpA is responsible for fibrils formation and substrate capture, the N-terminus seems to have a similar function to EcIbpB through facilitating further substrate protein disaggregation using HSP70. Moreover, our results indicate that prior to the final disaggregation process, AlIbpA can directly transfer the substrate to HSP100, thereby representing an alternative mechanism in the HSP interaction network.
Collapse
Affiliation(s)
- Liliya S. Chernova
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia;
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave. 4, 194064 St. Petersburg, Russia;
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Heinrich-Buff-Ring 26, 35392 Giessen, Germany; (J.B.); (K.M.T.)
| | - Innokentii E. Vishnyakov
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Ave. 4, 194064 St. Petersburg, Russia;
| | - Janek Börner
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Heinrich-Buff-Ring 26, 35392 Giessen, Germany; (J.B.); (K.M.T.)
| | - Mikhail I. Bogachev
- Centre for Digital Telecommunication Technologies, St. Petersburg Electrotechnical University, Professora Popova 5, 197376 St. Petersburg, Russia;
| | - Kai M. Thormann
- Institute of Microbiology and Molecular Biology, Justus Liebig University, Heinrich-Buff-Ring 26, 35392 Giessen, Germany; (J.B.); (K.M.T.)
| | - Airat R. Kayumov
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia;
| |
Collapse
|
4
|
Elucidation of the interaction proteome of mitochondrial chaperone Hsp78 highlights its role in protein aggregation during heat stress. J Biol Chem 2022; 298:102494. [PMID: 36115461 PMCID: PMC9574514 DOI: 10.1016/j.jbc.2022.102494] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 09/01/2022] [Accepted: 09/06/2022] [Indexed: 11/29/2022] Open
Abstract
Chaperones of the Hsp100/Clp family represent major components of protein homeostasis, conferring maintenance of protein activity under stress. The ClpB-type members of the family, present in bacteria, fungi, and plants, are able to resolubilize aggregated proteins. The mitochondrial member of the ClpB family in Saccharomyces cerevisiae is Hsp78. Although Hsp78 has been shown to contribute to proteostasis in elevated temperatures, the biochemical mechanisms underlying this mitochondria-specific thermotolerance are still largely unclear. To identify endogenous chaperone substrate proteins, here, we generated an Hsp78-ATPase mutant with stabilized substrate-binding behavior. We used two stable isotope labeling–based quantitative mass spectrometry approaches to analyze the role of Hsp78 during heat stress–induced mitochondrial protein aggregation and disaggregation on a proteomic level. We first identified the endogenous substrate spectrum of the Hsp78 chaperone, comprising a wide variety of proteins related to metabolic functions including energy production and protein synthesis, as well as other chaperones, indicating its crucial functions in mitochondrial stress resistance. We then compared these interaction data with aggregation and disaggregation processes in mitochondria under heat stress, which revealed specific aggregation-prone protein populations and demonstrated the direct quantitative impact of Hsp78 on stress-dependent protein solubility under different conditions. We conclude that Hsp78, together with its cofactors, represents a recovery system that protects major mitochondrial metabolic functions during heat stress as well as restores protein biogenesis capacity after the return to normal conditions.
Collapse
|
5
|
Harari A, Zoltsman G, Levin T, Rosenzweig R. Hsp104 N-terminal domain interaction with substrates plays a regulatory role in protein disaggregation. FEBS J 2022; 289:5359-5377. [PMID: 35305079 PMCID: PMC9541529 DOI: 10.1111/febs.16441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 02/01/2022] [Accepted: 03/17/2022] [Indexed: 01/19/2023]
Abstract
Heat shock protein 104 (Hsp104) protein disaggregases are powerful molecular machines that harness the energy derived from ATP binding and hydrolysis to disaggregate a wide range of protein aggregates and amyloids, as well as to assist in yeast prion propagation. Little is known, however, about how Hsp104 chaperones recognize such a diversity of substrates, or indeed the contribution of the substrate‐binding N‐terminal domain (NTD) to Hsp104 function. Herein, we present a NMR spectroscopy study, which structurally characterizes the Hsp104 NTD‐substrate interaction. We show that the NTD includes a substrate‐binding groove that specifically recognizes exposed hydrophobic stretches in unfolded, misfolded, amyloid and prion substrates of Hsp104. In addition, we find that the NTD itself has chaperoning activities which help to protect the exposed hydrophobic regions of its substrates from further misfolding and aggregation, thereby priming them for threading through the Hsp104 central channel. We further demonstrate that mutations to this substrate‐binding groove abolish Hsp104 activation by client proteins and keep the chaperone in a partially inhibited state. The Hsp104 variant with these mutations also exhibited significantly reduced disaggregation activity and cell survival at extreme temperatures. Together, our findings provide both a detailed characterization of the NTD‐substrate complex and insight into the functional regulatory role of the NTD in protein disaggregation and yeast thermotolerance.
Collapse
Affiliation(s)
- Anna Harari
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Guy Zoltsman
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Tal Levin
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Rina Rosenzweig
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| |
Collapse
|
6
|
Xia H, Chen L, Fan Z, Peng M, Zhao J, Chen W, Li H, Shi Y, Ding S, Li H. Heat Stress Tolerance Gene FpHsp104 Affects Conidiation and Pathogenicity of Fusarium pseudograminearum. Front Microbiol 2021; 12:695535. [PMID: 34394037 PMCID: PMC8355993 DOI: 10.3389/fmicb.2021.695535] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/30/2021] [Indexed: 11/13/2022] Open
Abstract
Heat shock protein Hsp104, a homolog of the bacterial chaperone ClpB and plant Hsp100, plays an essential part in the response to heat and various chemical agents in Saccharomyces cerevisiae. However, their functions remain largely unknown in plant fungal pathogens. Here, we report the identification and functional characterization of a plausible ortholog of yeast Hsp104 in Fusarium pseudograminearum, which we termed FpHsp104. Deletion mutant of FpHsp104 displayed severe defects in the resistance of heat shock during F. pseudograminearum mycelia and conidia when exposed to extreme heat. We also found that the protein showed dynamic localization to small particles under high temperature. However, no significant differences were detected in osmotic, oxidative, or cell wall stress responses between the wild-type and Δfphsp104 strains. Quantitative real-time PCR analysis showed that FpHsp104 was upregulated in the conidia, and disruption of FpHsp104 gene resulted in defects in conidia production, morphology, and germination. The transcript levels of conidiation-related genes of FpFluG, FpVosA, FpWetA, and FpAbaA were reduced in the Δfphsp104 mutant vs. the wild-type strain, but heat-shocked mRNA splicing repair was not affected in Δfphsp104. Moreover, Δfphsp104 mutant also showed attenuated virulence, but its DON synthesis was normal. These data from the first study of Hsp104 in F. pseudograminearum strongly suggest that FpHsp104 gene is an important element in the heat tolerance, development, and pathogenicity processes of F. pseudograminearum.
Collapse
Affiliation(s)
- Huiqing Xia
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Linlin Chen
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China.,National Key Laboratory of Wheat and Maize Crop Science, Zhengzhou, China
| | - Zhuo Fan
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Mengya Peng
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Jingya Zhao
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Wenbo Chen
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Haiyang Li
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Yan Shi
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Shengli Ding
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China.,National Key Laboratory of Wheat and Maize Crop Science, Zhengzhou, China
| | - Honglian Li
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China.,National Key Laboratory of Wheat and Maize Crop Science, Zhengzhou, China
| |
Collapse
|
7
|
Rogers AM, Egan MJ. Autophagy machinery promotes the chaperone-mediated formation and compartmentalization of protein aggregates during appressorium development by the rice blast fungus. Mol Biol Cell 2020; 31:2298-2305. [PMID: 32816646 PMCID: PMC7851963 DOI: 10.1091/mbc.e20-01-0068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The chaperone-mediated sequestration of misfolded proteins into specialized quality control compartments represents an important strategy for maintaining protein homeostasis in response to stress. However, precisely how this process is controlled in time and subcellular space and integrated with the cell's protein refolding and degradation pathways remains unclear. We set out to understand how aggregated proteins are managed during infection-related development by a globally devastating plant pathogenic fungus and to determine how impaired protein quality control impacts cellular differentiation and pathogenesis in this system. Here we show that in the absence of Hsp104 disaggregase activity, aggregated proteins are spatially sequestered into quality control compartments within conidia, but not within terminally differentiated infection cells, and thus spatial protein quality control is cell type–dependent. We demonstrate that impaired aggregate resolution results in a short-term developmental penalty but has no significant impact upon appressorium function. Finally, we show that, somewhat unexpectedly, the autophagy machinery is necessary for the normal formation and compartmentalization of protein aggregates. Taken together, our findings provide important new insight into spatial protein quality control during the process of terminal cellular differentiation by a globally important model eukaryote and reveal a new level of interplay between major proteostasis pathways.
Collapse
Affiliation(s)
- Audra Mae Rogers
- Department of Entomology and Plant Pathology, Division of Agriculture, University of Arkansas Systems, Fayetteville, AR 72701
| | - Martin John Egan
- Department of Entomology and Plant Pathology, Division of Agriculture, University of Arkansas Systems, Fayetteville, AR 72701.,Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR 72701
| |
Collapse
|
8
|
Jana B, Biswas I. Significance of Individual Domains of ClpL: A Novel Chaperone from Streptococcus mutans. Biochemistry 2020; 59:3368-3379. [PMID: 32791831 DOI: 10.1021/acs.biochem.0c00544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
ClpL is a member of the HSP100 family of AAA+ chaperones that is widely present in Gram-positive but surprisingly absent in Gram-negative bacteria. ClpL is involved in various cellular processes, including stress tolerance response, long-term survival, virulence, and antibiotic resistance. ClpL is poorly characterized, and its molecular mechanisms of chaperone activity are largely unclear. Here, we biochemically characterized the ClpL protein from Streptococcus mutans, a dental pathogen, to understand its biological functions. ClpL harbors five domains: N-domain, two nucleotide binding domains (NBD-1 and NBD-2), M-domain, and C-domain. NBD-1 and NBD-2 contain distinct Walker A and B motifs for ATP binding and hydrolysis, respectively. We found that ClpL predominantly exists as a trimer in solution; however, upon ATP binding, it rapidly forms a hexameric structure. To study structure-function activity, we constructed several substitution and deletion mutants. We found that mutations in the Walker A and B motifs interfered with ATP hydrolysis and oligomerization. Similarly, deletions of N-, M-, and C-domains abolished both ATPase activity and oligomerization. Because we previously found that ClpL acts as a chaperone, we analyzed the chaperone activity. Surprisingly, we found that the NBD-2 mutants did not display any chaperone activity, indicating that ATP binding and hydrolysis by NBD-2 are essential for the chaperone. However, NBD-1 mutants showed chaperone activities, but the activities were variable depending on the nature of the mutations. Our results indicate that unlike other HSP100 family chaperones, ClpL is a novel chaperone that does not require any additional secondary chaperones for its activity.
Collapse
Affiliation(s)
- Biswanath Jana
- Department of Microbiology, Molecular Genetics & Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160, United States
| | - Indranil Biswas
- Department of Microbiology, Molecular Genetics & Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160, United States
| |
Collapse
|
9
|
Tunable microsecond dynamics of an allosteric switch regulate the activity of a AAA+ disaggregation machine. Nat Commun 2019; 10:1438. [PMID: 30926805 PMCID: PMC6440998 DOI: 10.1038/s41467-019-09474-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 03/14/2019] [Indexed: 12/13/2022] Open
Abstract
Large protein machines are tightly regulated through allosteric communication channels. Here we demonstrate the involvement of ultrafast conformational dynamics in allosteric regulation of ClpB, a hexameric AAA+ machine that rescues aggregated proteins. Each subunit of ClpB contains a unique coiled-coil structure, the middle domain (M domain), proposed as a control element that binds the co-chaperone DnaK. Using single-molecule FRET spectroscopy, we probe the M domain during the chaperone cycle and find it to jump on the microsecond time scale between two states, whose structures are determined. The M-domain jumps are much faster than the overall activity of ClpB, making it an effectively continuous, tunable switch. Indeed, a series of allosteric interactions are found to modulate the dynamics, including binding of nucleotides, DnaK and protein substrates. This mode of dynamic control enables fast cellular adaptation and may be a general mechanism for the regulation of cellular machineries. Large protein machines are tightly regulated through allosteric communication channels. Here authors use single-molecule FRET and demonstrate the involvement of ultrafast conformational dynamics in the allosteric regulation of ClpB, a hexameric AAA+ machine that rescues aggregated proteins.
Collapse
|
10
|
Matthews KM, Pitman EL, de Koning-Ward TF. Illuminating how malaria parasites export proteins into host erythrocytes. Cell Microbiol 2019; 21:e13009. [PMID: 30656810 DOI: 10.1111/cmi.13009] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 12/06/2018] [Accepted: 12/17/2018] [Indexed: 12/11/2022]
Abstract
Plasmodium parasites that cause the disease malaria have developed an elaborate trafficking pathway to facilitate the export of hundreds of effector proteins into their host cell, the erythrocyte. In this review, we outline how certain effector proteins contribute to parasite survival, virulence, and immune evasion. We also highlight how parasite proteins destined for export are recognised at the endoplasmic reticulum to facilitate entry into the export pathway and how the effector proteins are able to transverse the bounding parasitophorous vaculoar membrane via the Plasmodium translocon of exported proteins to gain access to the host cell. Some of the gaps in our understanding of the export pathway are also presented. Finally, we examine the degree of conservation of some of the key components of the Plasmodium export pathway in closely related apicomplexan parasites, which may provide insight into how the diverse apicomplexan parasites have adapted to survival pressures encountered within their respective host cells.
Collapse
Affiliation(s)
| | - Ethan L Pitman
- School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
| | | |
Collapse
|
11
|
Batista FA, Dores-Silva PR, Borges JC. Molecular Chaperones Involved in Protein Recovery from Aggregates are Present in Protozoa Causative of Malaria and Leishmaniasis. CURR PROTEOMICS 2018. [DOI: 10.2174/1570164615666180626123823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Molecular chaperones have several critical functions in protein metabolism. Among them,
some are involved in processes that culminate in the extraction of entangled polypeptides from protein
aggregates, releasing unfolded structures prone to be refolded or directed to degradation. This action
avoids the effect of toxic aggregates on cells and tissues. Molecular chaperones belonging to the
Hsp100 family are widely distributed from unicellular and sessile organisms up to fungi and plants,
exerting key functions related to the reduction of the effects caused by different forms of stress. The
Hsp100 proteins belong to the AAA+ (ATPases Associated with diverse cellular Activities) family and
form multichaperone systems with Hsp70 and small Hsp chaperones families. However, Hsp100 are
absent in metazoan, where protein disaggregation action is performed by a system involving the Hsp70
family, including Hsp110 and J-protein co-chaperones. Here, the structural and functional aspects of
these protein disaggregation systems will be reviewed and discussed in the perspective of the Hsp100
system absent in the metazoan kingdom. This feature focuses on Hsp100 as a hot spot for drug discovery
against human infectious diseases such as leishmaniasis and malaria, as Hsp100 is critical for microorganisms.
The current data available for Hsp100 in Leishmania spp. and Plasmodium spp. are also
reviewed.
Collapse
Affiliation(s)
- Fernanda A.H. Batista
- Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos, SP, Brazil
| | - Paulo R. Dores-Silva
- Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos, SP, Brazil
| | - Júlio C. Borges
- Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Sao Carlos, SP, Brazil
| |
Collapse
|
12
|
Cloutier P, Poitras C, Durand M, Hekmat O, Fiola-Masson É, Bouchard A, Faubert D, Chabot B, Coulombe B. R2TP/Prefoldin-like component RUVBL1/RUVBL2 directly interacts with ZNHIT2 to regulate assembly of U5 small nuclear ribonucleoprotein. Nat Commun 2017; 8:15615. [PMID: 28561026 PMCID: PMC5460035 DOI: 10.1038/ncomms15615] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 04/12/2017] [Indexed: 01/11/2023] Open
Abstract
The R2TP/Prefoldin-like (R2TP/PFDL) complex has emerged as a cochaperone complex involved in the assembly of a number of critical protein complexes including snoRNPs, nuclear RNA polymerases and PIKK-containing complexes. Here we report on the use of multiple target affinity purification coupled to mass spectrometry to identify two additional complexes that interact with R2TP/PFDL: the TSC1–TSC2 complex and the U5 small nuclear ribonucleoprotein (snRNP). The interaction between R2TP/PFDL and the U5 snRNP is mostly mediated by the previously uncharacterized factor ZNHIT2. A more general function for the zinc-finger HIT domain in binding RUVBL2 is exposed. Disruption of ZNHIT2 and RUVBL2 expression impacts the protein composition of the U5 snRNP suggesting a function for these proteins in promoting the assembly of the ribonucleoprotein. A possible implication of R2TP/PFDL as a major effector of stress-, energy- and nutrient-sensing pathways that regulate anabolic processes through the regulation of its chaperoning activity is discussed. The R2TP/Prefoldin-like cochaperone complex is involved in the assembly of a number of protein complexes. Here the authors provide evidence that RUVBL1/RUVBL2, subunits of that cochaperone complex, directly interact with ZNHIT2 to regulate assembly of U5 small ribonucleoprotein.
Collapse
Affiliation(s)
- Philippe Cloutier
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Christian Poitras
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Mathieu Durand
- Laboratory of Functional Genomics, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1E 4K8
| | - Omid Hekmat
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Émilie Fiola-Masson
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Annie Bouchard
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Denis Faubert
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7
| | - Benoit Chabot
- Laboratory of Functional Genomics, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1E 4K8.,Département de Microbiologie et d'Infectiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1E 4K8
| | - Benoit Coulombe
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal (IRCM), Montreal, Quebec, Canada H2W 1R7.,Département de Biochimie, Université de Montréal, Montreal, Quebec, Canada H3T 1J4
| |
Collapse
|
13
|
Harding T, Roger AJ, Simpson AGB. Adaptations to High Salt in a Halophilic Protist: Differential Expression and Gene Acquisitions through Duplications and Gene Transfers. Front Microbiol 2017; 8:944. [PMID: 28611746 PMCID: PMC5447177 DOI: 10.3389/fmicb.2017.00944] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 05/11/2017] [Indexed: 11/13/2022] Open
Abstract
The capacity of halophiles to thrive in extreme hypersaline habitats derives partly from the tight regulation of ion homeostasis, the salt-dependent adjustment of plasma membrane fluidity, and the increased capability to manage oxidative stress. Halophilic bacteria, and archaea have been intensively studied, and substantial research has been conducted on halophilic fungi, and the green alga Dunaliella. By contrast, there have been very few investigations of halophiles that are phagotrophic protists, i.e., protozoa. To gather fundamental knowledge about salt adaptation in these organisms, we studied the transcriptome-level response of Halocafeteria seosinensis (Stramenopiles) grown under contrasting salinities. We provided further evolutionary context to our analysis by identifying genes that underwent recent duplications. Genes that were highly responsive to salinity variations were involved in stress response (e.g., chaperones), ion homeostasis (e.g., Na+/H+ transporter), metabolism and transport of lipids (e.g., sterol biosynthetic genes), carbohydrate metabolism (e.g., glycosidases), and signal transduction pathways (e.g., transcription factors). A significantly high proportion (43%) of duplicated genes were also differentially expressed, accentuating the importance of gene expansion in adaptation by H. seosinensis to high salt environments. Furthermore, we found two genes that were lateral acquisitions from bacteria, and were also highly up-regulated and highly expressed at high salt, suggesting that this evolutionary mechanism could also have facilitated adaptation to high salt. We propose that a transition toward high-salt adaptation in the ancestors of H. seosinensis required the acquisition of new genes via duplication, and some lateral gene transfers (LGTs), as well as the alteration of transcriptional programs, leading to increased stress resistance, proper establishment of ion gradients, and modification of cell structure properties like membrane fluidity.
Collapse
Affiliation(s)
- Tommy Harding
- Department of Biochemistry and Molecular Biology, Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie UniversityHalifax, NS, Canada
| | - Andrew J. Roger
- Department of Biochemistry and Molecular Biology, Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie UniversityHalifax, NS, Canada
| | - Alastair G. B. Simpson
- Department of Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie UniversityHalifax, NS, Canada
| |
Collapse
|
14
|
Johnston DM, Miot M, Hoskins JR, Wickner S, Doyle SM. Substrate Discrimination by ClpB and Hsp104. Front Mol Biosci 2017; 4:36. [PMID: 28611991 PMCID: PMC5447042 DOI: 10.3389/fmolb.2017.00036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 05/12/2017] [Indexed: 11/13/2022] Open
Abstract
ClpB of E. coli and yeast Hsp104 are homologous molecular chaperones and members of the AAA+ (ATPases Associated with various cellular Activities) superfamily of ATPases. They are required for thermotolerance and function in disaggregation and reactivation of aggregated proteins that form during severe stress conditions. ClpB and Hsp104 collaborate with the DnaK or Hsp70 chaperone system, respectively, to dissolve protein aggregates both in vivo and in vitro. In yeast, the propagation of prions depends upon Hsp104. Since protein aggregation and amyloid formation are associated with many diseases, including neurodegenerative diseases and cancer, understanding how disaggregases function is important. In this study, we have explored the innate substrate preferences of ClpB and Hsp104 in the absence of the DnaK and Hsp70 chaperone system. The results suggest that substrate specificity is determined by nucleotide binding domain-1.
Collapse
Affiliation(s)
- Danielle M Johnston
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of HealthBethesda, MD, United States
| | - Marika Miot
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of HealthBethesda, MD, United States
| | - Joel R Hoskins
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of HealthBethesda, MD, United States
| | - Sue Wickner
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of HealthBethesda, MD, United States
| | - Shannon M Doyle
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of HealthBethesda, MD, United States
| |
Collapse
|
15
|
Ciechanover A, Kwon YT. Protein Quality Control by Molecular Chaperones in Neurodegeneration. Front Neurosci 2017; 11:185. [PMID: 28428740 PMCID: PMC5382173 DOI: 10.3389/fnins.2017.00185] [Citation(s) in RCA: 194] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 03/20/2017] [Indexed: 12/14/2022] Open
Abstract
Protein homeostasis (proteostasis) requires the timely degradation of misfolded proteins and their aggregates by protein quality control (PQC), of which molecular chaperones are an essential component. Compared with other cell types, PQC in neurons is particularly challenging because they have a unique cellular structure with long extensions. Making it worse, neurons are postmitotic, i.e., cannot dilute toxic substances by division, and, thus, are highly sensitive to misfolded proteins, especially as they age. Failure in PQC is often associated with neurodegenerative diseases, such as Huntington's disease (HD), Alzheimer's disease (AD), Parkinson's disease (PD), and prion disease. In fact, many neurodegenerative diseases are considered to be protein misfolding disorders. To prevent the accumulation of disease-causing aggregates, neurons utilize a repertoire of chaperones that recognize misfolded proteins through exposed hydrophobic surfaces and assist their refolding. If such an effort fails, chaperones can facilitate the degradation of terminally misfolded proteins through either the ubiquitin (Ub)-proteasome system (UPS) or the autophagy-lysosome system (hereafter autophagy). If soluble, the substrates associated with chaperones, such as Hsp70, are ubiquitinated by Ub ligases and degraded through the proteasome complex. Some misfolded proteins carrying the KFERQ motif are recognized by the chaperone Hsc70 and delivered to the lysosomal lumen through a process called, chaperone-mediated autophagy (CMA). Aggregation-prone misfolded proteins that remain unprocessed are directed to macroautophagy in which cargoes are collected by adaptors, such as p62/SQSTM-1/Sequestosome-1, and delivered to the autophagosome for lysosomal degradation. The aggregates that have survived all these refolding/degradative processes can still be directly dissolved, i.e., disaggregated by chaperones. Studies have shown that molecular chaperones alleviate the pathogenic symptoms by neurodegeneration-causing protein aggregates. Chaperone-inducing drugs and anti-aggregation drugs are actively exploited for beneficial effects on symptoms of disease. Here, we discuss how chaperones protect misfolded proteins from aggregation and mediate the degradation of terminally misfolded proteins in collaboration with cellular degradative machinery. The topics also include therapeutic approaches to improve the expression and turnover of molecular chaperones and to develop anti-aggregation drugs.
Collapse
Affiliation(s)
- Aaron Ciechanover
- Department of Biomedical Sciences, Protein Metabolism Medical Research Center, College of Medicine, Seoul National UniversitySeoul, South Korea.,Technion Integrated Cancer Center, Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of TechnologyHaifa, Israel
| | - Yong Tae Kwon
- Department of Biomedical Sciences, Protein Metabolism Medical Research Center, College of Medicine, Seoul National UniversitySeoul, South Korea.,Ischemic/Hypoxic Disease Institute, College of Medicine, Seoul National UniversitySeoul, South Korea
| |
Collapse
|
16
|
Cappelli S, Penco A, Mannini B, Cascella R, Wilson MR, Ecroyd H, Li X, Buxbaum JN, Dobson CM, Cecchi C, Relini A, Chiti F. Effect of molecular chaperones on aberrant protein oligomers in vitro: super-versus sub-stoichiometric chaperone concentrations. Biol Chem 2016; 397:401-15. [PMID: 26812789 DOI: 10.1515/hsz-2015-0250] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 01/11/2016] [Indexed: 11/15/2022]
Abstract
Living systems protect themselves from aberrant proteins by a network of chaperones. We have tested in vitro the effects of different concentrations, ranging from 0 to 16 μm, of two molecular chaperones, namely αB-crystallin and clusterin, and an engineered monomeric variant of transthyretin (M-TTR), on the morphology and cytotoxicity of preformed toxic oligomers of HypF-N, which represent a useful model of misfolded protein aggregates. Using atomic force microscopy imaging and static light scattering analysis, all were found to bind HypF-N oligomers and increase the size of the aggregates, to an extent that correlates with chaperone concentration. SDS-PAGE profiles have shown that the large aggregates were predominantly composed of the HypF-N protein. ANS fluorescence measurements show that the chaperone-induced clustering of HypF-N oligomers does not change the overall solvent exposure of hydrophobic residues on the surface of the oligomers. αB-crystallin, clusterin and M-TTR can diminish the cytotoxic effects of the HypF-N oligomers at all chaperone concentration, as demonstrated by MTT reduction and Ca2+ influx measurements. The observation that the protective effect is primarily at all concentrations of chaperones, both when the increase in HypF-N aggregate size is minimal and large, emphasizes the efficiency and versatility of these protein molecules.
Collapse
|
17
|
Garcia-Huerta P, Bargsted L, Rivas A, Matus S, Vidal RL. ER chaperones in neurodegenerative disease: Folding and beyond. Brain Res 2016; 1648:580-587. [PMID: 27134034 DOI: 10.1016/j.brainres.2016.04.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 04/27/2016] [Accepted: 04/28/2016] [Indexed: 12/13/2022]
Abstract
Proteins along the secretory pathway are co-translationally translocated into the lumen of the endoplasmic reticulum (ER) as unfolded polypeptide chains. Afterwards, they are usually modified with N-linked glycans, correctly folded and stabilized by disulfide bonds. ER chaperones and folding enzymes control these processes. The accumulation of unfolded proteins in the ER activates a signaling response, termed the unfolded protein response (UPR). The hallmark of this response is the coordinated transcriptional up-regulation of ER chaperones and folding enzymes. In order to discuss the importance of the proper folding of certain substrates we will address the role of ER chaperones in normal physiological conditions and examine different aspects of its contribution in neurodegenerative disease. This article is part of a Special Issue entitled SI:ER stress.
Collapse
Affiliation(s)
- Paula Garcia-Huerta
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Leslie Bargsted
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Alexis Rivas
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Center for Molecular Studies of the Cell Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Soledad Matus
- Neurounion Biomedical Foundation, Santiago, Chile; Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; CENPAR, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.
| | - Rene L Vidal
- Neurounion Biomedical Foundation, Santiago, Chile; Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile; CENPAR, Santiago, Chile; Center for Geroscience, Brain Health and Metabolism, Santiago, Chile.
| |
Collapse
|
18
|
Abstract
UNLABELLED Cellular protein homeostasis (proteostasis) maintains the integrity of the proteome and includes protein synthesis, folding, oligomerization, and turnover; chaperone proteins assist with all of these processes. Neurons appear to be especially susceptible to failures in proteostasis, and this is now increasingly recognized as a major origin of neurodegenerative disease. This review, based on a mini-symposium presented at the 2015 Society for Neuroscience meeting, describes new work in the area of neuronal proteostasis, with a specific focus on the roles and therapeutic uses of protein chaperones. We first present a brief review of protein misfolding and aggregation in neurodegenerative disease. We then discuss different aspects of chaperone control of neuronal proteostasis on topics ranging from chaperone engineering, to chaperone-mediated blockade of protein oligomerization and cytotoxicity, to the potential rescue of neurodegenerative processes using modified chaperone proteins. SIGNIFICANCE STATEMENT Aberrant protein homeostasis within neurons results in protein misfolding and aggregation. In this review, we discuss specific roles for protein chaperones in the oligomerization, assembly, and disaggregation of proteins known to be abnormally folded in neurodegenerative disease. Collectively, our goal is to identify therapeutic mechanisms to reduce the cellular toxicity of abnormal aggregates.
Collapse
|
19
|
Egan MJ, McClintock MA, Hollyer IHL, Elliott HL, Reck-Peterson SL. Cytoplasmic dynein is required for the spatial organization of protein aggregates in filamentous fungi. Cell Rep 2016; 11:201-9. [PMID: 25865884 DOI: 10.1016/j.celrep.2015.03.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 02/10/2015] [Accepted: 03/11/2015] [Indexed: 01/01/2023] Open
Abstract
Eukaryotes have evolved multiple strategies for maintaining cellular protein homeostasis. One such mechanism involves neutralization of deleterious protein aggregates via their defined spatial segregation. Here, using the molecular disaggregase Hsp104 as a marker for protein aggregation, we describe the spatial and temporal dynamics of protein aggregates in the filamentous fungus Aspergillus nidulans. Filamentous fungi, such as A. nidulans, are a diverse group of species of major health and economic importance and also serve as model systems for studying highly polarized eukaryotic cells. We find that microtubules promote the formation of Hsp104-positive aggregates, which coalesce into discrete subcellular structures in a process dependent on the microtubule-based motor cytoplasmic dynein. Finally, we find that impaired clearance of these inclusions negatively impacts retrograde trafficking of endosomes, a conventional dynein cargo, indicating that microtubule-based transport can be overwhelmed by chronic cellular stress.
Collapse
|
20
|
Abstract
Chaperonins are nanomachines that facilitate protein folding by undergoing energy (ATP)-dependent movements that are coordinated in time and space owing to complex allosteric regulation. They consist of two back-to-back stacked oligomeric rings with a cavity at each end where protein substrate folding can take place. Here, we focus on the GroEL/GroES chaperonin system from Escherichia coli and, to a lesser extent, on the more poorly characterized eukaryotic chaperonin CCT/TRiC. We describe their various functional (allosteric) states and how they are affected by substrates and allosteric effectors that include ATP, ADP, nonfolded protein substrates, potassium ions, and GroES (in the case of GroEL). We also discuss the pathways of intra- and inter-ring allosteric communication by which they interconvert and the coupling between allosteric transitions and protein folding reactions.
Collapse
Affiliation(s)
- Ranit Gruber
- Department of Structural Biology, Weizmann Institute of Science , Rehovot 76100, Israel
| | - Amnon Horovitz
- Department of Structural Biology, Weizmann Institute of Science , Rehovot 76100, Israel
| |
Collapse
|
21
|
Rosenzweig R, Farber P, Velyvis A, Rennella E, Latham MP, Kay LE. ClpB N-terminal domain plays a regulatory role in protein disaggregation. Proc Natl Acad Sci U S A 2015; 112:E6872-81. [PMID: 26621746 PMCID: PMC4687599 DOI: 10.1073/pnas.1512783112] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
ClpB/Hsp100 is an ATP-dependent disaggregase that solubilizes and reactivates protein aggregates in cooperation with the DnaK/Hsp70 chaperone system. The ClpB-substrate interaction is mediated by conserved tyrosine residues located in flexible loops in nucleotide-binding domain-1 that extend into the ClpB central pore. In addition to the tyrosines, the ClpB N-terminal domain (NTD) was suggested to provide a second substrate-binding site; however, the manner in which the NTD recognizes and binds substrate proteins has remained elusive. Herein, we present an NMR spectroscopy study to structurally characterize the NTD-substrate interaction. We show that the NTD includes a substrate-binding groove that specifically recognizes exposed hydrophobic stretches in unfolded or aggregated client proteins. Using an optimized segmental labeling technique in combination with methyl-transverse relaxation optimized spectroscopy (TROSY) NMR, the interaction of client proteins with both the NTD and the pore-loop tyrosines in the 580-kDa ClpB hexamer has been characterized. Unlike contacts with the tyrosines, the NTD-substrate interaction is independent of the ClpB nucleotide state and protein conformational changes that result from ATP hydrolysis. The NTD interaction destabilizes client proteins, priming them for subsequent unfolding and translocation. Mutations in the NTD substrate-binding groove are shown to have a dramatic effect on protein translocation through the ClpB central pore, suggesting that, before their interaction with substrates, the NTDs block the translocation channel. Together, our findings provide both a detailed characterization of the NTD-substrate complex and insight into the functional regulatory role of the ClpB NTD in protein disaggregation.
Collapse
Affiliation(s)
- Rina Rosenzweig
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 1A8;
| | - Patrick Farber
- Program in Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8
| | - Algirdas Velyvis
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Enrico Rennella
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 1A8
| | - Michael P Latham
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061
| | - Lewis E Kay
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Biochemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Department of Chemistry, University of Toronto, Toronto, ON, Canada M5S 1A8; Program in Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, Canada M5G 1X8
| |
Collapse
|
22
|
Mokry DZ, Abrahão J, Ramos CH. Disaggregases, molecular chaperones that resolubilize protein aggregates. ACTA ACUST UNITED AC 2015; 87:1273-92. [DOI: 10.1590/0001-3765201520140671] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The process of folding is a seminal event in the life of a protein, as it is essential for proper protein function and therefore cell physiology. Inappropriate folding, or misfolding, can not only lead to loss of function, but also to the formation of protein aggregates, an insoluble association of polypeptides that harm cell physiology, either by themselves or in the process of formation. Several biological processes have evolved to prevent and eliminate the existence of non-functional and amyloidogenic aggregates, as they are associated with several human pathologies. Molecular chaperones and heat shock proteins are specialized in controlling the quality of the proteins in the cell, specifically by aiding proper folding, and dissolution and clearance of already formed protein aggregates. The latter is a function of disaggregases, mainly represented by the ClpB/Hsp104 subfamily of molecular chaperones, that are ubiquitous in all organisms but, surprisingly, have no orthologs in the cytosol of metazoan cells. This review aims to describe the characteristics of disaggregases and to discuss the function of yeast Hsp104, a disaggregase that is also involved in prion propagation and inheritance.
Collapse
Affiliation(s)
| | - Josielle Abrahão
- Universidade Estadual de Campinas, Brazil; Universidade Estadual de Campinas, Brazil
| | | |
Collapse
|
23
|
Chaperone-assisted protein aggregate reactivation: Different solutions for the same problem. Arch Biochem Biophys 2015; 580:121-34. [PMID: 26159839 DOI: 10.1016/j.abb.2015.07.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/02/2015] [Accepted: 07/04/2015] [Indexed: 12/15/2022]
Abstract
The oligomeric AAA+ chaperones Hsp104 in yeast and ClpB in bacteria are responsible for the reactivation of aggregated proteins, an activity essential for cell survival during severe stress. The protein disaggregase activity of these members of the Hsp100 family is linked to the activity of chaperones from the Hsp70 and Hsp40 families. The precise mechanism by which these proteins untangle protein aggregates remains unclear. Strikingly, Hsp100 proteins are not present in metazoans. This does not mean that animal cells do not have a disaggregase activity, but that this activity is performed by the Hsp70 system and a representative of the Hsp110 family instead of a Hsp100 protein. This review describes the actual view of Hsp100-mediated aggregate reactivation, including the ATP-induced conformational changes associated with their disaggregase activity, the dynamics of the oligomeric assembly that is regulated by its ATPase cycle and the DnaK system, and the tight allosteric coupling between the ATPase domains within the hexameric ring complexes. The lack of homologs of these disaggregases in metazoans has suggested that they might be used as potential targets to develop antimicrobials. The current knowledge of the human disaggregase machinery and the role of Hsp110 are also discussed.
Collapse
|
24
|
Alfonso C, del Castillo U, Martín I, Muga A, Rivas G. Sedimentation Equilibrium Analysis of ClpB Self-Association in Diluted and Crowded Solutions. Methods Enzymol 2015; 562:135-60. [PMID: 26412650 DOI: 10.1016/bs.mie.2015.04.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
ClpB belongs to the Hsp100 family of ring-forming heat-shock proteins involved in degradation of unfolded/misfolded proteins and in reactivation of protein aggregates. ClpB monomers reversibly associate to form the hexameric molecular chaperone that, together with the DnaK system, has the ability to disaggregate stress-denatured proteins. Here, we summarize the use of sedimentation equilibrium approaches, complemented with sedimentation velocity and composition-gradient static light scattering measurements, to study the self-association properties of ClpB in dilute and crowded solutions. As the functional unit of ClpB is the hexamer, we study the effect of environmental factors, i.e., ionic strength and natural ligands, in the association equilibrium of ClpB as well as the role of the flexible N-terminal and M domains of the protein in the self-association process. The application of the nonideal sedimentation equilibrium technique to measure the effects of volume exclusion, reproducing in part the natural crowded conditions inside a cell, on the self-association and on the stability of the oligomeric species of the disaggregase will be described. Finally, the biochemical and physiological implications of these studies and future experimental challenges to eventually reconstitute minimal disaggregating machineries will be discussed.
Collapse
Affiliation(s)
- Carlos Alfonso
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Urko del Castillo
- Unidad de Biofísica (CSIC/UPV-EHU), Departamento de Bioquímica y Biología Molecular, Universidad de País Vasco-Euskal Herriko Unibertsitatea (UPV-EHU), Bilbao, Biscay, Spain
| | - Ianire Martín
- Unidad de Biofísica (CSIC/UPV-EHU), Departamento de Bioquímica y Biología Molecular, Universidad de País Vasco-Euskal Herriko Unibertsitatea (UPV-EHU), Bilbao, Biscay, Spain
| | - Arturo Muga
- Unidad de Biofísica (CSIC/UPV-EHU), Departamento de Bioquímica y Biología Molecular, Universidad de País Vasco-Euskal Herriko Unibertsitatea (UPV-EHU), Bilbao, Biscay, Spain.
| | - Germán Rivas
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
| |
Collapse
|
25
|
Sharon M, Horovitz A. Probing allosteric mechanisms using native mass spectrometry. Curr Opin Struct Biol 2015; 34:7-16. [PMID: 26005781 DOI: 10.1016/j.sbi.2015.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 05/01/2015] [Accepted: 05/04/2015] [Indexed: 11/16/2022]
Abstract
Native mass spectrometry (MS) and ion mobility MS provide a way to discriminate between various allosteric mechanisms that cannot be distinguished using ensemble measurements of ligand binding in bulk protein solutions. Native MS, which yields mass measurements of intact assemblies, can be used to determine the values of ligand binding constants of multimeric allosteric proteins, thereby providing a way to distinguish, for example, between concerted and sequential allosteric models. Native MS can also be employed to study cooperativity owing to ligand-modulated protein oligomerization. The rotationally averaged cross-section areas of complexes obtained by ion mobility MS can be used to distinguish between induced fit and conformational selection. Native MS and its allied techniques are, therefore, becoming increasingly powerful tools for dissecting allosteric mechanisms.
Collapse
Affiliation(s)
- Michal Sharon
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Amnon Horovitz
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
| |
Collapse
|
26
|
Capo-Chichi JM, Boissel S, Brustein E, Pickles S, Fallet-Bianco C, Nassif C, Patry L, Dobrzeniecka S, Liao M, Labuda D, Samuels ME, Hamdan FF, Velde CV, Rouleau GA, Drapeau P, Michaud JL. Disruption ofCLPBis associated with congenital microcephaly, severe encephalopathy and 3-methylglutaconic aciduria. J Med Genet 2015; 52:303-11. [DOI: 10.1136/jmedgenet-2014-102952] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 01/12/2015] [Indexed: 11/04/2022]
|
27
|
Zeymer C, Fischer S, Reinstein J. trans-Acting arginine residues in the AAA+ chaperone ClpB allosterically regulate the activity through inter- and intradomain communication. J Biol Chem 2014; 289:32965-76. [PMID: 25253689 PMCID: PMC4239642 DOI: 10.1074/jbc.m114.608828] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The molecular chaperone ClpB/Hsp104, a member of the AAA+ superfamily (ATPases associated with various cellular activities), rescues proteins from the aggregated state in collaboration with the DnaK/Hsp70 chaperone system. ClpB/Hsp104 forms a hexameric, ring-shaped complex that functions as a tightly regulated, ATP-powered molecular disaggregation machine. Highly conserved and essential arginine residues, often called arginine fingers, are located at the subunit interfaces of the complex, which also harbor the catalytic sites. Several AAA+ proteins, including ClpB/Hsp104, possess a pair of such trans-acting arginines in the N-terminal nucleotide binding domain (NBD1), both of which were shown to be crucial for oligomerization and ATPase activity. Here, we present a mechanistic study elucidating the role of this conserved arginine pair. First, we found that the arginines couple nucleotide binding to oligomerization of NBD1, which is essential for the activity. Next, we designed a set of covalently linked, dimeric ClpB NBD1 variants, carrying single subunits deficient in either ATP binding or hydrolysis, to study allosteric regulation and intersubunit communication. Using this well defined environment of site-specifically modified, cross-linked AAA+ domains, we found that the conserved arginine pair mediates the cooperativity of ATP binding and hydrolysis in an allosteric fashion.
Collapse
Affiliation(s)
- Cathleen Zeymer
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
| | - Sebastian Fischer
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
| | - Jochen Reinstein
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
| |
Collapse
|
28
|
Jakob U, Kriwacki R, Uversky VN. Conditionally and transiently disordered proteins: awakening cryptic disorder to regulate protein function. Chem Rev 2014; 114:6779-805. [PMID: 24502763 PMCID: PMC4090257 DOI: 10.1021/cr400459c] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Ursula Jakob
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109-1048, United States
| | - Richard Kriwacki
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee 38105, United States
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
| | - Vladimir N. Uversky
- Department of Molecular Medicine, University of South Florida, Tampa, Florida 33612, United States
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia
| |
Collapse
|
29
|
Doyle SM, Genest O, Wickner S. Protein rescue from aggregates by powerful molecular chaperone machines. Nat Rev Mol Cell Biol 2013; 14:617-29. [PMID: 24061228 DOI: 10.1038/nrm3660] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein quality control within the cell requires the interplay of many molecular chaperones and proteases. When this quality control system is disrupted, polypeptides follow pathways leading to misfolding, inactivity and aggregation. Among the repertoire of molecular chaperones are remarkable proteins that forcibly untangle protein aggregates, called disaggregases. Structural and biochemical studies have led to new insights into how these proteins collaborate with co-chaperones and utilize ATP to power protein disaggregation. Understanding how energy-dependent protein disaggregating machines function is universally important and clinically relevant, as protein aggregation is linked to medical conditions such as Alzheimer's disease, Parkinson's disease, amyloidosis and prion diseases.
Collapse
Affiliation(s)
- Shannon M Doyle
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Bldg. 37, Room 5144, Bethesda, Maryland 20892, USA
| | | | | |
Collapse
|
30
|
Computer simulation of assembly and co-operativity of hexameric AAA ATPases. PLoS One 2013; 8:e67815. [PMID: 23869207 PMCID: PMC3711915 DOI: 10.1371/journal.pone.0067815] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 05/22/2013] [Indexed: 11/19/2022] Open
Abstract
AAA ATPases form a functionally diverse superfamily of proteins. Most members form homo-hexameric ring complexes, are catalytically active only in the fully assembled state, and show co-operativity among the six subunits. The mutual dependence among the subunits is clearly evidenced by the fact that incorporation of mutated, inactive subunits can decrease the activity of the remaining wild type subunits. For the first time, we develop here models to describe this form of allostery, evaluate them in a simulation study, and test them on experimental data. We show that it is important to consider the assembly reactions in the kinetic model, and to define a formal inhibition scheme. We simulate three inhibition scenarios explicitly, and demonstrate that they result in differing outcomes. Finally, we deduce fitting formulas, and test them on real and simulated data. A non-competitive inhibition formula fitted experimental and simulated data best. To our knowledge, our study is the first one that derives and tests formal allosteric schemes to explain the inhibitory effects of mutant subunits on oligomeric enzymes.
Collapse
|
31
|
Chopra S, Ramkissoon K, Anderson DC. A systematic quantitative proteomic examination of multidrug resistance in Acinetobacter baumannii. J Proteomics 2013; 84:17-39. [PMID: 23542354 DOI: 10.1016/j.jprot.2013.03.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 02/18/2013] [Accepted: 03/17/2013] [Indexed: 12/29/2022]
Abstract
UNLABELLED Multidrug-resistant Acinetobacter baumannii strains have been examined at the DNA sequence level, but seldom using large-scale quantitative proteomics. We have compared the proteome of the multidrug resistant strain BAA-1605, with the proteome of the drug-sensitive strain ATCC 17978, using iTRAQ labeling and online 2D LC/MS/MS for peptide/protein identification. Of 1484 proteins present in at least 2 of 4 independent experiments, 114 are 2-fold to 66-fold more abundant in BAA-1605, and 99 are 2-fold to 50-fold less abundant. Proteins with 2-fold or greater abundance in the multidrug resistant strain include drug-, antibiotic-, and heavy metal-resistance proteins, stress-related proteins, porins, membrane transporters, proteins important for acquisition of foreign DNA, biofilm-related proteins, cell-wall and exopolysaccharide-related proteins, lipoproteins, metabolic proteins, and many with no annotated function. The porin CarO, inactivated in carbapenem-resistant strains, is 2.3-fold more abundant in BAA-1605. Likewise, the porin OmpW, less abundant in carbapenem- and colistin-resistant A. baumannii strains, is 3-fold more abundant in BAA-1605. Nine proteins, all present in the drug-sensitive strain but from 2.2-fold to 16-fold more abundant in the MDR strain, can potentially account for the observed resistance of BAA-1605 to 18 antibiotics. BIOLOGICAL SIGNIFICANCE Multidrug resistant (MDR) strains of the pathogen Acinetobacter baumannii are a significant cause of hospital-acquired infections, are associated with increased mortality and length of stay, and may be a major factor underlying the spread of this pathogen, which is difficult to eradicate from clinical settings. To obtain a better understanding of antimicrobial resistance mechanisms in MDR A. baumannii, we report the first large scale 2D LC/MS/MS-based quantitative proteomics comparison of a drug-sensitive strain and an MDR strain of this pathogen. Ca. 20% of the expressed proteome changes 2-fold or more between the compared strains, including 42 proteins with literature or informatics annotations related to resistance mechanisms, modification of xenobiotics, or drug transport. Other categories of proteins differing 2-fold or more between strains include stress-response related proteins, porins, OMPs, transporters and secretion-related proteins, cell wall- and expolysaccharide-related proteins, lipoproteins, and DNA- and plasmid-related proteins. While the compared strains also differ in other aspects than multi-drug resistance, the observed differences, combined with protein functional annotation, suggest that complex protein expression changes may accompany the MDR phenotype. Expression changes of nine proteins in the MDR strain can potentially account for the observed resistance to 18 antibiotics.
Collapse
Affiliation(s)
- Sidharth Chopra
- Center for Infectious Disease and Biodefense Research, SRI International, 333 Ravenswood, Avenue, Menlo Park, CA 94025, USA
| | | | | |
Collapse
|
32
|
Zeymer C, Werbeck ND, Schlichting I, Reinstein J. The molecular mechanism of Hsp100 chaperone inhibition by the prion curing agent guanidinium chloride. J Biol Chem 2013; 288:7065-76. [PMID: 23341453 DOI: 10.1074/jbc.m112.432583] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The Hsp100 chaperones ClpB and Hsp104 utilize the energy from ATP hydrolysis to reactivate aggregated proteins in concert with the DnaK/Hsp70 chaperone system, thereby playing an important role in protein quality control. They belong to the family of AAA+ proteins (ATPases associated with various cellular activities), possess two nucleotide binding domains per monomer (NBD1 and NBD2), and oligomerize into hexameric ring complexes. Furthermore, Hsp104 is involved in yeast prion propagation and inheritance. It is well established that low concentrations of guanidinium chloride (GdmCl) inhibit the ATPase activity of Hsp104, leading to so called "prion curing," the loss of prion-related phenotypes. Here, we present mechanistic details about the Hsp100 chaperone inhibition by GdmCl using the Hsp104 homolog ClpB from Thermus thermophilus. Initially, we demonstrate that NBD1 of ClpB, which was previously considered inactive as a separately expressed construct, is a fully active ATPase on its own. Next, we show that only NBD1, but not NBD2, is affected by GdmCl. We present a crystal structure of ClpB NBD1 in complex with GdmCl and ADP, showing that the Gdm(+) ion binds specifically to the active site of NBD1. A conserved essential glutamate residue is involved in this interaction. Additionally, Gdm(+) interacts directly with the nucleotide, thereby increasing the nucleotide binding affinity of NBD1. We propose that both the interference with the essential glutamate and the modulation of nucleotide binding properties in NBD1 is responsible for the GdmCl-specific inhibition of Hsp100 chaperones.
Collapse
Affiliation(s)
- Cathleen Zeymer
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, 69120 Heidelberg, Germany
| | | | | | | |
Collapse
|