1
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Hendershot LM, Buck TM, Brodsky JL. The Essential Functions of Molecular Chaperones and Folding Enzymes in Maintaining Endoplasmic Reticulum Homeostasis. J Mol Biol 2024; 436:168418. [PMID: 38143019 DOI: 10.1016/j.jmb.2023.168418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 12/26/2023]
Abstract
It has been estimated that up to one-third of the proteins encoded by the human genome enter the endoplasmic reticulum (ER) as extended polypeptide chains where they undergo covalent modifications, fold into their native structures, and assemble into oligomeric protein complexes. The fidelity of these processes is critical to support organellar, cellular, and organismal health, and is perhaps best underscored by the growing number of disease-causing mutations that reduce the fidelity of protein biogenesis in the ER. To meet demands encountered by the diverse protein clientele that mature in the ER, this organelle is populated with a cadre of molecular chaperones that prevent protein aggregation, facilitate protein disulfide isomerization, and lower the activation energy barrier of cis-trans prolyl isomerization. Components of the lectin (glycan-binding) chaperone system also reside within the ER and play numerous roles during protein biogenesis. In addition, the ER houses multiple homologs of select chaperones that can recognize and act upon diverse peptide signatures. Moreover, redundancy helps ensure that folding-compromised substrates are unable to overwhelm essential ER-resident chaperones and enzymes. In contrast, the ER in higher eukaryotic cells possesses a single member of the Hsp70, Hsp90, and Hsp110 chaperone families, even though several homologs of these molecules reside in the cytoplasm. In this review, we discuss specific functions of the many factors that maintain ER quality control, highlight some of their interactions, and describe the vulnerabilities that arise from the absence of multiple members of some chaperone families.
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Affiliation(s)
- Linda M Hendershot
- Department of Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, United States.
| | - Teresa M Buck
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States
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2
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Koo J, Palli SR. StaufenC facilitates utilization of the ERAD pathway to transport dsRNA through the endoplasmic reticulum to the cytosol. Proc Natl Acad Sci U S A 2024; 121:e2322927121. [PMID: 38885386 PMCID: PMC11214074 DOI: 10.1073/pnas.2322927121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 05/14/2024] [Indexed: 06/20/2024] Open
Abstract
RNA interference (RNAi) is more efficient in coleopteran insects than other insects. StaufenC (StauC), a coleopteran-specific double-stranded RNA (dsRNA)-binding protein, is required for efficient RNAi in coleopterans. We investigated the function of StauC in the intracellular transport of dsRNA into the cytosol, where dsRNA is digested by Dicer enzymes and recruited by Argonauts to RNA-induced silencing complexes. Confocal microscopy and cellular organelle fractionation studies have shown that dsRNA is trafficked through the endoplasmic reticulum (ER) in coleopteran Colorado potato beetle (CPB) cells. StauC is localized to the ER in CPB cells, and StauC-knockdown caused the accumulation of dsRNA in the ER and a decrease in the cytosol, suggesting that StauC plays a key role in the intracellular transport of dsRNA through the ER. Using immunoprecipitation, we showed that StauC is required for dsRNA interaction with ER proteins in the ER-associated protein degradation (ERAD) pathway, and these interactions are required for RNAi in CPB cells. These results suggest that StauC works with the ERAD pathway to transport dsRNA through the ER to the cytosol. This information could be used to develop dsRNA delivery methods aimed at improving RNAi.
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Affiliation(s)
- Jinmo Koo
- Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY40546
| | - Subba Reddy Palli
- Department of Entomology, College of Agriculture, University of Kentucky, Lexington, KY40546
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3
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Katsuki R, Kanuka M, Ohta R, Yoshida S, Tamura T. Turnover of EDEM1, an ERAD-enhancing factor, is mediated by multiple degradation routes. Genes Cells 2024; 29:486-502. [PMID: 38682256 PMCID: PMC11163939 DOI: 10.1111/gtc.13117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/21/2024] [Accepted: 03/23/2024] [Indexed: 05/01/2024]
Abstract
Quality-based protein production and degradation in the endoplasmic reticulum (ER) are essential for eukaryotic cell survival. During protein maturation in the ER, misfolded or unassembled proteins are destined for disposal through a process known as ER-associated degradation (ERAD). EDEM1 is an ERAD-accelerating factor whose gene expression is upregulated by the accumulation of aberrant proteins in the ER, known as ER stress. Although the role of EDEM1 in ERAD has been studied in detail, the turnover of EDEM1 by intracellular degradation machinery, including the proteasome and autophagy, is not well understood. To clarify EDEM1 regulation in the protein level, degradation mechanism of EDEM1 was examined. Our results indicate that both ERAD and autophagy degrade EDEM1 alike misfolded degradation substrates, although each degradation machinery targets EDEM1 in different folded states of proteins. We also found that ERAD factors, including the SEL1L/Hrd1 complex, YOD1, XTP3B, ERdj3, VIMP, BAG6, and JB12, but not OS9, are involved in EDEM1 degradation in a mannose-trimming-dependent and -independent manner. Our results suggest that the ERAD accelerating factor, EDEM1, is turned over by the ERAD itself, similar to ERAD clients.
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Affiliation(s)
- Riko Katsuki
- Department of Life Science, Graduated School of Engineering ScienceAkita UniversityAkitaJapan
| | - Mai Kanuka
- Department of Life Science, Graduated School of Engineering ScienceAkita UniversityAkitaJapan
| | - Ren Ohta
- Department of Life Science, Graduated School of Engineering ScienceAkita UniversityAkitaJapan
| | - Shusei Yoshida
- Department of Life Science, Faculty of Engineering ScienceAkita UniversityAkitaJapan
| | - Taku Tamura
- Department of Life Science, Graduated School of Engineering ScienceAkita UniversityAkitaJapan
- Department of Life Science, Faculty of Engineering ScienceAkita UniversityAkitaJapan
- Present address:
Biococoon Laboratories Inc.4‐3‐5, UedaMoriokaJapan
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4
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Li C, Chi H, Deng S, Wang H, Yao H, Wang Y, Chen D, Guo X, Fang JY, He F, Xu J. THADA drives Golgi residency and upregulation of PD-L1 in cancer cells and provides promising target for immunotherapy. J Immunother Cancer 2021; 9:jitc-2021-002443. [PMID: 34341130 PMCID: PMC8330570 DOI: 10.1136/jitc-2021-002443] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2021] [Indexed: 12/28/2022] Open
Abstract
Background The abnormal upregulation of programmed death-ligand 1 (PD-L1) in cancer cells inhibits T cell-mediated cytotoxicity, but the molecular mechanisms that drive and maintain PD-L1 expression are still incompletely understood. Methods Combined analyses of genomes and proteomics were applied to find potential regulators of PD-L1. In vitro experiments were performed to investigate the regulatory mechanism of PD-L1 by thyroid adenoma associated gene (THADA) using human colorectal cancer (CRC) cells. The prevalence of THADA was analyzed using CRC tissue microarrays by immunohistochemistry. T cell killing assay, programmed cell death 1 binding assay and MC38 transplanted tumor models in C57BL/6 mice were developed to investigate the antitumor effect of THADA. Results THADA is critically required for the Golgi residency of PD-L1, and this non-redundant, coat protein complex II (COPII)-associated mechanism maintains PD-L1 expression in tumor cells. THADA mediated the interaction between PD-L1 as a cargo protein with SEC24A, a module on the COPII trafficking vesicle. Silencing THADA caused absence and endoplasmic reticulum (ER) retention of PD-L1 but not major histocompatibility complex-I, inducing PD-L1 clearance through ER-associated degradation. Targeting THADA substantially enhanced T cell-mediated cytotoxicity, and increased CD8+ T cells infiltration in mouse tumor tissues. Analysis on clinical tissue samples supported a potential role of THADA in upregulating PD-L1 expression in cancer. Conclusions Our data reveal a crucial cellular process for PD-L1 maturation and maintenance in tumor cells, and highlight THADA as a promising target for overcoming PD-L1-dependent immune evasion.
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Affiliation(s)
- Chushu Li
- Zhongshan-Xuhui Hospital, Institutes of Biomedical Sciences (visiting), Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan University, Shanghai, China.,Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hao Chi
- Zhongshan-Xuhui Hospital, Shanghai Xuhui Central Hospital, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan University, Shanghai, China
| | - Shouyan Deng
- Zhongshan-Xuhui Hospital, Institutes of Biomedical Sciences (visiting), Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan University, Shanghai, China.,Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Huanbin Wang
- Zhongshan-Xuhui Hospital, Institutes of Biomedical Sciences (visiting), Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan University, Shanghai, China
| | - Han Yao
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yungang Wang
- Zhongshan-Xuhui Hospital, Shanghai Xuhui Central Hospital, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan University, Shanghai, China
| | - Dawei Chen
- Innomodels Biotechnology (Beijing) Co., Ltd, Beijing, China
| | - Xun Guo
- Innomodels Biotechnology (Beijing) Co., Ltd, Beijing, China
| | - Jing-Yuan Fang
- Division of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Fang He
- Zhongshan-Xuhui Hospital, Shanghai Xuhui Central Hospital, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan University, Shanghai, China
| | - Jie Xu
- Zhongshan-Xuhui Hospital, Shanghai Xuhui Central Hospital, Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Fudan University, Shanghai, China
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5
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Ninagawa S. N-glycan Dependent Protein Quality Control System in the Endoplasmic Reticulum. TRENDS GLYCOSCI GLYC 2021. [DOI: 10.4052/tigg.2108.2e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Satoshi Ninagawa
- Department of Biophysics, Graduate School of Science, Kyoto University
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6
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Nakada EM, Sun R, Fujii U, Martin JG. The Impact of Endoplasmic Reticulum-Associated Protein Modifications, Folding and Degradation on Lung Structure and Function. Front Physiol 2021; 12:665622. [PMID: 34122136 PMCID: PMC8188853 DOI: 10.3389/fphys.2021.665622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/23/2021] [Indexed: 12/15/2022] Open
Abstract
The accumulation of unfolded/misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and induces the unfolded protein response (UPR) and other mechanisms to restore ER homeostasis, including translational shutdown, increased targeting of mRNAs for degradation by the IRE1-dependent decay pathway, selective translation of proteins that contribute to the protein folding capacity of the ER, and activation of the ER-associated degradation machinery. When ER stress is excessive or prolonged and these mechanisms fail to restore proteostasis, the UPR triggers the cell to undergo apoptosis. This review also examines the overlooked role of post-translational modifications and their roles in protein processing and effects on ER stress and the UPR. Finally, these effects are examined in the context of lung structure, function, and disease.
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Affiliation(s)
- Emily M. Nakada
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre (RI-MUHC), McGill University, Montreal, QC, Canada
- McGill University, Montreal, QC, Canada
| | - Rui Sun
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre (RI-MUHC), McGill University, Montreal, QC, Canada
- McGill University, Montreal, QC, Canada
| | - Utako Fujii
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre (RI-MUHC), McGill University, Montreal, QC, Canada
- McGill University, Montreal, QC, Canada
| | - James G. Martin
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre (RI-MUHC), McGill University, Montreal, QC, Canada
- McGill University, Montreal, QC, Canada
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7
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Ninagawa S. N-glycan Dependent Protein Quality Control System in the Endoplasmic Reticulum. TRENDS GLYCOSCI GLYC 2021. [DOI: 10.4052/tigg.2108.2j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Satoshi Ninagawa
- Department of Biophysics, Graduate School of Science, Kyoto University
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8
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Abstract
Folding of proteins is essential so that they can exert their functions. For proteins that transit the secretory pathway, folding occurs in the endoplasmic reticulum (ER) and various chaperone systems assist in acquiring their correct folding/subunit formation. N-glycosylation is one of the most conserved posttranslational modification for proteins, and in eukaryotes it occurs in the ER. Consequently, eukaryotic cells have developed various systems that utilize N-glycans to dictate and assist protein folding, or if they consistently fail to fold properly, to destroy proteins for quality control and the maintenance of homeostasis of proteins in the ER.
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9
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Ninagawa S, George G, Mori K. Mechanisms of productive folding and endoplasmic reticulum-associated degradation of glycoproteins and non-glycoproteins. Biochim Biophys Acta Gen Subj 2020; 1865:129812. [PMID: 33316349 DOI: 10.1016/j.bbagen.2020.129812] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND The quality of proteins destined for the secretory pathway is ensured by two distinct mechanisms in the endoplasmic reticulum (ER): productive folding of newly synthesized proteins, which is assisted by ER-localized molecular chaperones and in most cases also by disulfide bond formation and transfer of an oligosaccharide unit; and ER-associated degradation (ERAD), in which proteins unfolded or misfolded in the ER are recognized and processed for delivery to the ER membrane complex, retrotranslocated through the complex with simultaneous ubiquitination, extracted by AAA-ATPase to the cytosol, and finally degraded by the proteasome. SCOPE OF REVIEW We describe the mechanisms of productive folding and ERAD, with particular attention to glycoproteins versus non-glycoproteins, and to yeast versus mammalian systems. MAJOR CONCLUSION Molecular mechanisms of the productive folding of glycoproteins and non-glycoproteins mediated by molecular chaperones and protein disulfide isomerases are well conserved from yeast to mammals. Additionally, mammals have gained an oligosaccharide structure-dependent folding cycle for glycoproteins. The molecular mechanisms of ERAD are also well conserved from yeast to mammals, but redundant expression of yeast orthologues in mammals has been encountered, particularly for components involved in recognition and processing of glycoproteins and components of the ER membrane complex involved in retrotranslocation and simultaneous ubiquitination of glycoproteins and non-glycoproteins. This may reflect an evolutionary consequence of increasing quantity or quality needs toward mammals. GENERAL SIGNIFICANCE The introduction of innovative genome editing technology into analysis of the mechanisms of mammalian ERAD, as exemplified here, will provide new insights into the pathogenesis of various diseases.
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Affiliation(s)
- Satoshi Ninagawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
| | - Ginto George
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Kazutoshi Mori
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
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10
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Jiang L, Hu LG. Serpin peptidase inhibitor clade A member 1-overexpression in gastric cancer promotes tumor progression in vitro and is associated with poor prognosis. Oncol Lett 2020; 20:278. [PMID: 33014156 PMCID: PMC7520747 DOI: 10.3892/ol.2020.12141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 07/01/2020] [Indexed: 12/14/2022] Open
Abstract
Gastric cancer is the second most common cause of cancer-associated death in Asia. The incidence and mortality rates of gastric cancer have markedly increased in the past few decades. Therefore, the identification of novel gastric cancer biomarkers are needed to determine prognosis. The role of serpin peptidase inhibitor clade A member 1 (SERPINA1) has been studied in several types of cancer; however, little is known about its mechanism in gastric cancer. The present study aimed to evaluate SERPINA1 as a potential prognostic biomarker in gastric cancer and to identify the possible mechanisms underlying its action. The expression levels of SERPINA1 in several gastric cancer datasets were assessed, and it was identified that high expression of SERPINA1 was associated to poor clinical outcomes. Furthermore, using histochemical analysis, western blotting, apoptotic analysis, gap closure and invasion assays in cell lines, it was reported that silencing of SERPINA1 inhibited the formation of cellular pseudopodia and did not affect apoptosis, but promoted cell cycle S-phase entry. In addition, overexpression of SERPINA1 increased the migration and invasion of gastric cancer cells, whereas knockdown of SERPINA1 decreased these functions. Moreover, SERPINA1 overexpression increased the protein levels of SMAD4, which is a key regulator of the transforming growth factor (TGF)-β signaling pathway. Taken together, the present data demonstrated that SERPINA1 promotes gastric cancer progression through TGF-β signaling, and suggested that SERPINA1 may be a novel prognostic biomarker from tumor tissue biopsy in gastric cancer.
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Affiliation(s)
- Longchang Jiang
- Translational Safety and Bioanalytical Sciences, Amgen Research, Amgen Asia Research and Development Center, Shanghai 201210, P.R. China
| | - Liangbiao George Hu
- Translational Safety and Bioanalytical Sciences, Amgen Research, Amgen Asia Research and Development Center, Shanghai 201210, P.R. China
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11
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Kim P, Scott MR, Meador-Woodruff JH. Abnormal expression of ER quality control and ER associated degradation proteins in the dorsolateral prefrontal cortex in schizophrenia. Schizophr Res 2018; 197:484-491. [PMID: 29496332 PMCID: PMC6109614 DOI: 10.1016/j.schres.2018.02.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/27/2017] [Accepted: 02/12/2018] [Indexed: 11/19/2022]
Abstract
Abnormalities in posttranslational protein modifications (PTMs) that regulate protein targeting, trafficking, synthesis, and function have been implicated in the pathophysiology of schizophrenia. The endoplasmic reticulum (ER) contains specialized machinery that facilitate protein synthesis, ER entry and exit, quality control, and post-translational processing, steps required for protein maturation. Dysregulation of these systems could represent potential mechanisms for abnormalities of neurotransmitter associated proteins in schizophrenia. We hypothesized that expression of ER processing pathways is dysregulated in schizophrenia. We characterized protein and complex expression of essential components from protein folding, ER quality control (ERQC), and ER associated degradation (ERAD) processes in the dorsolateral prefrontal cortex of 12 matched pairs of elderly schizophrenia and comparison subjects. We found increased expression of proteins associated with recognizing and modifying misfolded proteins, including UDP-glucose/glycoprotein glucosyltransferase 2 (UGGT2), ER degradation enhancing alpha-mannosidase like protein 2 (EDEM2), and synoviolin (SYVN1)/HRD1. As SYVN1/HRD1 is a component of the ubiquitin ligase HRD1-SEL1L complex that facilitates ERAD, we immunoprecipitated SEL1L and measured expression of other proteins in this complex. In schizophrenia, SYVN1/HRD1 and OS-9, ERAD promoters, have increased association with SEL1L, while XTP3-B, which can prevent ERAD of substrates, has decreased association. Abnormal expression of proteins associated with ERQC and ERAD suggests dysregulation in ER localized protein processing pathways in schizophrenia. Interestingly, the deficits we found are not in the protein processing machinery itself, but in proteins that recognize and target incompletely or misfolded proteins. These changes may reflect potential mechanisms of abnormal neurotransmitter associated protein expression previously observed in schizophrenia.
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Affiliation(s)
- Pitna Kim
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Madeline R Scott
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - James H Meador-Woodruff
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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12
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Yu S, Ito S, Wada I, Hosokawa N. ER-resident protein 46 (ERp46) triggers the mannose-trimming activity of ER degradation-enhancing α-mannosidase-like protein 3 (EDEM3). J Biol Chem 2018; 293:10663-10674. [PMID: 29784879 DOI: 10.1074/jbc.ra118.003129] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 05/16/2018] [Indexed: 11/06/2022] Open
Abstract
Protein folding in the cell is regulated by several quality-control mechanisms. Correct folding of glycoproteins in the endoplasmic reticulum (ER) is tightly monitored by the recognition of glycan signals by lectins in the ER-associated degradation (ERAD) pathway. In mammals, mannose trimming from N-glycans is crucial for disposal of misfolded glycoproteins. The mannosidases responsible for this process are ER mannosidase I and ER degradation-enhancing α-mannosidase-like proteins (EDEMs). However, the molecular mechanism of mannose removal by EDEMs remains unclear, partly owing to the difficulty of reconstituting mannosidase activity in vitro Here, our analysis of EDEM3-mediated mannose-trimming activity on a misfolded glycoprotein revealed that ERp46, an ER-resident oxidoreductase, associates stably with EDEM3. This interaction, which depended on the redox activity of ERp46, involved formation of a disulfide bond between the cysteine residues of the ERp46 redox-active sites and the EDEM3 α-mannosidase domain. In a defined in vitro system consisting of recombinant proteins purified from HEK293 cells, the mannose-trimming activity of EDEM3 toward the model misfolded substrate, the glycoprotein T-cell receptor α locus (TCRα), was reconstituted only when ERp46 had established a covalent interaction with EDEM3. On the basis of these findings, we propose that disposal of misfolded glycoproteins through mannose trimming is tightly connected to redox-mediated regulation in the ER.
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Affiliation(s)
- Shangyu Yu
- From the Laboratory of Molecular and Cellular Biology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507
| | - Shinji Ito
- the Medical Research Support Center, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, and
| | - Ikuo Wada
- the Department of Cell Sciences, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan
| | - Nobuko Hosokawa
- From the Laboratory of Molecular and Cellular Biology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507,
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13
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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: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [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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14
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Fujimori T, Suno R, Iemura SI, Natsume T, Wada I, Hosokawa N. Endoplasmic reticulum proteins SDF2 and SDF2L1 act as components of the BiP chaperone cycle to prevent protein aggregation. Genes Cells 2017; 22:684-698. [PMID: 28597544 DOI: 10.1111/gtc.12506] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Accepted: 05/08/2017] [Indexed: 12/21/2022]
Abstract
The folding of newly synthesized proteins in the endoplasmic reticulum (ER) is assisted by ER-resident chaperone proteins. BiP (immunoglobulin heavy-chain-binding protein), a member of the HSP70 family, plays a central role in protein quality control. The chaperone function of BiP is regulated by its intrinsic ATPase activity, which is stimulated by ER-resident proteins of the HSP40/DnaJ family, including ERdj3. Here, we report that two closely related proteins, SDF2 and SDF2L1, regulate the BiP chaperone cycle. Both are ER-resident, but SDF2 is constitutively expressed, whereas SDF2L1 expression is induced by ER stress. Both luminal proteins formed a stable complex with ERdj3 and potently inhibited the aggregation of different types of misfolded ER cargo. These proteins associated with non-native proteins, thus promoting the BiP-substrate interaction cycle. A dominant-negative ERdj3 mutant that inhibits the interaction between ERdj3 and BiP prevented the dissociation of misfolded cargo from the ERdj3-SDF2L1 complex. Our findings indicate that SDF2 and SDF2L1 associate with ERdj3 and act as components in the BiP chaperone cycle to prevent the aggregation of misfolded proteins, partly explaining the broad folding capabilities of the ER under various physiological conditions.
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Affiliation(s)
- Tsutomu Fujimori
- Laboratory of Molecular and Cellular Biology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, 606-8507, Japan
| | - Ryoji Suno
- Department of Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan
| | - Shun-Ichiro Iemura
- Translational Research Center, Fukushima Medical University, Fukushima, 960-8031, Japan
| | - Tohru Natsume
- Molecular Profiling Research Center for Drug Discovery (molprof), National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, 135-0064, Japan
| | - Ikuo Wada
- Department of Cell Sciences, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, 960-1295, Japan
| | - Nobuko Hosokawa
- Laboratory of Molecular and Cellular Biology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, 606-8507, Japan
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15
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Wang T, Feugang JM, Crenshaw MA, Regmi N, Blanton JR, Liao SF. A Systems Biology Approach Using Transcriptomic Data Reveals Genes and Pathways in Porcine Skeletal Muscle Affected by Dietary Lysine. Int J Mol Sci 2017; 18:ijms18040885. [PMID: 28430144 PMCID: PMC5412465 DOI: 10.3390/ijms18040885] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 04/08/2017] [Accepted: 04/18/2017] [Indexed: 11/16/2022] Open
Abstract
Nine crossbred finishing barrows (body weight 94.4 ± 6.7 kg) randomly assigned to three dietary treatments were used to investigate the effects of dietary lysine on muscle growth related metabolic and signaling pathways. Muscle samples were collected from the longissimus dorsi of individual pigs after feeding the lysine-deficient (4.30 g/kg), lysine-adequate (7.10 g/kg), or lysine-excess (9.80 g/kg) diet for five weeks, and the total RNA was extracted afterwards. Affymetrix Porcine Gene 1.0 ST Array was used to quantify the expression levels of 19,211 genes. Statistical ANOVA analysis of the microarray data showed that 674 transcripts were differentially expressed (at p ≤ 0.05 level); 60 out of 131 transcripts (at p ≤ 0.01 level) were annotated in the NetAffx database. Ingenuity pathway analysis showed that dietary lysine deficiency may lead to: (1) increased muscle protein degradation via the ubiquitination pathway as indicated by the up-regulated DNAJA1, HSP90AB1 and UBE2B mRNA; (2) reduced muscle protein synthesis via the up-regulated RND3 and ZIC1 mRNA; (3) increased serine and glycine synthesis via the up-regulated PHGDH and PSPH mRNA; and (4) increased lipid accumulation via the up-regulated ME1, SCD, and CIDEC mRNA. Dietary lysine excess may lead to: (1) decreased muscle protein degradation via the down-regulated DNAJA1, HSP90AA1, HSPH1, and UBE2D3 mRNA; and (2) reduced lipid biosynthesis via the down-regulated CFD and ME1 mRNA. Collectively, dietary lysine may function as a signaling molecule to regulate protein turnover and lipid metabolism in the skeletal muscle of finishing pigs.
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Affiliation(s)
- Taiji Wang
- Department of Animal and Dairy Sciences, Mississippi State University, Starkville, MS 39762, USA.
| | - Jean M Feugang
- Department of Animal and Dairy Sciences, Mississippi State University, Starkville, MS 39762, USA.
| | - Mark A Crenshaw
- Department of Animal and Dairy Sciences, Mississippi State University, Starkville, MS 39762, USA.
| | - Naresh Regmi
- Department of Animal and Dairy Sciences, Mississippi State University, Starkville, MS 39762, USA.
| | - John R Blanton
- Department of Animal and Dairy Sciences, Mississippi State University, Starkville, MS 39762, USA.
| | - Shengfa F Liao
- Department of Animal and Dairy Sciences, Mississippi State University, Starkville, MS 39762, USA.
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16
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Abstract
Simple and complex carbohydrates (glycans) have long been known to play major metabolic, structural and physical roles in biological systems. Targeted microbial binding to host glycans has also been studied for decades. But such biological roles can only explain some of the remarkable complexity and organismal diversity of glycans in nature. Reviewing the subject about two decades ago, one could find very few clear-cut instances of glycan-recognition-specific biological roles of glycans that were of intrinsic value to the organism expressing them. In striking contrast there is now a profusion of examples, such that this updated review cannot be comprehensive. Instead, a historical overview is presented, broad principles outlined and a few examples cited, representing diverse types of roles, mediated by various glycan classes, in different evolutionary lineages. What remains unchanged is the fact that while all theories regarding biological roles of glycans are supported by compelling evidence, exceptions to each can be found. In retrospect, this is not surprising. Complex and diverse glycans appear to be ubiquitous to all cells in nature, and essential to all life forms. Thus, >3 billion years of evolution consistently generated organisms that use these molecules for many key biological roles, even while sometimes coopting them for minor functions. In this respect, glycans are no different from other major macromolecular building blocks of life (nucleic acids, proteins and lipids), simply more rapidly evolving and complex. It is time for the diverse functional roles of glycans to be fully incorporated into the mainstream of biological sciences.
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Affiliation(s)
- Ajit Varki
- Departments of Medicine and Cellular & Molecular Medicine, Glycobiology Research and Training Center, University of California at San Diego, La Jolla, CA 92093-0687, USA
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17
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Quality control of glycoprotein folding and ERAD: the role of N-glycan handling, EDEM1 and OS-9. Histochem Cell Biol 2016; 147:269-284. [DOI: 10.1007/s00418-016-1513-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2016] [Indexed: 02/03/2023]
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18
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Abstract
The endoplasmic reticulum is the port of entry for proteins into the secretory pathway and the site of synthesis for several important lipids, including cholesterol, triacylglycerol, and phospholipids. Protein production within the endoplasmic reticulum is tightly regulated by a cohort of resident machinery that coordinates the folding, modification, and deployment of secreted and integral membrane proteins. Proteins failing to attain their native conformation are degraded through the endoplasmic reticulum-associated degradation (ERAD) pathway via a series of tightly coupled steps: substrate recognition, dislocation, and ubiquitin-dependent proteasomal destruction. The same ERAD machinery also controls the flux through various metabolic pathways by coupling the turnover of metabolic enzymes to the levels of key metabolites. We review the current understanding and biological significance of ERAD-mediated regulation of lipid metabolism in mammalian cells.
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Affiliation(s)
- Julian Stevenson
- Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720;
| | - Edmond Y Huang
- Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720;
| | - James A Olzmann
- Program in Metabolic Biology, Department of Nutritional Sciences and Toxicology, University of California, Berkeley, California 94720;
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19
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Peters SL, Déry MA, LeBlanc AC. Familial prion protein mutants inhibit Hrd1-mediated retrotranslocation of misfolded proteins by depleting misfolded protein sensor BiP. Hum Mol Genet 2016; 25:976-88. [PMID: 26740554 DOI: 10.1093/hmg/ddv630] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 12/29/2015] [Indexed: 01/09/2023] Open
Abstract
Similar to many proteins trafficking through the secretory pathway, cellular prion protein (PrP) partly retrotranslocates from the endoplasmic reticulum to the cytosol through the endoplasmic reticulum-associated degradation (ERAD) pathway in an attempt to alleviate accumulation of cellular misfolded PrP. Surprisingly, familial PrP mutants fail to retrotranslocate and simultaneously block normal cellular PrP retrotranslocation. That impairments in retrotranslocation of misfolded proteins could lead to global disruptions in cellular homeostasis prompted further investigations into PrP mutant retrotranslocation defects. A gain- and loss-of-function approach identified human E3 ubiquitin ligase, Hrd1, as a critical regulator of PrP retrotranslocation in mammalian cells. Expression of familial human PrP mutants, V210I(129V) and M232R(129V), not only abolished PrP retrotranslocation, but also that of Hrd1-dependent ERAD substrates, transthyretin TTR(D18G) and α1-anti-trypsin A1AT(NHK). Mutant PrP expression decreased binding immunoglobulin protein (BiP) levels by 50% and attenuated ER stress-induced BiP by increasing BiP turnover 6-fold. Overexpression of BiP with PrP mutants rescued retrotranslocation of PrP, TTR(D18G) and A1AT(NHK). PrP mutants-induced cell death was also rescued by co-expression of BiP. These results show that PrP mutants highjack the Hrd1-dependent ERAD pathway, an action that would result in misfolded protein accumulation especially in terminally differentiated neurons. This could explain the age-dependent neuronal degeneration in familial prion diseases.
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Affiliation(s)
- Sarah L Peters
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Cote Ste-Catherine, Montreal, QC H3T 1E2, Canada and Department of Neurology and Neurosurgery, McGill University, 3775 University Street, Montreal, QC H2A 2B4, Canada
| | - Marc-André Déry
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Cote Ste-Catherine, Montreal, QC H3T 1E2, Canada and Department of Neurology and Neurosurgery, McGill University, 3775 University Street, Montreal, QC H2A 2B4, Canada
| | - Andrea C LeBlanc
- Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Ch. Cote Ste-Catherine, Montreal, QC H3T 1E2, Canada and Department of Neurology and Neurosurgery, McGill University, 3775 University Street, Montreal, QC H2A 2B4, Canada
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20
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Ninagawa S, Okada T, Sumitomo Y, Horimoto S, Sugimoto T, Ishikawa T, Takeda S, Yamamoto T, Suzuki T, Kamiya Y, Kato K, Mori K. Forcible destruction of severely misfolded mammalian glycoproteins by the non-glycoprotein ERAD pathway. J Cell Biol 2015; 211:775-84. [PMID: 26572623 PMCID: PMC4657166 DOI: 10.1083/jcb.201504109] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 10/07/2015] [Indexed: 11/27/2022] Open
Abstract
Higher eukaryotes, but not yeast, are able to extract severely misfolded glycoproteins from the endoplasmic reticulum–associated degradation (ERAD) pathway for glycoproteins and target them to the ERAD pathway for non-glycoproteins to maintain the homeostasis of the ER. Glycoproteins and non-glycoproteins possessing unfolded/misfolded parts in their luminal regions are cleared from the endoplasmic reticulum (ER) by ER-associated degradation (ERAD)-L with distinct mechanisms. Two-step mannose trimming from Man9GlcNAc2 is crucial in the ERAD-L of glycoproteins. We recently showed that this process is initiated by EDEM2 and completed by EDEM3/EDEM1. Here, we constructed chicken and human cells simultaneously deficient in EDEM1/2/3 and analyzed the fates of four ERAD-L substrates containing three potential N-glycosylation sites. We found that native but unstable or somewhat unfolded glycoproteins, such as ATF6α, ATF6α(C), CD3-δ–ΔTM, and EMC1, were stabilized in EDEM1/2/3 triple knockout cells. In marked contrast, degradation of severely misfolded glycoproteins, such as null Hong Kong (NHK) and deletion or insertion mutants of ATF6α(C), CD3-δ–ΔTM, and EMC1, was delayed only at early chase periods, but they were eventually degraded as in wild-type cells. Thus, higher eukaryotes are able to extract severely misfolded glycoproteins from glycoprotein ERAD and target them to the non-glycoprotein ERAD pathway to maintain the homeostasis of the ER.
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Affiliation(s)
- Satoshi Ninagawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan Institute for Molecular Science, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787, Japan Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787, Japan
| | - Tetsuya Okada
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yoshiki Sumitomo
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Satoshi Horimoto
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takehiro Sugimoto
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Tokiro Ishikawa
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Takashi Yamamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Tadashi Suzuki
- Glycometabolome Team, Systems Glycobiology Research Group, RIKEN Global Research Cluster, Wako, Saitama 351-0198, Japan
| | - Yukiko Kamiya
- Institute for Molecular Science, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787, Japan Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787, Japan
| | - Koichi Kato
- Institute for Molecular Science, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787, Japan Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Myodaiji, Okazaki 444-8787, Japan Graduate School of Pharmaceutical Sciences, Nagoya City University, Mizuho-ku, Nagoya, 467-8603, Japan
| | - Kazutoshi Mori
- Department of Biophysics, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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21
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Hosokawa N, Wada I. Association of the SEL1L protein transmembrane domain with HRD1 ubiquitin ligase regulates ERAD-L. FEBS J 2015; 283:157-72. [PMID: 26471130 DOI: 10.1111/febs.13564] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 09/25/2015] [Accepted: 10/13/2015] [Indexed: 11/28/2022]
Abstract
Misfolded proteins in the endoplasmic reticulum (ER) are transported to the cytoplasm for degradation by the ubiquitin-proteasome system, a process otherwise known as ER-associated degradation (ERAD). Mammalian HRD1, an integral membrane ubiquitin ligase that ubiquitinates ERAD substrates, forms a large assembly in the ER membrane including SEL1L, a single-pass membrane protein, and additional components. The mechanism by which these molecules export misfolded proteins through the ER membrane remains unclear. Unlike Hrd3p, the homologue in Saccharomyces cerevisiae, human SEL1L is an unstable protein, which is restored by the association with HRD1. Here we report that the inherently unstable nature of the human SEL1L protein lies in its transmembrane domain, and that association of HRD1 with the SEL1L transmembrane domain restored its stability. On the other hand, we found that the SEL1L luminal domain escaped degradation, and inhibited the degradation of misfolded α1 -antitrypsin variant null Hong Kong by retaining the misfolded cargo in the ER. Overexpression of HRD1 inhibited the degradation of unfolded secretory cargo, which was restored by the interaction of HRD1 with the SEL1L transmembrane domain. Hence, we propose that SEL1L critically regulates HRD1-mediated disposal of misfolded cargo through its short membrane spanning stretch.
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Affiliation(s)
- Nobuko Hosokawa
- Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences, Kyoto University, Japan
| | - Ikuo Wada
- Department of Cell Sciences, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Japan
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22
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D'Alessio C, Dahms NM. Glucosidase II and MRH-domain containing proteins in the secretory pathway. Curr Protein Pept Sci 2015; 16:31-48. [PMID: 25692846 DOI: 10.2174/1389203716666150213160438] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 08/25/2014] [Accepted: 11/13/2014] [Indexed: 12/24/2022]
Abstract
N-glycosylation in the endoplasmic reticulum (ER) consists of the transfer of a preassembled glycan conserved among species (Glc3Man9GlcNAc2) from a lipid donor to a consensus sequence within a nascent protein that is entering the ER. The protein-linked glycans are then processed by glycosidases and glycosyltransferases in the ER producing specific structures that serve as signalling molecules for the fate of the folding glycoprotein: to stay in the ER during the folding process, to be retrotranslocated to the cytosol for proteasomal degradation if irreversibly misfolded, or to pursue transit through the secretory pathway as a mature glycoprotein. In the ER, each glycan signalling structure is recognized by a specific lectin. A domain similar to that of the mannose 6-phosphate receptors (MPRs) has been identified in several proteins of the secretory pathway. These include the beta subunit of glucosidase II (GII), a key enzyme in the early processing of the transferred glycan that removes middle and innermost glucoses and is involved in quality control of glycoprotein folding in the ER (QC), the lectins OS-9 and XTP3-B, proteins involved in the delivery of ER misfolded proteins to degradation (ERAD), the gamma subunit of the Golgi GlcNAc-1-phosphotransferase, an enzyme involved in generating the mannose 6-phosphate (M6P) signal for sorting acidic hydrolases to lysosomes, and finally the MPRs that deliver those hydrolytic enzymes to the lysosome. Each of the MRH-containing proteins recognizes a different signalling N-glycan structure. Three-dimensional structures of some of the MRH domains have been solved, providing the basis to understand recognition mechanisms.
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Affiliation(s)
| | - Nancy M Dahms
- Laboratory of Glycobiology, Fundación Instituto Leloir - Instituto de Investigaciones Bioquimicas de Buenos Aires-CONICET, Av. Patricias Argentinas 435, C1405BWE, Buenos Aires, Argentina, and School of Sciences, University of Buenos Aires, C1428EHA, Buenos Aires, Argentina.
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23
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Xu C, Ng DTW. Glycosylation-directed quality control of protein folding. Nat Rev Mol Cell Biol 2015; 16:742-52. [PMID: 26465718 DOI: 10.1038/nrm4073] [Citation(s) in RCA: 255] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Membrane-bound and soluble proteins of the secretory pathway are commonly glycosylated in the endoplasmic reticulum. These adducts have many biological functions, including, notably, their contribution to the maturation of glycoproteins. N-linked glycans are of oligomeric structure, forming configurations that provide blueprints to precisely instruct the folding of protein substrates and the quality control systems that scrutinize it. O-linked mannoses are simpler in structure and were recently found to have distinct functions in protein quality control that do not require the complex structure of N-linked glycans. Together, recent studies reveal the breadth and sophistication of the roles of these glycan-directed modifications in protein biogenesis.
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Affiliation(s)
- Chengchao Xu
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604.,Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543
| | - Davis T W Ng
- Temasek Life Sciences Laboratory, National University of Singapore, 1 Research Link, Singapore 117604.,Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543.,Duke University-National University of Singapore Graduate Medical School, 8 College Road, Singapore 169857
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24
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Caramelo JJ, Parodi AJ. A sweet code for glycoprotein folding. FEBS Lett 2015; 589:3379-87. [PMID: 26226420 DOI: 10.1016/j.febslet.2015.07.021] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 07/15/2015] [Accepted: 07/15/2015] [Indexed: 12/11/2022]
Abstract
Glycoprotein synthesis is initiated in the endoplasmic reticulum (ER) lumen upon transfer of a glycan (Glc3Man9GlcNAc2) from a lipid derivative to Asn residues (N-glycosylation). N-Glycan-dependent quality control of glycoprotein folding in the ER prevents exit to Golgi of folding intermediates, irreparably misfolded glycoproteins and incompletely assembled multimeric complexes. It also enhances folding efficiency by preventing aggregation and facilitating formation of proper disulfide bonds. The control mechanism essentially involves four components, resident lectin-chaperones (calnexin and calreticulin) that recognize monoglucosylated polymannose protein-linked glycans, lectin-associated oxidoreductase acting on monoglucosylated glycoproteins (ERp57), a glucosyltransferase that creates monoglucosylated epitopes in protein-linked glycans (UGGT) and a glucosidase (GII) that removes the glucose units added by UGGT. This last enzyme is the only mechanism component sensing glycoprotein conformations as it creates monoglucosylated glycans exclusively in not properly folded glycoproteins or in not completely assembled multimeric glycoprotein complexes. Glycoproteins that fail to properly fold are eventually driven to proteasomal degradation in the cytosol following the ER-associated degradation pathway, in which the extent of N-glycan demannosylation by ER mannosidases play a relevant role in the identification of irreparably misfolded glycoproteins.
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Affiliation(s)
- Julio J Caramelo
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Avda. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.
| | - Armando J Parodi
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA-CONICET), Avda. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.
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25
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Emerging structural insights into glycoprotein quality control coupled with N-glycan processing in the endoplasmic reticulum. Molecules 2015; 20:2475-91. [PMID: 25647580 PMCID: PMC6272264 DOI: 10.3390/molecules20022475] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/04/2015] [Accepted: 01/22/2015] [Indexed: 01/22/2023] Open
Abstract
In the endoplasmic reticulum (ER), the sugar chain is initially introduced onto newly synthesized proteins as a triantennary tetradecasaccharide (Glc3Man9GlcNAc2). The attached oligosaccharide chain is subjected to stepwise trimming by the actions of specific glucosidases and mannosidases. In these processes, the transiently expressed N-glycans, as processing intermediates, function as signals for the determination of glycoprotein fates, i.e., folding, transport, or degradation through interactions of a series of intracellular lectins. The monoglucosylated glycoforms are hallmarks of incompletely folded states of glycoproteins in this system, whereas the outer mannose trimming leads to ER-associated glycoprotein degradation. This review outlines the recently emerging evidence regarding the molecular and structural basis of this glycoprotein quality control system, which is regulated through dynamic interplay among intracellular lectins, glycosidases, and glycosyltransferase. Structural snapshots of carbohydrate-lectin interactions have been provided at the atomic level using X-ray crystallographic analyses. Conformational ensembles of uncomplexed triantennary high-mannose-type oligosaccharides have been characterized in a quantitative manner using molecular dynamics simulation in conjunction with nuclear magnetic resonance spectroscopy. These complementary views provide new insights into glycoprotein recognition in quality control coupled with N-glycan processing.
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26
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Ferris SP, Kodali VK, Kaufman RJ. Glycoprotein folding and quality-control mechanisms in protein-folding diseases. Dis Model Mech 2015; 7:331-41. [PMID: 24609034 PMCID: PMC3944493 DOI: 10.1242/dmm.014589] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Biosynthesis of proteins – from translation to folding to export – encompasses a complex set of events that are exquisitely regulated and scrutinized to ensure the functional quality of the end products. Cells have evolved to capitalize on multiple post-translational modifications in addition to primary structure to indicate the folding status of nascent polypeptides to the chaperones and other proteins that assist in their folding and export. These modifications can also, in the case of irreversibly misfolded candidates, signal the need for dislocation and degradation. The current Review focuses on the glycoprotein quality-control (GQC) system that utilizes protein N-glycosylation and N-glycan trimming to direct nascent glycopolypeptides through the folding, export and dislocation pathways in the endoplasmic reticulum (ER). A diverse set of pathological conditions rooted in defective as well as over-vigilant ER quality-control systems have been identified, underlining its importance in human health and disease. We describe the GQC pathways and highlight disease and animal models that have been instrumental in clarifying our current understanding of these processes.
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Affiliation(s)
- Sean P Ferris
- Department of Biological Chemistry and Medical Scientist Training Program, University of Michigan, Ann Arbor, MI 48109, USA
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27
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Hirabayashi J, Tateno H, Shikanai T, Aoki-Kinoshita KF, Narimatsu H. The Lectin Frontier Database (LfDB), and data generation based on frontal affinity chromatography. Molecules 2015; 20:951-73. [PMID: 25580689 PMCID: PMC6272529 DOI: 10.3390/molecules20010951] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 12/31/2014] [Indexed: 12/03/2022] Open
Abstract
Lectins are a large group of carbohydrate-binding proteins, having been shown to comprise at least 48 protein scaffolds or protein family entries. They occur ubiquitously in living organisms—from humans to microorganisms, including viruses—and while their functions are yet to be fully elucidated, their main underlying actions are thought to mediate cell-cell and cell-glycoconjugate interactions, which play important roles in an extensive range of biological processes. The basic feature of each lectin’s function resides in its specific sugar-binding properties. In this regard, it is beneficial for researchers to have access to fundamental information about the detailed oligosaccharide specificities of diverse lectins. In this review, the authors describe a publicly available lectin database named “Lectin frontier DataBase (LfDB)”, which undertakes the continuous publication and updating of comprehensive data for lectin-standard oligosaccharide interactions in terms of dissociation constants (Kd’s). For Kd determination, an advanced system of frontal affinity chromatography (FAC) is used, with which quantitative datasets of interactions between immobilized lectins and >100 fluorescently labeled standard glycans have been generated. The FAC system is unique in its clear principle, simple procedure and high sensitivity, with an increasing number (>67) of associated publications that attest to its reliability. Thus, LfDB, is expected to play an essential role in lectin research, not only in basic but also in applied fields of glycoscience.
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Affiliation(s)
- Jun Hirabayashi
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central-2, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan.
| | - Hiroaki Tateno
- Research Center for Stem Cell Engineering, National Institute of Advanced Industrial Science and Technology, Central-2, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan.
| | - Toshihide Shikanai
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology, Central-2, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan.
| | - Kiyoko F Aoki-Kinoshita
- Department of Bioinformatics, Faculty of Engineering, Soka University, 1-236 Tangi-machi, Hachioji, Tokyo 192-8577, Japan.
| | - Hisashi Narimatsu
- Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology, Central-2, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568, Japan.
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28
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Hebert DN, Lamriben L, Powers ET, Kelly JW. The intrinsic and extrinsic effects of N-linked glycans on glycoproteostasis. Nat Chem Biol 2014; 10:902-10. [PMID: 25325701 PMCID: PMC4232232 DOI: 10.1038/nchembio.1651] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 08/28/2014] [Indexed: 01/29/2023]
Abstract
Proteins that traffic through the eukaryotic secretory pathway are commonly modified with N-linked carbohydrates. These bulky amphipathic modifications at asparagines intrinsically enhance solubility and folding energetics through carbohydrate-protein interactions. N-linked glycans can also extrinsically enhance glycoprotein folding by using the glycoprotein homeostasis or 'glycoproteostasis' network, which comprises numerous glycan binding and/or modification enzymes or proteins that synthesize, transfer, sculpt and use N-linked glycans to direct folding and trafficking versus degradation and trafficking of nascent N-glycoproteins through the cellular secretory pathway. If protein maturation is perturbed by misfolding, aggregation or both, stress pathways are often activated that result in transcriptional remodeling of the secretory pathway in an attempt to alleviate the insult (or insults). The inability to achieve glycoproteostasis is linked to several pathologies, including amyloidoses, cystic fibrosis and lysosomal storage diseases. Recent progress on genetic and pharmacologic adaptation of the glycoproteostasis network provides hope that drugs of this mechanistic class can be developed for these maladies in the near future.
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Affiliation(s)
- Daniel N. Hebert
- Department of Biochemistry and Molecular Biology, Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA 01003
| | - Lydia Lamriben
- Department of Biochemistry and Molecular Biology, Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA 01003
| | - Evan T. Powers
- Departments of Chemistry and Molecular and Experimental Medicine and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Jeffery W. Kelly
- Departments of Chemistry and Molecular and Experimental Medicine and the Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037
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Lackman JJ, Markkanen PMH, Hogue M, Bouvier M, Petäjä-Repo UE. N-Glycan-dependent and -independent quality control of human δ opioid receptor N-terminal variants. J Biol Chem 2014; 289:17830-42. [PMID: 24798333 DOI: 10.1074/jbc.m114.566273] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Quality control (QC) in the endoplasmic reticulum (ER) scrutinizes newly synthesized proteins and directs them either to ER export or ER-associated degradation (ERAD). Here, we demonstrate that the human δ-opioid receptor (hδOR) is subjected to ERQC in both N-glycan-dependent and -independent manners. This was shown by investigating the biosynthesis and trafficking of wild-type and non-N-glycosylated F27C variants in metabolic pulse-chase assays coupled with flow cytometry and cell surface biotinylation. Both QC mechanisms distinguished the minute one-amino acid difference between the variants, targeting a large fraction of hδOR-Cys(27) to ERAD. However, the N-glycan-independent QC was unable to compensate the N-glycan-dependent pathway, and some incompletely folded non-N-glycosylated hδOR-Cys(27) reached the cell surface in conformation incompatible with ligand binding. The turnover of receptors associating with the molecular chaperone calnexin (CNX) was significantly slower for the hδOR-Cys(27), pointing to an important role of CNX in the hδOR N-glycan-dependent QC. This was further supported by the fact that inhibiting the co-translational interaction of hδOR-Cys(27) precursors with CNX led to their ERAD. Opioid receptor pharmacological chaperones released the CNX-bound receptors to ER export and, furthermore, were able to rescue the Cys(27) variant from polyubiquitination and retrotranslocation to the cytosol whether carrying N-glycans or not. Taken together, the hδOR appears to rely primarily on the CNX-mediated N-glycan-dependent QC that has the capacity to assist in folding, whereas the N-glycan-independent mechanism constitutes an alternative, although less accurate, system for directing misfolded/incompletely folded receptors to ERAD, possibly in altered cellular conditions.
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Affiliation(s)
- Jarkko J Lackman
- From the Department of Anatomy and Cell Biology and the Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland and
| | - Piia M H Markkanen
- From the Department of Anatomy and Cell Biology and the Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland and
| | - Mireille Hogue
- the Department of Biochemistry, Institute for Research in Immunology and Cancer and Groupe de Recherche Universitaire sur le Médicament, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Michel Bouvier
- the Department of Biochemistry, Institute for Research in Immunology and Cancer and Groupe de Recherche Universitaire sur le Médicament, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Ulla E Petäjä-Repo
- From the Department of Anatomy and Cell Biology and the Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland and
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YAMAMOTO K. Intracellular lectins are involved in quality control of glycoproteins. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2014; 90:67-82. [PMID: 24522156 PMCID: PMC3948941 DOI: 10.2183/pjab.90.67] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Glycoprotein quality control is categorized into three kinds of reactions; the folding of nascent glycoproteins, ER-associated degradation of misfolded or unassembled glycoproteins, and transport and sorting of correctly folded glycoproteins. In all three processes, N-glycans on the glycoproteins are used as tags that are recognized by intracellular lectins. We analyzed the functions of these intracellular lectins and their sugar-binding specificities. The results clearly showed that the A, B, and C-arms of high mannose-type glycans participate in the folding, transport and sorting, and degradation, respectively, of newly synthesized peptides. After correctly folded glycoproteins are transported to the Golgi apparatus, N-glycans are trimmed into Man3GlcNAc2 and then rebuilt into various complex-type glycans in the Golgi, resulting in the addition of diverse sugar structures that allow glycoproteins to play various roles outside of the cells.
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Affiliation(s)
- Kazuo YAMAMOTO
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba, Japan
- Corresponding should be addressed: K. Yamamoto, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan (e-mail: )
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Olson LJ, Orsi R, Alculumbre SG, Peterson FC, Stigliano ID, Parodi AJ, D'Alessio C, Dahms NM. Structure of the lectin mannose 6-phosphate receptor homology (MRH) domain of glucosidase II, an enzyme that regulates glycoprotein folding quality control in the endoplasmic reticulum. J Biol Chem 2013; 288:16460-16475. [PMID: 23609449 DOI: 10.1074/jbc.m113.450239] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Here we report for the first time the three-dimensional structure of a mannose 6-phosphate receptor homology (MRH) domain present in a protein with enzymatic activity, glucosidase II (GII). GII is involved in glycoprotein folding in the endoplasmic reticulum. GII removes the two innermost glucose residues from the Glc3Man9GlcNAc2 transferred to nascent proteins and the glucose added by UDP-Glc:glycoprotein glucosyltransferase. GII is composed of a catalytic GIIα subunit and a regulatory GIIβ subunit. GIIβ participates in the endoplasmic reticulum localization of GIIα and mediates in vivo enhancement of N-glycan trimming by GII through its C-terminal MRH domain. We determined the structure of a functional GIIβ MRH domain by NMR spectroscopy. It adopts a β-barrel fold similar to that of other MRH domains, but its binding pocket is the most shallow known to date as it accommodates a single mannose residue. In addition, we identified a conserved residue outside the binding pocket (Trp-409) present in GIIβ but not in other MRHs that influences GII glucose trimming activity.
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Affiliation(s)
- Linda J Olson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Ramiro Orsi
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, C1405BWE Buenos Aires, Argentina
| | - Solana G Alculumbre
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, C1405BWE Buenos Aires, Argentina
| | - Francis C Peterson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
| | - Ivan D Stigliano
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, C1405BWE Buenos Aires, Argentina
| | - Armando J Parodi
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, C1405BWE Buenos Aires, Argentina
| | - Cecilia D'Alessio
- Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, C1405BWE Buenos Aires, Argentina; School of Sciences, University of Buenos Aires, C1428EHA Buenos Aires, Argentina.
| | - Nancy M Dahms
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226.
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