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Katz ML, Cook J, Vite CH, Campbell RS, Coghill LM, Lyons LA. Beta-mannosidosis in a domestic cat associated with a missense variant in MANBA. Gene 2024; 893:147941. [PMID: 37913889 PMCID: PMC10841995 DOI: 10.1016/j.gene.2023.147941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/20/2023] [Accepted: 10/27/2023] [Indexed: 11/03/2023]
Abstract
A 6-month-old cat of unknown ancestry presented for a neurologic evaluation due to progressive motor impairment. Complete physical and neurologic examinations suggested the disorder was likely to be hereditary, although the signs were not consistent with any previously described inherited disorders in cats. Due to the progression of disease signs including severely impaired motor function and cognitive decline, the cat was euthanized at approximately 10.5 months of age. Whole genome sequence analysis identified a homozygous missense variant c.2506G > A in MANBA that predicts a p.Gly836Arg alteration in the encoded lysosomal enzyme β -mannosidase. This variant was not present in the whole genome or whole exome sequences of any of the 424 cats represented in the 99 Lives Cat Genome dataset. β -Mannosidase enzyme activity was undetectable in brain tissue homogenates from the affected cat, whereas α-mannosidase enzyme activities were elevated compared to an unaffected cat. Postmortem examination of brain and retinal tissues revealed massive accumulations of vacuolar inclusions in most cells, similar to those reported in animals of other species with hereditary β -mannosidosis. Based on these findings, the cat likely suffered from β -mannosidosis due to the abolition of β -mannosidase activity associated with the p.Gly836Arg amino acid substitution. p.Gly836 is located in the C-terminal region of the protein and was not previously known to be involved in modulating enzyme activity. In addition to the vacuolar inclusions, some cells in the brain of the affected cat contained inclusions that exhibited lipofuscin-like autofluorescence. Electron microscopic examinations suggested these inclusions formed via an autophagy-like process.
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Affiliation(s)
- Martin L Katz
- Neurodegenerative Diseases Research Laboratory, University of Missouri, Columbia, MO 65212, USA.
| | - James Cook
- Specialists in Companion Animal Neurology, Clearwater, FL 33765, USA
| | - Charles H Vite
- Department of Clinical Sciences and Advanced Medicine, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Rebecca S Campbell
- Department of Clinical Sciences and Advanced Medicine, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA 19104, USA
| | - Lyndon M Coghill
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Leslie A Lyons
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; Department of Veterinary Medicine & Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
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2
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Chen X, Yao T, Cai J, Zhang Q, Li S, Li H, Fu X, Wu J. A novel genetic variant potentially altering the expression of MANBA in the cerebellum associated with attention deficit hyperactivity disorder in Han Chinese children. World J Biol Psychiatry 2022; 23:548-559. [PMID: 34870556 DOI: 10.1080/15622975.2021.2014248] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVES To obtain additional insight into the genetic factors of attention deficit hyperactivity disorder (ADHD). METHODS First, we performed a transcriptome-wide association study (TWAS) integrating human cerebellum-specific variant-expression/splicing correlations to identify ADHD susceptibility genes. Then, the associations between expression/splicing quantitative trait loci (eQTLs/sQTLs) of the transcriptome-wide significant genes and ADHD were observed in a case-control study of Han Chinese children. Furthermore, dual luciferase reporter gene assays were performed to validate the regulatory function of ADHD risk variants. Additionally, the transcription level of target genes in blood was detected by real-time quantitative polymerase chain reaction (RT-qPCR) assay. RESULTS TWAS identified that the genetically regulated expression of MANBA in the cerebellum was significantly associated with ADHD risk. Furthermore, we observed a higher risk of ADHD and more severe clinical symptoms in subjects harbouring heterozygous (TC) or mutant homozygous (TT) genotypes of MANBA rs1054037 than CC carriers. The dual luciferase reporter gene assay revealed that the mutation of rs1054037(C > T) potentially upregulated MANBA expression by eliminating the binding site for hsa-miR-5591-3P. Finally, RT-qPCR showed that MANBA expression in blood samples of patients was significantly higher than that of controls. CONCLUSIONS Taken together, these results suggest a role of MANBA in the development of ADHD.
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Affiliation(s)
- Xinzhen Chen
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ting Yao
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jinliang Cai
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qi Zhang
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shanyawen Li
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huiru Li
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xihang Fu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jing Wu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Epidemiology and Biostatistics, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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3
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Gu X, Yang H, Sheng X, Ko YA, Qiu C, Park J, Huang S, Kember R, Judy RL, Park J, Damrauer SM, Nadkarni G, Loos RJF, My VTH, Chaudhary K, Bottinger EP, Paranjpe I, Saha A, Brown C, Akilesh S, Hung AM, Palmer M, Baras A, Overton JD, Reid J, Ritchie M, Rader DJ, Susztak K. Kidney disease genetic risk variants alter lysosomal beta-mannosidase ( MANBA) expression and disease severity. Sci Transl Med 2021; 13:13/576/eaaz1458. [PMID: 33441424 DOI: 10.1126/scitranslmed.aaz1458] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 04/08/2020] [Accepted: 12/09/2020] [Indexed: 02/05/2023]
Abstract
More than 800 million people in the world suffer from chronic kidney disease (CKD). Genome-wide association studies (GWAS) have identified hundreds of loci where genetic variants are associated with kidney function; however, causal genes and pathways for CKD remain unknown. Here, we performed integration of kidney function GWAS and human kidney-specific expression quantitative trait analysis and identified that the expression of beta-mannosidase (MANBA) was lower in kidneys of subjects with CKD risk genotype. We also show an increased incidence of renal failure in subjects with rare heterozygous loss-of-function coding variants in MANBA using phenome-wide association analysis of 40,963 subjects with exome sequencing data. MANBA is a lysosomal gene highly expressed in kidney tubule cells. Deep phenotyping revealed structural and functional lysosomal alterations in human kidneys from subjects with CKD risk alleles and mice with genetic deletion of Manba Manba heterozygous and knockout mice developed more severe kidney fibrosis when subjected to toxic injury induced by cisplatin or folic acid. Manba loss altered multiple pathways, including endocytosis and autophagy. In the absence of Manba, toxic acute tubule injury induced inflammasome activation and fibrosis. Together, these results illustrate the convergence of common noncoding and rare coding variants in MANBA in kidney disease development and demonstrate the role of the endolysosomal system in kidney disease development.
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Affiliation(s)
- Xiangchen Gu
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Division of Nephrology, Yueyang Hospital of Integrative Traditional Chinese and Western Medicine, Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 200437, China
| | - Hongliu Yang
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Division of Nephrology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Xin Sheng
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yi-An Ko
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Chengxiang Qiu
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jihwan Park
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shizheng Huang
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rachel Kember
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Renae L Judy
- Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Joseph Park
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.,Department of Genetics Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Scott M Damrauer
- Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.,Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Girish Nadkarni
- Division of Nephrology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,The Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,The Hasso Plattner Institute of Digital Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ruth J F Loos
- The Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Vy Thi Ha My
- The Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kumardeep Chaudhary
- The Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Erwin P Bottinger
- The Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,The Hasso Plattner Institute of Digital Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Ishan Paranjpe
- The Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Aparna Saha
- The Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Christopher Brown
- Department of Genetics Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shreeram Akilesh
- Department of Pathology, University of Washington, Seattle, WA 98195, USA
| | - Adriana M Hung
- Nashville VA Medical Center, Nashville, TN 37212, USA.,Vanderbilt Center for Kidney Disease, Vanderbilt University Medical Center, Nashville, TN 37212, USA
| | - Matthew Palmer
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Aris Baras
- Regeneron Genetics Center (RGC), 777 Old Saw Mill River Rd., Tarrytown, NY 10591, USA
| | - John D Overton
- Regeneron Genetics Center (RGC), 777 Old Saw Mill River Rd., Tarrytown, NY 10591, USA
| | - Jeffrey Reid
- Regeneron Genetics Center (RGC), 777 Old Saw Mill River Rd., Tarrytown, NY 10591, USA
| | - Marylyn Ritchie
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.,Department of Genetics Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Daniel J Rader
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.,Department of Genetics Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Katalin Susztak
- Department of Medicine Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. .,Department of Genetics Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Gigliobianco MR, Di Martino P, Deng S, Casadidio C, Censi R. New Advanced Strategies for the Treatment of Lysosomal Diseases Affecting the Central Nervous System. Curr Pharm Des 2019; 25:1933-1950. [DOI: 10.2174/1381612825666190708213159] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 06/19/2019] [Indexed: 11/22/2022]
Abstract
Lysosomal Storage Disorders (LSDs), also known as lysosomal diseases (LDs) are a group of serious genetic diseases characterized by not only the accumulation of non-catabolized compounds in the lysosomes due to the deficiency of specific enzymes which usually eliminate these compounds, but also by trafficking, calcium changes and acidification. LDs mainly affect the central nervous system (CNS), which is difficult to reach for drugs and biological molecules due to the presence of the blood-brain barrier (BBB). While some therapies have proven highly effective in treating peripheral disorders in LD patients, they fail to overcome the BBB. Researchers have developed many strategies to circumvent this problem, for example, by creating carriers for enzyme delivery, which improve the enzyme’s half-life and the overexpression of receptors and transporters in the luminal or abluminal membranes of the BBB. This review aims to successfully examine the strategies developed during the last decade for the treatment of LDs, which mainly affect the CNS. Among the LD treatments, enzyme-replacement therapy (ERT) and gene therapy have proven effective, while nanoparticle, fusion protein, and small molecule-based therapies seem to offer considerable promise to treat the CNS pathology. This work also analyzed the challenges of the study to design new drug delivery systems for the effective treatment of LDs. Polymeric nanoparticles and liposomes are explored from their technological point of view and for the most relevant preclinical studies showing that they are excellent choices to protect active molecules and transport them through the BBB to target specific brain substrates for the treatment of LDs.
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Affiliation(s)
- Maria R. Gigliobianco
- School of Pharmacy, University of Camerino, Via A. D'Accoiso, 16, 62032, Camerino MC, Italy
| | - Piera Di Martino
- School of Pharmacy, University of Camerino, Via A. D'Accoiso, 16, 62032, Camerino MC, Italy
| | - Siyuan Deng
- School of Pharmacy, University of Camerino, Via A. D'Accoiso, 16, 62032, Camerino MC, Italy
| | - Cristina Casadidio
- School of Pharmacy, University of Camerino, Via A. D'Accoiso, 16, 62032, Camerino MC, Italy
| | - Roberta Censi
- School of Pharmacy, University of Camerino, Via A. D'Accoiso, 16, 62032, Camerino MC, Italy
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5
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Syed Haneef SA, Ranganathan S. Structural bioinformatics analysis of variants on GPCR function. Curr Opin Struct Biol 2019; 55:161-177. [PMID: 31174013 DOI: 10.1016/j.sbi.2019.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/20/2019] [Accepted: 04/22/2019] [Indexed: 10/26/2022]
Abstract
G protein-coupled receptors (GPCRs) are key membrane-embedded receptor proteins, with critical roles in cellular signal transduction. In the era of precision medicine, understanding the role of natural variants on GPCR function is critical, especially from a pharmacogenomics viewpoint. Studies involved in mapping variants to GPCR structures are briefly reviewed here. The endocannabinoid system involving the central nervous system (CNS), the human cannabinoid receptor 1 (CB1), is an important drug target and its variability has implications for disease susceptibility and altered drug and pain response. We have carried out a computational study to map deleterious non-synonymous single nucleotide polymorphisms (nsSNPs) to CB1. CB1 mutations were computationally evaluated from neutral to deleterious, and the top twelve deleterious mutations, with structural information, were found to be either close to the ligand binding region or the G-protein binding site. We have mapped these to the active and inactive CB1 X-ray crystallographic structures to correlate variants with available phenotypic information. We have also carried out molecular dynamics simulations to functionally characterize four selected mutants.
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Affiliation(s)
- Syed Askar Syed Haneef
- Department of Molecular Sciences, Faculty of Science and Engineering, Macquarie University, NSW 2109, Australia
| | - Shoba Ranganathan
- Department of Molecular Sciences, Faculty of Science and Engineering, Macquarie University, NSW 2109, Australia.
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6
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β-Mannosidosis caused by a novel homozygous intragenic inverted duplication in MANBA. Cold Spring Harb Mol Case Stud 2019; 5:mcs.a003954. [PMID: 30886116 PMCID: PMC6549551 DOI: 10.1101/mcs.a003954] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 03/04/2019] [Indexed: 11/25/2022] Open
Abstract
β-Mannosidosis is a lysosomal storage disorder characterized by accumulation of disaccharides due to deficiency of the lysosomal enzyme β-mannosidase. The disease is caused by mutations in MANBA and is extremely rare in humans. Although the clinical presentation is heterogeneous, common symptoms include various degrees of developmental delay, behavioral disturbances, hearing loss, and frequent infections. We report a 15-yr-old girl presenting with mild intellectual disability, sensorineural hearing loss, severe behavioral disturbances, dysmorphic traits, and evolving angiokeratomas. Copy-number variation analysis of next-generation sequencing (NGS) data indicated increased coverage in exons 8-11 of MANBA Low β-mannosidase activity (1 µkatal/kg protein, refv 25-40) established the diagnosis of β-mannosidosis. Whole-genome sequencing (WGS) and cDNA analysis revealed a novel homozygous intragenic inverted duplication in MANBA, where a 13.1-kb region between introns 7 and 11 was duplicated and inserted in an inverted orientation, creating a 67-base nonduplicated gap at the insertion point. Both junctions showed microhomology regions. The inverted duplication resulted in exon skipping of exons 8-9 or 8-10. Our report highlights the importance of copy-number variation analysis of data from NGS and in particular the power of WGS in the identification and characterization of copy-number variants.
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Gytz H, Liang J, Liang Y, Gorelik A, Illes K, Nagar B. The structure of mammalian β‐mannosidase provides insight into β‐mannosidosis and nystagmus. FEBS J 2019; 286:1319-1331. [DOI: 10.1111/febs.14731] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 11/28/2018] [Accepted: 12/13/2018] [Indexed: 11/27/2022]
Affiliation(s)
- Heidi Gytz
- Department of Biochemistry Groupe de Recherche Axé sur la Structure des Protéines McGill University Montreal Canada
| | - Jason Liang
- Department of Biochemistry Groupe de Recherche Axé sur la Structure des Protéines McGill University Montreal Canada
| | - Yingke Liang
- Department of Biochemistry Groupe de Recherche Axé sur la Structure des Protéines McGill University Montreal Canada
| | - Alexei Gorelik
- Department of Biochemistry Groupe de Recherche Axé sur la Structure des Protéines McGill University Montreal Canada
| | - Katalin Illes
- Department of Biochemistry Groupe de Recherche Axé sur la Structure des Protéines McGill University Montreal Canada
| | - Bhushan Nagar
- Department of Biochemistry Groupe de Recherche Axé sur la Structure des Protéines McGill University Montreal Canada
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Lysosomal storage disease in the brain: mutations of the β-mannosidase gene identified in autosomal dominant nystagmus. Genet Med 2015; 17:971-9. [PMID: 25741867 DOI: 10.1038/gim.2015.10] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/12/2015] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Genetic etiology of congenital/infantile nystagmus remains largely unknown. This study aimed to identify genomic mutations in patients with infantile nystagmus and an associated disease network. METHODS Patients with inherited and sporadic infantile nystagmus were recruited for whole-exome and Sanger sequencing. β-Mannosidase activities were measured. Gene expression, protein-protein interaction, and nystagmus-associated lysosomal storage disease (LSD) genes were analyzed. RESULTS A novel heterozygous mutation (c.2013G>A; p.R638H) of MANBA, which encodes lysosomal β-mannosidase, was identified in patients with autosomal-dominant nystagmus. An additional mutation (c.2346T>A; p.L749H) in MANBA was found by screening patients with sporadic nystagmus. MANBA was expressed in the pretectal nucleus of the developing midbrain, known to be involved in oculomotor and optokinetic nystagmus. Functional validation of these mutations demonstrated a significant decrease of β-mannosidase activities in the patients as well as in mutant-transfected HEK293T cells. Further analysis revealed that nystagmus is present in at least 24 different LSDs involving the brain. CONCLUSION This is the first identification of MANBA mutations in patients with autosomal-dominant nystagmus, suggesting a new clinical entity. Because β-mannosidase activities are required for development of the oculomotor nervous system, our findings shed new light on the role of LSD-associated genes in the pathogenesis of infantile nystagmus.
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Rosenbaum EE, Vasiljevic E, Brehm KS, Colley NJ. Mutations in four glycosyl hydrolases reveal a highly coordinated pathway for rhodopsin biosynthesis and N-glycan trimming in Drosophila melanogaster. PLoS Genet 2014; 10:e1004349. [PMID: 24785692 PMCID: PMC4006722 DOI: 10.1371/journal.pgen.1004349] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 03/18/2014] [Indexed: 01/16/2023] Open
Abstract
As newly synthesized glycoproteins move through the secretory pathway, the asparagine-linked glycan (N-glycan) undergoes extensive modifications involving the sequential removal and addition of sugar residues. These modifications are critical for the proper assembly, quality control and transport of glycoproteins during biosynthesis. The importance of N-glycosylation is illustrated by a growing list of diseases that result from defects in the biosynthesis and processing of N-linked glycans. The major rhodopsin in Drosophila melanogaster photoreceptors, Rh1, is highly unique among glycoproteins, as the N-glycan appears to be completely removed during Rh1 biosynthesis and maturation. However, much of the deglycosylation pathway for Rh1 remains unknown. To elucidate the key steps in Rh1 deglycosylation in vivo, we characterized mutant alleles of four Drosophila glycosyl hydrolases, namely α-mannosidase-II (α-Man-II), α-mannosidase-IIb (α-Man-IIb), a β-N-acetylglucosaminidase called fused lobes (Fdl), and hexosaminidase 1 (Hexo1). We have demonstrated that these four enzymes play essential and unique roles in a highly coordinated pathway for oligosaccharide trimming during Rh1 biosynthesis. Our results reveal that α-Man-II and α-Man-IIb are not isozymes like their mammalian counterparts, but rather function at distinct stages in Rh1 maturation. Also of significance, our results indicate that Hexo1 has a biosynthetic role in N-glycan processing during Rh1 maturation. This is unexpected given that in humans, the hexosaminidases are typically lysosomal enzymes involved in N-glycan catabolism with no known roles in protein biosynthesis. Here, we present a genetic dissection of glycoprotein processing in Drosophila and unveil key steps in N-glycan trimming during Rh1 biosynthesis. Taken together, our results provide fundamental advances towards understanding the complex and highly regulated pathway of N-glycosylation in vivo and reveal novel insights into the functions of glycosyl hydrolases in the secretory pathway.
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Affiliation(s)
- Erica E. Rosenbaum
- Department of Ophthalmology & Visual Sciences and Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Eva Vasiljevic
- Department of Ophthalmology & Visual Sciences and Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kimberley S. Brehm
- Department of Ophthalmology & Visual Sciences and Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Nansi Jo Colley
- Department of Ophthalmology & Visual Sciences and Department of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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10
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Sowmya G, Khan JM, Anand S, Ahn SB, Baker MS, Ranganathan S. A site for direct integrin αvβ6·uPAR interaction from structural modelling and docking. J Struct Biol 2014; 185:327-35. [DOI: 10.1016/j.jsb.2014.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Revised: 11/22/2013] [Accepted: 01/07/2014] [Indexed: 12/30/2022]
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11
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Schönbach C, Tan TW, Kelso J, Rost B, Nathan S, Ranganathan S. InCoB celebrates its tenth anniversary as first joint conference with ISCB-Asia. BMC Genomics 2011; 12 Suppl 3:S1. [PMID: 22369160 PMCID: PMC3333168 DOI: 10.1186/1471-2164-12-s3-s1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In 2009 the International Society for Computational Biology (ISCB) started to roll out regional bioinformatics conferences in Africa, Latin America and Asia. The open and competitive bid for the first meeting in Asia (ISCB-Asia) was awarded to Asia-Pacific Bioinformatics Network (APBioNet) which has been running the International Conference on Bioinformatics (InCoB) in the Asia-Pacific region since 2002. InCoB/ISCB-Asia 2011 is held from November 30 to December 2, 2011 in Kuala Lumpur, Malaysia. Of 104 manuscripts submitted to BMC Genomics and BMC Bioinformatics conference supplements, 49 (47.1%) were accepted. The strong showing of Asia among submissions (82.7%) and acceptances (81.6%) signals the success of this tenth InCoB anniversary meeting, and bodes well for the future of ISCB-Asia.
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Affiliation(s)
- Christian Schönbach
- Department of Bioscience and Bioinformatics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka 820-8502, Japan.
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