1
|
Cui Y, Wu B, Wu J, Zhang S, Guo P, Shu J, Li D, Cai C. Novel Genetic Variants Distinguishing Myelin Oligodendrocyte Glycoprotein-IgG-Positive From Myelin Oligodendrocyte Glycoprotein-IgG-Negative Pediatric Acute Disseminated Encephalomyelitis in Northern China. Pediatr Neurol 2024; 156:155-161. [PMID: 38781724 DOI: 10.1016/j.pediatrneurol.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 04/01/2024] [Accepted: 04/12/2024] [Indexed: 05/25/2024]
Abstract
BACKGROUND Acute disseminated encephalomyelitis (ADEM) is a common phenotype in children with myelin oligodendrocyte glycoprotein IgG (MOG-IgG)-associated disease. We aimed to identify novel genetic variants that distinguish children with MOG-IgG-positive ADEM (MOG-IgG+ ADEM) from children with MOG-IgG-negative ADEM (MOG-IgG- ADEM) using whole exome sequencing (WES) analysis. METHODS We conducted a two-stage study design. First, we performed WES on five patients with MOG-IgG+ ADEM and five patients with MOG-IgG- ADEM. Following bioinformatics analysis, the candidate variant list was constructed. Second, 29 children with MOG-IgG+ ADEM and 27 children with MOG-IgG- ADEM, together with discovery cohort, were genotyped to identify the novel variants. RESULTS WES resulted in 33,999 variants, and 5388 nonsynonymous variants were selected for downstream analysis. In total, 118 protein-affecting variants that were significantly different between the two groups were identified. Together with the five variants extracted from the literature, 49 variants were selected as the candidate variant list for genotyping in the replication cohort. Finally, we identified three variants: rs11171951 in NACα, rs231775 in CTLA4, and rs11171951 in GOLGA5, which were significantly different between MOG-IgG+ ADEM and MOG-IgG- ADEM. Only rs12440118 in NACα remained significant after Bonferroni correction for multiple testing (Padj < 0.001). CONCLUSIONS We identified strong associations between NACα, CTLA4, and GOLGA5 variants and MOG-IgG+ ADEM in a Han Chinese population of Northern China, which may present novel genetic risk factor distinguishing patients with MOG-IgG+ ADEM from those with MOG-IgG- ADEM.
Collapse
Affiliation(s)
- Yaqiong Cui
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Bo Wu
- Department of Neurology, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Jinying Wu
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Shuyue Zhang
- Basic Medical College, Tianjin Medical University, Tianjin, China
| | - Pan Guo
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China
| | - Jianbo Shu
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China.
| | - Dong Li
- Department of Neurology, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China.
| | - Chunquan Cai
- Tianjin Key Laboratory of Birth Defects for Prevention and Treatment, Tianjin Pediatric Research Institute, Tianjin Children's Hospital (Children's Hospital of Tianjin University), Tianjin, China.
| |
Collapse
|
2
|
Kinger S, Jagtap YA, Kumar P, Choudhary A, Prasad A, Prajapati VK, Kumar A, Mehta G, Mishra A. Proteostasis in neurodegenerative diseases. Adv Clin Chem 2024; 121:270-333. [PMID: 38797543 DOI: 10.1016/bs.acc.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Proteostasis is essential for normal function of proteins and vital for cellular health and survival. Proteostasis encompasses all stages in the "life" of a protein, that is, from translation to functional performance and, ultimately, to degradation. Proteins need native conformations for function and in the presence of multiple types of stress, their misfolding and aggregation can occur. A coordinated network of proteins is at the core of proteostasis in cells. Among these, chaperones are required for maintaining the integrity of protein conformations by preventing misfolding and aggregation and guide those with abnormal conformation to degradation. The ubiquitin-proteasome system (UPS) and autophagy are major cellular pathways for degrading proteins. Although failure or decreased functioning of components of this network can lead to proteotoxicity and disease, like neuron degenerative diseases, underlying factors are not completely understood. Accumulating misfolded and aggregated proteins are considered major pathomechanisms of neurodegeneration. In this chapter, we have described the components of three major branches required for proteostasis-chaperones, UPS and autophagy, the mechanistic basis of their function, and their potential for protection against various neurodegenerative conditions, like Alzheimer's, Parkinson's, and Huntington's disease. The modulation of various proteostasis network proteins, like chaperones, E3 ubiquitin ligases, proteasome, and autophagy-associated proteins as therapeutic targets by small molecules as well as new and unconventional approaches, shows promise.
Collapse
Affiliation(s)
- Sumit Kinger
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Yuvraj Anandrao Jagtap
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Prashant Kumar
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Akash Choudhary
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India
| | - Amit Prasad
- School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Amit Kumar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, Madhya Pradesh, India
| | - Gunjan Mehta
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana, India
| | - Amit Mishra
- Cellular and Molecular Neurobiology Unit, Indian Institute of Technology Jodhpur, Rajasthan, India.
| |
Collapse
|
3
|
Andrews SS, Wiley HS, Sauro HM. Design patterns of biological cells. Bioessays 2024; 46:e2300188. [PMID: 38247191 PMCID: PMC10922931 DOI: 10.1002/bies.202300188] [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: 09/30/2023] [Revised: 12/03/2023] [Accepted: 12/14/2023] [Indexed: 01/23/2024]
Abstract
Design patterns are generalized solutions to frequently recurring problems. They were initially developed by architects and computer scientists to create a higher level of abstraction for their designs. Here, we extend these concepts to cell biology to lend a new perspective on the evolved designs of cells' underlying reaction networks. We present a catalog of 21 design patterns divided into three categories: creational patterns describe processes that build the cell, structural patterns describe the layouts of reaction networks, and behavioral patterns describe reaction network function. Applying this pattern language to the E. coli central metabolic reaction network, the yeast pheromone response signaling network, and other examples lends new insights into these systems.
Collapse
Affiliation(s)
- Steven S. Andrews
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - H. Steven Wiley
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Herbert M. Sauro
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| |
Collapse
|
4
|
Yamada T, Yoshinari Y, Tobo M, Habara O, Nishimura T. Nacα protects the larval fat body from cell death by maintaining cellular proteostasis in Drosophila. Nat Commun 2023; 14:5328. [PMID: 37658058 PMCID: PMC10474126 DOI: 10.1038/s41467-023-41103-1] [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: 03/06/2023] [Accepted: 08/17/2023] [Indexed: 09/03/2023] Open
Abstract
Protein homeostasis (proteostasis) is crucial for the maintenance of cellular homeostasis. Impairment of proteostasis activates proteotoxic and unfolded protein response pathways to resolve cellular stress or induce apoptosis in damaged cells. However, the responses of individual tissues to proteotoxic stress and evoking cell death program have not been extensively explored in vivo. Here, we show that a reduction in Nascent polypeptide-associated complex protein alpha subunit (Nacα) specifically and progressively induces cell death in Drosophila fat body cells. Nacα mutants disrupt both ER integrity and the proteasomal degradation system, resulting in caspase activation through JNK and p53. Although forced activation of the JNK and p53 pathways was insufficient to induce cell death in the fat body, the reduction of Nacα sensitized fat body cells to intrinsic and environmental stresses. Reducing overall protein synthesis by mTor inhibition or Minute mutants alleviated the cell death phenotype in Nacα mutant fat body cells. Our work revealed that Nacα is crucial for protecting the fat body from cell death by maintaining cellular proteostasis, thus demonstrating the coexistence of a unique vulnerability and cell death resistance in the fat body.
Collapse
Affiliation(s)
- Takayuki Yamada
- Laboratory for Growth Control Signaling, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Hyogo, 650-0047, Japan
| | - Yuto Yoshinari
- Laboratory of Metabolic Regulation and Genetics, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma, 371-8512, Japan
| | - Masayuki Tobo
- Laboratory of Metabolic Regulation and Genetics, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma, 371-8512, Japan
| | - Okiko Habara
- Laboratory for Growth Control Signaling, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Hyogo, 650-0047, Japan
| | - Takashi Nishimura
- Laboratory for Growth Control Signaling, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Hyogo, 650-0047, Japan.
- Laboratory of Metabolic Regulation and Genetics, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma, 371-8512, Japan.
| |
Collapse
|
5
|
Shao W, Sun K, Ma T, Jiang H, Hahn M, Ma Z, Jiao C, Yin Y. SUMOylation regulates low-temperature survival and oxidative DNA damage tolerance in Botrytis cinerea. THE NEW PHYTOLOGIST 2023; 238:817-834. [PMID: 36651012 DOI: 10.1111/nph.18748] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 01/13/2023] [Indexed: 06/17/2023]
Abstract
SUMOylation as one of the protein post-translational modifications plays crucial roles in multiple biological processes of eukaryotic organisms. Botrytis cinerea is a devastating fungal pathogen and capable of infecting plant hosts at low temperature. However, the molecular mechanisms of low-temperature adaptation are largely unknown in fungi. Combining with biochemical methods and biological analyses, we report that SUMOylation regulates pathogen survival at low temperature and oxidative DNA damage response during infection in B. cinerea. The heat shock protein (Hsp70) BcSsb and E3 ubiquitin ligase BcRad18 were identified as substrates of SUMOylation; moreover, their SUMOylation both requires a single unique SUMO-interacting motif (SIM). SUMOylated BcSsb regulates β-tubulin accumulation, thereby affecting the stability of microtubules and consequently mycelial growth at low temperature. On the contrary, SUMOylated BcRad18 modulates mono-ubiquitination of the sliding clamp protein proliferating cell nuclear antigen (PCNA), which is involved in response to oxidative DNA damage during infection. Our study uncovers the molecular mechanisms of SUMOylation-mediated low-temperature survival and oxidative DNA damage tolerance during infection in a devastating fungal pathogen, which provides novel insights into low-temperature adaptation and pathogenesis for postharvest pathogens as well as new targets for inhibitor invention in disease control.
Collapse
Affiliation(s)
- Wenyong Shao
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Kewei Sun
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Tianling Ma
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Huixian Jiang
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Matthias Hahn
- Department of Biology, University of Kaiserslautern, PO Box 3049, 67653, Kaiserslautern, Germany
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Chen Jiao
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| | - Yanni Yin
- State Key Laboratory of Rice Biology, Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, China
| |
Collapse
|
6
|
Günnigmann M, Koubek J, Kramer G, Bukau B. Selective ribosome profiling as a tool to study interactions of translating ribosomes in mammalian cells. Methods Enzymol 2023; 684:1-38. [PMID: 37230585 DOI: 10.1016/bs.mie.2022.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The processing, membrane targeting and folding of newly synthesized polypeptides is closely linked to their synthesis at the ribosome. A network of enzymes, chaperones and targeting factors engages ribosome-nascent chain complexes (RNCs) to support these maturation processes. Exploring the modes of action of this machinery is critical for our understanding of functional protein biogenesis. Selective ribosome profiling (SeRP) is a powerful method for interrogating co-translational interactions of maturation factors with RNCs. It provides proteome-wide information on the factor's nascent chain interactome, the timing of factor binding and release during the progress of translation of individual nascent chain species, and the mechanisms and features controlling factor engagement. SeRP is based on the combination of two ribosome profiling (RP) experiments performed on the same cell population. In one experiment the ribosome-protected mRNA footprints of all translating ribosomes of the cell are sequenced (total translatome), while the other experiment detects only the ribosome footprints of the subpopulation of ribosomes engaged by the factor of interest (selected translatome). The codon-specific ratio of ribosome footprint densities from selected over total translatome reports on the factor enrichment at specific nascent chains. In this chapter, we provide a detailed SeRP protocol for mammalian cells. The protocol includes instructions on cell growth and cell harvest, stabilization of factor-RNC interactions, nuclease digest and purification of (factor-engaged) monosomes, as well as preparation of cDNA libraries from ribosome footprint fragments and deep sequencing data analysis. Purification protocols of factor-engaged monosomes and experimental results are exemplified for the human ribosomal tunnel exit-binding factor Ebp1 and chaperone Hsp90, but the protocols are readily adaptable to other co-translationally acting mammalian factors.
Collapse
Affiliation(s)
- Manuel Günnigmann
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Jiří Koubek
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, Heidelberg, Germany.
| |
Collapse
|
7
|
Neira JL, Palomino-Schätzlein M. Folding of the nascent polypeptide chain of a histidine phosphocarrier protein in vitro. Arch Biochem Biophys 2023; 736:109538. [PMID: 36738980 DOI: 10.1016/j.abb.2023.109538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/28/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
The phosphotransferase system (PTS), a metabolic pathway formed by five proteins, modulates the use of sugars in bacteria. The second protein in the chain is the histidine phosphocarrier, HPr, with the binding site at His15. The HPr kinase/phosphorylase (HPrK/P), involved in the bacterial use of carbon sources, phosphorylates HPr at Ser46, and it binds at its binding site. The regulator of sigma D protein (Rsd) also binds to HPr at His15. We have designed fragments of HPr, growing from its N-terminus and containing the His15. In this work, we obtained three fragments, HPr38, HPr58 and HPr70, comprising the first thirty-eight, fifty-eight and seventy residues of HPr, respectively. All fragments were mainly disordered, with evidence of a weak native-like, helical population around the binding site, as shown by fluorescence, far-ultraviolet circular dichroism, size exclusion chromatography and nuclear magnetic resonance. Although HPr38, HPr58 and HPr70 were disordered, they could bind to: (i) the N-terminal domain of first protein of the PTS, EIN; (ii) Rsd; and, (iii) HPrK/P, as shown by fluorescence and biolayer interferometry (BLI). The association constants for each protein to any of the fragments were in the low micromolar range, within the same range than those measured in the binding of HPr to each protein. Then, although acquisition of stable, native-like secondary and tertiary structures occurred at the last residues of the polypeptide, the ability to bind protein partners happened much earlier in the growing chain. Binding was related to the presence of the native-like structure around His15.
Collapse
Affiliation(s)
- José L Neira
- IDIBE, Universidad Miguel Hernández, 03202, Elche, Alicante, Spain; Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Joint Units IQFR-CSIC-BIFI and GBsC-CSIC-BIFI, Universidad de Zaragoza, 50018, Zaragoza, Spain.
| | - Martina Palomino-Schätzlein
- ProtoQSAR SL, CEEI-Valencia, Parque Tecnológico de Valencia, Av. Benjamin Franklin 12 (Dep. 8), 46980, Paterna, Valencia, Spain
| |
Collapse
|
8
|
Törner R, Kupreichyk T, Hoyer W, Boisbouvier J. The role of heat shock proteins in preventing amyloid toxicity. Front Mol Biosci 2022; 9:1045616. [PMID: 36589244 PMCID: PMC9798239 DOI: 10.3389/fmolb.2022.1045616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
The oligomerization of monomeric proteins into large, elongated, β-sheet-rich fibril structures (amyloid), which results in toxicity to impacted cells, is highly correlated to increased age. The concomitant decrease of the quality control system, composed of chaperones, ubiquitin-proteasome system and autophagy-lysosomal pathway, has been shown to play an important role in disease development. In the last years an increasing number of studies has been published which focus on chaperones, modulators of protein conformational states, and their effects on preventing amyloid toxicity. Here, we give a comprehensive overview of the current understanding of chaperones and amyloidogenic proteins and summarize the advances made in elucidating the impact of these two classes of proteins on each other, whilst also highlighting challenges and remaining open questions. The focus of this review is on structural and mechanistic studies and its aim is to bring novices of this field "up to speed" by providing insight into all the relevant processes and presenting seminal structural and functional investigations.
Collapse
Affiliation(s)
- Ricarda Törner
- University Grenoble Alpes, CNRS CEA Institut de Biologie Structurale (IBS), Grenoble, France,*Correspondence: Ricarda Törner, ; Jerome Boisbouvier,
| | - Tatsiana Kupreichyk
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany,Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Wolfgang Hoyer
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany,Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Jerome Boisbouvier
- University Grenoble Alpes, CNRS CEA Institut de Biologie Structurale (IBS), Grenoble, France,*Correspondence: Ricarda Törner, ; Jerome Boisbouvier,
| |
Collapse
|
9
|
Kim H, Moon S, Ham S, Lee K, Römling U, Lee C. Cytoplasmic molecular chaperones in Pseudomonas species. J Microbiol 2022; 60:1049-1060. [PMID: 36318358 DOI: 10.1007/s12275-022-2425-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/20/2022] [Accepted: 10/20/2022] [Indexed: 06/16/2023]
Abstract
Pseudomonas is widespread in various environmental and host niches. To promote rejuvenation, cellular protein homeostasis must be finely tuned in response to diverse stresses, such as extremely high and low temperatures, oxidative stress, and desiccation, which can result in protein homeostasis imbalance. Molecular chaperones function as key components that aid protein folding and prevent protein denaturation. Pseudomonas, an ecologically important bacterial genus, includes human and plant pathogens as well as growth-promoting symbionts and species useful for bioremediation. In this review, we focus on protein quality control systems, particularly molecular chaperones, in ecologically diverse species of Pseudomonas, including the opportunistic human pathogen Pseudomonas aeruginosa, the plant pathogen Pseudomonas syringae, the soil species Pseudomonas putida, and the psychrophilic Pseudomonas antarctica.
Collapse
Affiliation(s)
- Hyunhee Kim
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Seongjoon Moon
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Soojeong Ham
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea
| | - Kihyun Lee
- CJ Bioscience, Seoul, 04527, Republic of Korea
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Changhan Lee
- Department of Biological Sciences, Ajou University, Suwon, 16499, Republic of Korea.
| |
Collapse
|
10
|
Hu C, Yang J, Qi Z, Wu H, Wang B, Zou F, Mei H, Liu J, Wang W, Liu Q. Heat shock proteins: Biological functions, pathological roles, and therapeutic opportunities. MedComm (Beijing) 2022; 3:e161. [PMID: 35928554 PMCID: PMC9345296 DOI: 10.1002/mco2.161] [Citation(s) in RCA: 115] [Impact Index Per Article: 57.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 12/12/2022] Open
Abstract
The heat shock proteins (HSPs) are ubiquitous and conserved protein families in both prokaryotic and eukaryotic organisms, and they maintain cellular proteostasis and protect cells from stresses. HSP protein families are classified based on their molecular weights, mainly including large HSPs, HSP90, HSP70, HSP60, HSP40, and small HSPs. They function as molecular chaperons in cells and work as an integrated network, participating in the folding of newly synthesized polypeptides, refolding metastable proteins, protein complex assembly, dissociating protein aggregate dissociation, and the degradation of misfolded proteins. In addition to their chaperone functions, they also play important roles in cell signaling transduction, cell cycle, and apoptosis regulation. Therefore, malfunction of HSPs is related with many diseases, including cancers, neurodegeneration, and other diseases. In this review, we describe the current understandings about the molecular mechanisms of the major HSP families including HSP90/HSP70/HSP60/HSP110 and small HSPs, how the HSPs keep the protein proteostasis and response to stresses, and we also discuss their roles in diseases and the recent exploration of HSP related therapy and diagnosis to modulate diseases. These research advances offer new prospects of HSPs as potential targets for therapeutic intervention.
Collapse
Affiliation(s)
- Chen Hu
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
| | - Jing Yang
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
| | - Ziping Qi
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
| | - Hong Wu
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
| | - Beilei Wang
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
| | - Fengming Zou
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
| | - Husheng Mei
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- University of Science and Technology of ChinaHefeiAnhuiP. R. China
| | - Jing Liu
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
- University of Science and Technology of ChinaHefeiAnhuiP. R. China
| | - Wenchao Wang
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
- University of Science and Technology of ChinaHefeiAnhuiP. R. China
| | - Qingsong Liu
- Anhui Province Key Laboratory of Medical Physics and TechnologyInstitute of Health and Medical TechnologyHefei Institutes of Physical ScienceChinese Academy of SciencesHefeiAnhuiP. R. China
- Hefei Cancer HospitalChinese Academy of SciencesHefeiAnhuiP. R. China
- University of Science and Technology of ChinaHefeiAnhuiP. R. China
- Precision Medicine Research Laboratory of Anhui ProvinceHefeiAnhuiP. R. China
| |
Collapse
|
11
|
Micic J, Rodríguez-Galán O, Babiano R, Fitzgerald F, Fernández-Fernández J, Zhang Y, Gao N, Woolford JL, de la Cruz J. Ribosomal protein eL39 is important for maturation of the nascent polypeptide exit tunnel and proper protein folding during translation. Nucleic Acids Res 2022; 50:6453-6473. [PMID: 35639884 PMCID: PMC9226512 DOI: 10.1093/nar/gkac366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 04/04/2022] [Accepted: 05/12/2022] [Indexed: 11/29/2022] Open
Abstract
During translation, nascent polypeptide chains travel from the peptidyl transferase center through the nascent polypeptide exit tunnel (NPET) to emerge from 60S subunits. The NPET includes portions of five of the six 25S/5.8S rRNA domains and ribosomal proteins uL4, uL22, and eL39. Internal loops of uL4 and uL22 form the constriction sites of the NPET and are important for both assembly and function of ribosomes. Here, we investigated the roles of eL39 in tunnel construction, 60S biogenesis, and protein synthesis. We show that eL39 is important for proper protein folding during translation. Consistent with a delay in processing of 27S and 7S pre-rRNAs, eL39 functions in pre-60S assembly during middle nucleolar stages. Our biochemical assays suggest the presence of eL39 in particles at these stages, although it is not visualized in them by cryo-electron microscopy. This indicates that eL39 takes part in assembly even when it is not fully accommodated into the body of pre-60S particles. eL39 is also important for later steps of assembly, rotation of the 5S ribonucleoprotein complex, likely through long range rRNA interactions. Finally, our data strongly suggest the presence of alternative pathways of ribosome assembly, previously observed in the biogenesis of bacterial ribosomal subunits.
Collapse
Affiliation(s)
- Jelena Micic
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Reyes Babiano
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Fiona Fitzgerald
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - José Fernández-Fernández
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Yunyang Zhang
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Genética, Universidad de Sevilla, Seville, Spain
| |
Collapse
|
12
|
Structural remodeling of ribosome associated Hsp40-Hsp70 chaperones during co-translational folding. Nat Commun 2022; 13:3410. [PMID: 35701497 PMCID: PMC9197937 DOI: 10.1038/s41467-022-31127-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 06/02/2022] [Indexed: 11/16/2022] Open
Abstract
Ribosome associated complex (RAC), an obligate heterodimer of HSP40 and HSP70 (Zuo1 and Ssz1 in yeast), is conserved in eukaryotes and functions as co-chaperone for another HSP70 (Ssb1/2 in yeast) to facilitate co-translational folding of nascent polypeptides. Many mechanistic details, such as the coordination of one HSP40 with two HSP70s and the dynamic interplay between RAC-Ssb and growing nascent chains, remain unclear. Here, we report three sets of structures of RAC-containing ribosomal complexes isolated from Saccharomyces cerevisiae. Structural analyses indicate that RAC on the nascent-chain-free ribosome is in an autoinhibited conformation, and in the presence of a nascent chain at the peptide tunnel exit (PTE), RAC undergoes large-scale structural remodeling to make Zuo1 J-Domain more accessible to Ssb. Our data also suggest a role of Zuo1 in orienting Ssb-SBD proximal to the PTE for easy capture of the substrate. Altogether, in accordance with previous data, our work suggests a sequence of structural remodeling events for RAC-Ssb during co-translational folding, triggered by the binding and passage of growing nascent chain from one to another. Ribosome associated complex (RAC)- HSP70 (Ssb in yeast) is a eukaryotic chaperone system involved in co-translational folding. Here, authors report structures of RAC-containing ribosomal complexes, which suggest a working model for the dynamic actions of RAC-Ssb during the process.
Collapse
|
13
|
The Astonishing Large Family of HSP40/DnaJ Proteins Existing in Leishmania. Genes (Basel) 2022; 13:genes13050742. [PMID: 35627127 PMCID: PMC9141911 DOI: 10.3390/genes13050742] [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: 03/31/2022] [Revised: 04/14/2022] [Accepted: 04/21/2022] [Indexed: 02/04/2023] Open
Abstract
Abrupt environmental changes are faced by Leishmania parasites during transmission from a poikilothermic insect vector to a warm-blooded host. Adaptation to harsh environmental conditions, such as nutrient deprivation, hypoxia, oxidative stress and heat shock needs to be accomplished by rapid reconfiguration of gene expression and remodeling of protein interaction networks. Chaperones play a central role in the maintenance of cellular homeostasis, and they are responsible for crucial tasks such as correct folding of nascent proteins, protein translocation across different subcellular compartments, avoiding protein aggregates and elimination of damaged proteins. Nearly one percent of the gene content in the Leishmania genome corresponds to members of the HSP40 family, a group of proteins that assist HSP70s in a variety of cellular functions. Despite their expected relevance in the parasite biology and infectivity, little is known about their functions or partnership with the different Leishmania HSP70s. Here, we summarize the structural features of the 72 HSP40 proteins encoded in the Leishmania infantum genome and their classification into four categories. A review of proteomic data, together with orthology analyses, allow us to postulate cellular locations and possible functional roles for some of them. A detailed study of the members of this family would provide valuable information and opportunities for drug discovery and improvement of current treatments against leishmaniasis.
Collapse
|
14
|
Denney AS, Weems AD, McMurray MA. Selective functional inhibition of a tumor-derived p53 mutant by cytosolic chaperones identified using split-YFP in budding yeast. G3-GENES GENOMES GENETICS 2021; 11:6318398. [PMID: 34544131 PMCID: PMC8496213 DOI: 10.1093/g3journal/jkab230] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 06/17/2021] [Indexed: 11/25/2022]
Abstract
Life requires the oligomerization of individual proteins into higher-order assemblies. In order to form functional oligomers, monomers must adopt appropriate 3D structures. Molecular chaperones transiently bind nascent or misfolded proteins to promote proper folding. Single missense mutations frequently cause disease by perturbing folding despite chaperone engagement. A misfolded mutant capable of oligomerizing with wild-type proteins can dominantly poison oligomer function. We previously found evidence that human-disease-linked mutations in Saccharomyces cerevisiae septin proteins slow folding and attract chaperones, resulting in a kinetic delay in oligomerization that prevents the mutant from interfering with wild-type function. Here, we build upon our septin studies to develop a new approach for identifying chaperone interactions in living cells, and use it to expand our understanding of chaperone involvement, kinetic folding delays, and oligomerization in the recessive behavior of tumor-derived mutants of the tumor suppressor p53. We find evidence of increased binding of several cytosolic chaperones to a recessive, misfolding-prone mutant, p53(V272M). Similar to our septin results, chaperone overexpression inhibits the function of p53(V272M) with minimal effect on the wild type. Unlike mutant septins, p53(V272M) is not kinetically delayed under conditions in which it is functional. Instead, it interacts with wild-type p53 but this interaction is temperature sensitive. At high temperatures or upon chaperone overexpression, p53(V272M) is excluded from the nucleus and cannot function or perturb wild-type function. Hsp90 inhibition liberates mutant p53 to enter the nucleus. These findings provide new insights into the effects of missense mutations.
Collapse
Affiliation(s)
- Ashley S Denney
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Andrew D Weems
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Michael A McMurray
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| |
Collapse
|
15
|
Liu XJ, Sun J, Huang Y, Li C, Zheng P, Yuan Y, Chen H, Jan M, Zheng H, Du H, Tu J. Osj10gBTF3-Mediated Import of Chloroplast Protein Is Essential for Pollen Development in Rice. FRONTIERS IN PLANT SCIENCE 2021; 12:713544. [PMID: 34421965 PMCID: PMC8377413 DOI: 10.3389/fpls.2021.713544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 07/13/2021] [Indexed: 06/13/2023]
Abstract
Chloroplasts are crucial organelles for the generation of fatty acids and starch required for plant development. Nascent polypeptide-associated complex (NAC) proteins have been implicated in development as transcription factors. However, their chaperone roles in chloroplasts and their relationship with pollen development in plants remain to be elucidated. Here, we demonstrated that Osj10gBTF3, a NAC protein, regulates pollen and chloroplast development in rice by coordinating with a Hsp90 family chaperone OsHSP82 to mediate chloroplast import. Knockout of Osj10gBTF3 affects pollen and chloroplast development and significantly reduces the accumulation of fertility-related chloroplast protein OsPPR676. Both Osj10gBTF3 and OsHSP82 interact with OsPPR676. Interestingly, the interaction between OsHSP82 and OsPPR676 is only found in the cytoplasm, while the interaction between Osj10gBTF3 and OsPPR676 also occurs inside the chloroplast. The chloroplast stroma chaperone OsCpn60 can also be co-precipitated with Osj10gBTF3, but not with OsHSP82. Further investigation indicates that Osj10gBTF3 enters the chloroplast stroma possibly through the inner chloroplast membrane channel protein Tic110 and then recruits OsCpn60 for the folding or assembly of OsPPR676. Our results reveal a chaperone role of Osj10gBTF3 in chloroplast import different from Hsp90 and provide a link between chloroplast transport and pollen development in rice.
Collapse
Affiliation(s)
- Xue-jiao Liu
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| | - Jiaqi Sun
- Department of Biology, McGill University, Montreal, QC, Canada
| | - Yuqing Huang
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| | - Chao Li
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| | - Peng Zheng
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| | - Yue Yuan
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| | - Hao Chen
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| | - Mehmood Jan
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| | - Huanquan Zheng
- Department of Biology, McGill University, Montreal, QC, Canada
| | - Hao Du
- Institute of Crop Science, Zhejiang University, Hangzhou, China
- Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, China
| | - Jumin Tu
- Institute of Crop Science, Zhejiang University, Hangzhou, China
| |
Collapse
|
16
|
The HSP70 chaperone as sensor of the NEDD8 cycle upon DNA damage. Biochem Soc Trans 2021; 49:1075-1083. [PMID: 34156462 DOI: 10.1042/bst20200381] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/13/2021] [Accepted: 04/15/2021] [Indexed: 11/17/2022]
Abstract
Molecular chaperones are essential components of the protein quality control system and maintenance of homeostasis. Heat Shock Protein 70 (HSP70), a highly evolutionarily conserved family of chaperones is a key regulator of protein folding, oligomerisation and prevents the aggregation of misfolded proteins. HSP70 chaperone function depends on the so-called 'HSP70-cycle', where HSP70 interacts with and is released from substrates via ATP hydrolysis and the assistance of HSP70 co-factors/co-chaperones, which also provide substrate specificity. The identification of regulatory modules for HSP70 allows the elucidation of HSP70 specificity and target selectivity. Here, we discuss how the HSP70 cycle is functionally linked with the cycle of the Ubiquitin-like molecule NEDD8. Using as an example the DNA damage response, we present a model where HSP70 acts as a sensor of the NEDD8 cycle. The NEDD8 cycle acts as a regulatory module of HSP70 activity, where conversion of poly-NEDD8 chains into mono-NEDD8 upon DNA damage activates HSP70, facilitating the formation of the apoptosome and apoptosis execution.
Collapse
|
17
|
Zhao L, Castanié-Cornet MP, Kumar S, Genevaux P, Hayer-Hartl M, Hartl FU. Bacterial RF3 senses chaperone function in co-translational folding. Mol Cell 2021; 81:2914-2928.e7. [PMID: 34107307 DOI: 10.1016/j.molcel.2021.05.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 04/05/2021] [Accepted: 05/13/2021] [Indexed: 10/21/2022]
Abstract
Molecular chaperones assist with protein folding by interacting with nascent polypeptide chains (NCs) during translation. Whether the ribosome can sense chaperone defects and, in response, abort translation of misfolding NCs has not yet been explored. Here we used quantitative proteomics to investigate the ribosome-associated chaperone network in E. coli and the consequences of its dysfunction. Trigger factor and the DnaK (Hsp70) system are the major NC-binding chaperones. HtpG (Hsp90), GroEL, and ClpB contribute increasingly when DnaK is deficient. Surprisingly, misfolding because of defects in co-translational chaperone function or amino acid analog incorporation results in recruitment of the non-canonical release factor RF3. RF3 recognizes aberrant NCs and then moves to the peptidyltransferase site to cooperate with RF2 in mediating chain termination, facilitating clearance by degradation. This function of RF3 reduces the accumulation of misfolded proteins and is critical for proteostasis maintenance and cell survival under conditions of limited chaperone availability.
Collapse
Affiliation(s)
- Liang Zhao
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Marie-Pierre Castanié-Cornet
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Sneha Kumar
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| |
Collapse
|
18
|
Karunanayake C, Page RC. Cytosolic protein quality control machinery: Interactions of Hsp70 with a network of co-chaperones and substrates. Exp Biol Med (Maywood) 2021; 246:1419-1434. [PMID: 33730888 PMCID: PMC8243209 DOI: 10.1177/1535370221999812] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The chaperone heat shock protein 70 (Hsp70) and its network of co-chaperones serve as a central hub of cellular protein quality control mechanisms. Domain organization in Hsp70 dictates ATPase activity, ATP dependent allosteric regulation, client/substrate binding and release, and interactions with co-chaperones. The protein quality control activities of Hsp70 are classified as foldase, holdase, and disaggregase activities. Co-chaperones directly assisting protein refolding included J domain proteins and nucleotide exchange factors. However, co-chaperones can also be grouped and explored based on which domain of Hsp70 they interact. Here we discuss how the network of cytosolic co-chaperones for Hsp70 contributes to the functions of Hsp70 while closely looking at their structural features. Comparison of domain organization and the structures of co-chaperones enables greater understanding of the interactions, mechanisms of action, and roles played in protein quality control.
Collapse
Affiliation(s)
| | - Richard C Page
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| |
Collapse
|
19
|
A role for the ribosome-associated complex in activation of the IRE1 branch of UPR. Cell Rep 2021; 35:109217. [PMID: 34107246 DOI: 10.1016/j.celrep.2021.109217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 03/31/2021] [Accepted: 05/13/2021] [Indexed: 12/11/2022] Open
Abstract
The ubiquitous ribosome-associated complex (RAC) is a chaperone that spans ribosomes, making contacts near both the polypeptide exit tunnel and the decoding center, a position prime for sensing and coordinating translation and folding. Loss of RAC is known to result in growth defects and sensitization to translational and osmotic stresses. However, the physiological substrates of RAC and the mechanism(s) by which RAC is involved in responding to specific stresses in higher eukaryotes remain obscure. The data presented here uncover an essential function of mammalian RAC in the unfolded protein response (UPR). Knockdown of RAC sensitizes mammalian cells to endoplasmic reticulum (ER) stress and selectively interferes with IRE1 branch activation. Higher-order oligomerization of the inositol-requiring enzyme 1α (IRE1α) kinase/endoribonuclease depends upon RAC. These results reveal a surveillance function for RAC in the UPR, as follows: modulating IRE1α clustering as required for endonuclease activation and splicing of the substrate Xbp1 mRNA.
Collapse
|
20
|
Westrich LD, Gotsmann VL, Herkt C, Ries F, Kazek T, Trösch R, Armbruster L, Mühlenbeck JS, Ramundo S, Nickelsen J, Finkemeier I, Wirtz M, Storchová Z, Räschle M, Willmund F. The versatile interactome of chloroplast ribosomes revealed by affinity purification mass spectrometry. Nucleic Acids Res 2021; 49:400-415. [PMID: 33330923 PMCID: PMC7797057 DOI: 10.1093/nar/gkaa1192] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/19/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
In plant cells, chloroplast gene expression is predominantly controlled through post-transcriptional regulation. Such fine-tuning is vital for precisely orchestrating protein complex assembly as for the photosynthesis machinery and for quickly responding to environmental changes. While regulation of chloroplast protein synthesis is of central importance, little is known about the degree and nature of the regulatory network, mainly due to challenges associated with the specific isolation of transient ribosome interactors. Here, we established a ribosome affinity purification method, which enabled us to broadly uncover putative ribosome-associated proteins in chloroplasts. Endogenously tagging of a protein of the large or small subunit revealed not only interactors of the holo complex, but also preferential interactors of the two subunits. This includes known canonical regulatory proteins as well as several new proteins belonging to the categories of protein and RNA regulation, photosystem biogenesis, redox control and metabolism. The sensitivity of the here applied screen was validated for various transiently interacting proteins. We further provided evidence for the existence of a ribosome-associated Nα-acetyltransferase in chloroplasts and its ability to acetylate substrate proteins at their N-terminus. The broad set of ribosome interactors underscores the potential to regulate chloroplast gene expression on the level of protein synthesis.
Collapse
Affiliation(s)
- Lisa Désirée Westrich
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Vincent Leon Gotsmann
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Claudia Herkt
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Fabian Ries
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Tanja Kazek
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Raphael Trösch
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| | - Laura Armbruster
- Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Jens Stephan Mühlenbeck
- Plant Physiology, Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 7, 48149 Münster, Germany
| | - Silvia Ramundo
- Department of Biochemistry and Biophysics, University of California, 600 16th St, N316, San Francisco, CA 94143, USA
| | - Jörg Nickelsen
- Department of Molecular Plant Science, University of Munich, Grosshaderner-Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Iris Finkemeier
- Plant Physiology, Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 7, 48149 Münster, Germany
| | - Markus Wirtz
- Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Zuzana Storchová
- Molecular Genetics, University of Kaiserslautern, Paul-Ehrlich-Str. 24, 67663 Kaiserslautern, Germany
| | - Markus Räschle
- Molecular Genetics, University of Kaiserslautern, Paul-Ehrlich-Str. 24, 67663 Kaiserslautern, Germany
| | - Felix Willmund
- Molecular Genetics of Eukaryotes, University of Kaiserslautern, Paul-Ehrlich-Str. 23, 67663 Kaiserslautern, Germany
| |
Collapse
|
21
|
Rodríguez-Galán O, García-Gómez JJ, Rosado IV, Wei W, Méndez-Godoy A, Pillet B, Alekseenko A, Steinmetz L, Pelechano V, Kressler D, de la Cruz J. A functional connection between translation elongation and protein folding at the ribosome exit tunnel in Saccharomyces cerevisiae. Nucleic Acids Res 2021; 49:206-220. [PMID: 33330942 PMCID: PMC7797049 DOI: 10.1093/nar/gkaa1200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/18/2020] [Accepted: 12/14/2020] [Indexed: 12/03/2022] Open
Abstract
Proteostasis needs to be tightly controlled to meet the cellular demand for correctly de novo folded proteins and to avoid protein aggregation. While a coupling between translation rate and co-translational folding, likely involving an interplay between the ribosome and its associated chaperones, clearly appears to exist, the underlying mechanisms and the contribution of ribosomal proteins remain to be explored. The ribosomal protein uL3 contains a long internal loop whose tip region is in close proximity to the ribosomal peptidyl transferase center. Intriguingly, the rpl3[W255C] allele, in which the residue making the closest contact to this catalytic site is mutated, affects diverse aspects of ribosome biogenesis and function. Here, we have uncovered, by performing a synthetic lethal screen with this allele, an unexpected link between translation and the folding of nascent proteins by the ribosome-associated Ssb-RAC chaperone system. Our results reveal that uL3 and Ssb-RAC cooperate to prevent 80S ribosomes from piling up within the 5' region of mRNAs early on during translation elongation. Together, our study provides compelling in vivo evidence for a functional connection between peptide bond formation at the peptidyl transferase center and chaperone-assisted de novo folding of nascent polypeptides at the solvent-side of the peptide exit tunnel.
Collapse
Affiliation(s)
- Olga Rodríguez-Galán
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Juan J García-Gómez
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Iván V Rosado
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
| | - Wu Wei
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, USA
- CAS Key Lab of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, Shanghai Institutes for Biological Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Alfonso Méndez-Godoy
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Benjamin Pillet
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Alisa Alekseenko
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology. Karolinska Institutet, Solna, Sweden
| | - Lars M Steinmetz
- Stanford Genome Technology Center, Stanford University, Palo Alto, CA, USA
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany
- Department of Genetics, School of Medicine, Stanford, CA, USA
| | - Vicent Pelechano
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology. Karolinska Institutet, Solna, Sweden
| | - Dieter Kressler
- Unit of Biochemistry, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Jesús de la Cruz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- Departamento de Genética, Universidad de Sevilla, Seville, Spain
| |
Collapse
|
22
|
Build-UPS and break-downs: metabolism impacts on proteostasis and aging. Cell Death Differ 2021; 28:505-521. [PMID: 33398091 PMCID: PMC7862225 DOI: 10.1038/s41418-020-00682-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 12/30/2022] Open
Abstract
Perturbation of metabolism elicits cellular stress which profoundly modulates the cellular proteome and thus protein homeostasis (proteostasis). Consequently, changes in the cellular proteome due to metabolic shift require adaptive mechanisms by molecular protein quality control. The mechanisms vitally controlling proteostasis embrace the entire life cycle of a protein involving translational control at the ribosome, chaperone-assisted native folding, and subcellular sorting as well as proteolysis by the proteasome or autophagy. While metabolic imbalance and proteostasis decline have been recognized as hallmarks of aging and age-associated diseases, both processes are largely considered independently. Here, we delineate how proteome stability is governed by insulin/IGF1 signaling (IIS), mechanistic target of Rapamycin (TOR), 5′ adenosine monophosphate-activated protein kinase (AMPK), and NAD-dependent deacetylases (Sir2-like proteins known as sirtuins). This comprehensive overview is emphasizing the regulatory interconnection between central metabolic pathways and proteostasis, indicating the relevance of shared signaling nodes as targets for future therapeutic interventions. ![]()
Collapse
|
23
|
Bilyk KT, Zhuang X, Vargas-Chacoff L, Cheng CHC. Evolution of chaperome gene expression and regulatory elements in the antarctic notothenioid fishes. Heredity (Edinb) 2020; 126:424-441. [PMID: 33149264 DOI: 10.1038/s41437-020-00382-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 10/15/2020] [Accepted: 10/19/2020] [Indexed: 12/14/2022] Open
Abstract
Confined within the cold-stable Southern Ocean, Antarctic notothenioid fishes have undergone an evolutionary loss of the inducible heat shock response (HSR), while facing perpetual low-temperature challenges to cellular proteostasis. This study examines how evolution in chronic cold has affected the shared cellular apparatus that mediates proteostasis under normal and heat stressed states. To deduce Antarctic-specific changes, we compared native expression levels across the full suite of chaperome genes and assessed the structural integrity of two crucial HSR regulators - Heat Shock Factor 1 (HSF1) that activates HSR, and heat shock elements (HSEs), the binding sites for HSF1 - between Antarctic fishes and the basal temperate notothenioid Eleginops maclovinus. Native expression levels of Antarctic fish chaperomes showed very modest changes overall, contrary to the common view of constitutive upregulation in the cold. Only a few cytosolic HSP70 genes showed greater transcription, with only the ancestrally-inducible HSPA6 strongly upregulated across all Antarctic species. Additionally, the constant cold has apparently not relaxed the selective pressures on maintaining HSF1 and HSEs in Antarctic fish. Instead, we found HSF1 experienced intensified selective pressure, with conserved sequence changes in Antarctic species suggesting optimization for non-heat-stress functional roles. HSEs of the HSP70 gene family have largely remained conserved in canonical sequence motifs and copy numbers as in E. maclovinus, showing limited impact of relaxed selective pressure. This study shows that evolution in chronic cold has led to both subtle and distinctive changes in the cellular apparatus for proteostasis and HSR, with functional consequences amenable to experimental evaluation.
Collapse
Affiliation(s)
- Kevin T Bilyk
- Department of Biology, Montclair State University, 1 Normal Ave., Montclair, NJ, 07043, USA.
| | - Xuan Zhuang
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR, 72701, USA
| | - Luis Vargas-Chacoff
- Instituto de Ciencias Marinas y Limnológicas, Laboratorio de Fisiología de Peces, Centro Fondap de Investigación de Altas Latitudes (IDEAL), Universidad Austral de Chile, Valdivia, Chile
| | - C-H Christina Cheng
- Department of Evolution, Ecology, and Behavior, University of Illinois, Urbana-Champaign, IL, 61801, USA.
| |
Collapse
|
24
|
Wang X, Komatsu S. Review: Proteomic Techniques for the Development of Flood-Tolerant Soybean. Int J Mol Sci 2020; 21:E7497. [PMID: 33053653 PMCID: PMC7589014 DOI: 10.3390/ijms21207497] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 10/04/2020] [Accepted: 10/08/2020] [Indexed: 12/16/2022] Open
Abstract
Soybean, which is rich in protein and oil as well as phytochemicals, is cultivated in several climatic zones. However, its growth is markedly decreased by flooding stress, which is caused by climate change. Proteomic techniques were used for understanding the flood-response and -tolerant mechanisms in soybean. Subcellular proteomics has potential to elucidate localized cellular responses and investigate communications among subcellular components during plant growth and under stress stimuli. Furthermore, post-translational modifications play important roles in stress response and tolerance to flooding stress. Although many flood-response mechanisms have been reported, flood-tolerant mechanisms have not been fully clarified for soybean because of limitations in germplasm with flooding tolerance. This review provides an update on current biochemical and molecular networks involved in soybean tolerance against flooding stress, as well as recent developments in the area of functional genomics in terms of developing flood-tolerant soybeans. This work will expedite marker-assisted genetic enhancement studies in crops for developing high-yielding stress-tolerant lines or varieties under abiotic stress.
Collapse
Affiliation(s)
- Xin Wang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Setsuko Komatsu
- Faculty of Environmental and Information Sciences, Fukui University of Technology, Fukui 910-8505, Japan
| |
Collapse
|
25
|
Ghosh A, Shcherbik N. Cooperativity between the Ribosome-Associated Chaperone Ssb/RAC and the Ubiquitin Ligase Ltn1 in Ubiquitination of Nascent Polypeptides. Int J Mol Sci 2020; 21:ijms21186815. [PMID: 32957466 PMCID: PMC7554835 DOI: 10.3390/ijms21186815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/12/2020] [Accepted: 09/14/2020] [Indexed: 11/25/2022] Open
Abstract
Eukaryotic cells have evolved multiple mechanisms to detect and eliminate aberrant polypeptides. Co-translational protein surveillance systems play an important role in these mechanisms. These systems include ribosome-associated protein quality control (RQC) that detects aberrant nascent chains stalled on ribosomes and promotes their ubiquitination and degradation by the proteasome, and ribosome-associated chaperone Ssb/RAC, which ensures correct nascent chain folding. Despite the known function of RQC and Ssb/ribosome-associated complex (RAC) in monitoring the quality of newly generated polypeptides, whether they cooperate during initial stages of protein synthesis remains unexplored. Here, we provide evidence that Ssb/RAC and the ubiquitin ligase Ltn1, the major component of RQC, display genetic and functional cooperativity. Overexpression of Ltn1 rescues growth suppression of the yeast strain-bearing deletions of SSB genes during proteotoxic stress. Moreover, Ssb/RAC promotes Ltn1-dependent ubiquitination of nascent chains associated with 80S ribosomal particles but not with translating ribosomes. Consistent with this finding, quantitative western blot analysis revealed lower levels of Ltn1 associated with 80S ribosomes and with free 60S ribosomal subunits in the absence of Ssb/RAC. We propose a mechanism in which Ssb/RAC facilitates recruitment of Ltn1 to ribosomes, likely by detecting aberrations in nascent chains and leading to their ubiquitination and degradation.
Collapse
|
26
|
Singh AP, Salvatori R, Aftab W, Kohler A, Carlström A, Forne I, Imhof A, Ott M. Molecular Connectivity of Mitochondrial Gene Expression and OXPHOS Biogenesis. Mol Cell 2020; 79:1051-1065.e10. [PMID: 32877643 DOI: 10.1016/j.molcel.2020.07.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 01/05/2023]
Abstract
Mitochondria contain their own gene expression systems, including membrane-bound ribosomes dedicated to synthesizing a few hydrophobic subunits of the oxidative phosphorylation (OXPHOS) complexes. We used a proximity-dependent biotinylation technique, BioID, coupled with mass spectrometry to delineate in baker's yeast a comprehensive network of factors involved in biogenesis of mitochondrial encoded proteins. This mitochondrial gene expression network (MiGENet) encompasses proteins involved in transcription, RNA processing, translation, or protein biogenesis. Our analyses indicate the spatial organization of these processes, thereby revealing basic mechanistic principles and the proteins populating strategically important sites. For example, newly synthesized proteins are directly handed over to ribosomal tunnel exit-bound factors that mediate membrane insertion, co-factor acquisition, or their mounting into OXPHOS complexes in a special early assembly hub. Collectively, the data reveal the connectivity of mitochondrial gene expression, reflecting a unique tailoring of the mitochondrial gene expression system.
Collapse
Affiliation(s)
- Abeer Prakash Singh
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Roger Salvatori
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Wasim Aftab
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, 82152 Planegg-Martinsried, Germany; Graduate School for Quantitative Biosciences (QBM), Ludwig Maximilians University of Munich, 81377 Munich, Germany
| | - Andreas Kohler
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Andreas Carlström
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Ignasi Forne
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, 82152 Planegg-Martinsried, Germany
| | - Axel Imhof
- BioMedical Center, Faculty of Medicine, Ludwig Maximilians University of Munich, 82152 Planegg-Martinsried, Germany
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden; Department of Medical Biochemistry and Cell Biology, University of Gothenburg, 40530 Gothenburg, Sweden.
| |
Collapse
|
27
|
Proteotoxic Stress and Cell Death in Cancer Cells. Cancers (Basel) 2020; 12:cancers12092385. [PMID: 32842524 PMCID: PMC7563887 DOI: 10.3390/cancers12092385] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/19/2020] [Accepted: 08/20/2020] [Indexed: 02/06/2023] Open
Abstract
To maintain proteostasis, cells must integrate information and activities that supervise protein synthesis, protein folding, conformational stability, and also protein degradation. Extrinsic and intrinsic conditions can both impact normal proteostasis, causing the appearance of proteotoxic stress. Initially, proteotoxic stress elicits adaptive responses aimed at restoring proteostasis, allowing cells to survive the stress condition. However, if the proteostasis restoration fails, a permanent and sustained proteotoxic stress can be deleterious, and cell death ensues. Many cancer cells convive with high levels of proteotoxic stress, and this condition could be exploited from a therapeutic perspective. Understanding the cell death pathways engaged by proteotoxic stress is instrumental to better hijack the proliferative fate of cancer cells.
Collapse
|
28
|
Kumar R, Soni R, Heindl SE, Wiltshire DA, Khan S. Unravelling the Role of HSP70 as the Unexplored Molecular Target in Age-Related Macular Degeneration. Cureus 2020; 12:e8960. [PMID: 32766003 PMCID: PMC7398729 DOI: 10.7759/cureus.8960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The motive behind writing this paper was to highlight the relationship between heat shock protein 70 (HSP70) and age-related macular degeneration (AMD) to explore the potential role of HSP70 as a molecular target in AMD therapy. We performed a comprehensive literature search in various databases and finally found 43 relevant studies related to our objective. In our research, we found that in AMD, oxidative stress causes increased inflammation and excessive apoptosis due to the accumulation of aberrant proteins in retinal pigment epithelium (RPE) cells. The long-lasting overstimulation of the defence system leads to RPE degeneration and results in visual impairment or vision loss. However, after thorough research, it was found that HSP70's role as an immunomodulator, the guardian of the proteolytic pathway and regulator of apoptosis makes it a potential therapeutic target in AMD.
Collapse
Affiliation(s)
- Rajat Kumar
- Ophthalmology, California Institute of Behavioral Neurosciences and Psychology, Fairfield, USA
| | - Ravi Soni
- Neurology, California Institute of Behavioral Neurosciences and Psychology, Fairfield, USA
| | - Stacey E Heindl
- Medicine, California Institute of Behavioral Neurosciences and Psychology, Fairfield, USA
| | - Dwayne A Wiltshire
- Internal Medicine, California Institute of Behavioral Neurosciences and Psychology, Fairfield, USA
| | - Safeera Khan
- Internal Medicine, California Institute of Behavioral Neurosciences and Psychology, Fairfield, USA
| |
Collapse
|
29
|
Kelly JW. Pharmacologic Approaches for Adapting Proteostasis in the Secretory Pathway to Ameliorate Protein Conformational Diseases. Cold Spring Harb Perspect Biol 2020; 12:a034108. [PMID: 31088828 PMCID: PMC7197434 DOI: 10.1101/cshperspect.a034108] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Maintenance of the proteome, ensuring the proper locations, proper conformations, appropriate concentrations, etc., is essential to preserve the health of an organism in the face of environmental insults, infectious diseases, and the challenges associated with aging. Maintaining the proteome is even more difficult in the background of inherited mutations that render a given protein and others handled by the same proteostasis machinery misfolding prone and/or aggregation prone. Maintenance of the proteome or maintaining proteostasis requires the orchestration of protein synthesis, folding, trafficking, and degradation by way of highly conserved, interacting, and competitive proteostasis pathways. Each subcellular compartment has a unique proteostasis network compromising common and specialized proteostasis maintenance pathways. Stress-responsive signaling pathways detect the misfolding and/or aggregation of proteins in specific subcellular compartments using stress sensors and respond by generating an active transcription factor. Subsequent transcriptional programs up-regulate proteostasis network capacity (i.e., ability to fold and degrade proteins in that compartment). Stress-responsive signaling pathways can also be linked by way of signaling cascades to nontranscriptional means to reestablish proteostasis (e.g., by translational attenuation). Proteostasis is also strongly influenced by the inherent kinetics and thermodynamics of the folding, misfolding, and aggregation of individual proteins, and these sequence-based attributes in combination with proteostasis network capacity together influence proteostasis. In this review, we will focus on the growing body of evidence that proteostasis deficits leading to human pathology can be reversed by pharmacologic adaptation of proteostasis network capacity through stress-responsive signaling pathway activation. The power of this approach will be exemplified by focusing on the ATF6 arm of the unfolded protein response stress responsive-signaling pathway that regulates proteostasis network capacity of the secretory pathway.
Collapse
Affiliation(s)
- Jeffery W Kelly
- Departments of Chemistry and Molecular Medicine; and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037
| |
Collapse
|
30
|
Skuodas S, Clemons A, Hayes M, Goll A, Zora B, Weeks DL, Phillips BT, Fassler JS. The ABCF gene family facilitates disaggregation during animal development. Mol Biol Cell 2020; 31:1324-1345. [PMID: 32320318 PMCID: PMC7353142 DOI: 10.1091/mbc.e19-08-0443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Protein aggregation, once believed to be a harbinger and/or consequence of stress, age, and pathological conditions, is emerging as a novel concept in cellular regulation. Normal versus pathological aggregation may be distinguished by the capacity of cells to regulate the formation, modification, and dissolution of aggregates. We find that Caenorhabditis elegans aggregates are observed in large cells/blastomeres (oocytes, embryos) and in smaller, further differentiated cells (primordial germ cells), and their analysis using cell biological and genetic tools is straightforward. These observations are consistent with the hypothesis that aggregates are involved in normal development. Using cross-platform analysis in Saccharomyces cerevisiae, C. elegans, and Xenopus laevis, we present studies identifying a novel disaggregase family encoded by animal genomes and expressed embryonically. Our initial analysis of yeast Arb1/Abcf2 in disaggregation and animal ABCF proteins in embryogenesis is consistent with the possibility that members of the ABCF gene family may encode disaggregases needed for aggregate processing during the earliest stages of animal development.
Collapse
Affiliation(s)
- Sydney Skuodas
- Department of Biology, University of Iowa, Iowa City, IA 52242
| | - Amy Clemons
- Department of Biology, University of Iowa, Iowa City, IA 52242
| | - Michael Hayes
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242
| | - Ashley Goll
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242
| | - Betul Zora
- Department of Biology, University of Iowa, Iowa City, IA 52242
| | - Daniel L Weeks
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242
| | | | - Jan S Fassler
- Department of Biology, University of Iowa, Iowa City, IA 52242
| |
Collapse
|
31
|
Wang PH, Wu PC, Huang R, Chung KR. The Role of a Nascent Polypeptide-Associated Complex Subunit Alpha in Siderophore Biosynthesis, Oxidative Stress Response, and Virulence in Alternaria alternata. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:668-679. [PMID: 31928525 DOI: 10.1094/mpmi-11-19-0315-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The present study demonstrates that a nascent polypeptide-associated complex α subunit (Nac1) functions as a transcriptional regulator and plays both positive and negative roles in a vast array of functions in Alternaria alternata. Gain- and loss-of-function studies reveal that Nac1 is required for the formation and germination of conidia, likely via the regulation of Fus3 and Slt2 mitogen-activated protein kinase (MAPK)-coding genes, both implicated in conidiation. Nac1 negatively regulates hyphal branching and the production of cell wall-degrading enzymes. Importantly, Nac1 is required for the biosynthesis of siderophores, a novel phenotype that has not been reported to be associated with a Nac in fungi. The expression of Nac1 is positively regulated by iron, as well as by the Hog1 MAPK and the NADPH-dependent oxidase (Nox) complex. Nac1 confers cellular susceptibility to reactive oxygen species (ROS) likely via negatively regulating the expression of the genes encoding Yap1, Skn7, Hog1, and Nox, all involved in ROS resistance. The involvement of Nac1 in sensitivity to glucose-, mannitol-, or sorbitol-induced osmotic stress could be due to its ability to suppress the expression of Skn7. The requirement of Nac1 in resistance to salts is unlikely mediated through the transcriptional activation of Hog1. Although Nac1 plays no role in toxin production, Nac1 is required for fungal full virulence. All observed deficiencies can be restored by re-expressing a functional copy of Nac1, confirming that Nac1 contributes to the phenotypes. Thus, a dynamic regulation of gene expression via Nac1 is critical for developmental, physiological, and pathological processes of A. alternata.
Collapse
Affiliation(s)
- Pin-Hua Wang
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Pei-Ching Wu
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Richie Huang
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Kuang-Ren Chung
- Department of Plant Pathology, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, 40227, Taiwan
- Ph.D. Program in Microbial Genomics, National Chung Hsing University and Academia Sinica, Taichung 40227, Taiwan
| |
Collapse
|
32
|
Leznicki P, High S. SGTA associates with nascent membrane protein precursors. EMBO Rep 2020; 21:e48835. [PMID: 32216016 PMCID: PMC7202230 DOI: 10.15252/embr.201948835] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 02/25/2020] [Accepted: 02/28/2020] [Indexed: 01/15/2023] Open
Abstract
The endoplasmic reticulum (ER) is a major site for membrane protein synthesis in eukaryotes. The majority of integral membrane proteins are delivered to the ER membrane via the co‐translational, signal recognition particle (SRP)‐dependent route. However, tail‐anchored proteins employ an alternative, post‐translational route(s) that relies on distinct factors such as a cytosolic protein quality control component, SGTA. We now show that SGTA is selectively recruited to ribosomes synthesising a diverse range of membrane proteins, suggesting that its biosynthetic client base also includes precursors on the co‐translational ER delivery pathway. Strikingly, SGTA is recruited to nascent membrane proteins before their transmembrane domain emerges from the ribosome. Hence, SGTA is ideally placed to capture these aggregation prone regions shortly after their synthesis. For nascent membrane proteins on the co‐translational pathway, SGTA complements the role of SRP by reducing the co‐translational ubiquitination of clients with multiple hydrophobic signal sequences. On this basis, we propose that SGTA acts to mask specific transmembrane domains located in complex membrane proteins until they can engage the ER translocon and become membrane inserted.
Collapse
Affiliation(s)
- Pawel Leznicki
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Stephen High
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| |
Collapse
|
33
|
The ribosome-associated complex RAC serves in a relay that directs nascent chains to Ssb. Nat Commun 2020; 11:1504. [PMID: 32198371 PMCID: PMC7083937 DOI: 10.1038/s41467-020-15313-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 03/03/2020] [Indexed: 11/21/2022] Open
Abstract
The conserved ribosome-associated complex (RAC) consisting of Zuo1 (Hsp40) and Ssz1 (non-canonical Hsp70) acts together with the ribosome-bound Hsp70 chaperone Ssb in de novo protein folding at the ribosomal tunnel exit. Current models suggest that the function of Ssz1 is confined to the support of Zuo1, however, it is not known whether RAC by itself serves as a chaperone for nascent chains. Here we show that, via its rudimentary substrate binding domain (SBD), Ssz1 directly binds to emerging nascent chains prior to Ssb. Structural and biochemical analyses identify a conserved LP-motif at the Zuo1 N-terminus forming a polyproline-II helix, which binds to the Ssz1-SBD as a pseudo-substrate. The LP-motif competes with nascent chain binding to the Ssz1-SBD and modulates nascent chain transfer. The combined data indicate that Ssz1 is an active chaperone optimized for transient, low-affinity substrate binding, which ensures the flux of nascent chains through RAC/Ssb. The ribosome-associated complex (RAC), which contains the Hsp40 protein Zuo1 and the non-canonical Hsp70 protein Ssz1 forms a chaperone triad with the fungal-specific Hsp70 protein Ssb. Here the authors combine X-ray crystallography, crosslinking and biochemical experiments and present the structure of the Zuo1 N-terminus bound to Ssz1 and demonstrate that Ssz1 is an active chaperone for nascent chains.
Collapse
|
34
|
Rosenzweig R, Nillegoda NB, Mayer MP, Bukau B. The Hsp70 chaperone network. Nat Rev Mol Cell Biol 2020; 20:665-680. [PMID: 31253954 DOI: 10.1038/s41580-019-0133-3] [Citation(s) in RCA: 639] [Impact Index Per Article: 159.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The 70-kDa heat shock proteins (Hsp70s) are ubiquitous molecular chaperones that act in a large variety of cellular protein folding and remodelling processes. They function virtually at all stages of the life of proteins from synthesis to degradation and are thus crucial for maintaining protein homeostasis, with direct implications for human health. A large set of co-chaperones comprising J-domain proteins and nucleotide exchange factors regulate the ATPase cycle of Hsp70s, which is allosterically coupled to substrate binding and release. Moreover, Hsp70s cooperate with other cellular chaperone systems including Hsp90, Hsp60 chaperonins, small heat shock proteins and Hsp100 AAA+ disaggregases, together constituting a dynamic and functionally versatile network for protein folding, unfolding, regulation, targeting, aggregation and disaggregation, as well as degradation. In this Review we describe recent advances that have increased our understanding of the molecular mechanisms and working principles of the Hsp70 network. This knowledge showcases how the Hsp70 chaperone system controls diverse cellular functions, and offers new opportunities for the development of chemical compounds that modulate disease-related Hsp70 activities.
Collapse
Affiliation(s)
- Rina Rosenzweig
- Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel.
| | - Nadinath B Nillegoda
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany.,DKFZ-ZMBH Alliance, Heidelberg, Germany.,Australian Regenerative Medicine Institute (ARMI), Monash University, Clayton, VIC, Australia
| | - Matthias P Mayer
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany.,DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany. .,German Cancer Research Center (DKFZ), Heidelberg, Germany. .,DKFZ-ZMBH Alliance, Heidelberg, Germany.
| |
Collapse
|
35
|
Chaudhuri A, Das S, Das B. Localization elements and zip codes in the intracellular transport and localization of messenger RNAs in Saccharomyces cerevisiae. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1591. [PMID: 32101377 DOI: 10.1002/wrna.1591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 12/13/2022]
Abstract
Intracellular trafficking and localization of mRNAs provide a mechanism of regulation of expression of genes with excellent spatial control. mRNA localization followed by localized translation appears to be a mechanism of targeted protein sorting to a specific cell-compartment, which is linked to the establishment of cell polarity, cell asymmetry, embryonic axis determination, and neuronal plasticity in metazoans. However, the complexity of the mechanism and the components of mRNA localization in higher organisms prompted the use of the unicellular organism Saccharomyces cerevisiae as a simplified model organism to study this vital process. Current knowledge indicates that a variety of mRNAs are asymmetrically and selectively localized to the tip of the bud of the daughter cells, to the vicinity of endoplasmic reticulum, mitochondria, and nucleus in this organism, which are connected to diverse cellular processes. Interestingly, specific cis-acting RNA localization elements (LEs) or RNA zip codes play a crucial role in the localization and trafficking of these localized mRNAs by providing critical binding sites for the specific RNA-binding proteins (RBPs). In this review, we present a comprehensive account of mRNA localization in S. cerevisiae, various types of localization elements influencing the mRNA localization, and the RBPs, which bind to these LEs to implement a number of vital physiological processes. Finally, we emphasize the significance of this process by highlighting their connection to several neuropathological disorders and cancers. This article is categorized under: RNA Export and Localization > RNA Localization.
Collapse
Affiliation(s)
- Anusha Chaudhuri
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Subhadeep Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| | - Biswadip Das
- Department of Life Science and Biotechnology, Jadavpur University, Kolkata, India
| |
Collapse
|
36
|
Synonymous codon substitutions perturb cotranslational protein folding in vivo and impair cell fitness. Proc Natl Acad Sci U S A 2020; 117:3528-3534. [PMID: 32015130 DOI: 10.1073/pnas.1907126117] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
In the cell, proteins are synthesized from N to C terminus and begin to fold during translation. Cotranslational folding mechanisms are therefore linked to elongation rate, which varies as a function of synonymous codon usage. However, synonymous codon substitutions can affect many distinct cellular processes, which has complicated attempts to deconvolve the extent to which synonymous codon usage can promote or frustrate proper protein folding in vivo. Although previous studies have shown that some synonymous changes can lead to different final structures, other substitutions will likely be more subtle, perturbing predominantly the protein folding pathway without radically altering the final structure. Here we show that synonymous codon substitutions encoding a single essential enzyme lead to dramatically slower cell growth. These mutations do not prevent active enzyme formation; instead, they predominantly alter the protein folding mechanism, leading to enhanced degradation in vivo. These results support a model in which synonymous codon substitutions can impair cell fitness by significantly perturbing cotranslational protein folding mechanisms, despite the chaperoning provided by the cellular protein homeostasis network.
Collapse
|
37
|
Jayaraj GG, Hipp MS, Hartl FU. Functional Modules of the Proteostasis Network. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a033951. [PMID: 30833457 DOI: 10.1101/cshperspect.a033951] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cells invest in an extensive network of factors to maintain protein homeostasis (proteostasis) and prevent the accumulation of potentially toxic protein aggregates. This proteostasis network (PN) comprises the machineries for the biogenesis, folding, conformational maintenance, and degradation of proteins with molecular chaperones as central coordinators. Here, we review recent progress in understanding the modular architecture of the PN in mammalian cells and how it is modified during cell differentiation. We discuss the capacity and limitations of the PN in maintaining proteome integrity in the face of proteotoxic stresses, such as aggregate formation in neurodegenerative diseases. Finally, we outline various pharmacological interventions to ameliorate proteostasis imbalance.
Collapse
Affiliation(s)
- Gopal G Jayaraj
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Mark S Hipp
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| |
Collapse
|
38
|
Faust O, Rosenzweig R. Structural and Biochemical Properties of Hsp40/Hsp70 Chaperone System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1243:3-20. [DOI: 10.1007/978-3-030-40204-4_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
39
|
Zheng X, Zhang Y, Zhang X, Li C, Liu X, Lin Y, Liang S. Fhl1p protein, a positive transcription factor in Pichia pastoris, enhances the expression of recombinant proteins. Microb Cell Fact 2019; 18:207. [PMID: 31783868 PMCID: PMC6884909 DOI: 10.1186/s12934-019-1256-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 11/15/2019] [Indexed: 12/21/2022] Open
Abstract
Background The methylotrophic yeast Pichia pastoris is well-known for the production of a broad spectrum of functional types of heterologous proteins including enzymes, antigens, engineered antibody fragments, and next gen protein scaffolds and many transcription factors are utilized to address the burden caused by the high expression of heterologous proteins. In this article, a novel P. pastoris transcription factor currently annotated as Fhl1p, an activator of ribosome biosynthesis processing, was investigated for promoting the expression of the recombinant proteins. Results The function of Fhl1p of P. pastoris for improving the expression of recombinant proteins was verified in strains expressing phytase, pectinase and mRFP, showing that the productivity was increased by 20–35%. RNA-Seq was used to study the Fhl1p regulation mechanism in detail, confirming Fhl1p involved in the regulation of rRNA processing genes, ribosomal small/large subunit biogenesis genes, Golgi vesicle transport genes, etc., which contributed to boosting the expression of foreign proteins. The overexpressed Fhl1p strain exhibited increases in the polysome and monosome levels, showing improved translation activities. Conclusion This study illustrated that the transcription factor Fhl1p could effectively enhance recombinant protein expression in P. pastoris. Furthermore, we provided the evidence that overexpressed Fhl1p was related to more active translation state.
Collapse
Affiliation(s)
- Xueyun Zheng
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Yimin Zhang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Xinying Zhang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Cheng Li
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Xiaoxiao Liu
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China
| | - Ying Lin
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China. .,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.
| | - Shuli Liang
- Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China. .,Guangdong Research Center of Industrial Enzyme and Green Manufacturing Technology, School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.
| |
Collapse
|
40
|
Dao Duc K, Batra SS, Bhattacharya N, Cate JHD, Song YS. Differences in the path to exit the ribosome across the three domains of life. Nucleic Acids Res 2019; 47:4198-4210. [PMID: 30805621 PMCID: PMC6486554 DOI: 10.1093/nar/gkz106] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 02/22/2019] [Indexed: 01/07/2023] Open
Abstract
The ribosome exit tunnel is an important structure involved in the regulation of translation and other essential functions such as protein folding. By comparing 20 recently obtained cryo-EM and X-ray crystallography structures of the ribosome from all three domains of life, we here characterize the key similarities and differences of the tunnel across species. We first show that a hierarchical clustering of tunnel shapes closely reflects the species phylogeny. Then, by analyzing the ribosomal RNAs and proteins, we explain the observed geometric variations and show direct association between the conservations of the geometry, structure and sequence. We find that the tunnel is more conserved in the upper part close to the polypeptide transferase center, while in the lower part, it is substantially narrower in eukaryotes than in bacteria. Furthermore, we provide evidence for the existence of a second constriction site in eukaryotic exit tunnels. Overall, these results have several evolutionary and functional implications, which explain certain differences between eukaryotes and prokaryotes in their translation mechanisms. In particular, they suggest that major co-translational functions of bacterial tunnels were externalized in eukaryotes, while reducing the tunnel size provided some other advantages, such as facilitating the nascent chain elongation and enabling antibiotic resistance.
Collapse
Affiliation(s)
- Khanh Dao Duc
- Computer Science Division, University of California, Berkeley, CA 94720, USA
| | - Sanjit S Batra
- Computer Science Division, University of California, Berkeley, CA 94720, USA
| | | | - Jamie H D Cate
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.,Department of Chemistry, University of California, Berkeley, CA 94720, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Yun S Song
- Computer Science Division, University of California, Berkeley, CA 94720, USA.,Department of Statistics, University of California, Berkeley, CA 94720, USA.,Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| |
Collapse
|
41
|
Deuerling E, Gamerdinger M, Kreft SG. Chaperone Interactions at the Ribosome. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033977. [PMID: 30833456 DOI: 10.1101/cshperspect.a033977] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The continuous refreshment of the proteome is critical to maintain protein homeostasis and to adapt cells to changing conditions. Thus, de novo protein biogenesis by ribosomes is vitally important to every cellular system. This process is delicate and error-prone and requires, besides cytosolic chaperones, the guidance by a specialized set of molecular chaperones that bind transiently to the translation machinery and the nascent protein to support early folding events and to regulate cotranslational protein transport. These chaperones include the bacterial trigger factor (TF), the archaeal and eukaryotic nascent polypeptide-associated complex (NAC), and the eukaryotic ribosome-associated complex (RAC). This review focuses on the structures, functions, and substrates of these ribosome-associated chaperones and highlights the most recent findings about their potential mechanisms of action.
Collapse
Affiliation(s)
- Elke Deuerling
- Molecular Microbiology, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Martin Gamerdinger
- Molecular Microbiology, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Stefan G Kreft
- Molecular Microbiology, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| |
Collapse
|
42
|
Stein KC, Kriel A, Frydman J. Nascent Polypeptide Domain Topology and Elongation Rate Direct the Cotranslational Hierarchy of Hsp70 and TRiC/CCT. Mol Cell 2019; 75:1117-1130.e5. [PMID: 31400849 DOI: 10.1016/j.molcel.2019.06.036] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/24/2019] [Accepted: 06/25/2019] [Indexed: 02/03/2023]
Abstract
Cotranslational protein folding requires assistance from elaborate ribosome-associated chaperone networks. It remains unclear how the changing information in a growing nascent polypeptide dictates the recruitment of functionally distinct chaperones. Here, we used ribosome profiling to define the principles governing the cotranslational action of the chaperones TRiC/CCT and Hsp70/Ssb. We show that these chaperones are sequentially recruited to specific sites within domain-encoding regions of select nascent polypeptides. Hsp70 associates first, binding select sites throughout domains, whereas TRiC associates later, upon the emergence of nearly complete domains that expose an unprotected hydrophobic surface. This suggests that transient topological properties of nascent folding intermediates drive sequential chaperone association. Moreover, cotranslational recruitment of both TRiC and Hsp70 correlated with translation elongation slowdowns. We propose that the temporal modulation of the nascent chain structural landscape is coordinated with local elongation rates to regulate the hierarchical action of Hsp70 and TRiC for cotranslational folding.
Collapse
Affiliation(s)
- Kevin C Stein
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Allison Kriel
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
43
|
Wu Z, Tantray I, Lim J, Chen S, Li Y, Davis Z, Sitron C, Dong J, Gispert S, Auburger G, Brandman O, Bi X, Snyder M, Lu B. MISTERMINATE Mechanistically Links Mitochondrial Dysfunction with Proteostasis Failure. Mol Cell 2019; 75:835-848.e8. [PMID: 31378462 DOI: 10.1016/j.molcel.2019.06.031] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/04/2019] [Accepted: 06/21/2019] [Indexed: 10/26/2022]
Abstract
Mitochondrial dysfunction and proteostasis failure frequently coexist as hallmarks of neurodegenerative disease. How these pathologies are related is not well understood. Here, we describe a phenomenon termed MISTERMINATE (mitochondrial-stress-induced translational termination impairment and protein carboxyl terminal extension), which mechanistically links mitochondrial dysfunction with proteostasis failure. We show that mitochondrial dysfunction impairs translational termination of nuclear-encoded mitochondrial mRNAs, including complex-I 30kD subunit (C-I30) mRNA, occurring on the mitochondrial surface in Drosophila and mammalian cells. Ribosomes stalled at the normal stop codon continue to add to the C terminus of C-I30 certain amino acids non-coded by mRNA template. C-terminally extended C-I30 is toxic when assembled into C-I and forms aggregates in the cytosol. Enhancing co-translational quality control prevents C-I30 C-terminal extension and rescues mitochondrial and neuromuscular degeneration in a Parkinson's disease model. These findings emphasize the importance of efficient translation termination and reveal unexpected link between mitochondrial health and proteome homeostasis mediated by MISTERMINATE.
Collapse
Affiliation(s)
- Zhihao Wu
- Department of Pathology and Programs in Cancer Biology and Neurosciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Ishaq Tantray
- Department of Pathology and Programs in Cancer Biology and Neurosciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Junghyun Lim
- Department of Pathology and Programs in Cancer Biology and Neurosciences, Stanford University School of Medicine, Stanford, CA, USA; Department of Cancer Biology, Genentech Inc., South San Francisco, CA, USA
| | - Songjie Chen
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Yu Li
- Department of Pathology and Programs in Cancer Biology and Neurosciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Zoe Davis
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Cole Sitron
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Jason Dong
- Department of Pathology and Programs in Cancer Biology and Neurosciences, Stanford University School of Medicine, Stanford, CA, USA
| | - Suzana Gispert
- Experimental Neurology, Goethe University Medical School, Goethe, Germany
| | - Georg Auburger
- Experimental Neurology, Goethe University Medical School, Goethe, Germany
| | - Onn Brandman
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Xiaolin Bi
- Institute of Cancer Stem Cell, Dalian Medical University, Dalian, China
| | - Michael Snyder
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Bingwei Lu
- Department of Pathology and Programs in Cancer Biology and Neurosciences, Stanford University School of Medicine, Stanford, CA, USA.
| |
Collapse
|
44
|
Early Scanning of Nascent Polypeptides inside the Ribosomal Tunnel by NAC. Mol Cell 2019; 75:996-1006.e8. [PMID: 31377116 DOI: 10.1016/j.molcel.2019.06.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/08/2019] [Accepted: 06/19/2019] [Indexed: 11/24/2022]
Abstract
Cotranslational processing of newly synthesized proteins is fundamental for correct protein maturation. Protein biogenesis factors are thought to bind nascent polypeptides not before they exit the ribosomal tunnel. Here, we identify a nascent chain recognition mechanism deep inside the ribosomal tunnel by an essential eukaryotic cytosolic chaperone. The nascent polypeptide-associated complex (NAC) inserts the N-terminal tail of its β subunit (N-βNAC) into the ribosomal tunnel to sense substrates directly upon synthesis close to the peptidyl-transferase center. N-βNAC escorts the growing polypeptide to the cytosol and relocates to an alternate binding site on the ribosomal surface. Using C. elegans as an in vivo model, we demonstrate that the tunnel-probing activity of NAC is essential for organismal viability and critical to regulate endoplasmic reticulum (ER) protein transport by controlling ribosome-Sec61 translocon interactions. Thus, eukaryotic protein maturation relies on the early sampling of nascent chains inside the ribosomal tunnel.
Collapse
|
45
|
Selective ribosome profiling to study interactions of translating ribosomes in yeast. Nat Protoc 2019; 14:2279-2317. [PMID: 31332354 DOI: 10.1038/s41596-019-0185-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 04/18/2019] [Indexed: 11/08/2022]
Abstract
A number of enzymes, targeting factors and chaperones engage ribosomes to support fundamental steps of nascent protein maturation, including enzymatic processing, membrane targeting and co-translational folding. The selective ribosome profiling (SeRP) method is a new tool for studying the co-translational activity of maturation factors that provides proteome-wide information on a factor's nascent interactome, the onset and duration of binding and the mechanisms controlling factor engagement. SeRP is based on the combination of two ribosome-profiling (RP) experiments, sequencing the ribosome-protected mRNA fragments from all ribosomes (total translatome) and the ribosome subpopulation engaged by the factor of interest (factor-bound translatome). We provide a detailed SeRP protocol, exemplified for the yeast Hsp70 chaperone Ssb (stress 70 B), for studying factor interactions with nascent proteins that is readily adaptable to identifying nascent interactomes of other co-translationally acting eukaryotic factors. The protocol provides general guidance for experimental design and optimization, as well as detailed instructions for cell growth and harvest, the isolation of (factor-engaged) monosomes, the generation of a cDNA library and data analysis. Experience in biochemistry and RNA handling, as well as basic programing knowledge, is necessary to perform SeRP. Execution of a SeRP experiment takes 8-10 working days, and initial data analysis can be completed within 1-2 d. This protocol is an extension of the originally developed protocol describing SeRP in bacteria.
Collapse
|
46
|
Kramer G, Shiber A, Bukau B. Mechanisms of Cotranslational Maturation of Newly Synthesized Proteins. Annu Rev Biochem 2019; 88:337-364. [DOI: 10.1146/annurev-biochem-013118-111717] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The timely production of functional proteins is of critical importance for the biological activity of cells. To reach the functional state, newly synthesized polypeptides have to become enzymatically processed, folded, and assembled into oligomeric complexes and, for noncytosolic proteins, translocated across membranes. Key activities of these processes occur cotranslationally, assisted by a network of machineries that transiently engage nascent polypeptides at distinct phases of translation. The sequence of events is tuned by intrinsic features of the nascent polypeptides and timely association of factors with the translating ribosome. Considering the dynamics of translation, the heterogeneity of cellular proteins, and the diversity of interaction partners, it is a major cellular achievement that these processes are temporally and spatially so precisely coordinated, minimizing the generation of damaged proteins. This review summarizes the current progress we have made toward a comprehensive understanding of the cotranslational interactions of nascent chains, which pave the way to their functional state.
Collapse
Affiliation(s)
- Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, D-69120 Heidelberg, Germany;,
| | - Ayala Shiber
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, D-69120 Heidelberg, Germany;,
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, D-69120 Heidelberg, Germany;,
| |
Collapse
|
47
|
Abstract
Nuclear proteins participate in diverse cellular processes, many of which are essential for cell survival and viability. To maintain optimal nuclear physiology, the cell employs the ubiquitin-proteasome system to eliminate damaged and misfolded proteins in the nucleus that could otherwise harm the cell. In this review, we highlight the current knowledge about the major ubiquitin-protein ligases involved in protein quality control degradation (PQCD) in the nucleus and how they orchestrate their functions to eliminate misfolded proteins in different nuclear subcompartments. Many human disorders are causally linked to protein misfolding in the nucleus, hence we discuss major concepts that still need to be clarified to better understand the basis of the nuclear misfolded proteins' toxic effects. Additionally, we touch upon potential strategies for manipulating nuclear PQCD pathways to ameliorate diseases associated with protein misfolding and aggregation in the nucleus.
Collapse
Affiliation(s)
- Charisma Enam
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA; ,
| | - Yifat Geffen
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat-Ram, Jerusalem 91904, Israel; ,
| | - Tommer Ravid
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat-Ram, Jerusalem 91904, Israel; ,
| | - Richard G Gardner
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA; ,
| |
Collapse
|
48
|
Poidevin L, Unal D, Belda-Palazón B, Ferrando A. Polyamines as Quality Control Metabolites Operating at the Post-Transcriptional Level. PLANTS 2019; 8:plants8040109. [PMID: 31022874 PMCID: PMC6524035 DOI: 10.3390/plants8040109] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 04/17/2019] [Accepted: 04/19/2019] [Indexed: 01/04/2023]
Abstract
Plant polyamines (PAs) have been assigned a large number of physiological functions with unknown molecular mechanisms in many cases. Among the most abundant and studied polyamines, two of them, namely spermidine (Spd) and thermospermine (Tspm), share some molecular functions related to quality control pathways for tightly regulated mRNAs at the level of translation. In this review, we focus on the roles of Tspm and Spd to facilitate the translation of mRNAs containing upstream ORFs (uORFs), premature stop codons, and ribosome stalling sequences that may block translation, thus preventing their degradation by quality control mechanisms such as the nonsense-mediated decay pathway and possible interactions with other mRNA quality surveillance pathways.
Collapse
Affiliation(s)
- Laetitia Poidevin
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Dilek Unal
- Biotechnology Application and Research Center, and Department of Molecular Biology, Faculty of Science and Letter, Bilecik Seyh Edebali University, 11230 Bilecik, Turkey.
| | - Borja Belda-Palazón
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Alejandro Ferrando
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, 46022 Valencia, Spain.
| |
Collapse
|
49
|
Shen K, Gamerdinger M, Chan R, Gense K, Martin EM, Sachs N, Knight PD, Schlömer R, Calabrese AN, Stewart KL, Leiendecker L, Baghel A, Radford SE, Frydman J, Deuerling E. Dual Role of Ribosome-Binding Domain of NAC as a Potent Suppressor of Protein Aggregation and Aging-Related Proteinopathies. Mol Cell 2019; 74:729-741.e7. [PMID: 30982745 PMCID: PMC6527867 DOI: 10.1016/j.molcel.2019.03.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/22/2019] [Accepted: 03/08/2019] [Indexed: 01/11/2023]
Abstract
The nascent polypeptide-associated complex (NAC) is a conserved ribosome-associated protein biogenesis factor. Whether NAC exerts chaperone activity and whether this function is restricted to de novo protein synthesis is unknown. Here, we demonstrate that NAC directly exerts chaperone activity toward structurally diverse model substrates including polyglutamine (PolyQ) proteins, firefly luciferase, and Aβ40. Strikingly, we identified the positively charged ribosome-binding domain in the N terminus of the βNAC subunit (N-βNAC) as a major chaperone entity of NAC. N-βNAC by itself suppressed aggregation of PolyQ-expanded proteins in vitro, and the positive charge of this domain was critical for this activity. Moreover, we found that NAC also exerts a ribosome-independent chaperone function in vivo. Consistently, we found that a substantial fraction of NAC is non-ribosomal bound in higher eukaryotes. In sum, NAC is a potent suppressor of aggregation and proteotoxicity of mutant PolyQ-expanded proteins associated with human diseases like Huntington's disease and spinocerebellar ataxias.
Collapse
Affiliation(s)
- Koning Shen
- Department of Biology, Stanford University, Stanford, CA 94305-5430, USA
| | | | - Rebecca Chan
- Department of Biology, Stanford University, Stanford, CA 94305-5430, USA
| | - Karina Gense
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Esther M Martin
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Nadine Sachs
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Patrick D Knight
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Renate Schlömer
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Antonio N Calabrese
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Katie L Stewart
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Lukas Leiendecker
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Ankit Baghel
- Department of Biology, Stanford University, Stanford, CA 94305-5430, USA
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, CA 94305-5430, USA.
| | - Elke Deuerling
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany.
| |
Collapse
|
50
|
Stein KC, Frydman J. The stop-and-go traffic regulating protein biogenesis: How translation kinetics controls proteostasis. J Biol Chem 2018; 294:2076-2084. [PMID: 30504455 DOI: 10.1074/jbc.rev118.002814] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Generating a functional proteome requires the ribosome to carefully regulate disparate co-translational processes that determine the fate of nascent polypeptides. With protein synthesis being energetically expensive, the ribosome must balance the costs of efficiently making a protein with those of properly folding it. Emerging as a primary means of regulating this trade-off is the nonuniform rate of translation elongation that defines translation kinetics. The varying speeds with which the ribosome progresses along a transcript have been implicated in several aspects of protein biogenesis, including co-translational protein folding and translational fidelity, as well as gene expression by mediating mRNA decay and protein quality control pathways. The optimal translation kinetics required to efficiently execute these processes can be distinct. Thus, the ribosome is tasked with tightly regulating translation kinetics to balance these processes while maintaining adaptability for changing cellular conditions. In this review, we first discuss the regulatory role of translation elongation in protein biogenesis and what factors influence elongation kinetics. We then describe how changes in translation kinetics signal downstream pathways that dictate the fate of nascent polypeptides. By regulating these pathways, the kinetics of translation elongation has emerged as a critical tool for driving gene expression and maintaining proteostasis through varied mechanisms, including nascent chain folding and binding different ribosome-associated machinery. Indeed, a growing number of examples demonstrate the important role of local changes in elongation kinetics in modulating the pathophysiology of human disease.
Collapse
Affiliation(s)
| | - Judith Frydman
- From the Departments of Biology and .,Genetics, Stanford University, Stanford, California 94305
| |
Collapse
|