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Radhakrishnan A, Chellapandian H, Ramasamy P, Jeyachandran S. Back2Basics: animal lectins: an insight into a highly versatile recognition protein. JOURNAL OF PROTEINS AND PROTEOMICS 2023; 14:43-59. [PMID: 36597476 PMCID: PMC9799708 DOI: 10.1007/s42485-022-00102-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/15/2022] [Accepted: 12/08/2022] [Indexed: 12/31/2022]
Abstract
The rapid advancement of molecular research has contributed to the discovery of 'Lectin', a carbohydrate-binding protein which specifically interacts with receptors on surface glycan moieties that regulate various critical cellular activities. The first animal lectin reported was 'the asialoglycoprotein receptor' in mammalian cells which helped analyze how animal lectins differ in glycoconjugate binding. Animal lectins are classified into several families, depending on their diverse cellular localization, and the binding specificities of their Carbohydrate-Recognition Domain (CRD) modules. Earlier characterization of animal lectins classified them into two structural families, the C-type (Ca2+-dependent binding) and S-type galectins (sulfhydryl-dependent binding) lectins. The C-type lectin includes the most significant animal lectins, such as endocytic receptors, mannose receptors, selectins, and collectins. The recent developments in research based on the complexity of the carbohydrate ligands, the metabolic processes they perform, their expression levels, and their reliance on divalent cations have identified more than 100 animal lectins and classified them into around 13 different families, such as Calnexin, F-lectin, Intelectin, Chitinase-like lectin, F-box lectin, etc. Understanding their structure and expression patterns have aided in defining their significant functions including cell adhesion, antimicrobial activity, innate immunity, disease diagnostic biomarkers, and drug delivery through specific carbohydrate-protein interactions. Such extensive potential roles of animal lectins made it equally important to plant lectins among researchers. Hence, the review focuses on providing an overview of animal lectins, their taxonomy, structural characteristics, and functions in diverse aspects interconnected to their specific carbohydrate and glycoconjugate binding. Graphical abstract
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Affiliation(s)
- Akshaya Radhakrishnan
- PG & Research Department of Biotechnology & Microbiology, National College, Tiruchirappalli, Tamil Nadu 620001 India
| | - Hethesh Chellapandian
- PG & Research Department of Biotechnology & Microbiology, National College, Tiruchirappalli, Tamil Nadu 620001 India
| | - Pasiyappazham Ramasamy
- Department of Physiology, Saveetha Dental College & Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, Tamil Nadu 600077 India
| | - Sivakamavalli Jeyachandran
- PG & Research Department of Biotechnology & Microbiology, National College, Tiruchirappalli, Tamil Nadu 620001 India
- Centre for Biotechnology & Biosignal Transduction, Department of Orthodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, Tamil Nadu 600077 India
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2
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Gorelik A, Illes K, Bui KH, Nagar B. Structures of the mannose-6-phosphate pathway enzyme, GlcNAc-1-phosphotransferase. Proc Natl Acad Sci U S A 2022; 119:e2203518119. [PMID: 35939698 PMCID: PMC9388126 DOI: 10.1073/pnas.2203518119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 05/06/2022] [Indexed: 11/18/2022] Open
Abstract
The mannose-6-phosphate (M6P) pathway is responsible for the transport of hydrolytic enzymes to lysosomes. N-acetylglucosamine-1-phosphotransferase (GNPT) catalyzes the first step of tagging these hydrolases with M6P, which when recognized by receptors in the Golgi diverts them to lysosomes. Genetic defects in the GNPT subunits, GNPTAB and GNPTG, cause the lysosomal storage diseases mucolipidosis types II and III. To better understand its function, we determined partial three-dimensional structures of the GNPT complex. The catalytic domain contains a deep cavity for binding of uridine diphosphate-N-acetylglucosamine, and the surrounding residues point to a one-step transfer mechanism. An isolated structure of the gamma subunit of GNPT reveals that it can bind to mannose-containing glycans in different configurations, suggesting that it may play a role in directing glycans into the active site. These findings may facilitate the development of therapies for lysosomal storage diseases.
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Affiliation(s)
- Alexei Gorelik
- Department of Biochemistry, McGill University, Montreal, QC H3G 0B1, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 0C7, Canada
| | - Katalin Illes
- Department of Biochemistry, McGill University, Montreal, QC H3G 0B1, Canada
| | - Khanh Huy Bui
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 0C7, Canada
| | - Bhushan Nagar
- Department of Biochemistry, McGill University, Montreal, QC H3G 0B1, Canada
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3
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De Masi R, Orlando S. GANAB and N-Glycans Substrates Are Relevant in Human Physiology, Polycystic Pathology and Multiple Sclerosis: A Review. Int J Mol Sci 2022; 23:7373. [PMID: 35806376 PMCID: PMC9266668 DOI: 10.3390/ijms23137373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/22/2022] [Accepted: 06/28/2022] [Indexed: 11/29/2022] Open
Abstract
Glycans are one of the four fundamental macromolecular components of living matter, and they are highly regulated in the cell. Their functions are metabolic, structural and modulatory. In particular, ER resident N-glycans participate with the Glc3Man9GlcNAc2 highly conserved sequence, in protein folding process, where the physiological balance between glycosylation/deglycosylation on the innermost glucose residue takes place, according GANAB/UGGT concentration ratio. However, under abnormal conditions, the cell adapts to the glucose availability by adopting an aerobic or anaerobic regimen of glycolysis, or to external stimuli through internal or external recognition patterns, so it responds to pathogenic noxa with unfolded protein response (UPR). UPR can affect Multiple Sclerosis (MS) and several neurological and metabolic diseases via the BiP stress sensor, resulting in ATF6, PERK and IRE1 activation. Furthermore, the abnormal GANAB expression has been observed in MS, systemic lupus erythematous, male germinal epithelium and predisposed highly replicating cells of the kidney tubules and bile ducts. The latter is the case of Polycystic Liver Disease (PCLD) and Polycystic Kidney Disease (PCKD), where genetically induced GANAB loss affects polycystin-1 (PC1) and polycystin-2 (PC2), resulting in altered protein quality control and cyst formation phenomenon. Our topics resume the role of glycans in cell physiology, highlighting the N-glycans one, as a substrate of GANAB, which is an emerging key molecule in MS and other human pathologies.
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Affiliation(s)
- Roberto De Masi
- Complex Operative Unit of Neurology, “F. Ferrari” Hospital, Casarano, 73042 Lecce, Italy;
- Laboratory of Neuroproteomics, Multiple Sclerosis Centre, “F. Ferrari” Hospital, Casarano, 73042 Lecce, Italy
| | - Stefania Orlando
- Laboratory of Neuroproteomics, Multiple Sclerosis Centre, “F. Ferrari” Hospital, Casarano, 73042 Lecce, Italy
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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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Olson LJ, Misra SK, Ishihara M, Battaile KP, Grant OC, Sood A, Woods RJ, Kim JJP, Tiemeyer M, Ren G, Sharp JS, Dahms NM. Allosteric regulation of lysosomal enzyme recognition by the cation-independent mannose 6-phosphate receptor. Commun Biol 2020; 3:498. [PMID: 32908216 PMCID: PMC7481795 DOI: 10.1038/s42003-020-01211-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 08/11/2020] [Indexed: 01/09/2023] Open
Abstract
The cation-independent mannose 6-phosphate receptor (CI-MPR, IGF2 receptor or CD222), is a multifunctional glycoprotein required for normal development. Through the receptor's ability to bind unrelated extracellular and intracellular ligands, it participates in numerous functions including protein trafficking, lysosomal biogenesis, and regulation of cell growth. Clinically, endogenous CI-MPR delivers infused recombinant enzymes to lysosomes in the treatment of lysosomal storage diseases. Although four of the 15 domains comprising CI-MPR's extracellular region bind phosphorylated glycans on lysosomal enzymes, knowledge of how CI-MPR interacts with ~60 different lysosomal enzymes is limited. Here, we show by electron microscopy and hydroxyl radical protein footprinting that the N-terminal region of CI-MPR undergoes dynamic conformational changes as a consequence of ligand binding and different pH conditions. These data, coupled with X-ray crystallography, surface plasmon resonance and molecular modeling, allow us to propose a model explaining how high-affinity carbohydrate binding is achieved through allosteric domain cooperativity.
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Affiliation(s)
- Linda J Olson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
| | - Sandeep K Misra
- Department of BioMolecular Sciences, University of Mississippi, Oxford, MS, 38677, USA
| | - Mayumi Ishihara
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Kevin P Battaile
- IMCA-CAT, Hauptman-Woodward Medical Research Institute, Argonne, IL, USA
- New York Structural Biology Center, New York City, NY, 10027, USA
| | - Oliver C Grant
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Amika Sood
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Robert J Woods
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Jung-Ja P Kim
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Michael Tiemeyer
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Joshua S Sharp
- Department of BioMolecular Sciences, University of Mississippi, Oxford, MS, 38677, USA
| | - Nancy M Dahms
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
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Rao C, Guan B, Luo D, Deng Q, Peng Q, Lin Z, Huang M, Qi M, Zhong B, Lu X. Identification of pathogenic variants of ERLEC1 in individuals with Class III malocclusion by exome sequencing. Hum Mutat 2020; 41:1435-1446. [PMID: 32442352 DOI: 10.1002/humu.24054] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 05/05/2020] [Accepted: 05/18/2020] [Indexed: 11/11/2022]
Abstract
Class III malocclusion is a common dentofacial deformity. The underlying genetic alteration is largely unclear. In this study, we sought to determine the genetic etiology for Class III malocclusion. A four-generation pedigree of Class III malocclusion was recruited for exome sequencing analyses. The likely causative gene was verified via Sanger sequencing in an additional 90 unrelated sporadic Class III malocclusion patients. We identified a rare heterozygous variant in endoplasmic reticulum lectin 1 (ERLEC1; NM_015701.4(ERLEC1_v001):c.1237C>T, p.(His413Tyr), designated as ERLEC1-m in this article) that cosegregated with the deformity in pedigree members and three additional rare missense heterozygous variants (c.419C>G, p.(Thr140Ser), c.419C>T, p.(Thr140Ile), and c.1448A>G, p.(Asn483Ser)) in 3 of 90 unrelated sporadic subjects. Our results showed that ERLEC1 is highly expressed in mouse jaw osteoblasts and inhibits osteoblast proliferation. ERLEC1-m significantly enhanced this inhibitory effect of osteoblast proliferation. Our results also showed that the proper level of ERLEC1 expression is crucial for proper osteogenic differentiation. The ERLEC1 variant identified in this study is likely a causal mutation of Class III malocclusion. Our study reveals the genetic basis of Class III malocclusion and provides insights into the novel target for clinical management of Class III malocclusion, in addition to orthodontic treatment and orthodontic surgery.
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Affiliation(s)
- Chunbao Rao
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China.,Dongguan Key Laboratory of Child Genetic and Infectious Diseases, Dongguan, China
| | - Biyang Guan
- Department of Stomatology, Dongguan Children's Hospital, Dongguan, China
| | - Dong Luo
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China.,Dongguan Key Laboratory of Child Genetic and Infectious Diseases, Dongguan, China
| | - Qin Deng
- Department of Obstetrics, Dongguan Children's Hospital, Dongguan, China
| | - Qi Peng
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China.,Dongguan Key Laboratory of Child Genetic and Infectious Diseases, Dongguan, China
| | - Zitian Lin
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China.,Dongguan Key Laboratory of Child Genetic and Infectious Diseases, Dongguan, China
| | - Meihua Huang
- Department of Stomatology, Dongguan Children's Hospital, Dongguan, China
| | - Ming Qi
- Department of Human Genetics, School of Medicine, Zhejiang University, Hangzhou, China.,Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York
| | - Baimao Zhong
- Department of Stomatology, Dongguan Children's Hospital, Dongguan, China
| | - Xiaomei Lu
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, China.,Dongguan Key Laboratory of Child Genetic and Infectious Diseases, Dongguan, China
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Lin B, Qing X, Liao J, Zhuo K. Role of Protein Glycosylation in Host-Pathogen Interaction. Cells 2020; 9:E1022. [PMID: 32326128 PMCID: PMC7226260 DOI: 10.3390/cells9041022] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/11/2020] [Accepted: 04/16/2020] [Indexed: 02/07/2023] Open
Abstract
Host-pathogen interactions are fundamental to our understanding of infectious diseases. Protein glycosylation is one kind of common post-translational modification, forming glycoproteins and modulating numerous important biological processes. It also occurs in host-pathogen interaction, affecting host resistance or pathogen virulence often because glycans regulate protein conformation, activity, and stability, etc. This review summarizes various roles of different glycoproteins during the interaction, which include: host glycoproteins prevent pathogens as barriers; pathogen glycoproteins promote pathogens to attack host proteins as weapons; pathogens glycosylate proteins of the host to enhance virulence; and hosts sense pathogen glycoproteins to induce resistance. In addition, this review also intends to summarize the roles of lectin (a class of protein entangled with glycoprotein) in host-pathogen interactions, including bacterial adhesins, viral lectins or host lectins. Although these studies show the importance of protein glycosylation in host-pathogen interaction, much remains to be discovered about the interaction mechanism.
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Affiliation(s)
- Borong Lin
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, China; (B.L.); (J.L.)
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China
| | - Xue Qing
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China;
| | - Jinling Liao
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, China; (B.L.); (J.L.)
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China
- Guangdong Eco-Engineering Polytechnic, Guangzhou 510520, China
| | - Kan Zhuo
- Laboratory of Plant Nematology, South China Agricultural University, Guangzhou 510642, China; (B.L.); (J.L.)
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China
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Zhang J, Wu J, Liu L, Li J. The Crucial Role of Demannosylating Asparagine-Linked Glycans in ERADicating Misfolded Glycoproteins in the Endoplasmic Reticulum. FRONTIERS IN PLANT SCIENCE 2020; 11:625033. [PMID: 33510762 PMCID: PMC7835635 DOI: 10.3389/fpls.2020.625033] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/08/2020] [Indexed: 05/04/2023]
Abstract
Most membrane and secreted proteins are glycosylated on certain asparagine (N) residues in the endoplasmic reticulum (ER), which is crucial for their correct folding and function. Protein folding is a fundamentally inefficient and error-prone process that can be easily interfered by genetic mutations, stochastic cellular events, and environmental stresses. Because misfolded proteins not only lead to functional deficiency but also produce gain-of-function cellular toxicity, eukaryotic organisms have evolved highly conserved ER-mediated protein quality control (ERQC) mechanisms to monitor protein folding, retain and repair incompletely folded or misfolded proteins, or remove terminally misfolded proteins via a unique ER-associated degradation (ERAD) mechanism. A crucial event that terminates futile refolding attempts of a misfolded glycoprotein and diverts it into the ERAD pathway is executed by removal of certain terminal α1,2-mannose (Man) residues of their N-glycans. Earlier studies were centered around an ER-type α1,2-mannosidase that specifically cleaves the terminal α1,2Man residue from the B-branch of the three-branched N-linked Man9GlcNAc2 (GlcNAc for N-acetylglucosamine) glycan, but recent investigations revealed that the signal that marks a terminally misfolded glycoprotein for ERAD is an N-glycan with an exposed α1,6Man residue generated by members of a unique folding-sensitive α1,2-mannosidase family known as ER-degradation enhancing α-mannosidase-like proteins (EDEMs). This review provides a historical recount of major discoveries that led to our current understanding on the role of demannosylating N-glycans in sentencing irreparable misfolded glycoproteins into ERAD. It also discusses conserved and distinct features of the demannosylation processes of the ERAD systems of yeast, mammals, and plants.
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Affiliation(s)
- Jianjun Zhang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
| | - Jiarui Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
| | - Linchuan Liu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
| | - Jianming Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Guangdong Key Laboratory for Innovative Development and Utilization of Forest Plant Germplasm, College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
- *Correspondence: Jianming Li, ;
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Zeng Y, He X, Danyukova T, Pohl S, Kermode AR. Toward Engineering the Mannose 6-Phosphate Elaboration Pathway in Plants for Enzyme Replacement Therapy of Lysosomal Storage Disorders. J Clin Med 2019; 8:jcm8122190. [PMID: 31842258 PMCID: PMC6947217 DOI: 10.3390/jcm8122190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/06/2019] [Accepted: 12/07/2019] [Indexed: 12/22/2022] Open
Abstract
Mucopolysaccharidosis (MPS) I is a severe lysosomal storage disease caused by α-L-iduronidase (IDUA) deficiency, which results in accumulation of non-degraded glycosaminoglycans in lysosomes. Costly enzyme replacement therapy (ERT) is the conventional treatment for MPS I. Toward producing a more cost-effective and safe alternative to the commercial mammalian cell-based production systems, we have produced recombinant human IDUA in seeds of an Arabidopsis mutant to generate the enzyme in a biologically active and non-immunogenic form containing predominantly high mannose N-linked glycans. Recombinant enzyme in ERT is generally thought to require a mannose 6-phosphate (M6P) targeting signal for endocytosis into patient cells and for intracellular delivery to the lysosome. Toward effecting in planta phosphorylation, the human M6P elaboration machinery was successfully co-expressed along with the recombinant human IDUA using a single multi-gene construct. Uptake studies using purified putative M6P-IDUA generated in planta on cultured MPS I primary fibroblasts indicated that the endocytosed recombinant lysosomal enzyme led to substantial reduction of glycosaminoglycans. However, the efficiency of the putative M6P-IDUA in reducing glycosaminoglycan storage was comparable with the efficiency of the purified plant mannose-terminated IDUA, suggesting a poor in planta M6P-elaboration by the expressed machinery. Although the in planta M6P-tagging process efficiency would need to be improved, an exciting outcome of our work was that the plant-derived mannose-terminated IDUA yielded results comparable to those obtained with the commercial IDUA (Aldurazyme® (Sanofi, Paris, France)), and a significant amount of the plant-IDUA is trafficked by a M6P receptor-independent pathway. Thus, a plant-based platform for generating lysosomal hydrolases may represent an alternative and cost-effective strategy to the conventional ERT, without the requirement for additional processing to create the M6P motif.
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Affiliation(s)
- Ying Zeng
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A1S6, Canada; (Y.Z.); (X.H.)
| | - Xu He
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A1S6, Canada; (Y.Z.); (X.H.)
| | - Tatyana Danyukova
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (T.D.); (S.P.)
| | - Sandra Pohl
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany; (T.D.); (S.P.)
| | - Allison R. Kermode
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A1S6, Canada; (Y.Z.); (X.H.)
- Correspondence: ; Tel.: +778-782-3982
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10
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Abstract
My initial research experience involved studying how bacteria synthesize nucleotide sugars, the donors for the formation of cell wall polysaccharides. During this time, I became aware that mammalian cells also have a surface coat of sugars and was intrigued as to whether these sugars might be arranged in specific sequences that function as information molecules in biologic processes. Thus began a long journey that has taken me from glycan structural analysis and determination of plant lectin-binding preferences to the biosynthesis of Asn-linked oligosaccharides and the mannose 6-phosphate (Man-6-P) lysosomal enzyme targeting pathway. The Man-6-P system represents an early example of a glycan serving as an information molecule in a fundamental cellular function. The remarkable advances in the field of glycobiology since I entered have uncovered scores of additional examples of oligosaccharide-lectin interactions mediating critical biologic processes. It has been a rewarding experience to participate in the efforts that have established a central role for glycans in biology.
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Affiliation(s)
- Stuart Kornfeld
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
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Satoh T, Kato K. Structural Aspects of ER Glycoprotein Quality-Control System Mediated by Glucose Tagging. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1104:149-169. [PMID: 30484248 DOI: 10.1007/978-981-13-2158-0_8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
N-linked oligosaccharides attached to proteins act as tags for glycoprotein quality control, ensuring their appropriate folding and trafficking in cells. Interactions with a variety of intracellular lectins determine glycoprotein fates. Monoglucosylated glycoforms are the hallmarks of incompletely folded glycoproteins in the protein quality-control system, in which glucosidase II and UDP-glucose/glycoprotein glucosyltransferase are, respectively, responsible for glucose trimming and attachment. In this review, we summarize a recently emerging view of the structural basis of the functional mechanisms of these key enzymes as well as substrate N-linked oligosaccharides exhibiting flexible structures, as revealed by applying a series of biophysical techniques including small-angle X-ray scattering, X-ray crystallography, high-speed atomic force microscopy , electron microscopy , and computational simulation in conjunction with NMR spectroscopy.
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Affiliation(s)
- Tadashi Satoh
- Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi, Japan
| | - Koichi Kato
- Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi, Japan. .,Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, Japan.
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12
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Pierce OM, McNair GR, He X, Kajiura H, Fujiyama K, Kermode AR. N-glycan structures and downstream mannose-phosphorylation of plant recombinant human alpha-L-iduronidase: toward development of enzyme replacement therapy for mucopolysaccharidosis I. PLANT MOLECULAR BIOLOGY 2017; 95:593-606. [PMID: 29119347 DOI: 10.1007/s11103-017-0673-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/20/2017] [Indexed: 06/07/2023]
Abstract
Arabidopsis N-glycan processing mutants provide the basis for tailoring recombinant enzymes for use as replacement therapeutics to treat lysosomal storage diseases, including N-glycan mannose phosphorylation to ensure lysosomal trafficking and efficacy. Functional recombinant human alpha-L-iduronidase (IDUA; EC 3.2.1.76) enzymes were generated in seeds of the Arabidopsis thaliana complex-glycan-deficient (cgl) C5 background, which is deficient in the activity of N-acetylglucosaminyl transferase I, and in seeds of the Arabidopsis gm1 mutant, which lacks Golgi α-mannosidase I (GM1) activity. Both strategies effectively prevented N-glycan maturation and the resultant N-glycan structures on the consensus sites for N-glycosylation of the human enzyme revealed high-mannose N-glycans of predominantly Man5 (cgl-IDUA) or Man6-8 (gm1-IDUA) structures. Both forms of IDUA were equivalent with respect to their kinetic parameters characterized by cleavage of the artificial substrate 4-methylumbelliferyl-iduronide. Because recombinant lysosomal enzymes produced in plants require the addition of mannose-6-phosphate (M6P) in order to be suitable for lysosomal delivery in human cells, we characterized the two IDUA proteins for their amenability to downstream in vitro mannose phosphorylation mediated by a soluble form of the human phosphotransferase (UDP-GlcNAc: lysosomal enzyme N-acetylglucosamine [GlcNAc]-1-phosphotransferase). Gm1-IDUA exhibited a slight advantage over the cgl-IDUA in the in vitro M6P-tagging process, with respect to having a better affinity (i.e. lower K m) for the soluble phosphotransferase. This may be due to the greater number of mannose residues comprising the high-mannose N-glycans of gm1-IDUA. Our elite cgl- line produces IDUA at > 5.7% TSP (total soluble protein); screening of the gm1 lines showed a maximum yield of 1.5% TSP. Overall our findings demonstrate the relative advantages and disadvantages associated with the two platforms to create enzyme replacement therapeutics for lysosomal storage diseases.
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Affiliation(s)
- Owen M Pierce
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr., Burnaby, BC, V5A 1S6, Canada
| | - Grant R McNair
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr., Burnaby, BC, V5A 1S6, Canada
| | - Xu He
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr., Burnaby, BC, V5A 1S6, Canada
| | - Hiroyuki Kajiura
- International Center for Biotechnology, Osaka University, 2-1 Yamada-oka, Osaka, 565, Japan
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-hagashi, Kusatsu, Shiga, 525-8577, Japan
| | - Kazuhito Fujiyama
- International Center for Biotechnology, Osaka University, 2-1 Yamada-oka, Osaka, 565, Japan
| | - Allison R Kermode
- Department of Biological Sciences, Simon Fraser University, 8888 University Dr., Burnaby, BC, V5A 1S6, Canada.
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13
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Ward BK, Rea SL, Magno AL, Pedersen B, Brown SJ, Mullin S, Arulpragasam A, Ingley E, Conigrave AD, Ratajczak T. The endoplasmic reticulum-associated protein, OS-9, behaves as a lectin in targeting the immature calcium-sensing receptor. J Cell Physiol 2017; 233:38-56. [PMID: 28419469 DOI: 10.1002/jcp.25957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 04/13/2017] [Indexed: 11/07/2022]
Abstract
The mechanisms responsible for the processing and quality control of the calcium-sensing receptor (CaSR) in the endoplasmic reticulum (ER) are largely unknown. In a yeast two-hybrid screen of the CaSR C-terminal tail (residues 865-1078), we identified osteosarcoma-9 (OS-9) protein as a binding partner. OS-9 is an ER-resident lectin that targets misfolded glycoproteins to the ER-associated degradation (ERAD) pathway through recognition of specific N-glycans by its mannose-6-phosphate receptor homology (MRH) domain. We show by confocal microscopy that the CaSR and OS-9 co-localize in the ER in COS-1 cells. In immunoprecipitation studies with co-expressed OS-9 and CaSR, OS-9 specifically bound the immature form of wild-type CaSR in the ER. OS-9 also bound the immature forms of a CaSR C-terminal deletion mutant and a C677A mutant that remains trapped in the ER, although binding to neither mutant was favored over wild-type receptor. OS-9 binding to immature CaSR required the MRH domain of OS-9 indicating that OS-9 acts as a lectin most likely to target misfolded CaSR to ERAD. Our results also identify two distinct binding interactions between OS-9 and the CaSR, one involving both C-terminal domains of the two proteins and the other involving both N-terminal domains. This suggests the possibility of more than one functional interaction between OS-9 and the CaSR. When we investigated the functional consequences of altered OS-9 expression, neither knockdown nor overexpression of OS-9 was found to have a significant effect on CaSR cell surface expression or CaSR-mediated ERK1/2 phosphorylation.
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Affiliation(s)
- Bryan K Ward
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Laboratory for Molecular Endocrinology, Harry Perkins Institute of Medical Research and the Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Sarah L Rea
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Laboratory for Molecular Endocrinology, Harry Perkins Institute of Medical Research and the Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Aaron L Magno
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Laboratory for Molecular Endocrinology, Harry Perkins Institute of Medical Research and the Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Bernadette Pedersen
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Laboratory for Molecular Endocrinology, Harry Perkins Institute of Medical Research and the Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Suzanne J Brown
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Shelby Mullin
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Ajanthy Arulpragasam
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Laboratory for Molecular Endocrinology, Harry Perkins Institute of Medical Research and the Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Evan Ingley
- Cell Signalling Group, Harry Perkins Institute of Medical Research and the Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Arthur D Conigrave
- School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney, New South Wales, Australia
| | - Thomas Ratajczak
- Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Laboratory for Molecular Endocrinology, Harry Perkins Institute of Medical Research and the Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
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14
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Frabutt DA, Zheng YH. Arms Race between Enveloped Viruses and the Host ERAD Machinery. Viruses 2016; 8:v8090255. [PMID: 27657106 PMCID: PMC5035969 DOI: 10.3390/v8090255] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/12/2016] [Accepted: 09/12/2016] [Indexed: 12/12/2022] Open
Abstract
Enveloped viruses represent a significant category of pathogens that cause serious diseases in animals. These viruses express envelope glycoproteins that are singularly important during the infection of host cells by mediating fusion between the viral envelope and host cell membranes. Despite low homology at protein levels, three classes of viral fusion proteins have, as of yet, been identified based on structural similarities. Their incorporation into viral particles is dependent upon their proper sub-cellular localization after being expressed and folded properly in the endoplasmic reticulum (ER). However, viral protein expression can cause stress in the ER, and host cells respond to alleviate the ER stress in the form of the unfolded protein response (UPR); the effects of which have been observed to potentiate or inhibit viral infection. One important arm of UPR is to elevate the capacity of the ER-associated protein degradation (ERAD) pathway, which is comprised of host quality control machinery that ensures proper protein folding. In this review, we provide relevant details regarding viral envelope glycoproteins, UPR, ERAD, and their interactions in host cells.
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Affiliation(s)
- Dylan A Frabutt
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
| | - Yong-Hui Zheng
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
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15
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Satoh T, Toshimori T, Noda M, Uchiyama S, Kato K. Interaction mode between catalytic and regulatory subunits in glucosidase II involved in ER glycoprotein quality control. Protein Sci 2016; 25:2095-2101. [PMID: 27576940 DOI: 10.1002/pro.3031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 08/28/2016] [Accepted: 08/29/2016] [Indexed: 12/18/2022]
Abstract
The glycoside hydrolase family 31 (GH31) α-glucosidases play vital roles in catabolic and regulated degradation, including the α-subunit of glucosidase II (GIIα), which catalyzes trimming of the terminal glucose residues of N-glycan in glycoprotein processing coupled with quality control in the endoplasmic reticulum (ER). Among the known GH31 enzymes, only GIIα functions with its binding partner, regulatory β-subunit (GIIβ), which harbors a lectin domain for substrate recognition. Although the structural data have been reported for GIIα and the GIIβ lectin domain, the interaction mode between GIIα and GIIβ remains unknown. Here, we determined the structure of a complex formed between GIIα and the GIIα-binding domain of GIIβ, thereby providing a structural basis underlying the functional extension of this unique GH31 enzyme.
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Affiliation(s)
- Tadashi Satoh
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. .,JST, PRESTO, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan.
| | - Takayasu Toshimori
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan.,Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.,Institute for Molecular Science, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
| | - Masanori Noda
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Susumu Uchiyama
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.,Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Koichi Kato
- Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, 467-8603, Japan. .,Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan. .,Institute for Molecular Science, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
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16
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van Meel E, Lee WS, Liu L, Qian Y, Doray B, Kornfeld S. Multiple Domains of GlcNAc-1-phosphotransferase Mediate Recognition of Lysosomal Enzymes. J Biol Chem 2016; 291:8295-307. [PMID: 26833567 PMCID: PMC4825028 DOI: 10.1074/jbc.m116.714568] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/28/2016] [Indexed: 12/24/2022] Open
Abstract
The Golgi enzyme UDP-GlcNAc:lysosomal enzymeN-acetylglucosamine-1-phosphotransferase (GlcNAc-1-phosphotransferase), an α2β2γ2hexamer, mediates the initial step in the addition of the mannose 6-phosphate targeting signal on newly synthesized lysosomal enzymes. This tag serves to direct the lysosomal enzymes to lysosomes. A key property of GlcNAc-1-phosphotransferase is its unique ability to distinguish the 60 or so lysosomal enzymes from the numerous non-lysosomal glycoproteins with identical Asn-linked glycans. In this study, we demonstrate that the two Notch repeat modules and the DNA methyltransferase-associated protein interaction domain of the α subunit are key components of this recognition process. Importantly, different combinations of these domains are involved in binding to individual lysosomal enzymes. This study also identifies the γ-binding site on the α subunit and demonstrates that in the majority of instances the mannose 6-phosphate receptor homology domain of the γ subunit is required for optimal phosphorylation. These findings serve to explain how GlcNAc-1-phosphotransferase recognizes a large number of proteins that lack a common structural motif.
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Affiliation(s)
- Eline van Meel
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Wang-Sik Lee
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Lin Liu
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Yi Qian
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Balraj Doray
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Stuart Kornfeld
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
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17
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Structural basis for two-step glucose trimming by glucosidase II involved in ER glycoprotein quality control. Sci Rep 2016; 6:20575. [PMID: 26847925 PMCID: PMC4742823 DOI: 10.1038/srep20575] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 01/06/2016] [Indexed: 01/10/2023] Open
Abstract
The endoplasmic reticulum (ER) has a sophisticated protein quality control system for the efficient folding of newly synthesized proteins. In this system, a variety of N-linked oligosaccharides displayed on proteins serve as signals recognized by series of intracellular lectins. Glucosidase II catalyzes two-step hydrolysis at α1,3-linked glucose–glucose and glucose–mannose residues of high-mannose-type glycans to generate a quality control protein tag that is transiently expressed on glycoproteins and recognized by ER chaperones. Here we determined the crystal structures of the catalytic α subunit of glucosidase II (GIIα) complexed with two different glucosyl ligands containing the scissile bonds of first- and second-step reactions. Our structural data revealed that the nonreducing terminal disaccharide moieties of the two kinds of substrates can be accommodated in a gourd-shaped bilocular pocket, thereby providing a structural basis for substrate-binding specificity in the two-step deglucosylation catalyzed by this enzyme.
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18
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Lamriben L, Graham JB, Adams BM, Hebert DN. N-Glycan-based ER Molecular Chaperone and Protein Quality Control System: The Calnexin Binding Cycle. Traffic 2016; 17:308-26. [PMID: 26676362 DOI: 10.1111/tra.12358] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 12/14/2015] [Accepted: 12/14/2015] [Indexed: 12/17/2022]
Abstract
Helenius and colleagues proposed over 20-years ago a paradigm-shifting model for how chaperone binding in the endoplasmic reticulum was mediated and controlled for a new type of molecular chaperone- the carbohydrate-binding chaperones, calnexin and calreticulin. While the originally established basics for this lectin chaperone binding cycle holds true today, there has been a number of important advances that have expanded our understanding of its mechanisms of action, role in protein homeostasis, and its connection to disease states that are highlighted in this review.
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Affiliation(s)
- Lydia Lamriben
- Department of Biochemistry and Molecular Biology, Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Jill B Graham
- Department of Biochemistry and Molecular Biology, Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Benjamin M Adams
- Department of Biochemistry and Molecular Biology, Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Daniel N Hebert
- Department of Biochemistry and Molecular Biology, Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, 01003, USA
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19
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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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20
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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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21
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Hasanagic M, Waheed A, Eissenberg JC. Different Pathways to the Lysosome: Sorting out Alternatives. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 320:75-101. [PMID: 26614872 DOI: 10.1016/bs.ircmb.2015.07.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Considerable research supports a model in which hydrolytic enzymes of mammalian lysosomes are sorted to their destinations in a receptor-dependent mechanism. The ligand for the mammalian sorting receptors is mannose 6-phosphate (M6P). Two M6P receptors have been defined in mammals. Here, we review the foundational evidence supporting this mechanism and highlight the remaining gaps in our understanding of the mammalian mechanism, including evidence for M6P-independent sorting, and its relevance to lysosomal enzyme sorting in metazoa.
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Affiliation(s)
- Medina Hasanagic
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Doisy Research Center, Saint Louis University School of Medicine, St Louis, MO, USA
| | - Abdul Waheed
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Doisy Research Center, Saint Louis University School of Medicine, St Louis, MO, USA
| | - Joel C Eissenberg
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Doisy Research Center, Saint Louis University School of Medicine, St Louis, MO, USA
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22
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Olson LJ, Orsi R, Peterson FC, Parodi AJ, Kim JJP, D'Alessio C, Dahms NM. Crystal Structure and Functional Analyses of the Lectin Domain of Glucosidase II: Insights into Oligomannose Recognition. Biochemistry 2015; 54:4097-111. [PMID: 26062005 DOI: 10.1021/acs.biochem.5b00256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-Glycans are modified as part of a quality control mechanism during glycoprotein folding in the endoplasmic reticulum (ER). Glucosidase II (GII) plays a critical role by generating monoglucosylated glycans that are recognized by lectin chaperones, calnexin and calreticulin. To understand how the hydrolytic activity of GIIα is enhanced by the mannose 6-phosphate receptor (MPR) homology domain (MRH domain) of its β subunit, we now report a 1.6 Å resolution crystal structure of the MRH domain of GIIβ bound to mannose. A comparison of ligand-bound and unbound structures reveals no major difference in their overall fold, but rather a repositioning of side chains throughout the binding pocket, including Y372. Mutation of Y372 inhibits GII activity, demonstrating an important role for Y372 in regulating GII activity. Comparison of the MRH domains of GIIβ, MPRs, and the ER lectin OS-9 identified conserved residues that are critical for the structural integrity and architecture of the carbohydrate binding pocket. As shown by nuclear magnetic resonance spectroscopy, mutations of the primary binding pocket residues and adjacent W409, all of which inhibit the activity of GII both in vitro and in vivo, do not cause a significant change in the overall fold of the GIIβ MRH domain but impact locally the stability of the binding pocket. W409 does not directly contact mannose; rather, its indole ring is stabilized by binding into a hydrophobic pocket of an adjacent crystallographic neighbor. This suggests that W409 interacts with a hydrophobic region of the GIIβ or GIIα subunit to modulate its effect on GII activity.
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Affiliation(s)
- Linda J Olson
- †Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Ramiro Orsi
- ‡Laboratory of Glycobiology, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET, Buenos Aires, Argentina
| | - Francis C Peterson
- †Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Armando J Parodi
- ‡Laboratory of Glycobiology, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET, Buenos Aires, Argentina
| | - Jung-Ja P Kim
- †Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Cecilia D'Alessio
- ‡Laboratory of Glycobiology, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET, Buenos Aires, Argentina.,§School of Sciences, University of Buenos Aires, Buenos Aires, Argentina
| | - Nancy M Dahms
- †Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
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23
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Olson LJ, Castonguay AC, Lasanajak Y, Peterson FC, Cummings RD, Smith DF, Dahms NM. Identification of a fourth mannose 6-phosphate binding site in the cation-independent mannose 6-phosphate receptor. Glycobiology 2015; 25:591-606. [PMID: 25573276 DOI: 10.1093/glycob/cwv001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 01/05/2015] [Indexed: 11/12/2022] Open
Abstract
The 300 kDa cation-independent mannose 6-phosphate receptor (CI-MPR) plays an essential role in lysosome biogenesis by targeting ∼ 60 different phosphomannosyl-containing acid hydrolases to the lysosome. This type I membrane glycoprotein has a large extracellular region comprised of 15 homologous domains. Two mannose 6-phosphate (M6P) binding sites have been mapped to domains 3 and 9, whereas domain 5 binds preferentially to the phosphodiester, M6P-N-acetylglucosamine (GlcNAc). A structure-based sequence alignment predicts that the C-terminal domain 15 contains three out of the four conserved residues identified as essential for carbohydrate recognition by domains 3, 5 and 9 of the CI-MPR, but lacks two cysteine residues that are predicted to form a disulfide bond. To determine whether domain 15 of the CI-MPR has lectin activity and to probe its carbohydrate-binding specificity, truncated forms of the CI-MPR were tested for binding to acid hydrolases with defined N-glycans in surface plasmon resonance analyses, and used to interrogate a phosphorylated glycan microarray. The results show that a construct encoding domains 14-15 binds both M6P and M6P-GlcNAc with similar affinity (Kd = 13 and 17 μM, respectively). Site-directed mutagenesis studies demonstrate the essential role of the conserved Tyr residue in domain 15 for phosphomannosyl binding. A structural model of domain 15 was generated that predicted an Arg residue to be in the binding pocket and mutagenesis studies confirmed its important role in carbohydrate binding. Together, these results show that the CI-MPR contains a fourth carbohydrate-recognition site capable of binding both phosphomonoesters and phosphodiesters.
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Affiliation(s)
- Linda J Olson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Alicia C Castonguay
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Yi Lasanajak
- National Center for Functional Glycomics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Francis C Peterson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Richard D Cummings
- National Center for Functional Glycomics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David F Smith
- National Center for Functional Glycomics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Nancy M Dahms
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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24
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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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Matsushima H, Hirano M, Ito Y, Totani K. Diverse Effects of Macromolecular Crowding on the Sequential Glycan-Processing Pathway Involved in Glycoprotein Quality Control. Chembiochem 2013; 14:753-8. [DOI: 10.1002/cbic.201300028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Indexed: 12/20/2022]
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Fujimori T, Kamiya Y, Nagata K, Kato K, Hosokawa N. Endoplasmic reticulum lectin XTP3-B inhibits endoplasmic reticulum-associated degradation of a misfolded α1-antitrypsin variant. FEBS J 2013; 280:1563-75. [DOI: 10.1111/febs.12157] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 12/21/2012] [Accepted: 01/22/2013] [Indexed: 01/02/2023]
Affiliation(s)
- Tsutomu Fujimori
- Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences; Kyoto University; Japan
| | | | - Kazuhiro Nagata
- Laboratory of Molecular and Cellular Biology, Faculty of Life Sciences; Kyoto Sangyo University; Japan
| | | | - Nobuko Hosokawa
- Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences; Kyoto University; Japan
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Hebert DN, Molinari M. Flagging and docking: dual roles for N-glycans in protein quality control and cellular proteostasis. Trends Biochem Sci 2012; 37:404-10. [PMID: 22921611 PMCID: PMC3459134 DOI: 10.1016/j.tibs.2012.07.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/17/2012] [Accepted: 07/20/2012] [Indexed: 12/02/2022]
Abstract
Nascent polypeptides entering the endoplasmic reticulum (ER) are covalently modified with pre-assembled oligosaccharides. The terminal glucose and mannose residues are immediately removed after transfer of the oligosaccharide onto newly synthesized polypeptides. This processing determines whether the polypeptide will be retained in the ER, transported along the secretory pathway, or dislocated across the ER membrane for destruction. New avenues of research and some issues of controversy have recently been opened by the discovery that lectin–oligosaccharide interactions stabilize supramolecular complexes between regulators of ER-associated degradation (ERAD). In this Opinion article, we propose a unified model that depicts carbohydrates acting both as flags signaling the fitness of a maturing protein and as docking sites that regulate the assembly and stability of the ERAD machinery.
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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, USA.
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De Pourcq K, Tiels P, Van Hecke A, Geysens S, Vervecken W, Callewaert N. Engineering Yarrowia lipolytica to produce glycoproteins homogeneously modified with the universal Man3GlcNAc2 N-glycan core. PLoS One 2012; 7:e39976. [PMID: 22768188 PMCID: PMC3386995 DOI: 10.1371/journal.pone.0039976] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 05/30/2012] [Indexed: 11/18/2022] Open
Abstract
Yarrowia lipolytica is a dimorphic yeast that efficiently secretes various heterologous proteins and is classified as “generally recognized as safe.” Therefore, it is an attractive protein production host. However, yeasts modify glycoproteins with non-human high mannose-type N-glycans. These structures reduce the protein half-life in vivo and can be immunogenic in man. Here, we describe how we genetically engineered N-glycan biosynthesis in Yarrowia lipolytica so that it produces Man3GlcNAc2 structures on its glycoproteins. We obtained unprecedented levels of homogeneity of this glycanstructure. This is the ideal starting point for building human-like sugars. Disruption of the ALG3 gene resulted in modification of proteins mainly with Man5GlcNAc2 and GlcMan5GlcNAc2 glycans, and to a lesser extent with Glc2Man5GlcNAc2 glycans. To avoid underoccupancy of glycosylation sites, we concomitantly overexpressed ALG6. We also explored several approaches to remove the terminal glucose residues, which hamper further humanization of N-glycosylation; overexpression of the heterodimeric Apergillus niger glucosidase II proved to be the most effective approach. Finally, we overexpressed an α-1,2-mannosidase to obtain Man3GlcNAc2 structures, which are substrates for the synthesis of complex-type glycans. The final Yarrowia lipolytica strain produces proteins glycosylated with the trimannosyl core N-glycan (Man3GlcNAc2), which is the common core of all complex-type N-glycans. All these glycans can be constructed on the obtained trimannosyl N-glycan using either in vivo or in vitro modification with the appropriate glycosyltransferases. The results demonstrate the high potential of Yarrowia lipolytica to be developed as an efficient expression system for the production of glycoproteins with humanized glycans.
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Affiliation(s)
- Karen De Pourcq
- Unit for Medical Biotechnology, Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Petra Tiels
- Unit for Medical Biotechnology, Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- L-Probe, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
| | - Annelies Van Hecke
- Unit for Medical Biotechnology, Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Steven Geysens
- Unit for Medical Biotechnology, Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Oxyrane Belgium, Ghent, Belgium
| | - Wouter Vervecken
- Unit for Medical Biotechnology, Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
- Oxyrane Belgium, Ghent, Belgium
| | - Nico Callewaert
- Unit for Medical Biotechnology, Department for Molecular Biomedical Research, VIB, Ghent, Belgium
- L-Probe, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
- * E-mail:
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Hüttner S, Veit C, Schoberer J, Grass J, Strasser R. Unraveling the function of Arabidopsis thaliana OS9 in the endoplasmic reticulum-associated degradation of glycoproteins. PLANT MOLECULAR BIOLOGY 2012; 79:21-33. [PMID: 22328055 PMCID: PMC3332353 DOI: 10.1007/s11103-012-9891-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 01/29/2012] [Indexed: 05/18/2023]
Abstract
In the endoplasmic reticulum, immature polypeptides coincide with terminally misfolded proteins. Consequently, cells need a well-balanced quality control system, which decides about the fate of individual proteins and maintains protein homeostasis. Misfolded and unassembled proteins are sent for destruction via the endoplasmic reticulum-associated degradation (ERAD) machinery to prevent the accumulation of potentially toxic protein aggregates. Here, we report the identification of Arabidopsis thaliana OS9 as a component of the plant ERAD pathway. OS9 is an ER-resident glycoprotein containing a mannose-6-phosphate receptor homology domain, which is also found in yeast and mammalian lectins involved in ERAD. OS9 fused to the C-terminal domain of YOS9 can complement the ERAD defect of the corresponding yeast Δyos9 mutant. An A. thaliana OS9 loss-of-function line suppresses the severe growth phenotype of the bri1-5 and bri1-9 mutant plants, which harbour mutated forms of the brassinosteroid receptor BRI1. Co-immunoprecipitation studies demonstrated that OS9 associates with Arabidopsis SEL1L/HRD3, which is part of the plant ERAD complex and with the ERAD substrates BRI1-5 and BRI1-9, but only the binding to BRI1-5 occurs in a glycan-dependent way. OS9-deficiency results in activation of the unfolded protein response and reduces salt tolerance, highlighting the role of OS9 during ER stress. We propose that OS9 is a component of the plant ERAD machinery and may act specifically in the glycoprotein degradation pathway.
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Affiliation(s)
- Silvia Hüttner
- Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Christiane Veit
- Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Jennifer Schoberer
- Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
- Present Address: Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford, OX3 0BP UK
| | - Josephine Grass
- Department of Chemistry, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
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Castonguay AC, Lasanajak Y, Song X, Olson LJ, Cummings RD, Smith DF, Dahms NM. The glycan-binding properties of the cation-independent mannose 6-phosphate receptor are evolutionary conserved in vertebrates. Glycobiology 2012; 22:983-96. [PMID: 22369936 DOI: 10.1093/glycob/cws058] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The 300-kDa cation-independent mannose 6-phosphate receptor (CI-MPR) plays an essential role in the biogenesis of lysosomes by delivering newly synthesized lysosomal enzymes from the trans Golgi network to the endosomal system. The CI-MPR is expressed in most eukaryotes, with Saccharomyces cerevisiae and Caenorhabditis elegans being notable exceptions. Although the repertoire of glycans recognized by the bovine receptor has been studied extensively, little is known concerning the ligand-binding properties of the CI-MPR from non-mammalian species. To assess the evolutionary conservation of the CI-MPR, surface plasmon resonance analyses using lysosomal enzymes with defined N-glycans were carried out to probe the glycan-binding specificity of the Danio rerio CI-MPR. The results demonstrate that the D. rerio CI-MPR harbors three glycan-binding sites that, like the bovine CI-MPR, map to domains 3, 5 and 9 of its 15-domain-containing extracytoplasmic region. Analyses on a phosphorylated glycan microarray further demonstrated the unique binding properties of each of the three sites and showed that, similar to the bovine CI-MPR, only domain 5 of the D. rerio CI-MPR is capable of recognizing Man-P-GlcNAc-containing glycans.
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Affiliation(s)
- Alicia C Castonguay
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
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31
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Martinez Benitez E, Stolz A, Becher A, Wolf DH. Mnl2, a novel component of the ER associated protein degradation pathway. Biochem Biophys Res Commun 2011; 414:528-32. [DOI: 10.1016/j.bbrc.2011.09.100] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 09/20/2011] [Indexed: 11/26/2022]
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32
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Castonguay AC, Olson LJ, Dahms NM. Mannose 6-phosphate receptor homology (MRH) domain-containing lectins in the secretory pathway. Biochim Biophys Acta Gen Subj 2011; 1810:815-26. [PMID: 21723917 DOI: 10.1016/j.bbagen.2011.06.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Revised: 06/13/2011] [Accepted: 06/15/2011] [Indexed: 12/22/2022]
Abstract
BACKGROUND The mannose 6-phosphate receptor homology (MRH) domain-containing family of proteins, which include recycling receptors (mannose 6-phosphate receptors, MPRs), resident endoplasmic reticulum (ER) proteins (glucosidase II β-subunit, XTP3-B, OS-9), and a Golgi glycosyltransferase (GlcNAc-phosphotransferase γ-subunit), are characterized by the presence of one or more MRH domains. Many MRH domains act as lectins and bind specific phosphorylated (MPRs) or non-phosphorylated (glucosidase II β-subunit, XTP3-B and OS-9) high mannose-type N-glycans. The MPRs are the only proteins known to bind mannose 6-phosphate (Man-6-P) residues via their MRH domains. SCOPE OF REVIEW Recent biochemical and structural studies that have provided valuable insight into the glycan specificity and mechanisms of carbohydrate recognition by this diverse group of MRH domain-containing proteins are highlighted. MAJOR CONCLUSIONS Currently, three-dimensional structures are known for ten MRH domains, revealing the conservation of a similar fold. OS-9 and the MPRs use the same four residues (Gln, Arg, Glu, and Tyr) to bind mannose. GENERAL SIGNIFICANCE The MRH domain-containing proteins play key roles in the secretory pathway: glucosidase II, XTP3-B, and OS-9 are involved in the recognition of nascent glycoproteins, whereas the MPRs play an essential role in lysosome biogenesis by targeting Man-6-P-containing lysosomal enzymes to the lysosome.
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Affiliation(s)
- Alicia C Castonguay
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Stigliano ID, Alculumbre SG, Labriola CA, Parodi AJ, D'Alessio C. Glucosidase II and N-glycan mannose content regulate the half-lives of monoglucosylated species in vivo. Mol Biol Cell 2011; 22:1810-23. [PMID: 21471007 PMCID: PMC3103398 DOI: 10.1091/mbc.e11-01-0019] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
A decrease in N-glycan mannose content significantly diminishes in vivo glucosidase II–mediated deglucosylation rates but does not affect in vivo UDP-glucose:glycoprotein glucosyltransferase–mediated glucosylation, thus increasing the possibility of displaying monoglucosylated structures able to interact with calnexin/calreticulin for longer time periods. Glucosidase II (GII) sequentially removes the two innermost glucose residues from the glycan (Glc3Man9GlcNAc2) transferred to proteins. GII also participates in cycles involving the lectin/chaperones calnexin (CNX) and calreticulin (CRT) as it removes the single glucose unit added to folding intermediates and misfolded glycoproteins by the UDP-Glc:glycoprotein glucosyltransferase (UGGT). GII is a heterodimer in which the α subunit (GIIα) bears the active site, and the β subunit (GIIβ) modulates GIIα activity through its C-terminal mannose 6-phosphate receptor homologous (MRH) domain. Here we report that, as already described in cell-free assays, in live Schizosaccharomyces pombe cells a decrease in the number of mannoses in the glycan results in decreased GII activity. Contrary to previously reported cell-free experiments, however, no such effect was observed in vivo for UGGT. We propose that endoplasmic reticulum α-mannosidase–mediated N-glycan demannosylation of misfolded/slow-folding glycoproteins may favor their interaction with the lectin/chaperone CNX present in S. pombe by prolonging the half-lives of the monoglucosylated glycans (S. pombe lacks CRT). Moreover, we show that even N-glycans bearing five mannoses may interact in vivo with the GIIβ MRH domain and that the N-terminal GIIβ G2B domain is involved in the GIIα–GIIβ interaction. Finally, we report that protists that transfer glycans with low mannose content to proteins have nevertheless conserved the possibility of displaying relatively long-lived monoglucosylated glycans by expressing GIIβ MRH domains with a higher specificity for glycans with high mannose content.
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Affiliation(s)
- Ivan D Stigliano
- Laboratory of Glycobiology, Fundación Instituto Leloir and Instituto de Investigaciones Bioquímicas de Buenos Aires-CONICET, C1405BWE, Buenos Aires, Argentina
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Protein Quality Control, Retention, and Degradation at the Endoplasmic Reticulum. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 292:197-280. [DOI: 10.1016/b978-0-12-386033-0.00005-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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35
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Structural Basis for Oligosaccharide Recognition of Misfolded Glycoproteins by OS-9 in ER-Associated Degradation. Mol Cell 2010; 40:905-16. [DOI: 10.1016/j.molcel.2010.11.017] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 07/24/2010] [Accepted: 09/24/2010] [Indexed: 11/21/2022]
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36
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Structural basis for recognition of phosphodiester-containing lysosomal enzymes by the cation-independent mannose 6-phosphate receptor. Proc Natl Acad Sci U S A 2010; 107:12493-8. [PMID: 20615935 DOI: 10.1073/pnas.1004232107] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mannose 6-phosphate (Man-6-P)-dependent trafficking is vital for normal development. The biogenesis of lysosomes, a major cellular site of protein, carbohydrate, and lipid catabolism, depends on the 300-kDa cation-independent Man-6-P receptor (CI-MPR) that transports newly synthesized acid hydrolases from the Golgi. The CI-MPR recognizes lysosomal enzymes bearing the Man-6-P modification, which arises by the addition of GlcNAc-1-phosphate to mannose residues and subsequent removal of GlcNAc by the uncovering enzyme (UCE). The CI-MPR also recognizes lysosomal enzymes that elude UCE maturation and instead display the Man-P-GlcNAc phosphodiester. This ability of the CI-MPR to target phosphodiester-containing enzymes ensures lysosomal delivery when UCE activity is deficient. The extracellular region of the CI-MPR is comprised of 15 repetitive domains and contains three distinct Man-6-P binding sites located in domains 3, 5, and 9, with only domain 5 exhibiting a marked preference for phosphodiester-containing lysosomal enzymes. To determine how the CI-MPR recognizes phosphodiesters, the structure of domain 5 was determined by NMR spectroscopy. Although domain 5 contains only three of the four disulfide bonds found in the other seven domains whose structures have been determined to date, it adopts the same fold consisting of a flattened beta-barrel. Structure determination of domain 5 bound to N-acetylglucosaminyl 6-phosphomethylmannoside, along with mutagenesis studies, revealed the residues involved in diester recognition, including Y679. These results show the mechanism by which the CI-MPR recognizes Man-P-GlcNAc-containing ligands and provides new avenues to investigate the role of phosphodiester-containing lysosomal enzymes in the biogenesis of lysosomes.
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37
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Tamura T, Sunryd JC, Hebert DN. Sorting things out through endoplasmic reticulum quality control. Mol Membr Biol 2010; 27:412-27. [PMID: 20553226 DOI: 10.3109/09687688.2010.495354] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The endoplasmic reticulum (ER) is a highly organized and specialized organelle optimized for the production of proteins. It is comprised of a highly interconnected network of tubules that contain a large set of resident proteins dedicated to the maturation and processing of proteins that traverse the eukaryotic secretory pathway. As protein maturation is an imperfect process, frequently resulting in misfolding and/or the formation of aggregates, proteins are subjected to a series of evaluation processes within the ER. Proteins deemed native are sorted for anterograde trafficking, while immature or non-native proteins are initially retained in the ER in an attempt to rescue the aberrant products. Terminally misfolded substrates are eventually targeted for turnover through the ER-associated degradation or ERAD pathway to protect the cell from the release of a defective product. A clearer picture of the identity of the machinery involved in these quality control evaluation processes and their mechanisms of actions has emerged over the past decade.
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Affiliation(s)
- Taku Tamura
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
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38
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Määttänen P, Gehring K, Bergeron JJM, Thomas DY. Protein quality control in the ER: the recognition of misfolded proteins. Semin Cell Dev Biol 2010; 21:500-11. [PMID: 20347046 DOI: 10.1016/j.semcdb.2010.03.006] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 03/16/2010] [Accepted: 03/18/2010] [Indexed: 02/08/2023]
Abstract
The mechanism, in molecular terms of protein quality control, specifically of how the cell recognizes and discriminates misfolded proteins, remains a challenge. In the secretory pathway the folding status of glycoproteins passing through the endoplasmic reticulum is marked by the composition of the N-glycan. The different glycoforms are recognized by specialized lectins. The folding sensor UGGT acts as an unusual molecular chaperone and covalently modifies the Man9 N-glycan of a misfolded protein by adding a glucose moiety and converts it to Glc1Man9 that rebinds the lectin calnexin. However, further links between the folding status of a glycoprotein and the composition of the N-glycan are unclear. There is little unequivocal evidence for other proteins in the ER recognizing the N-glycan and also acting as molecular chaperones. Nevertheless, based upon a few examples, we suggest that this function is carried out by individual proteins in several different complexes. Thus, calnexin binds the protein disulfide isomerase ERp57, that acts upon Glc1Man9 glycoproteins. In another example the protein disulfide isomerase ERdj5 binds specifically to EDEM (which is probably a mannosidase) and a lectin OS9, and reduces the disulfide bonds of bound glycoproteins destined for ERAD. Thus the glycan recognition is performed by a lectin and the chaperone function performed by a specific partner protein that can recognize misfolded proteins. We predict that this will be a common arrangement of proteins in the ER and that members of protein foldase families such as PDI and PPI will bind specifically to lectins in the ER. Molecular chaperones BiP and GRp94 will assist in the folding of proteins bound in these complexes as well as in the folding of non-glycoproteins.
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Affiliation(s)
- Pekka Määttänen
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
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Endoplasmic reticulum associated protein degradation: a chaperone assisted journey to hell. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:694-705. [PMID: 20219571 DOI: 10.1016/j.bbamcr.2010.02.005] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 02/11/2010] [Accepted: 02/18/2010] [Indexed: 01/16/2023]
Abstract
Recognition and elimination of misfolded proteins are essential cellular processes. More than thirty percent of the cellular proteins are proteins of the secretory pathway. They fold in the lumen or membrane of the endoplasmic reticulum from where they are sorted to their site of action. The folding process, as well as any refolding after cell stress, depends on chaperone activity. In case proteins are unable to acquire their native conformation, chaperones with different substrate specificity and activity guide them to elimination. For most misfolded proteins of the endoplasmic reticulum this requires retro-translocation to the cytosol and polyubiquitylation of the misfolded protein by an endoplasmic reticulum associated machinery. Thereafter ubiquitylated proteins are guided to the proteasome for degradation. This review summarizes our up to date knowledge of chaperone classes and chaperone function in endoplasmic reticulum associated degradation of protein waste.
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40
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Bernasconi R, Galli C, Calanca V, Nakajima T, Molinari M. Stringent requirement for HRD1, SEL1L, and OS-9/XTP3-B for disposal of ERAD-LS substrates. ACTA ACUST UNITED AC 2010; 188:223-35. [PMID: 20100910 PMCID: PMC2812524 DOI: 10.1083/jcb.200910042] [Citation(s) in RCA: 147] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Soluble ERAD substrates require the Hrd1 E3 ligase for degradation compared with membrane-anchored peptides that use GP78. Sophisticated quality control mechanisms prolong retention of protein-folding intermediates in the endoplasmic reticulum (ER) until maturation while sorting out terminally misfolded polypeptides for ER-associated degradation (ERAD). The presence of structural lesions in the luminal, transmembrane, or cytosolic domains determines the classification of misfolded polypeptides as ERAD-L, -M, or -C substrates and results in selection of distinct degradation pathways. In this study, we show that disposal of soluble (nontransmembrane) polypeptides with luminal lesions (ERAD-LS substrates) is strictly dependent on the E3 ubiquitin ligase HRD1, the associated cargo receptor SEL1L, and two interchangeable ERAD lectins, OS-9 and XTP3-B. These ERAD factors become dispensable for degradation of the same polypeptides when membrane tethered (ERAD-LM substrates). Our data reveal that, in contrast to budding yeast, tethering of mammalian ERAD-L substrates to the membrane changes selection of the degradation pathway.
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41
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Xie W, Ng DTW. ERAD substrate recognition in budding yeast. Semin Cell Dev Biol 2010; 21:533-9. [PMID: 20178855 DOI: 10.1016/j.semcdb.2010.02.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Accepted: 02/15/2010] [Indexed: 11/17/2022]
Abstract
During protein synthesis, the orderly progression of folding, modification, and assembly is paramount to function and vis-à-vis cellular viability. Accordingly, sophisticated quality control mechanisms have evolved to monitor protein maturation throughout the cell. Proteins failing at any step are segregated and degraded as a preventative measure against potential toxicity. Although protein quality control is generally poorly understood, recent research advances in endoplasmic reticulum-associated degradation (ERAD) pathways have provided the most detailed view so far. The discovery of distinct substrate processing sites established a biochemical basis for genetic profiles of model misfolded proteins. Detailed mechanisms for substrate recognition were recently uncovered. For some proteins, sequential glycan trimming steps set a time window for folding. Proteins still unfolded at the final stage expose a specific degradation signal recognized by the ERAD machinery. Through this mechanism, the system does not in fact know that a molecule is "misfolded". Instead, it goes by the premise that proteins past due have veered off their normal folding pathways and therefore aberrant.
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Affiliation(s)
- Wei Xie
- Temasek Life Sciences Laboratory and Department of Biological Sciences, National University of Singapore, 1 Research Link, Singapore 117604, Singapore
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42
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Qian Y, Lee I, Lee WS, Qian M, Kudo M, Canfield WM, Lobel P, Kornfeld S. Functions of the alpha, beta, and gamma subunits of UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase. J Biol Chem 2010; 285:3360-70. [PMID: 19955174 PMCID: PMC2823453 DOI: 10.1074/jbc.m109.068650] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 11/30/2009] [Indexed: 11/06/2022] Open
Abstract
UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase is an alpha(2)beta(2)gamma(2) hexamer that mediates the first step in the synthesis of the mannose 6-phosphate recognition marker on lysosomal acid hydrolases. Using a multifaceted approach, including analysis of acid hydrolase phosphorylation in mice and fibroblasts lacking the gamma subunit along with kinetic studies of recombinant alpha(2)beta(2)gamma(2) and alpha(2)beta(2) forms of the transferase, we have explored the function of the alpha/beta and gamma subunits. The findings demonstrate that the alpha/beta subunits recognize the protein determinant of acid hydrolases in addition to mediating the catalytic function of the transferase. In mouse brain, the alpha/beta subunits phosphorylate about one-third of the acid hydrolases at close to wild-type levels but require the gamma subunit for optimal phosphorylation of the rest of the acid hydrolases. In addition to enhancing the activity of the alpha/beta subunits toward a subset of the acid hydrolases, the gamma subunit facilitates the addition of the second GlcNAc-P to high mannose oligosaccharides of these substrates. We postulate that the mannose 6-phosphate receptor homology domain of the gamma subunit binds and presents the high mannose glycans of the acceptor to the alpha/beta catalytic site in a favorable manner.
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Affiliation(s)
- Yi Qian
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Intaek Lee
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Wang-Sik Lee
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Meiqian Qian
- the Center for Advanced Biotechnology and Medicine and Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08851, and
| | - Mariko Kudo
- Genzyme Corporation, Oklahoma City, Oklahoma 73104
| | | | - Peter Lobel
- the Center for Advanced Biotechnology and Medicine and Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08851, and
| | - Stuart Kornfeld
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
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Hosokawa N, Kamiya Y, Kato K. The role of MRH domain-containing lectins in ERAD. Glycobiology 2010; 20:651-60. [PMID: 20118070 DOI: 10.1093/glycob/cwq013] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The endoplasmic reticulum (ER) quality control system ensures that newly synthesized proteins in the early secretory pathway are in the correct conformation. Polypeptides that have failed to fold into native conformers are subsequently retrotranslocated and degraded by the cytosolic ubiquitin-proteasome system, a process known as endoplasmic reticulum-associated degradation (ERAD). Most of the polypeptides that enter the ER are modified by the addition of N-linked oligosaccharides, and quality control of these glycoproteins is assisted by lectins that recognize specific sugar moieties and molecular chaperones that recognize unfolded proteins, resulting in proper protein folding and ERAD substrate selection. In Saccharomyces cerevisiae, Yos9p, a lectin that contains a mannose 6-phosphate receptor homology (MRH) domain, was identified as an important component of ERAD. Yos9p was shown to associate with the membrane-embedded ubiquitin ligase complex, Hrd1p-Hrd3p, and provide a proofreading mechanism for ERAD. Meanwhile, the function of the mammalian homologues of Yos9p, OS-9 and XTP3-B remained elusive until recently. Recent studies have determined that both OS-9 and XTP3-B are ER resident proteins that associate with the HRD1-SEL1L ubiquitin ligase complex and are important for the regulation of ERAD. Moreover, recent studies have identified the N-glycan species with which both yeast Yos9p and mammalian OS-9 associate as M7A, a Man(7)GlcNAc(2) isomer that lacks the alpha1,2-linked terminal mannose from both the B and C branches. M7A has since been demonstrated to be a degradation signal in both yeast and mammals.
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Affiliation(s)
- Nobuko Hosokawa
- Department of Molecular and Cellular Biology Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8397, Japan.
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D'Alessio C, Caramelo JJ, Parodi AJ. UDP-GlC:glycoprotein glucosyltransferase-glucosidase II, the ying-yang of the ER quality control. Semin Cell Dev Biol 2010; 21:491-9. [PMID: 20045480 DOI: 10.1016/j.semcdb.2009.12.014] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 12/17/2009] [Indexed: 12/22/2022]
Abstract
The N-glycan-dependent quality control of glycoprotein folding prevents endoplasmic to Golgi exit 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 that recognize monoglucosylated polymannose glycans, a lectin-associated oxidoreductase acting on monoglucosylated glycoproteins, a glucosyltransferase that creates monoglucosytlated epitopes in protein-linked glycans and a glucosidase that removes the glucose units added by the glucosyltransferase. This last enzyme is the only mechanism component sensing glycoprotein conformations as it creates monoglucosylated glycans exclusively in not properly folded species or in not completely assembled complexes. The glucosidase is a dimeric heterodimer composed of a catalytic subunit and an additional one that is partially responsible for the ER localization of the enzyme and for the enhancement of the deglucosylation rate as its mannose 6-phosphate receptor homologous domain presents the substrate to the catalytic site. This review deals with our present knowledge on the glucosyltransferase and the glucosidase.
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Affiliation(s)
- Cecilia D'Alessio
- Laboratory of Glycobiology, Fundación Instituto Leloir, Avda. Patricias Argentinas 435, C1405BWE, Buenos Aires, Argentina
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45
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Hosokawa N, Kato K, Kamiya Y. Mannose 6-phosphate receptor homology domain-containing lectins in mammalian endoplasmic reticulum-associated degradation. Methods Enzymol 2010; 480:181-97. [PMID: 20816211 DOI: 10.1016/s0076-6879(10)80010-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Quality control of glycoproteins synthesized in the endoplasmic reticulum (ER) is mediated by lectins and molecular chaperones. N-linked Glc(3)Man(9)GlcNAc(2) oligosaccharides attached to the nascent polypeptides are processed and recognized by lectins in the ER. OS-9 and XTP3-B/Erlectin, mannose 6-phosphate receptor homology (MRH) domain-containing lectins in mammals, were recently identified as ER luminal glycoproteins that participate in ER-associated degradation (ERAD) of misfolded proteins. Frontal affinity chromatography (FAC) and cell-surface expressed lectin assay revealed that both OS-9 and XTP3-B recognize high-mannose type N-glycans that lack the terminal mannose on the C branch. Furthermore, these lectins associate with the HRD1-SEL1L ubiquitin ligase complex on the ER membrane. In this chapter, we describe the FAC methods used to analyze the carbohydrate-recognition specificity of OS-9 and methods to examine the interaction and the effect on ERAD of these proteins in vivo. We also discuss the structure and function of OS-9 and XTP3-B, and the effect of these lectins on ERAD.
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Affiliation(s)
- Nobuko Hosokawa
- Department of Molecular and Cellular Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
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Yamaguchi D, Hu D, Matsumoto N, Yamamoto K. Human XTP3-B binds to 1-antitrypsin variant nullHong Kong via the C-terminal MRH domain in a glycan-dependent manner. Glycobiology 2009; 20:348-55. [DOI: 10.1093/glycob/cwp182] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mikami K, Yamaguchi D, Tateno H, Hu D, Qin SY, Kawasaki N, Yamada M, Matsumoto N, Hirabayashi J, Ito Y, Yamamoto K. The sugar-binding ability of human OS-9 and its involvement in ER-associated degradation. Glycobiology 2009; 20:310-21. [DOI: 10.1093/glycob/cwp175] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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Pearse BR, Hebert DN. Lectin chaperones help direct the maturation of glycoproteins in the endoplasmic reticulum. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1803:684-93. [PMID: 19891995 DOI: 10.1016/j.bbamcr.2009.10.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 10/09/2009] [Accepted: 10/20/2009] [Indexed: 02/06/2023]
Abstract
Eukaryotic secretory pathway cargo fold to their native structures within the confines of the endoplasmic reticulum (ER). To ensure a high degree of folding fidelity, a multitude of covalent and noncovalent constraints are imparted upon nascent proteins. These constraints come in the form of topological restrictions or membrane tethers, covalent modifications, and interactions with a series of molecular chaperones. N-linked glycosylation provides inherent benefits to proper folding and creates a platform for interactions with specific chaperones and Cys modifying enzymes. Recent insights into this timeline of protein maturation have revealed mechanisms for protein glycosylation and iterative targeting of incomplete folding intermediates, which provides nurturing interactions with molecular chaperones that assist in the efficient maturation of proteins in the eukaryotic secretory pathway.
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Affiliation(s)
- Bradley R Pearse
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
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Aebi M, Bernasconi R, Clerc S, Molinari M. N-glycan structures: recognition and processing in the ER. Trends Biochem Sci 2009; 35:74-82. [PMID: 19853458 DOI: 10.1016/j.tibs.2009.10.001] [Citation(s) in RCA: 342] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 09/30/2009] [Accepted: 10/01/2009] [Indexed: 11/26/2022]
Abstract
The processing of N-linked glycans determines secretory protein homeostasis in the eukaryotic cell. Folding and degradation of glycoproteins in the endoplasmic reticulum (ER) are regulated by molecular chaperones and enzymes recruited by specific oligosaccharide structures. Recent findings have identified several components of this protein quality control system that specifically modify N-linked glycans, thereby generating oligosaccharide structures recognized by carbohydrate-binding proteins, lectins. In turn, lectins direct newly synthesized polypeptides to the folding, secretion or degradation pathways. The "glyco-code of the ER" displays the folding status of a multitude of cargo proteins. Deciphering this code will be instrumental in understanding protein homeostasis regulation in eukaryotic cells and for intervention because such processes can have crucial importance for clinical and industrial applications.
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Affiliation(s)
- Markus Aebi
- Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, CH-8093 Zürich, Switzerland.
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Bohnsack RN, Song X, Olson LJ, Kudo M, Gotschall RR, Canfield WM, Cummings RD, Smith DF, Dahms NM. Cation-independent mannose 6-phosphate receptor: a composite of distinct phosphomannosyl binding sites. J Biol Chem 2009; 284:35215-26. [PMID: 19840944 DOI: 10.1074/jbc.m109.056184] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The 300-kDa cation-independent mannose 6-phosphate receptor (CI-MPR), which contains multiple mannose 6-phosphate (Man-6-P) binding sites that map to domains 3, 5, and 9 within its 15-domain extracytoplasmic region, functions as an efficient carrier of Man-6-P-containing lysosomal enzymes. To determine the types of phosphorylated N-glycans recognized by each of the three carbohydrate binding sites of the CI-MPR, a phosphorylated glycan microarray was probed with truncated forms of the CI-MPR. Surface plasmon resonance analyses using lysosomal enzymes with defined N-glycans were performed to evaluate whether multiple domains are needed to form a stable, high affinity carbohydrate binding pocket. Like domain 3, adjacent domains increase the affinity of domain 5 for phosphomannosyl residues, with domain 5 exhibiting approximately 60-fold higher affinity for lysosomal enzymes containing the phosphodiester Man-P-GlcNAc when in the context of a construct encoding domains 5-9. In contrast, domain 9 does not require additional domains for high affinity binding. The three sites differ in their glycan specificity, with only domain 5 being capable of recognizing Man-P-GlcNAc. In addition, domain 9, unlike domains 1-3, interacts with Man(8)GlcNAc(2) and Man(9)GlcNAc(2) oligosaccharides containing a single phosphomonoester. Together, these data indicate that the assembly of three unique carbohydrate binding sites allows the CI-MPR to interact with the structurally diverse phosphorylated N-glycans it encounters on newly synthesized lysosomal enzymes.
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Affiliation(s)
- Richard N Bohnsack
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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