1
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Wu L, Zhang L, Feng S, Chen L, Lin C, Wang G, Zhu Y, Wang P, Cheng G. An evolutionarily conserved ubiquitin ligase drives infection and transmission of flaviviruses. Proc Natl Acad Sci U S A 2024; 121:e2317978121. [PMID: 38593069 PMCID: PMC11032495 DOI: 10.1073/pnas.2317978121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 03/08/2024] [Indexed: 04/11/2024] Open
Abstract
Mosquito-borne flaviviruses such as dengue (DENV) and Zika (ZIKV) cause hundreds of millions of infections annually. The single-stranded RNA genome of flaviviruses is translated into a polyprotein, which is cleaved equally into individual functional proteins. While structural proteins are packaged into progeny virions and released, most of the nonstructural proteins remain intracellular and could become cytotoxic if accumulated over time. However, the mechanism by which nonstructural proteins are maintained at the levels optimal for cellular fitness and viral replication remains unknown. Here, we identified that the ubiquitin E3 ligase HRD1 is essential for flaviviruses infections in both mammalian hosts and mosquitoes. HRD1 directly interacts with flavivirus NS4A and ubiquitylates a conserved lysine residue for ER-associated degradation. This mechanism avoids excessive accumulation of NS4A, which otherwise interrupts the expression of processed flavivirus proteins in the ER. Furthermore, a small-molecule inhibitor of HRD1 named LS-102 effectively interrupts DENV2 infection in both mice and Aedes aegypti mosquitoes, and significantly disturbs DENV transmission from the infected hosts to mosquitoes owing to reduced viremia. Taken together, this study demonstrates that flaviviruses have evolved a sophisticated mechanism to exploit the ubiquitination system to balance the homeostasis of viral proteins for their own advantage and provides a potential therapeutic target to interrupt flavivirus infection and transmission.
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Affiliation(s)
- Linjuan Wu
- New Cornerstone Science Laboratory, Tsinghua University-Peking University Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing100084, China
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen518000, China
- Institute of Pathogenic Organisms, Shenzhen Center for Disease Control and Prevention, Shenzhen518055, China
| | - Liming Zhang
- New Cornerstone Science Laboratory, Tsinghua University-Peking University Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing100084, China
| | - Shengyong Feng
- New Cornerstone Science Laboratory, Tsinghua University-Peking University Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing100084, China
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen518000, China
- Institute of Pathogenic Organisms, Shenzhen Center for Disease Control and Prevention, Shenzhen518055, China
| | - Lu Chen
- New Cornerstone Science Laboratory, Tsinghua University-Peking University Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing100084, China
| | - Cai Lin
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen518000, China
| | - Gang Wang
- New Cornerstone Science Laboratory, Tsinghua University-Peking University Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing100084, China
| | - Yibin Zhu
- New Cornerstone Science Laboratory, Tsinghua University-Peking University Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing100084, China
- Institute of Pathogenic Organisms, Shenzhen Center for Disease Control and Prevention, Shenzhen518055, China
| | - Penghua Wang
- Department of Immunology, School of Medicine, University of Connecticut Health Center, Farmington, CT06030
| | - Gong Cheng
- New Cornerstone Science Laboratory, Tsinghua University-Peking University Joint Center for Life Sciences, School of Basic Medical Sciences, Tsinghua University, Beijing100084, China
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen518000, China
- Institute of Pathogenic Organisms, Shenzhen Center for Disease Control and Prevention, Shenzhen518055, China
- Southwest United Graduate School, Kunming650092, China
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2
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Moghadam RK, Daraei A, Haddadi M, Mardi A, Karamali N, Rezaiemanesh A. Casting Light on the Janus-Faced HMG-CoA Reductase Degradation Protein 1: A Comprehensive Review of Its Dualistic Impact on Apoptosis in Various Diseases. Mol Neurobiol 2024:10.1007/s12035-024-03994-z. [PMID: 38356096 DOI: 10.1007/s12035-024-03994-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/29/2024] [Indexed: 02/16/2024]
Abstract
Nowadays, it is well recognized that apoptosis, as a highly regulated cellular process, plays a crucial role in various biological processes, such as cell differentiation. Dysregulation of apoptosis is strongly implicated in the pathophysiology of numerous disorders, making it essential to comprehend its underlying mechanisms. One key factor that has garnered significant attention in the regulation of apoptotic pathways is HMG-CoA reductase degradation protein 1, also known as HRD1. HRD1 is an E3 ubiquitin ligase located in the endoplasmic reticulum (ER) membrane. Its primary role involves maintaining the quality control of ER proteins by facilitating the ER-associated degradation (ERAD) pathway. During ER stress, HRD1 aids in the elimination of misfolded proteins that accumulate within the ER. Therefore, HRD1 plays a pivotal role in the regulation of apoptotic pathways and maintenance of ER protein quality control. By targeting specific protein substrates and affecting apoptosis-related pathways, HRD1 could be an exclusive therapeutic target in different disorders. Dysregulation of HRD1-mediated processes contributes significantly to the pathophysiology of various diseases. The purpose of this review is to assess the effect of HRD1 on the pathways related to apoptosis in various diseases from a therapeutic perspective.
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Affiliation(s)
- Reihaneh Khaleghi Moghadam
- Student Research Committee, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Department of Immunology, School of Medicine, Kermanshah University of Medical Sciences, Daneshgah Street, Shahid Shiroudi Boulevard, PO-Box: 6714869914, Kermanshah, Iran
| | - Arshia Daraei
- Student Research Committee, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Department of Immunology, School of Medicine, Kermanshah University of Medical Sciences, Daneshgah Street, Shahid Shiroudi Boulevard, PO-Box: 6714869914, Kermanshah, Iran
| | - Maryam Haddadi
- Student Research Committee, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Department of Immunology, School of Medicine, Kermanshah University of Medical Sciences, Daneshgah Street, Shahid Shiroudi Boulevard, PO-Box: 6714869914, Kermanshah, Iran
| | - Amirhossein Mardi
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
- Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Negin Karamali
- Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
- Department of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Alireza Rezaiemanesh
- Department of Immunology, School of Medicine, Kermanshah University of Medical Sciences, Daneshgah Street, Shahid Shiroudi Boulevard, PO-Box: 6714869914, Kermanshah, Iran.
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3
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Faulkner RA, Yang Y, Tsien J, Qin T, DeBose-Boyd RA. Direct binding to sterols accelerates endoplasmic reticulum-associated degradation of HMG CoA reductase. Proc Natl Acad Sci U S A 2024; 121:e2318822121. [PMID: 38319967 PMCID: PMC10873557 DOI: 10.1073/pnas.2318822121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 01/09/2024] [Indexed: 02/08/2024] Open
Abstract
The maintenance of cholesterol homeostasis is crucial for normal function at both the cellular and organismal levels. Two integral membrane proteins, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) and Scap, are key targets of a complex feedback regulatory system that operates to ensure cholesterol homeostasis. HMGCR catalyzes the rate-limiting step in the transformation of the 2-carbon precursor acetate to 27-carbon cholesterol. Scap mediates proteolytic activation of sterol regulatory element-binding protein-2 (SREBP-2), a membrane-bound transcription factor that controls expression of genes involved in the synthesis and uptake of cholesterol. Sterol accumulation triggers binding of HMGCR to endoplasmic reticulum (ER)-localized Insig proteins, leading to the enzyme's ubiquitination and proteasome-mediated ER-associated degradation (ERAD). Sterols also induce binding of Insigs to Scap, which leads to sequestration of Scap and its bound SREBP-2 in the ER, thereby preventing proteolytic activation of SREBP-2 in the Golgi. The oxygenated cholesterol derivative 25-hydroxycholesterol (25HC) and the methylated cholesterol synthesis intermediate 24,25-dihydrolanosterol (DHL) differentially modulate HMGCR and Scap. While both sterols promote binding of HMGCR to Insigs for ubiquitination and subsequent ERAD, only 25HC inhibits the Scap-mediated proteolytic activation of SREBP-2. We showed previously that 1,1-bisphosphonate esters mimic DHL, accelerating ERAD of HMGCR while sparing SREBP-2 activation. Building on these results, our current studies reveal specific, Insig-independent photoaffinity labeling of HMGCR by photoactivatable derivatives of the 1,1-bisphosphonate ester SRP-3042 and 25HC. These findings disclose a direct sterol binding mechanism as the trigger that initiates the HMGCR ERAD pathway, providing valuable insights into the intricate mechanisms that govern cholesterol homeostasis.
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Affiliation(s)
- Rebecca A. Faulkner
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX75390-9046
| | - Yangyan Yang
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX75390-9046
| | - Jet Tsien
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX75390-9046
| | - Tian Qin
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX75390-9046
| | - Russell A. DeBose-Boyd
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX75390-9046
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4
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Avci D, Heidasch R, Costa M, Lüchtenborg C, Kale D, Brügger B, Lemberg MK. Intramembrane protease SPP defines a cholesterol-regulated abundance control of the mevalonate pathway enzyme squalene synthase. J Biol Chem 2024; 300:105644. [PMID: 38218226 PMCID: PMC10850959 DOI: 10.1016/j.jbc.2024.105644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 12/21/2023] [Accepted: 01/02/2024] [Indexed: 01/15/2024] Open
Abstract
Intramembrane proteolysis regulates important processes such as signaling and transcriptional and posttranslational abundance control of proteins with key functions in metabolic pathways. This includes transcriptional control of mevalonate pathway genes, thereby ensuring balanced biosynthesis of cholesterol and other isoprenoids. Our work shows that, at high cholesterol levels, signal peptide peptidase (SPP) cleaves squalene synthase (SQS), an enzyme that defines the branching point for allocation of isoprenoids to the sterol and nonsterol arms of the mevalonate pathway. This intramembrane cleavage releases SQS from the membrane and targets it for proteasomal degradation. Regulation of this mechanism is achieved by the E3 ubiquitin ligase TRC8 that, in addition to ubiquitinating SQS in response to cholesterol levels, acts as an allosteric activator of SPP-catalyzed intramembrane cleavage of SQS. Cellular cholesterol levels increase in the absence of SPP activity. We infer from these results that, SPP-TRC8 mediated abundance control of SQS acts as a regulation step within the mevalonate pathway.
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Affiliation(s)
- Dönem Avci
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany; Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany.
| | - Ronny Heidasch
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Martina Costa
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany; Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany
| | | | - Dipali Kale
- Biochemistry Center of Heidelberg University (BZH), Heidelberg, Germany
| | - Britta Brügger
- Biochemistry Center of Heidelberg University (BZH), Heidelberg, Germany
| | - Marius K Lemberg
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany; Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany.
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5
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Zhang J, Cruz-Cosme R, Zhang C, Liu D, Tang Q, Zhao RY. Endoplasmic reticulum-associated SARS-CoV-2 ORF3a elicits heightened cytopathic effects despite robust ER-associated degradation. mBio 2024; 15:e0303023. [PMID: 38078754 PMCID: PMC10790703 DOI: 10.1128/mbio.03030-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 01/17/2024] Open
Abstract
IMPORTANCE The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has tragically claimed millions of lives through coronavirus disease 2019 (COVID-19), and there remains a critical gap in our understanding of the precise molecular mechanisms responsible for the associated fatality. One key viral factor of interest is the SARS-CoV-2 ORF3a protein, which has been identified as a potent inducer of host cellular proinflammatory responses capable of triggering the catastrophic cytokine storm, a primary contributor to COVID-19-related deaths. Moreover, ORF3a, much like the spike protein, exhibits a propensity for frequent mutations, with certain variants linked to the severity of COVID-19. Our previous research unveiled two distinct types of ORF3a mutant proteins, categorized by their subcellular localizations, setting the stage for a comparative investigation into the functional and mechanistic disparities between these two types of ORF3a variants. Given the clinical significance and functional implications of the natural ORF3a mutations, the findings of this study promise to provide invaluable insights into the potential roles undertaken by these mutant ORF3a proteins in the pathogenesis of COVID-19.
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Affiliation(s)
- Jiantao Zhang
- Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ruth Cruz-Cosme
- Department of Microbiology, Howard University College of Medicine, Washington, DC, USA
| | - Chenyu Zhang
- Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Dongxiao Liu
- Department of Microbiology, Howard University College of Medicine, Washington, DC, USA
| | - Qiyi Tang
- Department of Microbiology, Howard University College of Medicine, Washington, DC, USA
| | - Richard Y. Zhao
- Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Institute of Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Research & Development Service, VA Maryland Health Care System, Baltimore, Maryland, USA
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6
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Mesquita FS, Abrami L, Samurkas A, van der Goot FG. S-acylation: an orchestrator of the life cycle and function of membrane proteins. FEBS J 2024; 291:45-56. [PMID: 37811679 DOI: 10.1111/febs.16972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 09/06/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
S-acylation is a covalent post-translational modification of proteins with fatty acids, achieved by enzymatic attachment via a labile thioester bond. This modification allows for dynamic control of protein properties and functions in association with cell membranes. This lipid modification regulates a substantial portion of the human proteome and plays an increasingly recognized role throughout the lifespan of affected proteins. Recent technical advancements have propelled the S-acylation field into a 'molecular era', unveiling new insights into its mechanistic intricacies and far-reaching implications. With a striking increase in the number of studies on this modification, new concepts are indeed emerging on the roles of S-acylation in specific cell biology processes and features. After a brief overview of the enzymes involved in S-acylation, this viewpoint focuses on the importance of S-acylation in the homeostasis, function, and coordination of integral membrane proteins. In particular, we put forward the hypotheses that S-acylation is a gatekeeper of membrane protein folding and turnover and a regulator of the formation and dynamics of membrane contact sites.
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Affiliation(s)
| | - Laurence Abrami
- Global Health Institute, School of Life Sciences, EPFL, Lausanne, Switzerland
| | - Arthur Samurkas
- Global Health Institute, School of Life Sciences, EPFL, Lausanne, Switzerland
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7
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Cai X, Ito S, Noi K, Inoue M, Ushioda R, Kato Y, Nagata K, Inaba K. Mechanistic characterization of disulfide bond reduction of an ERAD substrate mediated by cooperation between ERdj5 and BiP. J Biol Chem 2023; 299:105274. [PMID: 37739037 PMCID: PMC10591012 DOI: 10.1016/j.jbc.2023.105274] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 08/28/2023] [Accepted: 09/11/2023] [Indexed: 09/24/2023] Open
Abstract
Endoplasmic reticulum (ER)-associated degradation (ERAD) is a protein quality control process that eliminates misfolded proteins from the ER. DnaJ homolog subfamily C member 10 (ERdj5) is a protein disulfide isomerase family member that accelerates ERAD by reducing disulfide bonds of aberrant proteins with the help of an ER-resident chaperone BiP. However, the detailed mechanisms by which ERdj5 acts in concert with BiP are poorly understood. In this study, we reconstituted an in vitro system that monitors ERdj5-mediated reduction of disulfide-linked J-chain oligomers, known to be physiological ERAD substrates. Biochemical analyses using purified proteins revealed that J-chain oligomers were reduced to monomers by ERdj5 in a stepwise manner via trimeric and dimeric intermediates, and BiP synergistically enhanced this action in an ATP-dependent manner. Single-molecule observations of ERdj5-catalyzed J-chain disaggregation using high-speed atomic force microscopy, demonstrated the stochastic release of small J-chain oligomers through repeated actions of ERdj5 on peripheral and flexible regions of large J-chain aggregates. Using systematic mutational analyses, ERAD substrate disaggregation mediated by ERdj5 and BiP was dissected at the molecular level.
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Affiliation(s)
- Xiaohan Cai
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, Japan; Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Shogo Ito
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, Japan; Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Kentaro Noi
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei, Tokyo, Japan
| | - Michio Inoue
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, Japan
| | - Ryo Ushioda
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
| | - Yukinari Kato
- Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Kazuhiro Nagata
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, Japan; Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan; Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Agency for Medical Research and Development (AMED), Tokyo, Japan.
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8
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Son SH, Lee J, Cho SN, Choi JA, Kim J, Nguyen TD, Lee SA, Son D, Song CH. Herp regulates intracellular survival of Mycobacterium tuberculosis H37Ra in macrophages by regulating reactive oxygen species-mediated autophagy. mBio 2023; 14:e0153523. [PMID: 37800958 PMCID: PMC10653826 DOI: 10.1128/mbio.01535-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 08/21/2023] [Indexed: 10/07/2023] Open
Abstract
IMPORTANCE Several studies have suggested that endoplasmic reticulum (ER) stress is important in the pathogenesis of infectious diseases; however, the precise function of ER stress regulation and the role of Herp as a regulator in Mtb H37Ra-induced ER stress remain elusive. Therefore, our study investigated ER stress and autophagy associated with Herp expression in Mycobacterium tuberculosis-infected macrophages to determine the role of Herp in the pathogenesis of tuberculosis.
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Affiliation(s)
- Sang-Hun Son
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Junghwan Lee
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
- Translational Immunology Institute, Chungnam National University, Daejeon, South Korea
| | - Soo-Na Cho
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Ji-Ae Choi
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
- Translational Immunology Institute, Chungnam National University, Daejeon, South Korea
| | - Jaewhan Kim
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Tam Doan Nguyen
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Seong-Ahn Lee
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Doyi Son
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
| | - Chang-Hwa Song
- Department of Microbiology, College of Medicine, Chungnam National University, Daejeon, South Korea
- Department of Medical Science, College of Medicine, Chungnam National University, Daejeon, South Korea
- Translational Immunology Institute, Chungnam National University, Daejeon, South Korea
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9
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Rudinskiy M, Molinari M. ER-to-lysosome-associated degradation in a nutshell: mammalian, yeast, and plant ER-phagy as induced by misfolded proteins. FEBS Lett 2023; 597:1928-1945. [PMID: 37259628 DOI: 10.1002/1873-3468.14674] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 05/10/2023] [Accepted: 05/22/2023] [Indexed: 06/02/2023]
Abstract
Conserved catabolic pathways operate to remove aberrant polypeptides from the endoplasmic reticulum (ER), the major biosynthetic organelle of eukaryotic cells. The best known are the ER-associated degradation (ERAD) pathways that control the retrotranslocation of terminally misfolded proteins across the ER membrane for clearance by the cytoplasmic ubiquitin/proteasome system. In this review, we catalog folding-defective mammalian, yeast, and plant proteins that fail to engage ERAD machineries. We describe that they rather segregate in ER subdomains that eventually vesiculate. These ER-derived vesicles are captured by double membrane autophagosomes, engulfed by endolysosomes/vacuoles, or fused with degradative organelles to clear cells from their toxic cargo. These client-specific, mechanistically diverse ER-phagy pathways are grouped under the umbrella term of ER-to-lysosome-associated degradation for description in this essay.
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Affiliation(s)
- Mikhail Rudinskiy
- Università della Svizzera italiana, Lugano, Switzerland
- Institute for Research in Biomedicine, Bellinzona, Switzerland
- Department of Biology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Maurizio Molinari
- Università della Svizzera italiana, Lugano, Switzerland
- Institute for Research in Biomedicine, Bellinzona, Switzerland
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Switzerland
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10
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Uegaki K, Tokunaga Y, Inoue M, Takashima S, Inaba K, Takeuchi K, Ushioda R, Nagata K. The oxidative folding of nascent polypeptides provides electrons for reductive reactions in the ER. Cell Rep 2023; 42:112742. [PMID: 37421625 DOI: 10.1016/j.celrep.2023.112742] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 03/20/2023] [Accepted: 06/19/2023] [Indexed: 07/10/2023] Open
Abstract
The endoplasmic reticulum (ER) maintains an oxidative redox environment that is advantageous for the oxidative folding of nascent polypeptides entering the ER. Reductive reactions within the ER are also crucial for maintaining ER homeostasis. However, the mechanism by which electrons are supplied for the reductase activity within the ER remains unknown. Here, we identify ER oxidoreductin-1α (Ero1α) as an electron donor for ERdj5, an ER-resident disulfide reductase. During oxidative folding, Ero1α catalyzes disulfide formation in nascent polypeptides through protein disulfide isomerase (PDI) and then transfers the electrons to molecular oxygen via flavin adenine dinucleotide (FAD), ultimately yielding hydrogen peroxide (H2O2). Besides this canonical electron pathway, we reveal that ERdj5 accepts electrons from specific cysteine pairs in Ero1α, demonstrating that the oxidative folding of nascent polypeptides provides electrons for reductive reactions in the ER. Moreover, this electron transfer pathway also contributes to maintaining ER homeostasis by reducing H2O2 production in the ER.
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Affiliation(s)
- Kaiku Uegaki
- Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Yuji Tokunaga
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan; Graduate School of Pharmaceutical Sciences, the University of Tokyo, Tokyo 113-0033, Japan
| | - Michio Inoue
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Miyagi 980-8577, Japan
| | - Seiji Takashima
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan
| | - Kenji Inaba
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan; Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Miyagi 980-8577, Japan
| | - Koh Takeuchi
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, Tokyo 135-0064, Japan; Graduate School of Pharmaceutical Sciences, the University of Tokyo, Tokyo 113-0033, Japan
| | - Ryo Ushioda
- Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan; Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto 603-8555, Japan.
| | - Kazuhiro Nagata
- Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan; Institute for Protein Dynamics, Kyoto Sangyo University, Kyoto 603-8555, Japan; JT Biohistory Research Hall, Murasaki Town 1-1, Takatsuki City, Osaka 569-1125, Japan.
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11
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Divya S, Ravanan P. Cellular battle against endoplasmic reticulum stress and its adverse effect on health. Life Sci 2023; 323:121705. [PMID: 37075943 DOI: 10.1016/j.lfs.2023.121705] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 04/21/2023]
Abstract
The endoplasmic reticulum (ER) is a dynamic organelle and a reliable performer for precisely folded proteins. To maintain its function and integrity, arrays of sensory and quality control systems enhance protein folding fidelity and resolve the highest error-prone areas. Yet numerous internal and external factors disrupt its homeostasis and trigger ER stress responses. Cells try to reduce the number of misfolded proteins via the UPR mechanism, and ER-related garbage disposals systems like ER-associated degradation (ERAD), ER-lysosome-associated degradation (ERLAD), ER-Associated RNA Silencing (ERAS), extracellular chaperoning, and autophagy systems, which activates and increase the cell survival rate by degrading misfolded proteins, prevent the aggregated proteins and remove the dysfunctional organelles. Throughout life, organisms must confront environmental stress to survive and develop. Communication between the ER & other organelles, signaling events mediated by calcium, reactive oxygen species, and inflammation are linked to diverse stress signaling pathways and regulate cell survival or cell death mechanisms. Unresolved cellular damages can cross the threshold limit of their survival, resulting in cell death or driving for various diseases. The multifaceted ability of unfolded protein response facilitates the therapeutic target and a biomarker for various diseases, helping with early diagnosis and detecting the severity of diseases.
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Affiliation(s)
- Subramaniyan Divya
- Functional Genomics Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610005, Tamil Nadu, India
| | - Palaniyandi Ravanan
- Functional Genomics Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur, 610005, Tamil Nadu, India.
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12
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Chen APF, Chea L, Lee EJ, Lin JH. Lysine Ubiquitylation Drives Rhodopsin Protein Turnover. Adv Exp Med Biol 2023; 1415:493-498. [PMID: 37440077 DOI: 10.1007/978-3-031-27681-1_72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Rhodopsin is a G-protein-coupled receptor that is specifically and abundantly expressed in rod photoreceptors. Over 150 rhodopsin mutations cause autosomal dominant retinitis pigmentosa (adRP). The most common mutation in the United States is the conversion of proline to histidine at position 23 (P23H) in the N-terminal domain of rhodopsin. We previously found that P23H rhodopsin was misfolded, ubiquitinylated, and rapidly degraded. Here, we investigated the role of lysine residues on P23H rhodopsin ubiquitinylation and turnover. We transfected HEK293 cells with a P23H human rhodopsin construct where all 11 lysine residues were mutated to arginine (K-null P23H). We found that the K-null P23H rhodopsin was significantly less ubiquitylated than intact P23H rhodopsin. We found that K-null P23H protein turnover was significantly slower compared to P23H rhodopsin through cycloheximide chase analysis. Finally, we also generated a wild-type rhodopsin construct where all lysines were converted to arginine and found significantly reduced ubiquitylation. Our findings identify ubiquitinylation of lysine residues as an important posttranslational modification involved in P23H rhodopsin protein degradation.
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Affiliation(s)
- Allen P F Chen
- Medical Scientist Training Program, Renaissance School of Medicine at Stony Brook University, Stony Brook, NY, USA
| | - Leon Chea
- Department of Ophthalmology, Palo Alto, CA, USA
- Department of Pathology, Stanford University, Palo Alto, CA, USA
- VA Palo Alto Healthcare System, Palo Alto, CA, USA
| | - Eun-Jin Lee
- Department of Ophthalmology, Palo Alto, CA, USA
- Department of Pathology, Stanford University, Palo Alto, CA, USA
- VA Palo Alto Healthcare System, Palo Alto, CA, USA
- USC ROSKI Eye Institute and Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jonathan H Lin
- Department of Ophthalmology, Palo Alto, CA, USA.
- Department of Pathology, Stanford University, Palo Alto, CA, USA.
- VA Palo Alto Healthcare System, Palo Alto, CA, USA.
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13
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Shoji T, Saito K. A RING membrane-anchor E3 ubiquitin ligase gene is co-expressed with steroidal glycoalkaloid biosynthesis genes in tomato. Plant Biotechnol (Tokyo) 2022; 39:421-425. [PMID: 37283616 PMCID: PMC10240918 DOI: 10.5511/plantbiotechnology.22.1031a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 10/31/2022] [Indexed: 06/08/2023]
Abstract
RING membrane-anchor (RMA) E3 ubiquitin ligases are involved in endoplasmic reticulum (ER)-associated protein degradation, which mediates the regulated destruction of ER-resident enzymes in various organisms. We determined that the transcription factor JASMONATE-RESPONSIVE ETHYLENE RESPONSE FACTOR 4 (JRE4) co-regulates the expression of the RMA-type ligase gene SlRMA1, but not its homolog SlRMA2, with steroidal glycoalkaloid biosynthesis genes in tomato, perhaps to prevent the overaccumulation of these metabolites.
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Affiliation(s)
- Tsubasa Shoji
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Kazuki Saito
- RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
- Plant Molecular Science Center, Chiba University, Chuo-ku, Chiba, Chiba 260-8675, Japan
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14
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McKenna MJ, Adams BM, Chu V, Paulo JA, Shao S. ATP13A1 prevents ERAD of folding-competent mislocalized and misoriented proteins. Mol Cell 2022; 82:4277-4289.e10. [PMID: 36283413 PMCID: PMC9675726 DOI: 10.1016/j.molcel.2022.09.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/18/2022] [Accepted: 09/26/2022] [Indexed: 11/18/2022]
Abstract
The biosynthesis of thousands of proteins requires targeting a signal sequence or transmembrane segment (TM) to the endoplasmic reticulum (ER). These hydrophobic ɑ helices must localize to the appropriate cellular membrane and integrate in the correct topology to maintain a high-fidelity proteome. Here, we show that the P5A-ATPase ATP13A1 prevents the accumulation of mislocalized and misoriented proteins, which are eliminated by different ER-associated degradation (ERAD) pathways in mammalian cells. Without ATP13A1, mitochondrial tail-anchored proteins mislocalize to the ER through the ER membrane protein complex and are cleaved by signal peptide peptidase for ERAD. ATP13A1 also facilitates the topogenesis of a subset of proteins with an N-terminal TM or signal sequence that should insert into the ER membrane with a cytosolic N terminus. Without ATP13A1, such proteins accumulate in the wrong orientation and are targeted for ERAD by distinct ubiquitin ligases. Thus, ATP13A1 prevents ERAD of diverse proteins capable of proper folding.
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Affiliation(s)
- Michael J McKenna
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA
| | - Benjamin M Adams
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA
| | - Vincent Chu
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA
| | - Sichen Shao
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA.
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15
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Chen J, Du H, Liu Z, Li T, Du H, Wang W, Aslam M, Chen W, Li P, Luo H, Fang H, Liu X. Endoplasmic reticulum-quality control pathway and endoplasmic reticulum-associated degradation mechanism regulate the N-glycoproteins and N-glycan structures in the diatom Phaeodactylum tricornutum. Microb Cell Fact 2022; 21:219. [PMID: 36266689 DOI: 10.1186/s12934-022-01941-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/02/2022] [Indexed: 11/10/2022] Open
Abstract
Tunicamycin inhibits the first step of protein N-glycosylation modification. However, the physiological, transcriptomic, and N-glycomic effects of tunicamycin on important marine diatom Phaeodactylum tricornutum are still unknown. In this study, comprehensive approaches were used to study the effects of tunicamycin stress. The results showed that cell growth and photosynthesis were significantly inhibited in P. tricornutum under the tunicamycin stress. The soluble protein content was significantly decreased, while the soluble sugar and neutral lipid were dramatically increased to orchestrate the balance of carbon and nitrogen metabolisms. The stress of 0.3 μg ml-1 tunicamycin resulted in the differential expression of ERQC and ERAD related genes. The upregulation of genes involved in ERQC pathway, the activation of anti-oxidases and the differential expression of genes related with ERAD mechanism might be important for maintaining homeostasis in cell. The identification of N-glycans, especially complex-type N-glycan structures enriched the N-glycan database of diatom P. tricornutum and provided important information for studying the function of N-glycosylation modification on proteins. As a whole, our study proposed working models of ERQC and ERAD will provide a solid foundation for further in-depth study of the related mechanism and the diatom expression system.
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16
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Wei X, Zheng Z, Feng Z, Zheng L, Tao S, Zheng B, Huang B, Zhang X, Liu J, Chen Y, Zong W, Shan Z, Fan S, Chen J, Zhao F. Sigma-1 receptor attenuates osteoclastogenesis by promoting ER-associated degradation of SERCA2. EMBO Mol Med 2022; 14:e15373. [PMID: 35611810 PMCID: PMC9260208 DOI: 10.15252/emmm.202115373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 12/04/2022] Open
Abstract
Sigma-1 receptor (Sigmar1) is a specific chaperone located in the mitochondria-associated endoplasmic reticulum membrane (MAM) and plays a role in several physiological processes. However, the role of Sigmar1 in bone homeostasis remains unknown. Here, we show that mice lacking Sigmar1 exhibited severe osteoporosis in an ovariectomized model. In contrast, overexpression of Sigmar1 locally alleviated the osteoporosis phenotype. Treatment with Sigmar1 agonists impaired both human and mice osteoclast formation in vitro. Mechanistically, SERCA2 was identified to interact with Sigmar1 based on the immunoprecipitation-mass spectrum (IP-MS) and co-immunoprecipitation (co-IP) assays, and Q615 of SERCA2 was confirmed to be the critical residue for their binding. Furthermore, Sigmar1 promoted SERCA2 degradation through Hrd1/Sel1L-dependent ER-associated degradation (ERAD). Ubiquitination of SERCA2 at K460 and K541 was responsible for its proteasomal degradation. Consequently, inhibition of SERCA2 impeded Sigmar1 deficiency enhanced osteoclastogenesis. Moreover, we found that dimemorfan, an FDA-approved Sigmar1 agonist, effectively rescued bone mass in various established bone-loss models. In conclusion, Sigmar1 is a negative regulator of osteoclastogenesis, and activation of Sigmar1 by dimemorfan may be a potential treatment for osteoporosis in clinical practice.
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Affiliation(s)
- Xiaoan Wei
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Zeyu Zheng
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Zhenhua Feng
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Lin Zheng
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Siyue Tao
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Bingjie Zheng
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Bao Huang
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Xuyang Zhang
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Junhui Liu
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Yilei Chen
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Wentian Zong
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Zhi Shan
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Shunwu Fan
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Jian Chen
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
| | - Fengdong Zhao
- Department of Orthopaedic SurgerySir Run Run Shaw HospitalZhejiang University School of MedicineHangzhouChina
- Key Laboratory of Musculoskeletal System Degeneration and RegenerationTranslational Research of Zhejiang ProvinceHangzhouChina
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17
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Wiseman RL, Mesgarzadeh JS, Hendershot LM. Reshaping endoplasmic reticulum quality control through the unfolded protein response. Mol Cell 2022; 82:1477-1491. [PMID: 35452616 PMCID: PMC9038009 DOI: 10.1016/j.molcel.2022.03.025] [Citation(s) in RCA: 93] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/28/2022] [Accepted: 03/18/2022] [Indexed: 01/09/2023]
Abstract
Endoplasmic reticulum quality control (ERQC) pathways comprising chaperones, folding enzymes, and degradation factors ensure the fidelity of ER protein folding and trafficking to downstream secretory environments. However, multiple factors, including tissue-specific secretory proteomes, environmental and genetic insults, and organismal aging, challenge ERQC. Thus, a key question is: how do cells adapt ERQC to match the diverse, ever-changing demands encountered during normal physiology and in disease? The answer lies in the unfolded protein response (UPR), a signaling mechanism activated by ER stress. In mammals, the UPR comprises three signaling pathways regulated downstream of the ER membrane proteins IRE1, ATF6, and PERK. Upon activation, these UPR pathways remodel ERQC to alleviate cellular stress and restore ER function. Here, we describe how UPR signaling pathways adapt ERQC, highlighting their importance for maintaining ER function across tissues and the potential for targeting the UPR to mitigate pathologies associated with protein misfolding diseases.
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Affiliation(s)
- R. Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037,To whom correspondences should be addressed: Linda Hendershot, ; R. Luke Wiseman,
| | - Jaleh S. Mesgarzadeh
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037
| | - Linda M. Hendershot
- Department of Tumor Biology, St Jude Children’s Research Hospital, Memphis, TN 38105,To whom correspondences should be addressed: Linda Hendershot, ; R. Luke Wiseman,
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18
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Huber M, Armbruster L, Etherington RD, De La Torre C, Hawkesford MJ, Sticht C, Gibbs DJ, Hell R, Wirtz M. Disruption of the N α-Acetyltransferase NatB Causes Sensitivity to Reductive Stress in Arabidopsis thaliana. Front Plant Sci 2022; 12:799954. [PMID: 35046984 PMCID: PMC8761761 DOI: 10.3389/fpls.2021.799954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 11/22/2021] [Indexed: 06/14/2023]
Abstract
In Arabidopsis thaliana, the evolutionary conserved N-terminal acetyltransferase (Nat) complexes NatA and NatB co-translationally acetylate 60% of the proteome. Both have recently been implicated in the regulation of plant stress responses. While NatA mediates drought tolerance, NatB is required for pathogen resistance and the adaptation to high salinity and high osmolarity. Salt and osmotic stress impair protein folding and result in the accumulation of misfolded proteins in the endoplasmic reticulum (ER). The ER-membrane resident E3 ubiquitin ligase DOA10 targets misfolded proteins for degradation during ER stress and is conserved among eukaryotes. In yeast, DOA10 recognizes conditional degradation signals (Ac/N-degrons) created by NatA and NatB. Assuming that this mechanism is preserved in plants, the lack of Ac/N-degrons required for efficient removal of misfolded proteins might explain the sensitivity of NatB mutants to protein harming conditions. In this study, we investigate the response of NatB mutants to dithiothreitol (DTT) and tunicamycin (TM)-induced ER stress. We report that NatB mutants are hypersensitive to DTT but not TM, suggesting that the DTT hypersensitivity is caused by an over-reduction of the cytosol rather than an accumulation of unfolded proteins in the ER. In line with this hypothesis, the cytosol of NatB depleted plants is constitutively over-reduced and a global transcriptome analysis reveals that their reductive stress response is permanently activated. Moreover, we demonstrate that doa10 mutants are susceptible to neither DTT nor TM, ruling out a substantial role of DOA10 in ER-associated protein degradation (ERAD) in plants. Contrary to previous findings in yeast, our data indicate that N-terminal acetylation (NTA) does not inhibit ER targeting of a substantial amount of proteins in plants. In summary, we provide further evidence that NatB-mediated imprinting of the proteome is vital for the response to protein harming stress and rule out DOA10 as the sole recognin for substrates in the plant ERAD pathway, leaving the role of DOA10 in plants ambiguous.
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Affiliation(s)
- Monika Huber
- Centre for Organismal Studies, Molecular Biology of Plants Group, Heidelberg University, Heidelberg, Germany
| | - Laura Armbruster
- Centre for Organismal Studies, Molecular Biology of Plants Group, Heidelberg University, Heidelberg, Germany
| | | | - Carolina De La Torre
- Institute of Clinical Chemistry, NGS Core Facility, Medical Faculty Mannheim of Heidelberg University, Heidelberg, Germany
| | | | - Carsten Sticht
- Institute of Clinical Chemistry, NGS Core Facility, Medical Faculty Mannheim of Heidelberg University, Heidelberg, Germany
| | - Daniel J. Gibbs
- School of Biosciences, University of Birmingham, Edgbaston, United Kingdom
| | - Rüdiger Hell
- Centre for Organismal Studies, Molecular Biology of Plants Group, Heidelberg University, Heidelberg, Germany
| | - Markus Wirtz
- Centre for Organismal Studies, Molecular Biology of Plants Group, Heidelberg University, Heidelberg, Germany
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19
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Elsabrouty R, Jo Y, Hwang S, Jun DJ, DeBose-Boyd RA. Type 1 polyisoprenoid diphosphate phosphatase modulates geranylgeranyl-mediated control of HMG CoA reductase and UBIAD1. eLife 2021; 10:64688. [PMID: 34842525 PMCID: PMC8641950 DOI: 10.7554/elife.64688] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 11/28/2021] [Indexed: 11/18/2022] Open
Abstract
UbiA prenyltransferase domain-containing protein-1 (UBIAD1) utilizes geranylgeranyl pyrophosphate (GGpp) to synthesize the vitamin K2 subtype menaquinone-4. The prenyltransferase has emerged as a key regulator of sterol-accelerated, endoplasmic reticulum (ER)-associated degradation (ERAD) of HMG CoA reductase, the rate-limiting enzyme in synthesis of cholesterol and nonsterol isoprenoids including GGpp. Sterols induce binding of UBIAD1 to reductase, inhibiting its ERAD. Geranylgeraniol (GGOH), the alcohol derivative of GGpp, disrupts this binding and thereby stimulates ERAD of reductase and translocation of UBIAD1 to Golgi. We now show that overexpression of Type 1 polyisoprenoid diphosphate phosphatase (PDP1), which dephosphorylates GGpp and other isoprenyl pyrophosphates to corresponding isoprenols, abolishes protein geranylgeranylation as well as GGOH-induced ERAD of reductase and Golgi transport of UBIAD1. Conversely, these reactions are enhanced in the absence of PDP1. Our findings indicate PDP1-mediated hydrolysis of GGpp significantly contributes to a feedback mechanism that maintains optimal intracellular levels of the nonsterol isoprenoid.
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Affiliation(s)
- Rania Elsabrouty
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
| | - Youngah Jo
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
| | - Seonghwan Hwang
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
| | - Dong-Jae Jun
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
| | - Russell A DeBose-Boyd
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
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20
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Liu X, Yu J, Xu L, Umphred-Wilson K, Peng F, Ding Y, Barton BM, Lv X, Zhao MY, Sun S, Hong Y, Qi L, Adoro S, Chen X. Notch-induced endoplasmic reticulum-associated degradation governs mouse thymocyte β-selection. eLife 2021; 10:e69975. [PMID: 34240701 PMCID: PMC8315795 DOI: 10.7554/elife.69975] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/05/2021] [Indexed: 11/13/2022] Open
Abstract
Signals from the pre-T cell receptor and Notch coordinately instruct β-selection of CD4-CD8-double negative (DN) thymocytes to generate αβ T cells in the thymus. However, how these signals ensure a high-fidelity proteome and safeguard the clonal diversification of the pre-selection TCR repertoire given the considerable translational activity imposed by β-selection is largely unknown. Here, we identify the endoplasmic reticulum (ER)-associated degradation (ERAD) machinery as a critical proteostasis checkpoint during β-selection. Expression of the SEL1L-HRD1 complex, the most conserved branch of ERAD, is directly regulated by the transcriptional activity of the Notch intracellular domain. Deletion of Sel1l impaired DN3 to DN4 thymocyte transition and severely impaired mouse αβ T cell development. Mechanistically, Sel1l deficiency induced unresolved ER stress that triggered thymocyte apoptosis through the PERK pathway. Accordingly, genetically inactivating PERK rescued T cell development from Sel1l-deficient thymocytes. In contrast, IRE1α/XBP1 pathway was induced as a compensatory adaptation to alleviate Sel1l-deficiency-induced ER stress. Dual loss of Sel1l and Xbp1 markedly exacerbated the thymic defect. Our study reveals a critical developmental signal controlled proteostasis mechanism that enforces T cell development to ensure a healthy adaptive immunity.
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Affiliation(s)
- Xia Liu
- Department of Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of MedicineHoustonUnited States
| | - Jingjing Yu
- Department of Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of MedicineHoustonUnited States
| | - Longyong Xu
- Department of Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of MedicineHoustonUnited States
| | - Katharine Umphred-Wilson
- Department of Pathology, School of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Fanglue Peng
- Department of Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of MedicineHoustonUnited States
| | - Yao Ding
- Department of Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of MedicineHoustonUnited States
| | - Brendan M Barton
- Department of Pathology, School of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Xiangdong Lv
- Department of Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
| | - Michael Y Zhao
- Department of Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
| | - Shengyi Sun
- Center for Molecular Medicine and Genetics, Wayne State UniversityDetroitUnited States
| | - Yuning Hong
- Department of Chemistry and Physics, La Trobe UniversityMelbourneAustralia
| | - Ling Qi
- Department of Molecular and Integrative Physiology, University of Michigan Medical SchoolAnn ArborUnited States
| | - Stanley Adoro
- Department of Pathology, School of Medicine, Case Western Reserve UniversityClevelandUnited States
| | - Xi Chen
- Department of Molecular and Cellular Biology, Baylor College of MedicineHoustonUnited States
- Lester and Sue Smith Breast Center and Dan L Duncan Comprehensive Cancer Center, Baylor College of MedicineHoustonUnited States
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21
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Kim H, Wei J, Song Z, Mottillo E, Samavati L, Zhang R, Li L, Chen X, Jena BP, Lin JD, Fang D, Zhang K. Regulation of hepatic circadian metabolism by the E3 ubiquitin ligase HRD1-controlled CREBH/PPARα transcriptional program. Mol Metab 2021; 49:101192. [PMID: 33592335 PMCID: PMC7966871 DOI: 10.1016/j.molmet.2021.101192] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE The endoplasmic reticulum (ER)-resident E3 ligase HRD1 and its co-activator Sel1L are major components of ER-associated degradation (ERAD) machinery. Here, we investigated the molecular mechanism and functional significance underlying the circadian regulation of HRD1/Sel1L-mediated protein degradation program in hepatic energy metabolism. METHODS Genetically engineered animal models as well as gain- and loss-of-function studies were employed to address the circadian regulatory mechanism and functional significance. Gene expression, transcriptional activation, protein-protein interaction, and animal metabolic phenotyping analyses were performed to dissect the molecular network and metabolic pathways. RESULTS Hepatic HRD1 and Sel1L expression exhibits circadian rhythmicity that is controlled by the ER-tethered transcriptional activator CREBH, the nuclear receptor peroxisome proliferator-activated receptor α (PPARα), and the core clock oscillator BMAL1 in mouse livers. HRD1/Sel1L mediates polyubiquitination and degradation of the CREBH protein across the circadian cycle to modulate rhythmic expression of the genes encoding the rate-limiting enzymes or regulators in fatty acid (FA) oxidation, triglyceride (TG) lipolysis, lipophagy, and gluconeogenesis. HRD1 liver-specific knockout (LKO) mice displayed increased expression of the genes involved in lipid and glucose metabolism and impaired circadian profiles of circulating TG, FA, and glucose due to overproduction of CREBH. The circadian metabolic activities of HRD1 LKO mice were inversely correlated with those of CREBH KO mice. Suppressing CREBH overproduction in the livers of HRD1 LKO mice restored the diurnal levels of circulating TG and FA of HRD1 LKO mice. CONCLUSION Our work revealed a key circadian-regulated molecular network through which the E3 ubiquitin ligase HRD1 and its co-activator Sel1L regulate hepatic circadian metabolism.
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Affiliation(s)
- Hyunbae Kim
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Juncheng Wei
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Zhenfeng Song
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Emilio Mottillo
- Hypertension and Vascular Research Division, Henry Ford Hospital, Detroit, MI 48202, USA
| | - Lobelia Samavati
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Ren Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Li Li
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Xuequn Chen
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Bhanu P Jena
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA; NanoBioScience Institute, Wayne State University, Detroit, MI 48201, USA
| | - Jiandie D Lin
- Life Sciences Institute and Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Deyu Fang
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| | - Kezhong Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA; Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, MI 48201, USA; NanoBioScience Institute, Wayne State University, Detroit, MI 48201, USA.
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22
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Abstract
The polytopic, endoplasmic reticulum (ER) membrane protein 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase produces mevalonate, the key intermediate in the synthesis of cholesterol and many nonsterol isoprenoids including geranylgeranyl pyrophosphate (GGpp). Transcriptional, translational, and posttranslational feedback mechanisms converge on this reductase to ensure cells maintain a sufficient supply of essential nonsterol isoprenoids but avoid overaccumulation of cholesterol and other sterols. The focus of this review is mechanisms for the posttranslational regulation of HMG CoA reductase, which include sterol-accelerated ubiquitination and ER-associated degradation (ERAD) that is augmented by GGpp. We discuss how GGpp-induced ER-to-Golgi trafficking of the vitamin K2 synthetic enzyme UbiA prenyltransferase domain-containing protein-1 (UBIAD1) modulates HMG CoA reductase ERAD to balance the synthesis of sterol and nonsterol isoprenoids. We also summarize the characterization of genetically manipulated mice, which established that sterol-accelerated, UBIAD1-modulated ERAD plays a major role in regulation of HMG CoA reductase and cholesterol metabolism in vivo.
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Affiliation(s)
- Marc M Schumacher
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA;
| | - Russell A DeBose-Boyd
- Department of Molecular Genetics, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA;
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23
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Dederer V, Lemberg MK. Transmembrane dislocases: a second chance for protein targeting. Trends Cell Biol 2021; 31:898-911. [PMID: 34147299 DOI: 10.1016/j.tcb.2021.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 12/31/2022]
Abstract
Precise distribution of proteins is essential to sustain the viability of cells. A complex network of protein synthesis and targeting factors cooperate with protein quality control systems to ensure protein homeostasis. Defective proteins are inevitably degraded by the ubiquitin-proteasome system and lysosomes. However, due to overlapping targeting information and limited targeting fidelity, certain proteins become mislocalized. In this review, we present the idea that transmembrane dislocases recognize and remove mislocalized membrane proteins from cellular organelles. This enables other targeting attempts and prevents degradation of mislocalized but otherwise functional proteins. These transmembrane dislocases can be found in the outer mitochondrial membrane (OMM) and endoplasmic reticulum (ER). We highlight common principles regarding client recognition and outline open questions in our understanding of transmembrane dislocases.
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Affiliation(s)
- Verena Dederer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany; Current address: Institute for Pharmaceutical Biology and Buchmann Institute for Molecular Life Science, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - Marius K Lemberg
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany; Center for Biochemistry, Medical Faculty, University of Cologne, 50931 Cologne, Germany.
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24
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Fang YC, Fu SJ, Hsu PH, Chang PT, Huang JJ, Chiu YC, Liao YF, Jow GM, Tang CY, Jeng CJ. Identification of MKRN1 as a second E3 ligase for Eag1 potassium channels reveals regulation via differential degradation. J Biol Chem 2021; 296:100484. [PMID: 33647316 PMCID: PMC8039722 DOI: 10.1016/j.jbc.2021.100484] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 02/17/2021] [Accepted: 02/25/2021] [Indexed: 11/02/2022] Open
Abstract
Mutations in the human gene encoding the neuron-specific Eag1 voltage-gated K+ channel are associated with neurodevelopmental diseases, indicating an important role of Eag1 during brain development. A disease-causing Eag1 mutation is linked to decreased protein stability that involves enhanced protein degradation by the E3 ubiquitin ligase cullin 7 (CUL7). The general mechanisms governing protein homeostasis of plasma membrane- and endoplasmic reticulum (ER)-localized Eag1 K+ channels, however, remain unclear. By using yeast two-hybrid screening, we identified another E3 ubiquitin ligase, makorin ring finger protein 1 (MKRN1), as a novel binding partner primarily interacting with the carboxyl-terminal region of Eag1. MKRN1 mainly interacts with ER-localized immature core-glycosylated, as well as nascent nonglycosylated, Eag1 proteins. MKRN1 promotes polyubiquitination and ER-associated proteasomal degradation of immature Eag1 proteins. Although both CUL7 and MKRN1 contribute to ER quality control of immature core-glycosylated Eag1 proteins, MKRN1, but not CUL7, associates with and promotes degradation of nascent, nonglycosylated Eag1 proteins at the ER. In direct contrast to the role of CUL7 in regulating both ER and peripheral quality controls of Eag1, MKRN1 is exclusively responsible for the early stage of Eag1 maturation at the ER. We further demonstrated that both CUL7 and MKRN1 contribute to protein quality control of additional disease-causing Eag1 mutants associated with defective protein homeostasis. Our data suggest that the presence of this dual ubiquitination system differentially maintains Eag1 protein homeostasis and may ensure efficient removal of disease-associated misfolded Eag1 mutant channels.
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Affiliation(s)
- Ya-Ching Fang
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ssu-Ju Fu
- Department of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Po-Hao Hsu
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Pei-Tzu Chang
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Jing-Jia Huang
- Department of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yi-Chih Chiu
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Fan Liao
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Guey-Mei Jow
- School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Chih-Yung Tang
- Department of Physiology, College of Medicine, National Taiwan University, Taipei, Taiwan.
| | - Chung-Jiuan Jeng
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Brain Research Center, National Yang-Ming University, Taipei, Taiwan.
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25
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Katsube M, Ebara N, Maeda M, Kimura Y. Cytosolic Free N-Glycans Are Retro-Transported Into the Endoplasmic Reticulum in Plant Cells. Front Plant Sci 2021; 11:610124. [PMID: 33537045 PMCID: PMC7847903 DOI: 10.3389/fpls.2020.610124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
During endoplasmic reticulum (ER)-associated degradation, free N-glycans (FNGs) are produced from misfolded nascent glycoproteins via the combination of the cytosolic peptide N-glycanase (cPNGase) and endo-β-N-acetylglucosaminidase (ENGase) in the plant cytosol. The resulting high-mannose type (HMT)-FNGs, which carry one GlcNAc residue at the reducing end (GN1-FNGs), are ubiquitously found in developing plant cells. In a previous study, we found that HMT-FNGs assisted in protein folding and inhibited β-amyloid fibril formation, suggesting a possible biofunction of FNGs involved in the protein folding system. However, whether these HMT-FNGs occur in the ER, an organelle involved in protein folding, remained unclear. On the contrary, we also reported the presence of plant complex type (PCT)-GN1-FNGs, which carry the Lewisa epitope at the non-reducing end, indicating that these FNGs had been fully processed in the Golgi apparatus. Since plant ENGase was active toward HMT-N-glycans but not PCT-N-glycans that carry β1-2xylosyl and/or α1-3 fucosyl residue(s), these PCT-GN1-FNGs did not appear to be produced from fully processed glycoproteins that harbored PCT-N-glycans via ENGase activity. Interestingly, PCT-GN1-FNGs were found in the extracellular space, suggesting that HMT-GN1-FNGs formed in the cytosol might be transported back to the ER and processed in the Golgi apparatus through the protein secretion pathway. As the first step in elucidating the production mechanism of PCT-GN1-FNGs, we analyzed the structures of free oligosaccharides in plant microsomes and proved that HMT-FNGs (Man9-7GlcNAc1 and Man9-8GlcNAc2) could be found in microsomes, which almost consist of the ER compartments.
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26
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Tang CHA, Lee AC, Chang S, Xu Q, Shao A, Lo Y, Spalek WT, Pinilla-Ibarz JA, Del Valle JR, Hu CCA. STING regulates BCR signaling in normal and malignant B cells. Cell Mol Immunol 2020; 18:1016-1031. [PMID: 32999453 PMCID: PMC8115116 DOI: 10.1038/s41423-020-00552-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 09/02/2020] [Indexed: 12/22/2022] Open
Abstract
STING is an endoplasmic reticulum (ER)-resident protein critical for sensing cytoplasmic DNA and promoting the production of type I interferons; however, the role of STING in B cell receptor (BCR) signaling remains unclear. We generated STING V154M knock-in mice and showed that B cells carrying constitutively activated STING specifically degraded membrane-bound IgM, Igα, and Igβ via SEL1L/HRD1-mediated ER-associated degradation (ERAD). B cells with activated STING were thus less capable of responding to BCR activation by phosphorylating Igα and Syk than those without activated STING. When immunized with T-independent antigens, STING V154M mice produced significantly fewer antigen-specific plasma cells and antibodies than immunized wild-type (WT) mice. We further generated B cell-specific STINGKO mice and showed that STINGKO B cells indeed responded to activation by transducing stronger BCR signals than their STING-proficient counterparts. When B cell-specific STINGKO mice were T-independently immunized, they produced significantly more antigen-specific plasma cells and antibodies than immunized STINGWT mice. Since both human and mouse IGHV-unmutated malignant chronic lymphocytic leukemia (CLL) cells downregulated the expression of STING, we explored whether STING downregulation could contribute to the well-established robust BCR signaling phenotype in malignant CLL cells. We generated a STING-deficient CLL mouse model and showed that STING-deficient CLL cells were indeed more responsive to BCR activation than their STING-proficient counterparts. These results revealed a novel B cell-intrinsic role of STING in negatively regulating BCR signaling in both normal and malignant B cells.
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Affiliation(s)
| | - Avery C Lee
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA, 19104, USA
| | - Shiun Chang
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA, 19104, USA
| | - Qin Xu
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA, 19104, USA
| | - Andong Shao
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA, 19104, USA
| | - Yun Lo
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA, 19104, USA
| | - Walker T Spalek
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA, 19104, USA
| | - Javier A Pinilla-Ibarz
- Department of Malignant Hematology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, 33612, USA
| | - Juan R Del Valle
- Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, USA
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27
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van de Weijer ML, Krshnan L, Liberatori S, Guerrero EN, Robson-Tull J, Hahn L, Lebbink RJ, Wiertz EJHJ, Fischer R, Ebner D, Carvalho P. Quality Control of ER Membrane Proteins by the RNF185/Membralin Ubiquitin Ligase Complex. Mol Cell 2020; 79:768-781.e7. [PMID: 32738194 PMCID: PMC7482433 DOI: 10.1016/j.molcel.2020.07.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/06/2020] [Accepted: 07/07/2020] [Indexed: 12/16/2022]
Abstract
Misfolded proteins in the endoplasmic reticulum (ER) are degraded by ER-associated degradation (ERAD). Although ERAD components involved in degradation of luminal substrates are well characterized, much less is known about quality control of membrane proteins. Here, we analyzed the degradation pathways of two short-lived ER membrane model proteins in mammalian cells. Using a CRISPR-Cas9 genome-wide library screen, we identified an ERAD branch required for quality control of a subset of membrane proteins. Using biochemical and mass spectrometry approaches, we showed that this ERAD branch is defined by an ER membrane complex consisting of the ubiquitin ligase RNF185, the ubiquitin-like domain containing proteins TMUB1/2 and TMEM259/Membralin, a poorly characterized protein. This complex cooperates with cytosolic ubiquitin ligase UBE3C and p97 ATPase in degrading their membrane substrates. Our data reveal that ERAD branches have remarkable specificity for their membrane substrates, suggesting that multiple, perhaps combinatorial, determinants are involved in substrate selection. The RNF185 ubiquitin ligase, Membralin, and TMUB1/2 assemble into an ERAD complex RNF185/Membralin complex targets membrane proteins, including CYP51A1 and TMUB2 RNF185/Membralin and TEB4 ERAD complexes recognize distinct substrate features TEB4 ERAD complex recognizes substrates through their transmembrane domain
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Affiliation(s)
- Michael L van de Weijer
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Logesvaran Krshnan
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Sabrina Liberatori
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Elena Navarro Guerrero
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK
| | - Jacob Robson-Tull
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Lilli Hahn
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Robert Jan Lebbink
- Medical Microbiology, University Medical Center Utrecht, 3584 Utrecht, the Netherlands
| | - Emmanuel J H J Wiertz
- Medical Microbiology, University Medical Center Utrecht, 3584 Utrecht, the Netherlands
| | - Roman Fischer
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK
| | - Daniel Ebner
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK
| | - Pedro Carvalho
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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28
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Nachtigal AL, Milenkovic A, Brandl C, Schulz HL, Duerr LMJ, Lang GE, Reiff C, Herrmann P, Kellner U, Weber BHF. Mutation-Dependent Pathomechanisms Determine the Phenotype in the Bestrophinopathies. Int J Mol Sci 2020; 21:E1597. [PMID: 32111077 DOI: 10.3390/ijms21051597] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 12/11/2022] Open
Abstract
Best vitelliform macular dystrophy (BD), autosomal dominant vitreoretinochoroidopathy (ADVIRC), and the autosomal recessive bestrophinopathy (ARB), together known as the bestrophinopathies, are caused by mutations in the bestrophin-1 (BEST1) gene affecting anion transport through the plasma membrane of the retinal pigment epithelium (RPE). To date, while no treatment exists a better understanding of BEST1-related pathogenesis may help to define therapeutic targets. Here, we systematically characterize functional consequences of mutant BEST1 in thirteen RPE patient cell lines differentiated from human induced pluripotent stem cells (hiPSCs). Both BD and ARB hiPSC-RPEs display a strong reduction of BEST1-mediated anion transport function compared to control, while ADVIRC mutations trigger an increased anion permeability suggesting a stabilized open state condition of channel gating. Furthermore, BD and ARB hiPSC-RPEs differ by the degree of mutant protein turnover and by the site of subcellular protein quality control with adverse effects on lysosomal pH only in the BD-related cell lines. The latter finding is consistent with an altered processing of catalytic enzymes in the lysosomes. The present study provides a deeper insight into distinct molecular mechanisms of the three bestrophinopathies facilitating functional categorization of the more than 300 known BEST1 mutations that result into the distinct retinal phenotypes.
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29
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Began J, Cordier B, Březinová J, Delisle J, Hexnerová R, Srb P, Rampírová P, Kožíšek M, Baudet M, Couté Y, Galinier A, Veverka V, Doan T, Strisovsky K. Rhomboid intramembrane protease YqgP licenses bacterial membrane protein quality control as adaptor of FtsH AAA protease. EMBO J 2020; 39:e102935. [PMID: 31930742 PMCID: PMC7231995 DOI: 10.15252/embj.2019102935] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 11/18/2019] [Accepted: 12/12/2019] [Indexed: 12/31/2022] Open
Abstract
Magnesium homeostasis is essential for life and depends on magnesium transporters, whose activity and ion selectivity need to be tightly controlled. Rhomboid intramembrane proteases pervade the prokaryotic kingdom, but their functions are largely elusive. Using proteomics, we find that Bacillus subtilis rhomboid protease YqgP interacts with the membrane‐bound ATP‐dependent processive metalloprotease FtsH and cleaves MgtE, the major high‐affinity magnesium transporter in B. subtilis. MgtE cleavage by YqgP is potentiated in conditions of low magnesium and high manganese or zinc, thereby protecting B. subtilis from Mn2+/Zn2+ toxicity. The N‐terminal cytosolic domain of YqgP binds Mn2+ and Zn2+ ions and facilitates MgtE cleavage. Independently of its intrinsic protease activity, YqgP acts as a substrate adaptor for FtsH, a function that is necessary for degradation of MgtE. YqgP thus unites protease and pseudoprotease function, hinting at the evolutionary origin of rhomboid pseudoproteases such as Derlins that are intimately involved in eukaryotic ER‐associated degradation (ERAD). Conceptually, the YqgP‐FtsH system we describe here is analogous to a primordial form of “ERAD” in bacteria and exemplifies an ancestral function of rhomboid‐superfamily proteins.
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Affiliation(s)
- Jakub Began
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic.,Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Baptiste Cordier
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Univ, Marseille Cedex 20, France
| | - Jana Březinová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic.,Department of Biochemistry, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jordan Delisle
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Univ, Marseille Cedex 20, France
| | - Rozálie Hexnerová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Pavel Srb
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Petra Rampírová
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Milan Kožíšek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
| | - Mathieu Baudet
- CEA, Inserm, IRIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Yohann Couté
- CEA, Inserm, IRIG-BGE, Univ. Grenoble Alpes, Grenoble, France
| | - Anne Galinier
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Univ, Marseille Cedex 20, France
| | - Václav Veverka
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic.,Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Thierry Doan
- Laboratoire de Chimie Bactérienne (LCB), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7283, Aix Marseille Univ, Marseille Cedex 20, France.,Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie de la Méditerranée (IMM), CNRS, UMR 7255, Aix Marseille Univ, Marseille Cedex 20, France
| | - Kvido Strisovsky
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Prague, Czech Republic
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30
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Shi J, Hu X, Guo Y, Wang L, Ji J, Li J, Zhang ZR. A technique for delineating the unfolding requirements for substrate entry into retrotranslocons during endoplasmic reticulum-associated degradation. J Biol Chem 2019; 294:20084-20096. [PMID: 31748412 DOI: 10.1074/jbc.ra119.010019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/13/2019] [Indexed: 11/06/2022] Open
Abstract
The endoplasmic reticulum-associated degradation (ERAD) pathway mediates the endoplasmic reticulum-to-cytosol retrotranslocation of defective proteins through protein complexes called retrotranslocons. Defective proteins usually have complex conformations and topologies, and it is unclear how ERAD can thread these conformationally diverse protein substrates through the retrotranslocons. Here, we investigated the substrate conformation flexibility necessary for transport via retrotranslocons on the ERAD-L, ERAD-M, and HIV-encoded protein Vpu-hijacked ERAD branches. To this end, we appended various ERAD substrates with specific domains whose conformations were tunable in flexibility or tightness by binding to appropriate ligands. With this technique, we could define the capacity of specific retrotranslocons in disentangling very tight, less tight but well-folded, and unstructured conformations. The Hrd1 complex, the retrotranslocon on the ERAD-L branch, permitted the passage of substrates with a proteinase K-resistant tight conformation, whereas the E3 ligase gp78-mediated ERAD-M allowed passage only of nearly completely disordered but not well-folded substrates and thus may have the least unfoldase activity. Vpu-mediated ERAD, containing a potential retrotranslocon, could unfold well-folded substrates for successful retrotranslocation. However, substrate retrotranslocation in Vpu-mediated ERAD was blocked by enhanced conformational tightness of the substrate. On the basis of these findings, we propose a mechanism underlying polypeptide movement through the endoplasmic reticulum membrane. We anticipate that our biochemical system paves the way for identifying the factors necessary for the retrotranslocation of membrane proteins.
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Affiliation(s)
- Junfen Shi
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Xianyan Hu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Yuan Guo
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Linhan Wang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Jia Ji
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Jiqiang Li
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China.,University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Zai-Rong Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China .,University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
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31
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Abstract
Inositol-requiring enzyme 1 (IRE1) is an endoplasmic reticulum (ER)-resident transmembrane protein that senses ER stress and is evolutionarily conserved from yeast to humans. IRE1 possesses both Ser/Thr protein kinase and endoribonuclease (RNase) activities within its cytoplasmic domain and is activated through autophosphorylation and dimerization/oligomerization. It mediates a critical arm of the unfolded protein response to manage ER stress provoked by lumenal overload of unfolded/misfolded proteins. Emerging lines of evidence have revealed that in mammals, IRE1α functions as a multifunctional signal transducer that responds to metabolic cues and nutrient stress conditions, exerting profound and broad effects on metabolic homeostasis. In this review, we cover recent advances in our understanding of how IRE1α integrates a variety of metabolic and stress signals and highlight its tissue-specific or context-dependent metabolic activities. We also discuss how dysregulation of this metabolic stress sensor during handling of excessive nutrients in cells contributes to the progression of obesity and metabolic disorders.
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Affiliation(s)
- Shijia Huang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Yuying Xing
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Yong Liu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
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32
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Zhan Z, Fang W, Ma X, Chen T, Cui G, Ma Y, Kang L, Nan T, Lin H, Tang J, Zhang Y, Lai C, Ren Z, Wang Y, Zhao Y, Shen Y, Wang L, Zeng W, Guo J, Huang L. Metabolome and transcriptome analyses reveal quality change in the orange-rooted Salvia miltiorrhiza (Danshen) from cultivated field. Chin Med 2019; 14:42. [PMID: 31592267 DOI: 10.1186/s13020-019-0265-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 09/23/2019] [Indexed: 01/10/2023] Open
Abstract
Background The dry root and rhizome of Salvia miltiorrhiza Bunge, or Danshen, is a well-known, traditional Chinese medicine. Tanshinones are active compounds that accumulate in the periderm, resulting in red-colored roots. However, lines with orange roots have been observed in cultivated fields. Here, we performed metabolome and transcriptome analyses to investigate the changes of orange-rooted Danshen. Methods Metabolome analysis was performed by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-Tof–MS) to investigate the metabolites variation between orange Danshen and normal Danshen. RNA sequencing and KEGG enrichment analysis were performed to analyzing the differentially expressed genes between orange-rooted and normal Danshen. Results In total, 40 lipophilic components were detected in metabolome analysis, and seven compounds were significantly decreased in the orange Danshen, including the most abundant active compounds, tanshinone IIA and tanshinone I in normal Danshen. Systematic analysis of transcriptome profiles revealed that the down-regulated genes related to catalytic dehydrogenation was not detected. However, two genes related to stress resistance, and four genes related to endoplasmic reticulum (ER)-associated degradation of proteins were up-regulated in orange Danshen. Conclusions Decreases in the content of dehydrogenated furan ring tanshinones such as tanshinone IIA resulted in phenotypic changes and quality degradation of Danshen. Transcriptome analysis indicated that incorrect folding and ER-associated degradation of corresponding enzymes, which could catalyze C15-C16 dehydrogenase, might be contributed to the decrease in dehydrogenated furan ring tanshinones, rather than lower expression of the relative genes. This limited dehydrogenation of cryptotanshinone and dihydrotanshinone I into tanshinones IIA and I products, respectively, led to a reduced quality of Danshen in cultivated fields.
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De Leonibus C, Cinque L, Settembre C. Emerging lysosomal pathways for quality control at the endoplasmic reticulum. FEBS Lett 2019; 593:2319-2329. [PMID: 31388984 DOI: 10.1002/1873-3468.13571] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 07/30/2019] [Accepted: 08/02/2019] [Indexed: 01/01/2023]
Abstract
Protein misfolding occurring in the endoplasmic reticulum (ER) might eventually lead to aggregation and cellular distress, and is a primary pathogenic mechanism in multiple human disorders. Mammals have developed evolutionary-conserved quality control mechanisms at the level of the ER. The best characterized is the ER-associated degradation (ERAD) pathway, through which misfolded proteins translocate from the ER to the cytosol and are subsequently proteasomally degraded. However, increasing evidence indicates that additional quality control mechanisms apply for misfolded ER clients that are not eligible for ERAD. This review focuses on the alternative, ERAD-independent, mechanisms of clearance of misfolded polypeptides from the ER. These processes, collectively referred to as ER-to-lysosome-associated degradation, involve ER-phagy, microautophagy or vesicular transport. The identification of the underlying molecular mechanisms is particularly important for developing new therapeutic approaches for human diseases associated with protein aggregate formation.
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Affiliation(s)
| | - Laura Cinque
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
| | - Carmine Settembre
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy.,Department of Medical and Translational Science, University of Naples "Federico II", Italy
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34
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Osaki Y, Matsuhisa K, Che W, Kaneko M, Asada R, Masaki T, Imaizumi K, Saito A. Calnexin promotes the folding of mutant iduronate 2-sulfatase related to mucopolysaccharidosis type II. Biochem Biophys Res Commun 2019; 514:217-223. [PMID: 31029429 DOI: 10.1016/j.bbrc.2019.04.115] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 04/15/2019] [Indexed: 01/01/2023]
Abstract
Mucopolysaccharidosis type II (MPS II) is one of the most common mucopolysaccharidoses, which is caused by mutation of the gene encoding iduronate 2-sulfatase (IDS). The loss of function of IDS leads to the accumulation of heparan sulfate and dermatan sulfate of glycosaminoglycans throughout the body, resulting in skeletal deformities, mental retardation, rigid joints, and thick skin. Recently, enzyme replacement therapy has become a common strategy for treating this condition. However, its effectiveness on the central nervous system (CNS) is limited because intravenously administered recombinant IDS (rIDS) cannot pass through the blood brain barrier. Therefore, several methods for delivering rIDS to the CNS, using anti-human transferrin receptor antibody and adeno-associated virus 9, have been explored. To investigate additional approaches for treatment, more cognition about the intracellular dynamics of mutant IDS is essential. We have already found that mutant IDS accumulated in the endoplasmic reticulum (ER) and was degraded by ER-associated degradation (ERAD). Although the dynamics of degradation of mutant IDS was revealed, the molecular mechanism related to the folding of mutant IDS in the ER remained unclear. In this research, we confirmed that mutant IDS retained in the ER would be folded by binding with calnexin (CNX). Thus, knockdown of CNX reduced the translocation of mutant IDS from ER to lysosome and its enzyme activity, indicating that the correct folding of this protein via interaction with CNX ensures its functional activity. These findings reveal the possibility that modifying the interaction of mutant IDS and CNX could contribute to alternative therapeutic strategies for MPS II.
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Affiliation(s)
- Yosuke Osaki
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan; Department of Stress Protein Processing, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan; Department of Nephrology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Koji Matsuhisa
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Wang Che
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Masayuki Kaneko
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Rie Asada
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan; Department of Medicine, Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Takao Masaki
- Department of Nephrology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan
| | - Kazunori Imaizumi
- Department of Biochemistry, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
| | - Atsushi Saito
- Department of Stress Protein Processing, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
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35
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Kouga T, Koizume S, Aoki S, Jimbo E, Yamagata T, Inoue K, Osaka H. Drug screening for Pelizaeus-Merzbacher disease by quantifying the total levels and membrane localization of PLP1. Mol Genet Metab Rep 2019; 20:100474. [PMID: 31110947 DOI: 10.1016/j.ymgmr.2019.100474] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 04/28/2019] [Indexed: 01/01/2023] Open
Abstract
Background Pelizaeus-Merzbacher disease (PMD) is caused by point mutations or copy number changes in the proteolipid protein 1 gene (PLP1). PLP1 is exclusively localized in the myelin sheath of oligodendrocytes. Amino acid-substituted PLP1 protein is unable to fold properly and is subsequently degraded and/or restrictedly translated, resulting in a decrease in the PLP1 protein level and a failure to localize to the membrane. Furthermore, misfolded proteins increase the burden on the intracellular quality control system and trafficking, finally resulting in cell apoptosis. The objective of this study was to identify therapeutic chemicals for PMD by quantifying the total levels and membrane localization of PLP1. Method We established a cell line stably expressing PLP1A243V fused with green fluorescent protein in oligodendrocyte-derived MO3.13 cells. We screened a chemical library composed of drugs approved for central nervous system disorders that increased both the total intensity of PLP1A243V in the whole cell and the cell membrane localization. We analyzed the change in the endoplasmic reticulum (ER) stress and the gene expression of candidate chemicals using a micro-array analysis. Finally, we tested the in vivo effectiveness using myelin synthesis deficient (msd) mice with PlpA243V. Results and conclusion Piracetam significantly increased the PLP1A243V intensity and membrane localization and decreased the ER stress. It was also shown to reverse the gene expression changes induced by PLP1A243V in a micro-array analysis. However, in vivo treatment of piracetam did not improve the survival of msd mice (Plp1A243V).
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Key Words
- CNS, Central nervous systems
- Drug screening
- EGFP, Enhanced green fluorescent protein
- ER, Endoplasmic reticulum
- ER-associated degradation
- Gene expression
- IPA, Ingenuity pathways analysis
- IRE1 α, Inositol requiring enzyme 1 α
- Membrane protein
- Oligodendrocyte
- PLP1
- PLP1, Proteolipid protein 1
- PMD, Pelizaeus-Merzbacher disease
- UPR, Unfolded protein response
- XBP1, X-box binding protein 1
- msd, Myelin synthesis deficient
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36
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Matsusaki M, Kanemura S, Kinoshita M, Lee YH, Inaba K, Okumura M. The Protein Disulfide Isomerase Family: from proteostasis to pathogenesis. Biochim Biophys Acta Gen Subj 2019; 1864:129338. [PMID: 30986509 DOI: 10.1016/j.bbagen.2019.04.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 03/08/2019] [Accepted: 04/02/2019] [Indexed: 12/13/2022]
Abstract
In mammalian cells, nearly one-third of proteins are inserted into the endoplasmic reticulum (ER), where they undergo oxidative folding and chaperoning assisted by approximately 20 members of the protein disulfide isomerase family (PDIs). PDIs consist of multiple thioredoxin-like domains and recognize a wide variety of proteins via highly conserved interdomain flexibility. Although PDIs have been studied intensely for almost 50 years, exactly how they maintain protein homeostasis in the ER remains unknown, and is important not only for fundamental biological understanding but also for protein misfolding- and aggregation-related pathophysiology. Herein, we review recent advances in structural biology and biophysical approaches that explore the underlying mechanism by which PDIs fulfil their distinct functions to promote productive protein folding and scavenge misfolded proteins in the ER, the primary factory for efficient production of the secretome.
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Affiliation(s)
- Motonori Matsusaki
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki aza Aoba 6-3, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Shingo Kanemura
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki aza Aoba 6-3, Aoba-ku, Sendai, Miyagi 980-8578, Japan; School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan
| | - Misaki Kinoshita
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki aza Aoba 6-3, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Young-Ho Lee
- Protein Structure Group, Korea Basic Science Institute, Ochang, Chungbuk 28199, South Korea; Bio-Analytical Science, University of Science and Technology, Daejeon 34113, South Korea
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, Miyagi 980-8577, Japan.
| | - Masaki Okumura
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Aramaki aza Aoba 6-3, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
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Zheng L, Chen Y, Ding D, Zhou Y, Ding L, Wei J, Wang H. Endoplasmic reticulum-localized UBC34 interaction with lignin repressors MYB221 and MYB156 regulates the transactivity of the transcription factors in Populus tomentosa. BMC Plant Biol 2019; 19:97. [PMID: 30866808 PMCID: PMC6416899 DOI: 10.1186/s12870-019-1697-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 02/27/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Regulation of lignin biosynthesis is known to occur at the level of transcription factors (TFs), of which R2R3-MYB family members have been proposed to play a central role via the AC cis-elements. Despite the important roles of TFs in lignin biosynthesis, the post-translational regulation of these TFs, particularly their ubiquitination regulation, has not been thoroughly explored. RESULTS We describe the discovery of a Populus tomentosa E2 ubiquitin-conjugating enzyme 34 (PtoUBC34), which is involved in the post-translational regulation of transactivation activity of lignin-associated transcriptional repressors PtoMYB221 and PtoMYB156. PtoUBC34 is localized at the endoplasmic reticulum (ER) membrane where it interacts with transcriptional repressors PtoMYB221 and PtoMYB156. This specific interaction allows for the translocation of TFs PtoMYB221 and PtoMYB156 to the ER and reduces their repression activity in a PtoUBC34 abundance-dependent manner. By taking a molecular biology approach with quantitative real-time polymerase chain reaction (qRT-PCR) analysis, we found that PtoUBC34 is expressed in all aboveground tissues of trees in P. tomentosa, and in particular, it is ubiquitous in all distinct differentiation stages across wood formation, including phloem differentiation, cambium maintaining, early and developing xylem differentiation, secondary cell wall thickening, and programmed cell death. Additionally, we discovered that PtoUBC34 is induced by treatment with sodium chloride and heat shock. CONCLUSIONS Our data suggest a possible mechanism by which lignin biosynthesis is regulated by ER-localized PtoUBC34 in poplar, probably through the ER-associated degradation (ERAD) of lignin-associated repressors PtoMYB221 and PtoMYB156.
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Affiliation(s)
- Lin Zheng
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
| | - Yajuan Chen
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
| | - Dong Ding
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
| | - Ying Zhou
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
| | - Liping Ding
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
| | - Jianhua Wei
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
| | - Hongzhi Wang
- Beijing Agro-Biotechnology Research Center, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
- Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology, Beijing Academy of Agricultural and Forestry Sciences, No. 9, Shuguang Huayuan Middle Road, Haidian District, Beijing, 100097 People’s Republic of China
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38
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Jo Y, Hamilton JS, Hwang S, Garland K, Smith GA, Su S, Fuentes I, Neelam S, Thompson BM, McDonald JG, DeBose-Boyd RA. Schnyder corneal dystrophy-associated UBIAD1 inhibits ER-associated degradation of HMG CoA reductase in mice. eLife 2019; 8:44396. [PMID: 30785396 PMCID: PMC6402834 DOI: 10.7554/elife.44396] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/19/2019] [Indexed: 12/14/2022] Open
Abstract
Autosomal-dominant Schnyder corneal dystrophy (SCD) is characterized by corneal opacification owing to overaccumulation of cholesterol. SCD is caused by mutations in UBIAD1, which utilizes geranylgeranyl pyrophosphate (GGpp) to synthesize vitamin K2. Using cultured cells, we previously showed that sterols trigger binding of UBIAD1 to the cholesterol biosynthetic enzyme HMG CoA reductase (HMGCR), thereby inhibiting its endoplasmic reticulum (ER)-associated degradation (ERAD) (Schumacher et al. 2015). GGpp triggers release of UBIAD1 from HMGCR, allowing maximal ERAD and ER-to-Golgi transport of UBIAD1. SCD-associated UBIAD1 resists GGpp-induced release and is sequestered in ER to inhibit ERAD. We now report knockin mice expressing SCD-associated UBIAD1 accumulate HMGCR in several tissues resulting from ER sequestration of mutant UBIAD1 and inhibition of HMGCR ERAD. Corneas from aged knockin mice exhibit signs of opacification and sterol overaccumulation. These results establish the physiological significance of UBIAD1 in cholesterol homeostasis and indicate inhibition of HMGCR ERAD contributes to SCD pathogenesis.
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Affiliation(s)
- Youngah Jo
- Departments of Molecular Genetics, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jason S Hamilton
- Departments of Molecular Genetics, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Seonghwan Hwang
- Departments of Molecular Genetics, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Kristina Garland
- Departments of Molecular Genetics, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Gennipher A Smith
- Departments of Molecular Genetics, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Shan Su
- Departments of Molecular Genetics, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Iris Fuentes
- Departments of Molecular Genetics, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Sudha Neelam
- Department of Ophthalmology, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Bonne M Thompson
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Jeffrey G McDonald
- Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
| | - Russell A DeBose-Boyd
- Departments of Molecular Genetics, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, United States
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Abstract
Identification and degradation of misfolded proteins by the ubiquitin-proteasome system (UPS) is crucial for maintaining proteostasis, but only a handful of UPS components have been linked to the recognition of specific substrates. Studies in Saccharomyces cerevisiae using systematic perturbation of nonessential genes have uncovered UPS components that recognize and ubiquitylate model substrates of the UPS; however, similar analyses in metazoans have been limited. In this chapter, we describe methods for using CRISPR/Cas9 technology combined with genome-wide high complexity single guide (sgRNA) libraries and a transcriptional shutoff strategy for phenotypic selection based on kinetic measurements of protein turnover to identify the genes required to degrade model clients of the mammalian ER-associated degradation system. We also discuss considerations for screen design, execution, and interpretation.
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Affiliation(s)
- Dara E Leto
- Department of Biology, Stanford University, Stanford, CA, United States
| | - Ron R Kopito
- Department of Biology, Stanford University, Stanford, CA, United States.
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40
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Li Q, Chen D, Xiang Q, Nicholas J. Insulin-Like Growth Factor 2 Receptor Expression Is Promoted by Human Herpesvirus 8-Encoded Interleukin-6 and Contributes to Viral Latency and Productive Replication. J Virol 2019; 93:e02026-18. [PMID: 30541844 DOI: 10.1128/JVI.02026-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 11/29/2018] [Indexed: 12/29/2022] Open
Abstract
Human herpesvirus 8 (HHV-8) viral interleukin-6 (vIL-6) localizes largely to the endoplasmic reticulum (ER) and here associates functionally with both the gp130 signal transducer and the novel ER membrane protein vitamin K epoxide reductase complex subunit 1 variant-2 (VKORC1v2). The latter interaction contributes to the viability of latently infected primary effusion lymphoma (PEL) cells and to HHV-8 productive replication, in part via promotion of ER-associated degradation (ERAD) of nascent pro-cathepsin D (pCatD) and consequent suppression of lysosome-localized proapoptotic mature CatD. Here we report that VKORC1v2 associates with insulin-like growth factor 2 receptor (IGF2R), also known as cation-independent mannose-6-phosphate receptor, which is involved in trafficking of mannose-6-phosphate-conjugated glycoproteins to lysosomes. VKORC1v2 effected reduced IGF2R expression in a manner dependent on VKORC1v2-IGF2R interaction, while vIL-6, which could inhibit VKORC1v2-IGF2R interaction, effected increased expression of IGF2R. These effects were independent of changes in IGF2R mRNA levels, indicating likely posttranslational mechanisms. In kinetic analyses involving labeling of either newly synthesized or preexisting IGF2R, vIL-6 promoted accumulation of the former while having no detectable effect on the latter. Furthermore, vIL-6 led to decreased K48-linked ubiquitination of IGF2R and suppression of ERAD proteins effected increased IGF2R expression and loss of IGF2R regulation by vIL-6. Depletion-based experiments identified IGF2R as a promoter of PEL cell viability and virus yields from lytically reactivated cultures. Our findings identify ER-transiting nascent IGF2R as an interaction partner of VKORC1v2 and target of vIL-6 regulation and IGF2R as a positive contributor to HHV-8 biology, thereby extending understanding of the mechanisms of VKORC1v2-associated vIL-6 function.IMPORTANCE HHV-8 vIL-6 promotes productive replication in the context of reactivated lytic replication in primary effusion lymphoma (PEL) and endothelial cells and sustains latently infected PEL cell viability. Viral IL-6 is also considered to contribute significantly to HHV-8-associated pathogenesis, since vIL-6 can promote cell proliferation, cell survival, and angiogenesis that are characteristic of HHV-8-associated Kaposi's sarcoma, PEL and multicentric Castleman's disease (MCD), in addition to proinflammatory activities observed in MCD-like "Kaposi's sarcoma-associated herpesvirus-induced cytokine syndrome." We show in the present study that vIL-6 can promote productive replication and latent PEL cell viability through upregulation of the mannose-6-phosphate- and peptide hormone-interacting receptor IGF2R, which is a positive factor in HHV-8 biology via these activities. VKORC1v2-enhanced ER-associated degradation of IGF2R and vIL-6 promotion of IGF2R expression through prevention of its interaction with VKORC1v2 and consequent rescue from degradation represent newly recognized activities of VKOCR1v2 and vIL-6.
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Thomas R, Kermode AR. Enzyme enhancement therapeutics for lysosomal storage diseases: Current status and perspective. Mol Genet Metab 2019; 126:83-97. [PMID: 30528228 DOI: 10.1016/j.ymgme.2018.11.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/20/2018] [Accepted: 11/21/2018] [Indexed: 01/28/2023]
Abstract
Small-molecule- enzyme enhancement therapeutics (EETs) have emerged as attractive agents for the treatment of lysosomal storage diseases (LSDs), a broad group of genetic diseases caused by mutations in genes encoding lysosomal enzymes, or proteins required for lysosomal function. The underlying enzyme deficiencies characterizing LSDs cause a block in the stepwise degradation of complex macromolecules (e.g. glycosaminoglycans, glycolipids and others), such that undegraded or partially degraded substrates progressively accumulate in lysosomal and non-lysosomal compartments, a process leading to multisystem pathology via primary and secondary mechanisms. Missense mutations underlie many of the LSDs; the resultant mutant variant enzyme hydrolase is often impaired in its folding and maturation making it subject to rapid disposal by endoplasmic reticulum (ER)-associated degradation (ERAD). Enzyme deficiency in the lysosome is the result, even though the mutant enzyme may retain significant catalytic functioning. Small molecule modulators - pharmacological chaperones (PCs), or proteostasis regulators (PRs) are being identified through library screens and computational tools, as they may offer a less costly approach than enzyme replacement therapy (ERT) for LSDs, and potentially treat neuronal forms of the diseases. PCs, capable of directly stabilizing the mutant protein, and PRs, which act on other cellular elements to enhance protein maturation, both allow a proportion of the synthesized variant protein to reach the lysosome and function. Proof-of-principle for PCs and PRs as therapeutic agents has been demonstrated for several LSDs, yet definitive data of their efficacy in disease models and/or in downstream clinical studies in many cases has yet to be achieved. Basic research to understand the cellular consequences of protein misfolding such as perturbed organellar crosstalk, redox status, and calcium balance is needed. Likewise, an elucidation of the early in cellulo pathogenic events underlying LSDs is vital and may lead to the discovery of new small molecule modulators and/or to other therapeutic approaches for driving proteostasis toward protein rescue.
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Affiliation(s)
- Ryan Thomas
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr., Burnaby B.C. V5A 1S6, Canada
| | - Allison R Kermode
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr., Burnaby B.C. V5A 1S6, Canada.
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Abstract
The antiviral mechanism of action of iminosugars against many enveloped viruses, including dengue virus (DENV), HIV, influenza and hepatitis C virus, is believed to be mediated by inducing misfolding of viral N-linked glycoproteins through inhibition of host endoplasmic reticulum-resident α-glucosidase enzymes. This leads to reduced secretion and/or infectivity of virions and hence lower viral titres, both in vitro and in vivo. Free oligosaccharide analysis from iminosugar-treated cells shows that antiviral activity correlates with production of mono- and tri-glucosylated sugars, indicative of inhibition of ER α-glucosidases. We demonstrate that glucose-mimicking iminosugars inhibit isolated glycoprotein and glycolipid processing enzymes and that this inhibition also occurs in primary cells treated with these drugs. Galactose-mimicking iminosugars that have been tested do not inhibit glycoprotein processing but do inhibit glycolipid processing, and are not antiviral against DENV. By comparison, the antiviral activity of glucose-mimetic iminosugars that inhibit endoplasmic reticulum-resident α-glucosidases, but not glycolipid processing, demonstrates that inhibition of α-glucosidases is responsible for iminosugar antiviral activity against DENV. This monograph will review the investigations of many researchers into the mechanisms of action of iminosugars and the contribution of our current understanding of these mechanisms for optimising clinical delivery of iminosugars. The effects of iminosugars on enzymes other than glucosidases, the induction of ER stress and viral receptors will be also put into context. Data suggest that inhibition of α-glucosidases results in inhibited release of virus and is the primary antiviral mechanism of action of iminosugars against DENV.
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Cesaratto F, Sasset L, Myers MP, Re A, Petris G, Burrone OR. BiP/GRP78 Mediates ERAD Targeting of Proteins Produced by Membrane-Bound Ribosomes Stalled at the STOP-Codon. J Mol Biol 2018; 431:123-141. [PMID: 30367842 PMCID: PMC7094721 DOI: 10.1016/j.jmb.2018.10.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 11/29/2022]
Abstract
Translational stalling of ribosome bound to endoplasmic reticulum (ER) membrane requires an accurate clearance of the associated polypeptides, which is not completely understood in mammals. We characterized in mammalian cells the model of ribosomal stalling at the STOP-codon based on proteins tagged at the C-terminus with the picornavirus 2A peptide followed by a termination codon instead of the Proline (2A*). We exploited the 2A* stalling model to characterize the pathway of degradation of ER-targeted polypeptides. We report that the ER chaperone BiP/GRP78 is a new main factor involved. Moreover, degradation of the ER-stalled polypeptides required the activities of the AAA-ATPase VCP/p97, its associated deubiquitinylase YOD1, the ribosome-associated ubiquitin ligase Listerin and the proteasome. In human proteome, we found two human C-terminal amino acid sequences that cause similar stalling at the STOP-codon. Our data suggest that translational stalling at the ER membrane activates protein degradation at the interface of ribosomal- and ER-associated quality control systems. Ribosomal stalling at the STOP-codon causes degradation of the translated protein. Picornavirus 2A peptide and related sequences cause ribosome stalling at STOP-codon. BiP/GRP78 recognizes polypeptides produced by membrane-bound stalled ribosomes. ER-stalled polypeptides are disposed of through the ERAD pathway. BIP/GRP78 is a novel key player for ERAD targeting of stalled ribosomal peptides.
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Affiliation(s)
- Francesca Cesaratto
- Laboratory of Molecular Immunology, International Centre for Genetic Engineering and Biotechnology, ICGEB, Padriciano 99, 34149 Trieste, Italy
| | - Linda Sasset
- Laboratory of Molecular Immunology, International Centre for Genetic Engineering and Biotechnology, ICGEB, Padriciano 99, 34149 Trieste, Italy
| | - Michael P Myers
- Laboratory of Protein Networks, International Centre for Genetic Engineering and Biotechnology, ICGEB, Padriciano 99, 34149 Trieste, Italy
| | - Angela Re
- Centre for Integrative Biology (CIBIO), University of Trento, Via Sommarive 9, 38123 Trento, Italy; Center for Sustainable Future Technologies, Fondazione Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino, Italy; Center for Sustainable Future Technologies, Fondazione Istituto Italiano di Tecnologia, C.so Trento 21, 10129 Torino, Italy
| | - Gianluca Petris
- Centre for Integrative Biology (CIBIO), University of Trento, Via Sommarive 9, 38123 Trento, Italy.
| | - Oscar R Burrone
- Laboratory of Molecular Immunology, International Centre for Genetic Engineering and Biotechnology, ICGEB, Padriciano 99, 34149 Trieste, Italy.
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Mehrtash AB, Hochstrasser M. Ubiquitin-dependent protein degradation at the endoplasmic reticulum and nuclear envelope. Semin Cell Dev Biol 2018; 93:111-124. [PMID: 30278225 DOI: 10.1016/j.semcdb.2018.09.013] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/26/2018] [Accepted: 09/27/2018] [Indexed: 01/01/2023]
Abstract
Numerous nascent proteins undergo folding and maturation within the luminal and membrane compartments of the endoplasmic reticulum (ER). Despite the presence of various factors in the ER that promote protein folding, many proteins fail to properly fold and assemble and are subsequently degraded. Regulatory proteins in the ER also undergo degradation in a way that is responsive to stimuli or the changing needs of the cell. As in most cellular compartments, the ubiquitin-proteasome system (UPS) is responsible for the majority of the degradation at the ER-in a process termed ER-associated degradation (ERAD). Autophagic processes utilizing ubiquitin-like protein-conjugating systems also play roles in protein degradation at the ER. The ER is continuous with the nuclear envelope (NE), which consists of the outer nuclear membrane (ONM) and inner nuclear membrane (INM). While ERAD is known also to occur at the NE, only some of the ERAD ubiquitin-ligation pathways function at the INM. Protein degradation machineries in the ER/NE target a wide variety of substrates in multiple cellular compartments, including the cytoplasm, nucleoplasm, ER lumen, ER membrane, and the NE. Here, we review the protein degradation machineries of the ER and NE and the underlying mechanisms dictating recognition and processing of substrates by these machineries.
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Affiliation(s)
- Adrian B Mehrtash
- Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, 06520, CT, USA.
| | - Mark Hochstrasser
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, 06520, USA; Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, 06520, CT, USA.
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Kuscuoglu D, Janciauskiene S, Hamesch K, Haybaeck J, Trautwein C, Strnad P. Liver - master and servant of serum proteome. J Hepatol 2018; 69:512-524. [PMID: 29709680 DOI: 10.1016/j.jhep.2018.04.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 04/13/2018] [Accepted: 04/16/2018] [Indexed: 12/20/2022]
Abstract
Hepatocytes synthesise the majority of serum proteins. This production occurs in the endoplasmic reticulum (ER) and is adjusted by complex local and systemic regulatory mechanisms. Accordingly, serum levels of hepatocyte-made proteins constitute important biomarkers that reflect both systemic processes and the status of the liver. For example, C-reactive protein is an established marker of inflammatory reaction, whereas transferrin emerges as a liver stress marker and an attractive mortality predictor. The high protein flow through the ER poses a continuous challenge that is handled by a complex proteostatic network consisting of ER folding machinery, ER stress response, ER-associated degradation and autophagy. Various disorders disrupt this delicate balance and result in protein accumulation in the ER. These include chronic hepatitis B infection with overproduction of hepatitis B surface antigen or inherited alpha1-antitrypsin deficiency that give rise to ground glass hepatocytes and alpha1-antitrypsin aggregates, respectively. We review these ER storage disorders and their downstream consequences. The interaction between proteotoxic stress and other ER challenges such as lipotoxicity is also discussed. Collectively, this article aims to sharpen our view of liver hepatocytes as the central hubs of protein metabolism.
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Affiliation(s)
- Deniz Kuscuoglu
- Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany; The Interdisciplinary Center for Clinical Research (IZKF), University Hospital Aachen, Aachen, Germany
| | - Sabina Janciauskiene
- Department of Respiratory Medicine, Hannover Medical School, BREATH, German Center for Lung Research (DZL), Hannover, Germany
| | - Karim Hamesch
- Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Johannes Haybaeck
- Institute of Pathology, Medical University Graz, Graz, Austria; Department of Pathology, Medical Faculty, Otto-von-Guericke University of Magdeburg, Magdeburg, Germany
| | - Christian Trautwein
- Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany
| | - Pavel Strnad
- Medical Clinic III, Gastroenterology, Metabolic Diseases and Intensive Care, University Hospital RWTH Aachen, Aachen, Germany; The Interdisciplinary Center for Clinical Research (IZKF), University Hospital Aachen, Aachen, Germany.
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van der Goot AT, Pearce MMP, Leto DE, Shaler TA, Kopito RR. Redundant and Antagonistic Roles of XTP3B and OS9 in Decoding Glycan and Non-glycan Degrons in ER-Associated Degradation. Mol Cell 2018; 70:516-530.e6. [PMID: 29706535 DOI: 10.1016/j.molcel.2018.03.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 02/15/2018] [Accepted: 03/21/2018] [Indexed: 12/25/2022]
Abstract
Glycoproteins engaged in unproductive folding in the ER are marked for degradation by a signal generated by progressive demannosylation of substrate N-glycans that is decoded by ER lectins, but how the two lectins, OS9 and XTP3B, contribute to non-glycosylated protein triage is unknown. We generated cell lines with homozygous deletions of both lectins individually and in combination. We found that OS9 and XTP3B redundantly promote glycoprotein degradation and stabilize the SEL1L/HRD1 dislocon complex, that XTP3B profoundly inhibits the degradation of non-glycosylated proteins, and that OS9 antagonizes this inhibition. The relative expression of OS9 and XTP3B and the distribution of glycan and non-glycan degrons within the same protein contribute to the fidelity and processivity of glycoprotein triage and, therefore, determine the fates of newly synthesized proteins in the early secretory pathway.
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Affiliation(s)
| | | | - Dara E Leto
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | - Ron R Kopito
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
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Rahmati M, Moosavi MA, McDermott MF. ER Stress: A Therapeutic Target in Rheumatoid Arthritis? Trends Pharmacol Sci 2018; 39:610-623. [PMID: 29691058 DOI: 10.1016/j.tips.2018.03.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/21/2018] [Accepted: 03/27/2018] [Indexed: 12/12/2022]
Abstract
Diverse physiological and pathological conditions that impact on protein folding of the endoplasmic reticulum (ER) cause ER stress. The unfolded protein response (UPR) and the ER-associated degradation (ERAD) pathway are activated to cope with ER stress. In rheumatoid arthritis (RA), inflammation and ER stress work in parallel by driving inflammatory cells to release cytokines that induce chronic ER stress pathways. This chronic ER stress may contribute to the pathogenesis of RA through synoviocyte proliferation and proinflammatory cytokine production. Therefore, ER stress pathways and their constituent elements are attractive targets for RA drug development. In this review, we integrate current knowledge of the contribution of ER stress to the overall pathogenesis of RA, and suggest some therapeutic implications of these discoveries.
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Affiliation(s)
- Marveh Rahmati
- Cancer Biology Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences, Tehran, Iran; These authors contributed equally to this work.
| | - Mohammad Amin Moosavi
- Department of Molecular Medicine, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, P.O Box:14965/161, Tehran, Iran; These authors contributed equally to this work
| | - Michael F McDermott
- Leeds Institute of Rheumatic and Musculoskeletal Medicine (LIRMM), Wellcome Trust Brenner Building, St James's University Hospital, Beckett Street, Leeds LS9 7TF, UK.
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Luo H, Jiang M, Lian G, Liu Q, Shi M, Li TY, Song L, Ye J, He Y, Yao L, Zhang C, Lin ZZ, Zhang CS, Zhao TJ, Jia WP, Li P, Lin SY, Lin SC. AIDA Selectively Mediates Downregulation of Fat Synthesis Enzymes by ERAD to Retard Intestinal Fat Absorption and Prevent Obesity. Cell Metab 2018; 27:843-853.e6. [PMID: 29617643 DOI: 10.1016/j.cmet.2018.02.021] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/05/2017] [Accepted: 02/21/2018] [Indexed: 01/24/2023]
Abstract
The efficiency of intestinal absorption of dietary fat constitutes a primary determinant accounting for individual vulnerability to obesity. However, how fat absorption is controlled and contributes to obesity remains unclear. Here, we show that inhibition of endoplasmic-reticulum-associated degradation (ERAD) increases the abundance of triacylglycerol synthesis enzymes and fat absorption in small intestine. The C2-domain protein AIDA acts as an essential factor for the E3-ligase HRD1 of ERAD to downregulate rate-limiting acyltransferases GPAT3, MOGAT2, and DGAT2. Aida-/- mice, when grown in a thermal-neutral condition or fed high-fat diet, display increased intestinal fatty acid re-esterification, circulating and tissue triacylglycerol, accompanied with severely increased adiposity without enhancement of adipogenesis. Intestine-specific knockout of Aida largely phenocopies its whole-body knockout, strongly indicating that increased intestinal TAG synthesis is a primary impetus to obesity. The AIDA-mediated ERAD system may thus represent an anti-thrifty mechanism impinging on the enzymes for intestinal fat absorption and systemic fat storage.
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Jiang LY, Jiang W, Tian N, Xiong YN, Liu J, Wei J, Wu KY, Luo J, Shi XJ, Song BL. Ring finger protein 145 (RNF145) is a ubiquitin ligase for sterol-induced degradation of HMG-CoA reductase. J Biol Chem 2018; 293:4047-4055. [PMID: 29374057 PMCID: PMC5857978 DOI: 10.1074/jbc.ra117.001260] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 01/15/2018] [Indexed: 12/21/2022] Open
Abstract
Cholesterol biosynthesis is tightly regulated in the cell. For example, high sterol concentrations can stimulate degradation of the rate-limiting cholesterol biosynthetic enzyme 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase, HMGCR). HMGCR is broken down by the endoplasmic reticulum membrane-associated protein complexes consisting of insulin-induced genes (Insigs) and the E3 ubiquitin ligase gp78. Here we found that HMGCR degradation is partially blunted in Chinese hamster ovary (CHO) cells lacking gp78 (gp78-KO). To identify other ubiquitin ligase(s) that may function together with gp78 in triggering HMGCR degradation, we performed a small-scale short hairpin RNA-based screening targeting endoplasmic reticulum-localized E3s. We found that knockdown of both ring finger protein 145 (Rnf145) and gp78 genes abrogates sterol-induced degradation of HMGCR in CHO cells. We also observed that RNF145 interacts with Insig-1 and -2 proteins and ubiquitinates HMGCR. Moreover, the tetrapeptide sequence YLYF in the sterol-sensing domain and the Cys-537 residue in the RING finger domain were essential for RNF145 binding to Insigs and RNF145 E3 activity, respectively. Of note, amino acid substitutions in the YLYF or of Cys-537 completely abolished RNF145-mediated HMGCR degradation. In summary, our study reveals that RNF145, along with gp78, promotes HMGCR degradation in response to elevated sterol levels and identifies residues essential for RNF145 function.
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Affiliation(s)
- Lu-Yi Jiang
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Wei Jiang
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Na Tian
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Yan-Ni Xiong
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Jie Liu
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Jian Wei
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Kai-Yue Wu
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Jie Luo
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Xiong-Jie Shi
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Bao-Liang Song
- From the Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
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Arunagiri A, Haataja L, Cunningham CN, Shrestha N, Tsai B, Qi L, Liu M, Arvan P. Misfolded proinsulin in the endoplasmic reticulum during development of beta cell failure in diabetes. Ann N Y Acad Sci 2018; 1418:5-19. [PMID: 29377149 DOI: 10.1111/nyas.13531] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 09/14/2017] [Accepted: 09/25/2017] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum (ER) is broadly distributed throughout the cytoplasm of pancreatic beta cells, and this is where all proinsulin is initially made. Healthy beta cells can synthesize 6000 proinsulin molecules per second. Ordinarily, nascent proinsulin entering the ER rapidly folds via the formation of three evolutionarily conserved disulfide bonds (B7-A7, B19-A20, and A6-A11). A modest amount of proinsulin misfolding, including both intramolecular disulfide mispairing and intermolecular disulfide-linked protein complexes, is a natural by-product of proinsulin biosynthesis, as is the case for many proteins. The steady-state level of misfolded proinsulin-a potential ER stressor-is linked to (1) production rate, (2) ER environment, (3) presence or absence of naturally occurring (mutational) defects in proinsulin, and (4) clearance of misfolded proinsulin molecules. Accumulation of misfolded proinsulin beyond a certain threshold begins to interfere with the normal intracellular transport of bystander proinsulin, leading to diminished insulin production and hyperglycemia, as well as exacerbating ER stress. This is most obvious in mutant INS gene-induced Diabetes of Youth (MIDY; an autosomal dominant disease) but also likely to occur in type 2 diabetes owing to dysregulation in proinsulin synthesis, ER folding environment, or clearance.
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Affiliation(s)
- Anoop Arunagiri
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan
| | - Leena Haataja
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan
| | - Corey N Cunningham
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan
| | - Neha Shrestha
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Billy Tsai
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan
| | - Ling Qi
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Ming Liu
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan.,Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, Michigan
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