1
|
With or without You: Co-Chaperones Mediate Health and Disease by Modifying Chaperone Function and Protein Triage. Cells 2021; 10:cells10113121. [PMID: 34831344 PMCID: PMC8619055 DOI: 10.3390/cells10113121] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 01/18/2023] Open
Abstract
Heat shock proteins (HSPs) are a family of molecular chaperones that regulate essential protein refolding and triage decisions to maintain protein homeostasis. Numerous co-chaperone proteins directly interact and modify the function of HSPs, and these interactions impact the outcome of protein triage, impacting everything from structural proteins to cell signaling mediators. The chaperone/co-chaperone machinery protects against various stressors to ensure cellular function in the face of stress. However, coding mutations, expression changes, and post-translational modifications of the chaperone/co-chaperone machinery can alter the cellular stress response. Importantly, these dysfunctions appear to contribute to numerous human diseases. Therapeutic targeting of chaperones is an attractive but challenging approach due to the vast functions of HSPs, likely contributing to the off-target effects of these therapies. Current efforts focus on targeting co-chaperones to develop precise treatments for numerous diseases caused by defects in protein quality control. This review focuses on the recent developments regarding selected HSP70/HSP90 co-chaperones, with a concentration on cardioprotection, neuroprotection, cancer, and autoimmune diseases. We also discuss therapeutic approaches that highlight both the utility and challenges of targeting co-chaperones.
Collapse
|
2
|
Bohush A, Niewiadomska G, Weis S, Filipek A. HSP90 and Its Novel Co-Chaperones, SGT1 and CHP-1, in Brain of Patients with Parkinson's Disease and Dementia with Lewy Bodies. JOURNAL OF PARKINSONS DISEASE 2020; 9:97-107. [PMID: 30741686 PMCID: PMC6398563 DOI: 10.3233/jpd-181443] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Background: Parkinson’s disease (PD) is a neurodegenerative disorder characterized by the presence of inclusions known as Lewy bodies in some brain regions. Lewy bodies consist of α-synuclein and many other proteins including chaperones. Objective: To learn more about the role of chaperone complexes in PD and a related disorder, i.e., dementia with Lewy bodies (DLB), in this work we analyzed the expression of HSP90 and its two quite recently identified co-chaperones, SGT1 and CHP-1, in selected brain regions from patients suffering from these diseases. Methods: To fulfill the aim of our study we used human material and applied immunohistochemistry, Western blot analysis and real time/quantitative PCR (RT-qPCR). Results: We have found that HSP90 mRNA level is higher in the temporal cortex of PD and in frontal cortex of DLB brains, even though level of protein does not change significantly. The mRNA level of SGT1 is higher in the frontal and temporal cortex of PD and in substantia nigra of DLB brains while no significant changes in the level of protein were noticed. Similarly, the mRNA level of CHP-1 was found to be higher in the frontal and temporal cortex of PD and in all examined regions i.e. substantia nigra, frontal and temporal cortex of DLB brains. In the case of CHP-1 the protein level was found to be higher in frontal cortex of PD and in all examined areas of DLB patients. Conclusions: Our data indicate that the level of HSP90, SGT1 and CHP-1 is upregulated in the majority of cases of PD and DLB, which suggests that the examined proteins might be involved in these pathologies.
Collapse
Affiliation(s)
- Anastasiia Bohush
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Grażyna Niewiadomska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Serge Weis
- Division of Neuropathology, Neuromed Campus, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Anna Filipek
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
3
|
Deep Transcriptomic Analysis of Black Rockfish (Sebastes schlegelii) Provides New Insights on Responses to Acute Temperature Stress. Sci Rep 2018; 8:9113. [PMID: 29904092 PMCID: PMC6002380 DOI: 10.1038/s41598-018-27013-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/27/2018] [Indexed: 12/19/2022] Open
Abstract
In the present study, we conducted an RNA-Seq analysis to characterize the genes and pathways involved in acute thermal and cold stress responses in the liver of black rockfish, a viviparous teleost that has the ability to cope with a wide range of temperature changes. A total of 584 annotated differentially expressed genes (DEGs) were identified in all three comparisons (HT vs NT, HT vs LT and LT vs NT). Based on an enrichment analysis, DEGs with a potential role in stress accommodation were classified into several categories, including protein folding, metabolism, immune response, signal transduction, molecule transport, membrane, and cell proliferation/apoptosis. Considering that thermal stress has a greater effect than cold stress in black rockfish, 24 shared DEGs in the intersection of the HT vs LT and HT vs NT groups were enriched in 2 oxidation-related gene ontology (GO) terms. Nine important heat-stress-reducing pathways were significantly identified and classified into 3 classes: immune and infectious diseases, organismal immune system and endocrine system. Eight DEGs (early growth response protein 1, bile salt export pump, abcb11, hsp70a, rtp3, 1,25-dihydroxyvitamin d(3) 24-hydroxylase, apoa4, transcription factor jun-b-like and an uncharacterized gene) were observed among all three comparisons, strongly implying their potentially important roles in temperature stress responses.
Collapse
|
4
|
Góral A, Bartkowska K, Djavadian RL, Filipek A. CacyBP/SIP, a Hsp90 binding chaperone, in cellular stress response. Int J Biochem Cell Biol 2018; 99:178-185. [PMID: 29660399 DOI: 10.1016/j.biocel.2018.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 04/10/2018] [Accepted: 04/12/2018] [Indexed: 11/24/2022]
Abstract
CacyBP/SIP interacts with Hsp90 and is able to protect proteins from denaturation and/or aggregation induced by elevated temperature. In this work we studied the influence of different stress factors on CacyBP/SIP level in HEp-2 cells. We have found that H2O2 and radicicol treatment resulted in a significant increase (up to 40%) in the CacyBP/SIP level. We have also found that HEp-2 cells overexpressing CacyBP/SIP were more resistant to stress-induced death. Further studies have revealed that the Hsf1 transcription factor binds to the CacyBP/SIP gene promoter and up-regulates CacyBP/SIP expression under stress conditions. To check whether the CacyBP/SIP protein might play a role in stress responses in vivo, we analyzed its level in selected brain structures of control and stressed mice. We have found that the level of the CacyBP/SIP protein was higher in the thalamus/hypothalamus, hippocampus and brainstem of stressed mice. Thus, the presented results clearly indicate that CacyBP/SIP is involved in cellular stress response.
Collapse
Affiliation(s)
- Agnieszka Góral
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Katarzyna Bartkowska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Ruzanna L Djavadian
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland
| | - Anna Filipek
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093 Warsaw, Poland.
| |
Collapse
|
5
|
Liu Q, Yang T, Yu T, Zhang S, Mao X, Zhao J, Wang X, Dong J, Liu B. Integrating Small RNA Sequencing with QTL Mapping for Identification of miRNAs and Their Target Genes Associated with Heat Tolerance at the Flowering Stage in Rice. FRONTIERS IN PLANT SCIENCE 2017; 8:43. [PMID: 28174587 PMCID: PMC5258760 DOI: 10.3389/fpls.2017.00043] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 01/09/2017] [Indexed: 05/03/2023]
Abstract
Although, microRNAs (miRNAs) have been reported to be associated with heat tolerance at the seedling stage in rice, their involvement in heat tolerance at the flowering stage is still unknown. In this study, small RNA profiling was conducted in a heat-tolerant variety Gan-Xiang-Nuo (GXN) and a heat-sensitive variety Hua-Jing-Xian-74 (HJX), respectively. Totally, 102 miRNAs were differentially expressed (DE) under heat stress. Compared to HJX, GXN had more DE miRNAs and its DE miRNAs changed earlier under heat stress. Plant Ontology (PO) analysis of the target genes revealed that many DE miRNAs were involved in flower development. As a parallel experiment, QTL mapping was also conducted and four QTLs for heat tolerance at the flowering stage were identified using chromosome single-segment substitution lines derived from GXN and HJX. Further, through integrating analysis of DE miRNAs with QTLs, we identified 8 target genes corresponding to 26 miRNAs within the four QTL regions. Some meaningful target genes such as LOC_Os12g42400, SGT1, and pectinesterase were within the QTL regions. The negative correlation between miR169r-5p and its target gene LOC_Os12g42400 was confirmed under heat stress, and overexpression of miR169r-5p enhanced heat tolerance at flowering stage in rice. Our results demonstrate that the integrated analysis of genome-wide miRNA profiling with QTL mapping can facilitate identification of miRNAs and their target genes associated with the target traits and the limited candidates identified in this study offer an important source for further functional analysis and molecular breeding for heat tolerance in rice.
Collapse
Affiliation(s)
- Qing Liu
- Guangdong Key Laboratory of New Technology in Rice BreedingGuangzhou, China
- Rice Research Institute, Guangdong Academy of Agricultural SciencesGuangzhou, China
| | - Tifeng Yang
- Guangdong Key Laboratory of New Technology in Rice BreedingGuangzhou, China
- Rice Research Institute, Guangdong Academy of Agricultural SciencesGuangzhou, China
| | - Ting Yu
- Agro-biological Gene Research Center, Guangdong Academy of Agricultural SciencesGuangzhou, China
| | - Shaohong Zhang
- Guangdong Key Laboratory of New Technology in Rice BreedingGuangzhou, China
- Rice Research Institute, Guangdong Academy of Agricultural SciencesGuangzhou, China
| | - Xingxue Mao
- Guangdong Key Laboratory of New Technology in Rice BreedingGuangzhou, China
- Rice Research Institute, Guangdong Academy of Agricultural SciencesGuangzhou, China
| | - Junliang Zhao
- Guangdong Key Laboratory of New Technology in Rice BreedingGuangzhou, China
- Rice Research Institute, Guangdong Academy of Agricultural SciencesGuangzhou, China
| | - Xiaofei Wang
- Guangdong Key Laboratory of New Technology in Rice BreedingGuangzhou, China
- Rice Research Institute, Guangdong Academy of Agricultural SciencesGuangzhou, China
| | - Jingfang Dong
- Guangdong Key Laboratory of New Technology in Rice BreedingGuangzhou, China
- Rice Research Institute, Guangdong Academy of Agricultural SciencesGuangzhou, China
| | - Bin Liu
- Guangdong Key Laboratory of New Technology in Rice BreedingGuangzhou, China
- Rice Research Institute, Guangdong Academy of Agricultural SciencesGuangzhou, China
- *Correspondence: Bin Liu
| |
Collapse
|
6
|
Krzemień-Ojak Ł, Góral A, Joachimiak E, Filipek A, Fabczak H. Interaction of a Novel Chaperone PhLP2A With the Heat Shock Protein Hsp90. J Cell Biochem 2016; 118:420-429. [PMID: 27496612 DOI: 10.1002/jcb.25669] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 08/04/2016] [Indexed: 01/23/2023]
Abstract
PhLP2 is a small cytosolic protein that belongs to the highly conserved phosducin-like family of proteins. In amniote genomes there are two PhLP2 homologs, PhLP2A and PhLP2B. It has been shown that mammalian PhLP2A modulates the CCT/TRiC chaperonin activity during folding of cytoskeletal proteins. In order to better understand the function of PhLP2A in cellular protein quality control system, in the present study we have searched for its protein targets. Applying immunoprecipitation followed by mass spectrometry analysis we have identified Hsp90 as a partner of PhLP2A. With pull down experiments, we have confirmed this interaction in protein lysate and using purified proteins we have shown that PhLP2A interacts directly with Hsp90. Furthermore, the proximity ligation assay (PLA) performed on mIMCD-3 cells has shown that PhLP2A forms complexes with Hsp90 which are mainly localized in the cytoplasm of these cells. Further analysis has indicated that the level of PhLP2A increases after heat shock or radicicol treatment, similarly as the level of Hsp90, and that expression of PhLP2A after heat shock is regulated at the transcriptional level. Moreover, using recombinant luciferase we have shown that PhLP2A stabilizes this enzyme in a folding competent state and prevents its denaturation and aggregation. In addition, overexpression of PhLP2A in HEK-293 cells leads to increased heat stress resistance. Altogether, our results have shown that PhLP2A interacts with Hsp90 and exhibits molecular chaperone activity toward denatured proteins. J. Cell. Biochem. 118: 420-429, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Łucja Krzemień-Ojak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Agnieszka Góral
- Laboratory of Calcium Binding Proteins, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Anna Filipek
- Laboratory of Calcium Binding Proteins, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| | - Hanna Fabczak
- Laboratory of Cytoskeleton and Cilia Biology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, Warsaw, 02-093, Poland
| |
Collapse
|
7
|
Hong TJ, Hahn JS. Application of SGT1-Hsp90 chaperone complex for soluble expression of NOD1 LRR domain in E. coli. Biochem Biophys Res Commun 2016; 478:1647-52. [PMID: 27591899 DOI: 10.1016/j.bbrc.2016.08.174] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 08/30/2016] [Indexed: 12/17/2022]
Abstract
NOD1 is an intracellular sensor of innate immunity which is related to a number of inflammatory diseases. NOD1 is known to be difficult to express and purify for structural and biochemical studies. Based on the fact that Hsp90 and its cochaperone SGT1 are necessary for the stabilization and activation of NOD1 in mammals, SGT1 was chosen as a fusion partner of the leucine-rich repeat (LRR) domain of NOD1 for its soluble expression in Escherichia coli. Fusion of human SGT1 (hSGT1) to NOD1 LRR significantly enhanced the solubility, and the fusion protein was stabilized by coexpression of mouse Hsp90α. The expression level of hSGT1-NOD1 LRR was further enhanced by supplementation of rare codon tRNAs and exchange of antibiotic marker genes.
Collapse
Affiliation(s)
- Tae-Joon Hong
- School of Chemical and Biological Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Ji-Sook Hahn
- School of Chemical and Biological Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
| |
Collapse
|
8
|
Góral A, Bieganowski P, Prus W, Krzemień-Ojak Ł, Kądziołka B, Fabczak H, Filipek A. Calcyclin Binding Protein/Siah-1 Interacting Protein Is a Hsp90 Binding Chaperone. PLoS One 2016; 11:e0156507. [PMID: 27249023 PMCID: PMC4889068 DOI: 10.1371/journal.pone.0156507] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 05/16/2016] [Indexed: 11/19/2022] Open
Abstract
The Hsp90 chaperone activity is tightly regulated by interaction with many co-chaperones. Since CacyBP/SIP shares some sequence homology with a known Hsp90 co-chaperone, Sgt1, in this work we performed a set of experiments in order to verify whether CacyBP/SIP can interact with Hsp90. By applying the immunoprecipitation assay we have found that CacyBP/SIP binds to Hsp90 and that the middle (M) domain of Hsp90 is responsible for this binding. Furthermore, the proximity ligation assay (PLA) performed on HEp-2 cells has shown that the CacyBP/SIP-Hsp90 complexes are mainly localized in the cytoplasm of these cells. Using purified proteins and applying an ELISA we have shown that Hsp90 interacts directly with CacyBP/SIP and that the latter protein does not compete with Sgt1 for the binding to Hsp90. Moreover, inhibitors of Hsp90 do not perturb CacyBP/SIP-Hsp90 binding. Luciferase renaturation assay and citrate synthase aggregation assay with the use of recombinant proteins have revealed that CacyBP/SIP exhibits chaperone properties. Also, CacyBP/SIP-3xFLAG expression in HEp-2 cells results in the appearance of more basic Hsp90 forms in 2D electrophoresis, which may indicate that CacyBP/SIP dephosphorylates Hsp90. Altogether, the obtained results suggest that CacyBP/SIP is involved in regulation of the Hsp90 chaperone machinery.
Collapse
Affiliation(s)
- Agnieszka Góral
- Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | | | - Wiktor Prus
- Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | | | - Beata Kądziołka
- Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Hanna Fabczak
- Nencki Institute of Experimental Biology PAS, Warsaw, Poland
| | - Anna Filipek
- Nencki Institute of Experimental Biology PAS, Warsaw, Poland
- * E-mail:
| |
Collapse
|
9
|
SGT1 is required in PcINF1/SRC2-1 induced pepper defense response by interacting with SRC2-1. Sci Rep 2016; 6:21651. [PMID: 26898479 PMCID: PMC4761932 DOI: 10.1038/srep21651] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 01/28/2016] [Indexed: 02/06/2023] Open
Abstract
PcINF1 was previously found to induce pepper defense response by interacting with SRC2-1, but the underlying mechanism remains uninvestigated. Herein, we describe the involvement of SGT1 in the PcINF1/SRC2-1-induced immunity. SGT1 was observed to be up-regulated by Phytophthora capsici inoculation and synergistically transient overexpression of PcINF1/SRC2-1 in pepper plants. SGT1-silencing compromised HR cell death, blocked H2O2 accumulation, and downregulated HR-associated and hormones-dependent marker genes’ expression triggered by PcINF1/SRC2-1 co-overexpression. The interaction between SRC2-1 and SGT1 was found by the yeast two hybrid system and was further confirmed by bimolecular fluorescence complementation and co-immunoprecipitation analyses. The SGT1/SRC2-1 interaction was enhanced by transient overexpression of PcINF1 and Phytophthora capsici inoculation, and SGT1-silencing attenuated PcINF1/SRC2-1 interaction. Additionally, by modulating subcellular localizations of SRC2-1, SGT1, and the interacting complex of SGT1/SRC2-1, it was revealed that exclusive nuclear targeting of the SGT1/SRC2-1 complex blocks immunity triggered by formation of SGT1/SRC2-1, and a translocation of the SGT1/SRC2-1 complex from the plasma membrane and cytoplasm to the nuclei upon the inoculation of P. capsici. Our data demonstrate that the SGT1/SRC2-1 interaction, and its nucleocytoplasmic partitioning, is involved in pepper’s immunity against P. capsici, thus providing a molecular link between Ca2+ signaling associated SRC2-1 and SGT1-mediated defense signaling.
Collapse
|
10
|
Lin L, Jiang P, Park JW, Wang J, Lu ZX, Lam MPY, Ping P, Xing Y. The contribution of Alu exons to the human proteome. Genome Biol 2016; 17:15. [PMID: 26821878 PMCID: PMC4731929 DOI: 10.1186/s13059-016-0876-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/08/2016] [Indexed: 12/19/2022] Open
Abstract
Background Alu elements are major contributors to lineage-specific new exons in primate and human genomes. Recent studies indicate that some Alu exons have high transcript inclusion levels or tissue-specific splicing profiles, and may play important regulatory roles in modulating mRNA degradation or translational efficiency. However, the contribution of Alu exons to the human proteome remains unclear and controversial. The prevailing view is that exons derived from young repetitive elements, such as Alu elements, are restricted to regulatory functions and have not had adequate evolutionary time to be incorporated into stable, functional proteins. Results We adopt a proteotranscriptomics approach to systematically assess the contribution of Alu exons to the human proteome. Using RNA sequencing, ribosome profiling, and proteomics data from human tissues and cell lines, we provide evidence for the translational activities of Alu exons and the presence of Alu exon derived peptides in human proteins. These Alu exon peptides represent species-specific protein differences between primates and other mammals, and in certain instances between humans and closely related primates. In the case of the RNA editing enzyme ADARB1, which contains an Alu exon peptide in its catalytic domain, RNA sequencing analyses of A-to-I editing demonstrate that both the Alu exon skipping and inclusion isoforms encode active enzymes. The Alu exon derived peptide may fine tune the overall editing activity and, in limited cases, the site selectivity of ADARB1 protein products. Conclusions Our data indicate that Alu elements have contributed to the acquisition of novel protein sequences during primate and human evolution. Electronic supplementary material The online version of this article (doi:10.1186/s13059-016-0876-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Lan Lin
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - Peng Jiang
- Regenerative Biology, Morgridge Institute for Research, Madison, WI, 53707, USA.
| | - Juw Won Park
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, 90095, USA. .,Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY, 40292, USA. .,KBRIN Bioinformatics Core, University of Louisville, Louisville, KY, 40202, USA.
| | - Jinkai Wang
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - Zhi-Xiang Lu
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - Maggie P Y Lam
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - Peipei Ping
- Department of Physiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA. .,Department of Medicine, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| | - Yi Xing
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
| |
Collapse
|
11
|
Novosylna O, Jurewicz E, Pydiura N, Goral A, Filipek A, Negrutskii B, El'skaya A. Translation elongation factor eEF1A1 is a novel partner of a multifunctional protein Sgt1. Biochimie 2015; 119:137-45. [DOI: 10.1016/j.biochi.2015.10.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2015] [Accepted: 10/31/2015] [Indexed: 11/29/2022]
|
12
|
Pagani M, Rockstroh M, Schuster M, Rossetti G, Moro M, Crosti M, Tomm JM. Reference proteome of highly purified human Th1 cells reveals strong effects on metabolism and protein ubiquitination upon differentiation. Proteomics 2015; 15:3644-7. [PMID: 26332097 DOI: 10.1002/pmic.201400139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 05/19/2015] [Accepted: 08/26/2015] [Indexed: 11/12/2022]
Abstract
The differentiation of human CD4(+) T cells into T helper cell subtypes and regulatory T cells is crucial to the immune response. Among subtypes, Th1 cells are dominant, representing approximately 50% of all lymphocytes. Thus far, most global proteomic studies have used only partially purified T helper cell subpopulations and/or have employed artificial protocols for inducing specific T helper cell subtypes and/or used gel-based approaches. These studies have shed light on molecular details of certain aspects of the proteome; nevertheless a global analysis of high purity primary naïve and Th1 cells by LC-MS/MS is required to provide a reference dataset for proteome-based T cell subtype characterization. The utilization of highly purified Th1 cells for a global proteome assessment and the bioinformatic comparison to naïve cells reveals changes in cell metabolism and the ubiquitination pathway upon T cell differentiation. All MS data have been deposited in the ProteomeXchange with identifier PXD001066 (http://proteomecentral.proteomexchange.org/dataset/PXD001066).
Collapse
Affiliation(s)
- Massimiliano Pagani
- Integrative Biology Program, INGM - National Institute for Molecular Genetics, Milan, Italy
| | - Maxie Rockstroh
- Department of Proteomics, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Maj Schuster
- Department of Proteomics, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Grazisa Rossetti
- Integrative Biology Program, INGM - National Institute for Molecular Genetics, Milan, Italy
| | - Monica Moro
- Integrative Biology Program, INGM - National Institute for Molecular Genetics, Milan, Italy
| | - Mariacristina Crosti
- Integrative Biology Program, INGM - National Institute for Molecular Genetics, Milan, Italy
| | - Janina M Tomm
- Department of Proteomics, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| |
Collapse
|
13
|
Park MR, Seo JK, Kim KH. Viral and nonviral elements in potexvirus replication and movement and in antiviral responses. Adv Virus Res 2013; 87:75-112. [PMID: 23809921 DOI: 10.1016/b978-0-12-407698-3.00003-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In Potato virus X, a member of the genus Potexvirus, special sequences and structures at the 5' and 3' ends of the nontranslated region function as cis-acting elements for viral replication. These elements greatly affect interactions between viral RNAs and those between viral RNAs and host factors. The potexvirus genome encodes five open-reading frames. Viral replicase, which is required for the synthesis of viral RNA, binds viral RNA elements and host factors to form a viral replication complex at the host cellular membrane. The coat protein (CP) and three viral movement proteins (TGB1, TGB2, and TGB3) have critical roles in mediating cell-to-cell viral movement through plasmodesmata by virion formation or by nonvirion ribonucleoprotein (RNP) complex formation with viral movement proteins (TGBs). The RNP complex, like TGB1-CP-viral RNA, is associated with viral replicase and used for immediate reinitiation of viral replication in newly invaded cells. Higher plants have defense mechanisms against potexviruses such as Rx-mediated resistance and RNA silencing. The CP acts as an avirulence effector for plant defense mechanisms, while TGB1 functions as a viral suppressor of RNA silencing, which is the mechanism of innate immune resistance. Here, we describe recent findings concerning the involvement of viral and host factors in potexvirus replication and in antiviral responses to potexvirus infection.
Collapse
Affiliation(s)
- Mi-Ri Park
- Department of Agricultural Biotechnology, Plant Genomics and Breeding Institute, Seoul National University, Seoul, Republic of Korea
| | | | | |
Collapse
|
14
|
Hsp90 and its co-chaperone, Sgt1, as autoantigens in dilated cardiomyopathy. Heart Vessels 2013; 28:114-9. [PMID: 22286152 DOI: 10.1007/s00380-011-0226-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 12/16/2011] [Indexed: 01/04/2023]
Abstract
Recently, it has been suggested that some heat shock proteins such as Hsp70 and Hsp60 are involved in autoimmune diseases including cardiospecific ones. In this work we focused on the involvement of another wellknown heat shock protein, Hsp90, and its novel co-chaperone,Sgt1, in dilated cardiomyopathy (DCM). We found that the level of autoantibodies against these two proteins was significantly higher in patients with DCM and ischemic heart disease than in sera of healthy donors. We have also analyzed the expression level and subcellular localization of Hsp90 and Sgt1 in diseased myocardia. Using Western blot we found changes in subcellular localization of Hsp90 in the left ventricle of DCM hearts while the total level of this protein remained unchanged. Regarding the Sgt1 protein, we found an increased level in DCM and no changes in subcellular localization. Taken together, our data suggest that Hsp90 and Sgt1 might be involved in the progression of heart failure and might serve as markers for cardiomyopathies of different origin.
Collapse
|
15
|
Pickering C, Ericson M, Söderpalm B. Chronic phencyclidine increases synapsin-1 and synaptic adaptation proteins in the medial prefrontal cortex. ISRN PSYCHIATRY 2013; 2013:620361. [PMID: 23738220 PMCID: PMC3658391 DOI: 10.1155/2013/620361] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 01/13/2013] [Indexed: 12/03/2022]
Abstract
Phencyclidine (PCP) mimics many aspects of schizophrenia, yet the underlying mechanism of neurochemical adaptation for PCP is unknown. We therefore used proteomics to study changes in the medial prefrontal cortex in animals with PCP-induced behavioural deficits. Male Wistar rats were injected with saline or 5 mg/kg phencyclidine for 5 days followed by two days of washout. Spontaneous alternation behaviour was tested in a Y-maze and then proteins were extracted from the medial prefrontal cortex. 2D-DIGE analysis followed by spot picking and protein identification with mass spectrometry then provided a list of differentially expressed proteins. Treatment with 5 mg/kg phencyclidine decreased the percentage of correct alternations in the Y-maze compared to saline-treated controls. Proteomics analysis of the medial prefrontal cortex found upregulation of 6 proteins (synapsin-1, Dpysl3, Aco2, Fscn1, Tuba1c, and Mapk1) and downregulation of 11 (Bin1, Dpysl2, Sugt1, ApoE, Psme1, ERp29, Pgam1, Uchl1, Ndufv2, Pcmt1, and Vdac1). A trend to upregulation was observed for Gnb4 and Capza2, while downregulation trends were noted for alpha-enolase and Fh. Many of the hits in this study concur with recent postmortem data from schizophrenic patients and this further validates the use of phencyclidine in preclinical translational research.
Collapse
Affiliation(s)
- Chris Pickering
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, P.O. Box 410, 405 30 Gothenburg, Sweden
| | - Mia Ericson
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, P.O. Box 410, 405 30 Gothenburg, Sweden
| | - Bo Söderpalm
- Addiction Biology Unit, Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, P.O. Box 410, 405 30 Gothenburg, Sweden
- Beroendekliniken, Sahlgrenska University Hospital, Gothenburg, Sweden
| |
Collapse
|
16
|
Calderwood SK. Molecular cochaperones: tumor growth and cancer treatment. SCIENTIFICA 2013; 2013:217513. [PMID: 24278769 PMCID: PMC3820307 DOI: 10.1155/2013/217513] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/01/2013] [Indexed: 05/12/2023]
Abstract
Molecular chaperones play important roles in all cellular organisms by maintaining the proteome in an optimally folded state. They appear to be at a premium in cancer cells whose evolution along the malignant pathways requires the fostering of cohorts of mutant proteins that are employed to overcome tumor suppressive regulation. To function at significant rates in cells, HSPs interact with cochaperones, proteins that assist in catalyzing individual steps in molecular chaperoning as well as in posttranslational modification and intracellular localization. We review current knowledge regarding the roles of chaperones such as heat shock protein 90 (Hsp90) and Hsp70 and their cochaperones in cancer. Cochaperones are potential targets for cancer therapy in themselves and can be used to assess the likely prognosis of individual malignancies. Hsp70 cochaperones Bag1, Bag3, and Hop play significant roles in the etiology of some cancers as do Hsp90 cochaperones Aha1, p23, Cdc37, and FKBP1. Others such as the J domain protein family, HspBP1, TTC4, and FKBPL appear to be associated with more benign tumor phenotypes. The key importance of cochaperones for many pathways of protein folding in cancer suggests high promise for the future development of novel pharmaceutical agents.
Collapse
Affiliation(s)
- Stuart K. Calderwood
- Division of Molecular and Cellular Biology, Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, 99 Brookline Avenue, Boston, MA 02215, USA
- *Stuart K. Calderwood:
| |
Collapse
|
17
|
Ye CM, Kelly V, Payton M, Dickman MB, Verchot J. SGT1 is induced by the potato virus X TGBp3 and enhances virus accumulation in Nicotiana benthamiana. MOLECULAR PLANT 2012; 5:1151-3. [PMID: 22461666 DOI: 10.1093/mp/sss026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
|
18
|
Park JH, Kim WY, Chae HB, Kim MG, Lee SY. Serine/threonine protein phosphatase 5 (PP5) interacts with substrate under heat stress conditions and forms protein complex in Arabidopsis. PLANT SIGNALING & BEHAVIOR 2012; 7:535-8. [PMID: 22516824 PMCID: PMC3419013 DOI: 10.4161/psb.19699] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Protein phosphatase 5 plays a pivotal role in signal transduction in animal and plant cells, and it was previously shown that Arabidopsis protein phosphatase 5 (AtPP5) performs multiple enzymatic activities that are mediated by conformational changes induced by heat shock stress. In addition, transgenic overexpression of AtPP5 gene conferred enhanced heat shock resistance compared with wild-type plant. However, the molecular mechanism underlying this enhanced heat shock tolerance through functional and conformational changes upon heat stress is not clear. In this report, AtPP5 was shown to preferentially interact with its substrate, MDH, under heat stress conditions. In addition, in co-IP analysis, AtPP5 was observed to form a complex with AtHsp90 in Arabidopsis. These results suggest that AtPP5 may enhance thermotolerance via forming multi-chaperone complexes under heat shock conditions in Arabidopsis. Finally, we show that AtPP5 is primarily localized in the cytoplasm of Arabidopsis.
Collapse
Affiliation(s)
- Jin Ho Park
- Division of Applied Life Science (BK21 Program); Gyeongsang National University; Jinju, Korea
| | - Woe Yeon Kim
- Division of Applied Life Science (BK21 Program); Gyeongsang National University; Jinju, Korea
| | - Ho Byoung Chae
- Division of Applied Life Science (BK21 Program); Gyeongsang National University; Jinju, Korea
| | - Min Gab Kim
- College of Pharmacy; Gyeongsang National University; Jinju, Korea
- Correspondence to: Min Gab Kim, and Sang Yeol Lee,
| | - Sang Yeol Lee
- Division of Applied Life Science (BK21 Program); Gyeongsang National University; Jinju, Korea
- Correspondence to: Min Gab Kim, and Sang Yeol Lee,
| |
Collapse
|
19
|
Prus W, Zabka M, Bieganowski P, Filipek A. Nuclear translocation of Sgt1 depends on its phosphorylation state. Int J Biochem Cell Biol 2011; 43:1747-53. [DOI: 10.1016/j.biocel.2011.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 07/26/2011] [Accepted: 08/09/2011] [Indexed: 11/27/2022]
|
20
|
Park JH, Lee SY, Kim WY, Jung YJ, Chae HB, Jung HS, Kang CH, Shin MR, Kim SY, Su'udi M, Yun DJ, Lee KO, Kim MG, Lee SY. Heat-induced chaperone activity of serine/threonine protein phosphatase 5 enhances thermotolerance in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2011; 191:692-705. [PMID: 21564098 DOI: 10.1111/j.1469-8137.2011.03734.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
• This study reports that Arabidopsis thaliana protein serine/threonine phosphatase 5 (AtPP5) plays a pivotal role in heat stress resistance. A high-molecular-weight (HMW) form of AtPP5 was isolated from heat-treated A. thaliana suspension cells. AtPP5 performs multiple functions, acting as a protein phosphatase, foldase chaperone, and holdase chaperone. The enzymatic activities of this versatile protein are closely associated with its oligomeric status, ranging from low oligomeric protein species to HMW complexes. • The phosphatase and foldase chaperone functions of AtPP5 are associated primarily with the low-molecular-weight (LMW) form, whereas the HMW form exhibits holdase chaperone activity. Transgenic over-expression of AtPP5 conferred enhanced heat shock resistance to wild-type A. thaliana and a T-DNA insertion knock-out mutant was defective in acquired thermotolerance. A recombinant phosphatase mutant (H290N) showed markedly increased holdase chaperone activity. • In addition, enhanced thermotolerance was observed in transgenic plants over-expressing H290N, which suggests that the holdase chaperone activity of AtPP5 is primarily responsible for AtPP5-mediated thermotolerance. • Collectively, the results from this study provide the first evidence that AtPP5 performs multiple enzymatic activities that are mediated by conformational changes induced by heat-shock stress.
Collapse
Affiliation(s)
- Jin Ho Park
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Sun Yong Lee
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Woe Yeon Kim
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Young Jun Jung
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Ho Byoung Chae
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Hyun Suk Jung
- Division of Electron Microscopic Research, Korea Basic Science Institute, 52 Eoeun-dong, Daejeon 305-333, Korea
| | - Chang Ho Kang
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Mi Rim Shin
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Sun Young Kim
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Mukhamad Su'udi
- National Academy of Agricultural Science, RDA, Suwon 441-856, Korea
| | - Dae Jin Yun
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Kyun Oh Lee
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| | - Min Gab Kim
- National Academy of Agricultural Science, RDA, Suwon 441-856, Korea
| | - Sang Yeol Lee
- Division of Applied Life Science, Gyeongsang National University, Jinju 660-701, Korea
| |
Collapse
|
21
|
Zhu XJ, Liu X, Jin Q, Cai Y, Yang Y, Zhou T. The L279P mutation of nuclear distribution gene C (NudC) influences its chaperone activity and lissencephaly protein 1 (LIS1) stability. J Biol Chem 2010; 285:29903-10. [PMID: 20675372 DOI: 10.1074/jbc.m110.105494] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
LIS1, a gene mutated in classical lissencephaly, plays essential roles in cytoplasmic dynein regulation, mitosis and cell migration. However, the regulation of LIS1 (lissencephaly protein 1) protein remains largely unknown. Genetic studies in Aspergillus nidulans have uncovered that the Nud (nuclear distribution) pathway is involved in the regulation of cytoplasmic dynein complex and a temperature-sensitive mutation in the nudC gene (L146P) greatly reduces the protein levels of NudF, an Aspergillus ortholog of LIS1. Here, we showed that L146 in Aspergillus NudC and its flanking region were highly conservative during evolution. The similar mutation in human NudC (L279P) obviously led to reduced LIS1 and cellular phenotypes similar to those of LIS1 down-regulation. To explore the underlying mechanism, we found that the p23 domain-containing protein NudC bound to the molecular chaperone Hsp90, which is also associated with LIS1. Inhibition of Hsp90 chaperone function by either geldanamycin or radicicol resulted in a decrease in LIS1 levels. Ectopic expression of Hsp90 partially reversed the degradation of LIS1 caused by overexpression of NudC-L279P. Furthermore, NudC was found to regulate the ATPase activity of Hsp90, which was repressed by the mutation of L279P. Interestingly, NudC itself was shown to possess a chaperone function, which also was suppressed by the L279P mutation. Together, these data suggest that NudC may be involved in the regulation of LIS1 stability by its chaperone function.
Collapse
Affiliation(s)
- Xiao-Jing Zhu
- Department of Cell Biology and Program in Molecular Cell Biology, Zhejiang University School of Medicine, Hangzhou 310058, China
| | | | | | | | | | | |
Collapse
|
22
|
Michowski W, Ferretti R, Wisniewska MB, Ambrozkiewicz M, Beresewicz M, Fusella F, Skibinska-Kijek A, Zablocka B, Brancaccio M, Tarone G, Kuznicki J. Morgana/CHP-1 is a novel chaperone able to protect cells from stress. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:1043-9. [PMID: 20493909 DOI: 10.1016/j.bbamcr.2010.05.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 05/04/2010] [Accepted: 05/11/2010] [Indexed: 11/19/2022]
Abstract
Morgana/CHP-1 (CHORD containing protein-1) has been recently shown to be necessary for proper cell divisions. However, the presence of the protein in postmitotic tissues such as brain and striated muscle suggests that morgana/CHP-1 has additional cellular functions. Here we show that morgana/CHP-1 behaves like an HSP90 co-chaperone and possesses an independent molecular chaperone activity towards denatured proteins. The expression time profile of morgana/Chp-1 in NIH3T3 cells in response to heat stress is similar to that of Hsp70, a classical effector of Heat Shock Factor-1 mediated stress response. Moreover, overexpression of morgana/CHP-1 in NIH3T3 cells leads to the increased stress resistance of the cells. Interestingly, morgana/Chp-1 upregulation in response to transient global brain ischemia lasts longer in ischemia-resistant regions of the gerbil hippocampus than in vulnerable ones, suggesting the involvement of morgana/CHP-1 in natural protective mechanisms in vivo.
Collapse
Affiliation(s)
- Wojciech Michowski
- International Institute of Molecular and Cell Biology; ul. Ks. Trojdena 4, 02-109 Warsaw, Poland.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
S100A6 mediates nuclear translocation of Sgt1: a heat shock-regulated protein. Amino Acids 2010; 41:781-7. [DOI: 10.1007/s00726-010-0526-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 02/11/2010] [Indexed: 10/19/2022]
|
24
|
Cazalé AC, Clément M, Chiarenza S, Roncato MA, Pochon N, Creff A, Marin E, Leonhardt N, Noël LD. Altered expression of cytosolic/nuclear HSC70-1 molecular chaperone affects development and abiotic stress tolerance in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:2653-64. [PMID: 19443614 DOI: 10.1093/jxb/erp109] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Molecular chaperones of the heat shock cognate 70 kDa (HSC70) family are highly conserved in all living organisms and assist nascent protein folding in normal physiological conditions as well as in biotic and abiotic stress conditions. In the absence of specific inhibitors or viable knockout mutants, cytosolic/nuclear HSC70-1 overexpression (OE) and mutants in the HSC70 co-chaperone SGT1 (suppressor of G(2)/M allele of skp1) were used as genetic tools to identify HSC70/SGT1 functions in Arabidopsis development and abiotic stress responses. HSC70-1 OE caused a reduction in root and shoot meristem activities, thus explaining the dwarfism of those plants. In addition, HSC70-1 OE did not impair auxin-dependent phenotypes, suggesting that SGT1 functions previously identified in auxin signalling are HSC70 independent. While responses to abiotic stimuli such as UV-C exposure, phosphate starvation, or seedling de-etiolation were not perturbed by HSC70-1 OE, it specifically conferred gamma-ray hypersensitivity and tolerance to salt, cadmium (Cd), and arsenic (As). Cd and As perception was not perturbed, but plants overexpressing HSC70-1 accumulated less Cd, thus providing a possible molecular explanation for their tolerance phenotype. In summary, genetic evidence is provided for HSC70-1 involvement in a limited set of physiological processes, illustrating the essential and yet specific functions of this chaperone in development and abiotic stress responses in Arabidopsis.
Collapse
|
25
|
Abstract
The nucleotide-binding domain and leucine-rich repeat-containing (NLR) proteins function as immune sensors in both plants and animals. NLR proteins recognize, directly or indirectly, pathogen-derived molecules and trigger immune responses. To function as a sensor, NLR proteins must be correctly folded and maintained in a recognition-competent state in the appropriate cellular location. Upon pathogen recognition, conformational changes and/or translocation of the sensors would activate the downstream immunity signaling pathways. Misfolded or used sensors are a threat to the cell and must be immediately inactivated and discarded to avoid inappropriate activation of downstream pathways. Such maintenance of NLR-type sensors requires the SGT1-HSP90 pair, a chaperone complex that is structurally and functionally conserved in eukaryotes. Deciphering how the chaperone machinery works would facilitate an understanding of the mechanisms of pathogen recognition and signal transduction by NLR proteins in both plants and animals.
Collapse
Affiliation(s)
- Ken Shirasu
- RIKEN Plant Science Center, Yokohama City, Kanagawa 230-0045, Japan.
| |
Collapse
|