1
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Fasimoye R, Dong W, Nirujogi RS, Rawat ES, Iguchi M, Nyame K, Phung TK, Bagnoli E, Prescott AR, Alessi DR, Abu-Remaileh M. Golgi-IP, a tool for multimodal analysis of Golgi molecular content. Proc Natl Acad Sci U S A 2023; 120:e2219953120. [PMID: 37155866 PMCID: PMC10193996 DOI: 10.1073/pnas.2219953120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 04/05/2023] [Indexed: 05/10/2023] Open
Abstract
The Golgi is a membrane-bound organelle that is essential for protein and lipid biosynthesis. It represents a central trafficking hub that sorts proteins and lipids to various destinations or for secretion from the cell. The Golgi has emerged as a docking platform for cellular signaling pathways including LRRK2 kinase whose deregulation leads to Parkinson disease. Golgi dysfunction is associated with a broad spectrum of diseases including cancer, neurodegeneration, and cardiovascular diseases. To allow the study of the Golgi at high resolution, we report a rapid Golgi immunoprecipitation technique (Golgi-IP) to isolate intact Golgi mini-stacks for subsequent analysis of their content. By fusing the Golgi-resident protein TMEM115 to three tandem HA epitopes (GolgiTAG), we purified the Golgi using Golgi-IP with minimal contamination from other compartments. We then established an analysis pipeline using liquid chromatography coupled with mass spectrometry to characterize the human Golgi proteome, metabolome, and lipidome. Subcellular proteomics confirmed known Golgi proteins and identified proteins not previously associated with the Golgi. Metabolite profiling established the human Golgi metabolome and revealed the enrichment of uridine-diphosphate (UDP) sugars and their derivatives, which is consistent with their roles in protein and lipid glycosylation. Furthermore, targeted metabolomics validated SLC35A2 as the subcellular transporter for UDP-hexose. Finally, lipidomics analysis showed that phospholipids including phosphatidylcholine, phosphatidylinositol, and phosphatidylserine are the most abundant Golgi lipids and that glycosphingolipids are enriched in this compartment. Altogether, our work establishes a comprehensive molecular map of the human Golgi and provides a powerful method to study the Golgi with high precision in health and disease.
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Affiliation(s)
- Rotimi Fasimoye
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Wentao Dong
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
| | - Raja S. Nirujogi
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Eshaan S. Rawat
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
| | - Miharu Iguchi
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
| | - Kwamina Nyame
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA94305
| | - Toan K. Phung
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Enrico Bagnoli
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Alan R. Prescott
- Dundee Imaging Facility, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
| | - Dario R. Alessi
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, DundeeDD1 5EH, United Kingdom
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
| | - Monther Abu-Remaileh
- Aligning Science Across Parkinson’s Collaborative Research Network, Chevy Chase, MD20815
- Department of Chemical Engineering, Stanford University, Stanford, CA94305
- Department of Genetics, Stanford University, Stanford, CA94305
- The Institute for Chemistry, Engineering & Medicine for Human Health, Stanford University, Stanford, CA94305
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2
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Premageetha GTR, Dhanabalan K, Bose S, Manjunath L, Joseph D, Paz A, Grandfield S, Nayak V, Bredeston LM, Abramson J, Ramaswamy S. Biochemical characterization of a GDP-mannose transporter from Chaetomium thermophilum. PLoS One 2023; 18:e0280975. [PMID: 37079572 PMCID: PMC10118193 DOI: 10.1371/journal.pone.0280975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 04/04/2023] [Indexed: 04/21/2023] Open
Abstract
Nucleotide Sugar Transporters (NSTs) belong to the SLC35 family (human solute carrier) of membrane transport proteins and are crucial components of the glycosylation machinery. NSTs are localized in the ER and Golgi apparatus membranes, where they accumulate nucleotide sugars from the cytosol for subsequent polysaccharide biosynthesis. Loss of NST function impacts the glycosylation of cell surface molecules. Mutations in NSTs cause several developmental disorders, immune disorders, and increased susceptibility to infection. Atomic resolution structures of three NSTs have provided a blueprint for a detailed molecular interpretation of their biochemical properties. In this work, we have identified, cloned, and expressed 18 members of the SLC35 family from various eukaryotic organisms in Saccharomyces cerevisiae. Out of 18 clones, we determined Vrg4 from Chaetomium thermophilum (CtVrg4) is a GDP-mannose transporter with an enhanced melting point temperature (Tm) of 56.9°C, which increases with the addition of substrates, GMP and GDP-mannose. In addition, we report-for the first time-that the CtVrg4 shows an affinity to bind to phosphatidylinositol lipids.
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Affiliation(s)
- Gowtham Thambra Rajan Premageetha
- Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, Karnataka, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - KanagaVijayan Dhanabalan
- Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, Karnataka, India
| | - Sucharita Bose
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, Karnataka, India
| | - Lavanyaa Manjunath
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, Karnataka, India
| | - Deepthi Joseph
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, Karnataka, India
| | - Aviv Paz
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - Samuel Grandfield
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - Vinod Nayak
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, Karnataka, India
| | - Luis M. Bredeston
- Departamento de Química Biológica-IQUIFIB, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires-CONICET, Ciudad Autónoma de Buenos Aires, Junín, Argentina
| | - Jeff Abramson
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States of America
| | - Subramanian Ramaswamy
- Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- Institute for Stem Cell Science and Regenerative Medicine, Bengaluru, Karnataka, India
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3
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Delivery of Nucleotide Sugars to the Mammalian Golgi: A Very Well (un)Explained Story. Int J Mol Sci 2022; 23:ijms23158648. [PMID: 35955785 PMCID: PMC9368800 DOI: 10.3390/ijms23158648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/31/2022] [Accepted: 08/02/2022] [Indexed: 11/25/2022] Open
Abstract
Nucleotide sugars (NSs) serve as substrates for glycosylation reactions. The majority of these compounds are synthesized in the cytoplasm, whereas glycosylation occurs in the endoplasmic reticulum (ER) and Golgi lumens, where catalytic domains of glycosyltransferases (GTs) are located. Therefore, translocation of NS across the organelle membranes is a prerequisite. This process is thought to be mediated by a group of multi-transmembrane proteins from the SLC35 family, i.e., nucleotide sugar transporters (NSTs). Despite many years of research, some uncertainties/inconsistencies related with the mechanisms of NS transport and the substrate specificities of NSTs remain. Here we present a comprehensive review of the NS import into the mammalian Golgi, which consists of three major parts. In the first part, we provide a historical view of the experimental approaches used to study NS transport and evaluate the most important achievements. The second part summarizes various aspects of knowledge concerning NSTs, ranging from subcellular localization up to the pathologies related with their defective function. In the third part, we present the outcomes of our research performed using mammalian cell-based models and discuss its relevance in relation to the general context.
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4
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Rautengarten C, Quarrell OW, Stals K, Caswell RC, De Franco E, Baple E, Burgess N, Jokhi R, Heazlewood JL, Offiah AC, Ebert B, Ellard S. A hypomorphic allele of SLC35D1 results in Schneckenbecken-like dysplasia. Hum Mol Genet 2020; 28:3543-3551. [PMID: 31423530 PMCID: PMC6927460 DOI: 10.1093/hmg/ddz200] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 12/13/2022] Open
Abstract
We report the case of a consanguineous couple who lost four pregnancies associated with skeletal dysplasia. Radiological examination of one fetus was inconclusive. Parental exome sequencing showed that both parents were heterozygous for a novel missense variant, p.(Pro133Leu), in the SLC35D1 gene encoding a nucleotide sugar transporter. The affected fetus was homozygous for the variant. The radiological features were reviewed, and being similar, but atypical, the phenotype was classified as a ‘Schneckenbecken-like dysplasia.’ The effect of the missense change was assessed using protein modelling techniques and indicated alterations in the mouth of the solute channel. A detailed biochemical investigation of SLC35D1 transport function and that of the missense variant p.(Pro133Leu) revealed that SLC35D1 acts as a general UDP-sugar transporter and that the p.(Pro133Leu) mutation resulted in a significant decrease in transport activity. The reduced transport activity observed for p.(Pro133Leu) was contrasted with in vitro activity for SLC35D1 p.(Thr65Pro), the loss-of-function mutation was associated with Schneckenbecken dysplasia. The functional classification of SLC35D1 as a general nucleotide sugar transporter of the endoplasmic reticulum suggests an expanded role for this transporter beyond chondroitin sulfate biosynthesis to a variety of important glycosylation reactions occurring in the endoplasmic reticulum.
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Affiliation(s)
| | - Oliver W Quarrell
- Department of Clinical Genetics, Sheffield Children's Hospital, Western Bank, Sheffield S10 2TH, UK
| | - Karen Stals
- Department of Molecular Genetics, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Richard C Caswell
- University of Exeter School of Medicine, Barrack Road, Exeter EX2 5DW, UK
| | - Elisa De Franco
- Department of Molecular Genetics, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Emma Baple
- Department of Molecular Genetics, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK.,University of Exeter School of Medicine, Barrack Road, Exeter EX2 5DW, UK
| | - Nadia Burgess
- Department of Histology, Sheffield Children's Hospital NHS Foundation Trust, Western Bank, Sheffield UK. S10 2TH, UK
| | - Roobin Jokhi
- Department of Obstetrics and Gynaecology, Sheffield Teaching Hospitals, Jessop Wing Tree Root Walk, Sheffield S10 2SF, UK
| | - Joshua L Heazlewood
- School of BioSciences, The University of Melbourne, Victoria 3010, Australia
| | - Amaka C Offiah
- University of Sheffield, Academic Unit of Child Health, Sheffield Children's Hospital NHS Foundation Trust, Western Bank, Sheffield S10 2TH, UK
| | - Berit Ebert
- School of BioSciences, The University of Melbourne, Victoria 3010, Australia
| | - Sian Ellard
- Department of Molecular Genetics, Royal Devon & Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK.,University of Exeter School of Medicine, Barrack Road, Exeter EX2 5DW, UK
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5
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Ukaegbu OI, DeMeester KE, Liang H, Brown AR, Jones ZS, Grimes CL. Utility of bacterial peptidoglycan recycling enzymes in the chemoenzymatic synthesis of valuable UDP sugar substrates. Methods Enzymol 2020; 638:1-26. [PMID: 32416908 DOI: 10.1016/bs.mie.2020.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Uridine diphosphate (UDP) sugars are essential precursors for glycosylation reactions in all forms of life. Reactions that transfer the carbohydrate from the UDP donor are catalyzed by glycosyltransferases (Gtfs). While the stereochemistry and negative physiological charge of UDP-sugars are essential for their biochemical function in the cell, these characteristics make them challenging molecules to synthesize and purify on scale in the laboratory. This chapter focuses on the utilization of a chemoenzymatic synthesis of muramyl UDP-sugars, key building blocks in the bacterial cell peptidoglycan. A scalable strategy to obtain UDP-N-acetyl muramic acid derivatives (UDP-NAM), the first committed intermediate used solely in peptidoglycan biosynthesis, is described herein. This methodology utilizes two enzymes involving the cell wall recycling enzymes MurNAc/GlcNAc anomeric kinase (AmgK) and NAM α-1-phosphate uridylyl transferase (MurU), respectively. The promiscuity of these enzymes allows for the unique chemical functionality to be embedded in bacterial peptidoglycan both in vitro and in whole bacterial cells for subsequent structural and functional studies of this important biopolymer.
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Affiliation(s)
- Ophelia I Ukaegbu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, United States
| | - Kristen E DeMeester
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, United States
| | - Hai Liang
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, United States
| | - Ashley R Brown
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, United States
| | - Zachary S Jones
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, United States
| | - Catherine Leimkuhler Grimes
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE, United States; Department of Biological Sciences, University of Delaware, Newark, DE, United States.
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6
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Fic W, Faria C, St Johnston D. IMP regulates Kuzbanian to control the timing of Notch signalling in Drosophila follicle cells. Development 2019; 146:dev.168963. [PMID: 30635283 PMCID: PMC6361131 DOI: 10.1242/dev.168963] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 12/19/2018] [Indexed: 12/31/2022]
Abstract
The timing of Drosophila egg chamber development is controlled by a germline Delta signal that activates Notch in the follicle cells to induce them to cease proliferation and differentiate. Here, we report that follicle cells lacking the RNA-binding protein IMP go through one extra division owing to a delay in the Delta-dependent S2 cleavage of Notch. The timing of Notch activation has previously been shown to be controlled by cis-inhibition by Delta in the follicle cells, which is relieved when the miRNA pathway represses Delta expression. imp mutants are epistatic to Delta mutants and give an additive phenotype with belle and Dicer-1 mutants, indicating that IMP functions independently of both cis-inhibition and the miRNA pathway. We find that the imp phenotype is rescued by overexpression of Kuzbanian, the metalloprotease that mediates the Notch S2 cleavage. Furthermore, Kuzbanian is not enriched at the apical membrane in imp mutants, accumulating instead in late endosomes. Thus, IMP regulates Notch signalling by controlling the localisation of Kuzbanian to the apical domain, where Notch cleavage occurs, revealing a novel regulatory step in the Notch pathway.
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Affiliation(s)
| | | | - Daniel St Johnston
- The Gurdon Institute and The Department of Genetics, University of Cambridge, Tennis Court Rd, Cambridge CB2 1QN, UK
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7
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Negreiros E, Herszterg S, Kang KH, Câmara A, Dias WB, Carneiro K, Bier E, Todeschini AR, Araujo H. N-linked glycosylation restricts the function of Short gastrulation to bind and shuttle BMPs. Development 2018; 145:dev.167338. [PMID: 30355725 DOI: 10.1242/dev.167338] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/14/2018] [Indexed: 12/11/2022]
Abstract
Disorders of N-linked glycosylation are increasingly reported in the literature. However, the targets that are responsible for the associated developmental and physiological defects are largely unknown. Bone morphogenetic proteins (BMPs) act as highly dynamic complexes to regulate several functions during development. The range and strength of BMP activity depend on interactions with glycosylated protein complexes in the extracellular milieu. Here, we investigate the role of glycosylation for the function of the conserved extracellular BMP antagonist Short gastrulation (Sog). We identify conserved N-glycosylated sites and describe the effect of mutating these residues on BMP pathway activity in Drosophila Functional analysis reveals that loss of individual Sog glycosylation sites enhances BMP antagonism and/or increases the spatial range of Sog effects in the tissue. Mechanistically, we provide evidence that N-terminal and stem glycosylation controls extracellular Sog levels and distribution. The identification of similar residues in vertebrate Chordin proteins suggests that N-glycosylation may be an evolutionarily conserved process that adds complexity to the regulation of BMP activity.
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Affiliation(s)
- Erika Negreiros
- Institute for Biomedical Sciences, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902.,Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902
| | - Sophie Herszterg
- Institute for Biomedical Sciences, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902
| | - Kyung-Hwa Kang
- Division of Biological Sciences, University of California at San Diego, CA 92093-0349, USA
| | - Amanda Câmara
- Institute for Biomedical Sciences, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902.,Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902
| | - Wagner B Dias
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902
| | - Katia Carneiro
- Institute for Biomedical Sciences, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902
| | - Ethan Bier
- Division of Biological Sciences, University of California at San Diego, CA 92093-0349, USA
| | - Adriane Regina Todeschini
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902
| | - Helena Araujo
- Institute for Biomedical Sciences, Federal University of Rio de Janeiro, RJ, Brazil, 21941-902 .,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Brasil (INCT-ENEM)
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8
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Piombo V, Jochmann K, Hoffmann D, Wuelling M, Vortkamp A. Signaling systems affecting the severity of multiple osteochondromas. Bone 2018; 111:71-81. [PMID: 29545125 DOI: 10.1016/j.bone.2018.03.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/12/2018] [Accepted: 03/09/2018] [Indexed: 01/01/2023]
Abstract
Multiple osteochondromas (MO) syndrome is a dominant autosomal bone disorder characterized by the formation of cartilage-capped bony outgrowths that develop at the juxtaposition of the growth plate of endochondral bones. MO has been linked to mutations in either EXT1 or EXT2, two glycosyltransferases required for the synthesis of heparan sulfate (HS). The establishment of mouse mutants demonstrated that a clonal, homozygous loss of Ext1 in a wild type background leads to the development of osteochondromas. Here we investigate mechanisms that might contribute to the variation in the severity of the disease observed in human patients. Our results show that residual amounts of HS are sufficient to prevent the development of osteochondromas strongly supporting that loss of heterozygosity is required for osteochondroma formation. Furthermore, we demonstrate that different signaling pathways affect size and frequency of the osteochondromas thereby modulating the severity of the disease. Reduced Fgfr3 signaling, which regulates proliferation and differentiation of chondrocytes, increases osteochondroma number, while activated Fgfr3 signaling reduces osteochondroma size. Both, activation and reduction of Wnt/β-catenin signaling decrease osteochondroma size and frequency by interfering with the chondrogenic fate of the mutant cells. Reduced Ihh signaling does not change the development of the osteochondromas, while elevated Ihh signaling increases the cellularity and inhibits chondrocyte differentiation in a subset of osteochondromas and might thus predispose osteochondromas to the transformation into chondrosarcomas.
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Affiliation(s)
- Virginia Piombo
- Department of Developmental Biology, Centre of Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Katja Jochmann
- Department of Developmental Biology, Centre of Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Daniel Hoffmann
- Research Group Bioinformatics, Centre of Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Manuela Wuelling
- Department of Developmental Biology, Centre of Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany
| | - Andrea Vortkamp
- Department of Developmental Biology, Centre of Medical Biotechnology, Faculty of Biology, University of Duisburg-Essen, Essen, Germany.
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9
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Abstract
Glycans play diverse biological roles, ranging from structural and regulatory functions to mediating cellular interactions. For pathogens, they are also often required for virulence and survival in the host. In Cryptococcus neoformans, an opportunistic pathogen of humans, the acidic monosaccharide glucuronic acid (GlcA) is a critical component of multiple essential glycoconjugates. One of these glycoconjugates is the polysaccharide capsule, a major virulence factor that enables this yeast to modulate the host immune response and resist antimicrobial defenses. This allows cryptococci to colonize the lung and brain, leading to hundreds of thousands of deaths each year worldwide. Synthesis of most glycans, including capsule polysaccharides, occurs in the secretory pathway. However, the activated precursors for this process, nucleotide sugars, are made primarily in the cytosol. This topological problem is resolved by the action of nucleotide sugar transporters (NSTs). We discovered that Uut1 is the sole UDP-GlcA transporter in C. neoformans and is unique among NSTs for its narrow substrate range and high affinity for UDP-GlcA. Mutant cells with UUT1 deleted lack capsule polysaccharides and are highly sensitive to environmental stress. As a result, the deletion mutant is internalized and cleared by phagocytes more readily than wild-type cells are and is completely avirulent in mice. These findings expand our understanding of the requirements for capsule synthesis and cryptococcal virulence and elucidate a critical protein family.IMPORTANCECryptococcus neoformans causes lethal meningitis in almost two hundred thousand immunocompromised patients each year. Much of this fungal pathogen's ability to resist host defenses and cause disease is mediated by carbohydrate structures, including a complex polysaccharide capsule around the cell. Like most eukaryotic glycoconjugates, capsule polysaccharides are made within the secretory pathway, although their precursors are generated in the cytosol. Specific transporters are therefore required to convey these raw materials to the site of synthesis. One precursor of particular interest is UDP-glucuronic acid, which donates glucuronic acid to growing capsule polysaccharides. We discovered a highly specific, high-affinity transporter for this molecule. Deletion of the gene encoding this unusual protein abolishes capsule synthesis, alters stress resistance, and eliminates fungal virulence. In this work, we have identified a novel transporter, elucidated capsule synthesis and thereby aspects of fungal pathogenesis, and opened directions for potential antifungal therapy.
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10
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Salazar JL, Yamamoto S. Integration of Drosophila and Human Genetics to Understand Notch Signaling Related Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1066:141-185. [PMID: 30030826 PMCID: PMC6233323 DOI: 10.1007/978-3-319-89512-3_8] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Notch signaling research dates back to more than one hundred years, beginning with the identification of the Notch mutant in the fruit fly Drosophila melanogaster. Since then, research on Notch and related genes in flies has laid the foundation of what we now know as the Notch signaling pathway. In the 1990s, basic biological and biochemical studies of Notch signaling components in mammalian systems, as well as identification of rare mutations in Notch signaling pathway genes in human patients with rare Mendelian diseases or cancer, increased the significance of this pathway in human biology and medicine. In the 21st century, Drosophila and other genetic model organisms continue to play a leading role in understanding basic Notch biology. Furthermore, these model organisms can be used in a translational manner to study underlying mechanisms of Notch-related human diseases and to investigate the function of novel disease associated genes and variants. In this chapter, we first briefly review the major contributions of Drosophila to Notch signaling research, discussing the similarities and differences between the fly and human pathways. Next, we introduce several biological contexts in Drosophila in which Notch signaling has been extensively characterized. Finally, we discuss a number of genetic diseases caused by mutations in genes in the Notch signaling pathway in humans and we expand on how Drosophila can be used to study rare genetic variants associated with these and novel disorders. By combining modern genomics and state-of-the art technologies, Drosophila research is continuing to reveal exciting biology that sheds light onto mechanisms of disease.
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Affiliation(s)
- Jose L Salazar
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, USA.
- Program in Developmental Biology, BCM, Houston, TX, USA.
- Department of Neuroscience, BCM, Houston, TX, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.
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11
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Marini C, Hardies K, Pisano T, May P, Weckhuysen S, Cellini E, Suls A, Mei D, Balling R, Jonghe PD, Helbig I, Garozzo D, Guerrini R. Recessive mutations in SLC35A3 cause early onset epileptic encephalopathy with skeletal defects. Am J Med Genet A 2017; 173:1119-1123. [PMID: 28328131 DOI: 10.1002/ajmg.a.38112] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 10/28/2016] [Accepted: 12/09/2016] [Indexed: 11/08/2022]
Abstract
We describe the clinical and whole genome sequencing (WGS) study of a non-consanguineous Italian family in which two siblings, a boy and a girl, manifesting a severe epileptic encephalopathy (EE) with skeletal abnormalities, carried novel SLC35A3 compound heterozygous mutations. Both siblings exhibited infantile spasms, associated with focal, and tonic vibratory seizures from early infancy. EEG recordings showed a suppression-burst (SB) pattern and multifocal paroxysmal activity in both. In addition both had quadriplegia, acquired microcephaly, and severe intellectual disability. General examination showed distal arthrogryposis predominant in the hands in both siblings and severe left dorso-lumbar convex scoliosis in one. WGS of the siblings-parents quartet identified novel compound heterozygous mutations in SLC35A3 in both children. SLC35A3 encodes the major Golgi uridine diphosphate N-acetylglucosamine transporter. With this study, we add SLC35A3 to the gene list of epilepsies. Neurological symptoms and skeletal abnormalities might result from impaired glycosylation of proteins involved in normal development and function of the central nervous system and skeletal apparatus.
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Affiliation(s)
- Carla Marini
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy
| | - Katia Hardies
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Tiziana Pisano
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy
| | - Patrick May
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Luxembourg, Luxembourg.,Institute for Systems Biology (ISB), Seattle, Washington
| | - Sarah Weckhuysen
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Elena Cellini
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy
| | - Arvid Suls
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | - Davide Mei
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy
| | - Rudi Balling
- Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, Luxembourg, Luxembourg
| | - Peter D Jonghe
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium.,Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium.,Division of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Ingo Helbig
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein, Christian-Albrechts University, Kiel, Germany.,Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Domenico Garozzo
- CNR, Institute of Chemistry and Technology of Polymers, Section of Catania, Catania, Italy
| | | | - Renzo Guerrini
- Neurology Unit and Neurogenetics Laboratories, Meyer Children Hospital, Florence, Italy.,University of Florence, Florence, Italy
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12
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Walia G, Smith AD, Riches Z, Collier AC, Coughtrie MWH. The effects of UDP-sugars, UDP and Mg 2+on uridine diphosphate glucuronosyltransferase activity in human liver microsomes. Xenobiotica 2017; 48:882-890. [PMID: 28868965 DOI: 10.1080/00498254.2017.1376260] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
1. The UDP-glucuronosyltransferase (UGT) enzymes are important in the metabolism, elimination and detoxification of many xenobiotics and endogenous compounds. As extrapolation of in vitro kinetics of drug metabolizing enzymes to predict in vivo clearance rates becomes more sophisticated, it is important to ensure proper optimization of enzyme assays. The luminal location of the enzyme active site (i.e. latency), and the complexity of UGT kinetics, results in consistent under-prediction of clearance of drugs metabolized by glucuronidation. 2. We examined inhibition of UGT activity in alamethicin-disrupted human liver microsomes (HLM) by uridine diphosphate (UDP), a UGT reaction product, and its reversal by Mg2+ ions. We also determined whether UDP-sugars other than the co-substrate UDP-glucuronic acid (UDP-GlcA) affected glucuronidation. 3. We show that other UDP-sugars do not significantly influence glucuronidation. We also demonstrate that UDP inhibits HLM UGT activity and that this is reversed by including Mg2+ in the assay. The Mg2+ effect can be offset using EDTA, and is dependent on the concentration of UDP-GlcA in the assay. 4. We propose that formation of a Mg2+-UDP complex prevents UDP from affecting the enzyme. Our results suggest that 5 mM UDP-GlcA and 10 mM Mg2+ be used for UGT assays in fully disrupted HLM.
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Affiliation(s)
- Gurinder Walia
- a Faculty of Pharmaceutical Sciences, The University of British Columbia , Vancouver , Canada
| | - Alexander D Smith
- a Faculty of Pharmaceutical Sciences, The University of British Columbia , Vancouver , Canada
| | - Zoe Riches
- a Faculty of Pharmaceutical Sciences, The University of British Columbia , Vancouver , Canada
| | - Abby C Collier
- a Faculty of Pharmaceutical Sciences, The University of British Columbia , Vancouver , Canada
| | - Michael W H Coughtrie
- a Faculty of Pharmaceutical Sciences, The University of British Columbia , Vancouver , Canada
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13
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Liu Y, Coughtrie MWH. Revisiting the Latency of Uridine Diphosphate-Glucuronosyltransferases (UGTs)-How Does the Endoplasmic Reticulum Membrane Influence Their Function? Pharmaceutics 2017; 9:E32. [PMID: 28867809 PMCID: PMC5620573 DOI: 10.3390/pharmaceutics9030032] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 08/26/2017] [Accepted: 08/28/2017] [Indexed: 11/18/2022] Open
Abstract
Uridine diphosphate-glucuronosyltransferases (UGTs) are phase 2 conjugation enzymes mainly located in the endoplasmic reticulum (ER) of the liver and many other tissues, and can be recovered in artificial ER membrane preparations (microsomes). They catalyze glucuronidation reactions in various aglycone substrates, contributing significantly to the body's chemical defense mechanism. There has been controversy over the last 50 years in the UGT field with respect to the explanation for the phenomenon of latency: full UGT activity revealed by chemical or physical disruption of the microsomal membrane. Because latency can lead to inaccurate measurements of UGT activity in vitro, and subsequent underprediction of drug clearance in vivo, it is important to understand the mechanisms behind this phenomenon. Three major hypotheses have been advanced to explain UGT latency: compartmentation, conformation, and adenine nucleotide inhibition. In this review, we discuss the evidence behind each hypothesis in depth, and suggest some additional studies that may reveal more information on this intriguing phenomenon.
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Affiliation(s)
- Yuejian Liu
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| | - Michael W H Coughtrie
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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14
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Agerholm JS, Bendixen C, Arnbjerg J, Andersen O. Morphological Variation of “Complex Vertebral Malformation” in Holstein Calves. J Vet Diagn Invest 2016; 16:548-53. [PMID: 15586570 DOI: 10.1177/104063870401600609] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A study was performed to investigate the morphological expression of the inherited syndrome “complex vertebral malformation” (CVM) in Holstein calves. A total of 107 late-term aborted, premature, or neonatal calves suspected of having CVM were necropsied and retrospectively analyzed for the causal mutation in the gene SLC35A3. Sixty-two calves were homozygous affected, 16 were heterozygous, and 29 were homozygous normal. Calves affected by CVM were growth retarded. Vertebral lesions identified by radiography were present in 61 cases, of which 58 also had costal malformation. Malformation of the head, primarily in the form of dysplasia or palatoschisis, was present in 15 cases. Bilateral symmetric flexion of the carpal and metacarpophalangeal joints was present in all cases, whereas posterior arthrogryposis was found in 54 cases. Interventricular septal defects occurred in 33 calves, often in combination with other cardiac malformations. A wide spectrum of additional malformations was found. Other congenital syndromes were in most cases distinguishable from CVM on a morphological basis. However, a calf with a prenatal infection with bovine virus diarrhea virus constituted a phenocopy. The study demonstrated that the morphological expression of CVM is wide, but certain aspects, i.e., growth retardation, vertebral malformation, and symmetric arthrogryposis, are almost constant findings. However, cases without vertebral defects and phenocopies constitute a diagnostic problem. A presumptive diagnosis of CVM can in most cases be based on necropsy findings combined with information on descent and paternal CVM genotype, whereas a definitive diagnosis requires genotyping.
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Affiliation(s)
- Jorgen S Agerholm
- Department of Veterinary Pathobiology and Clinical Studies, Royal Veterinary and Agricultural University, Bulowsvej 17, DK-1870 Frederiksberg C, Denmark
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15
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Orellana A, Moraga C, Araya M, Moreno A. Overview of Nucleotide Sugar Transporter Gene Family Functions Across Multiple Species. J Mol Biol 2016; 428:3150-3165. [PMID: 27261257 DOI: 10.1016/j.jmb.2016.05.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/19/2016] [Accepted: 05/23/2016] [Indexed: 11/16/2022]
Abstract
Glycoproteins and glycolipids are crucial in a number of cellular processes, such as growth, development, and responses to external cues, among others. Polysaccharides, another class of sugar-containing molecules, also play important structural and signaling roles in the extracellular matrix. The additions of glycans to proteins and lipids, as well as polysaccharide synthesis, are processes that primarily occur in the Golgi apparatus, and the substrates used in this biosynthetic process are nucleotide sugars. These proteins, lipids, and polysaccharides are also modified by the addition of sulfate groups in the Golgi apparatus in a series of reactions where nucleotide sulfate is needed. The required nucleotide sugar substrates are mainly synthesized in the cytosol and transported into the Golgi apparatus by nucleotide sugar transporters (NSTs), which can additionally transport nucleotide sulfate. Due to the critical role of NSTs in eukaryotic organisms, any malfunction of these could change glycan and polysaccharide structures, thus affecting function and altering organism physiology. For example, mutations or deletion on NST genes lead to pathological conditions in humans or alter cell walls in plants. In recent years, many NSTs have been identified and functionally characterized, but several remain unanalyzed. This study examined existing information on functionally characterized NSTs and conducted a phylogenetic analysis of 257 NSTs predicted from nine animal and plant model species, as well as from protists and fungi. From this analysis, relationships between substrate specificity and the primary NST structure can be inferred, thereby advancing understandings of nucleotide sugar gene family functions across multiple species.
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Affiliation(s)
- Ariel Orellana
- Centro de Biotecnología Vegetal, Universidad Andres Bello, Av. República 217, Santiago, RM 837-0146, Chile; FONDAP Center for Genome Regulation, Santiago, RM,Chile.
| | - Carol Moraga
- Centro de Biotecnología Vegetal, Universidad Andres Bello, Av. República 217, Santiago, RM 837-0146, Chile.
| | - Macarena Araya
- Centro de Biotecnología Vegetal, Universidad Andres Bello, Av. República 217, Santiago, RM 837-0146, Chile.
| | - Adrian Moreno
- Centro de Biotecnología Vegetal, Universidad Andres Bello, Av. República 217, Santiago, RM 837-0146, Chile; FONDAP Center for Genome Regulation, Santiago, RM,Chile.
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16
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Matsumoto K, Ayukawa T, Ishio A, Sasamura T, Yamakawa T, Matsuno K. Dual Roles of O-Glucose Glycans Redundant with Monosaccharide O-Fucose on Notch in Notch Trafficking. J Biol Chem 2016; 291:13743-52. [PMID: 27129198 DOI: 10.1074/jbc.m115.710483] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Indexed: 12/25/2022] Open
Abstract
Notch is a transmembrane receptor that mediates cell-cell interactions and controls various cell-fate specifications in metazoans. The extracellular domain of Notch contains multiple epidermal growth factor (EGF)-like repeats. At least five different glycans are found in distinct sites within these EGF-like repeats. The function of these individual glycans in Notch signaling has been investigated, primarily by disrupting their individual glycosyltransferases. However, we are just beginning to understand the potential functional interactions between these glycans. Monosaccharide O-fucose and O-glucose trisaccharide (O-glucose-xylose-xylose) are added to many of the Notch EGF-like repeats. In Drosophila, Shams adds a xylose specifically to the monosaccharide O-glucose. We found that loss of the terminal dixylose of O-glucose-linked saccharides had little effect on Notch signaling. However, our analyses of double mutants of shams and other genes required for glycan modifications revealed that both the monosaccharide O-glucose and the terminal dixylose of O-glucose-linked saccharides function redundantly with the monosaccharide O-fucose in Notch activation and trafficking. The terminal dixylose of O-glucose-linked saccharides and the monosaccharide O-glucose were required in distinct Notch trafficking processes: Notch transport from the apical plasma membrane to adherens junctions, and Notch export from the endoplasmic reticulum, respectively. Therefore, the monosaccharide O-glucose and terminal dixylose of O-glucose-linked saccharides have distinct activities in Notch trafficking, although a loss of these activities is compensated for by the presence of monosaccharide O-fucose. Given that various glycans attached to a protein motif may have redundant functions, our results suggest that these potential redundancies may lead to a serious underestimation of glycan functions.
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Affiliation(s)
- Kenjiroo Matsumoto
- From the Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 and
| | - Tomonori Ayukawa
- the Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-1500, Japan
| | - Akira Ishio
- the Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo 125-1500, Japan
| | - Takeshi Sasamura
- From the Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 and
| | - Tomoko Yamakawa
- From the Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 and
| | - Kenji Matsuno
- From the Department of Biological Sciences, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 and
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17
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Yamamoto-Hino M, Yoshida H, Ichimiya T, Sakamura S, Maeda M, Kimura Y, Sasaki N, Aoki-Kinoshita KF, Kinoshita-Toyoda A, Toyoda H, Ueda R, Nishihara S, Goto S. Phenotype-based clustering of glycosylation-related genes by RNAi-mediated gene silencing. Genes Cells 2015; 20:521-42. [PMID: 25940448 PMCID: PMC4682476 DOI: 10.1111/gtc.12246] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/24/2015] [Indexed: 01/16/2023]
Abstract
Glycan structures are synthesized by a series of reactions conducted by glycosylation-related (GR) proteins such as glycosyltransferases, glycan-modifying enzymes, and nucleotide-sugar transporters. For example, the common core region of glycosaminoglycans (GAGs) is sequentially synthesized by peptide-O-xylosyltransferase, β1,4-galactosyltransferase I, β1,3-galactosyltransferase II, and β1,3-glucuronyltransferase. This raises the possibility that functional impairment of GR proteins involved in synthesis of the same glycan might result in the same phenotypic abnormality. To examine this possibility, comprehensive silencing of genes encoding GR and proteoglycan core proteins was conducted in Drosophila. Drosophila GR candidate genes (125) were classified into five functional groups for synthesis of GAGs, N-linked, O-linked, Notch-related, and unknown glycans. Spatiotemporally regulated silencing caused a range of malformed phenotypes that fell into three types: extra veins, thick veins, and depigmentation. The clustered phenotypes reflected the biosynthetic pathways of GAGs, Fringe-dependent glycan on Notch, and glycans placed at or near nonreducing ends (herein termed terminal domains of glycans). Based on the phenotypic clustering, CG33145 was predicted to be involved in formation of terminal domains. Our further analysis showed that CG33145 exhibited galactosyltransferase activity in synthesis of terminal N-linked glycans. Phenotypic clustering, therefore, has potential for the functional prediction of novel GR genes.
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Affiliation(s)
- Miki Yamamoto-Hino
- Department of Life Science, Rikkyo University, Toshima-ku, Tokyo, Japan.,Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan
| | - Hideki Yoshida
- Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan.,Department of Bioinformatics, Faculty of Engineering, Soka University, Hachioji, Tokyo, Japan.,Department of Applied Biology, Insect Biomedical Research Center, Kyoto Institute of Technology, Sakyo-ku, Kyoto, Japan
| | - Tomomi Ichimiya
- Department of Bioinformatics, Faculty of Engineering, Soka University, Hachioji, Tokyo, Japan
| | - Sho Sakamura
- Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Megumi Maeda
- Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Yoshinobu Kimura
- Department of Biofunctional Chemistry, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Norihiko Sasaki
- Department of Bioinformatics, Faculty of Engineering, Soka University, Hachioji, Tokyo, Japan.,Research Team for Geriatric Medicine (Vascular Medicine), Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo, Japan
| | - Kiyoko F Aoki-Kinoshita
- Department of Bioinformatics, Faculty of Engineering, Soka University, Hachioji, Tokyo, Japan
| | - Akiko Kinoshita-Toyoda
- Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan.,College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Hidenao Toyoda
- Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan.,College of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Ryu Ueda
- Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan.,Invertebrate Genetics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Shoko Nishihara
- Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan.,Department of Bioinformatics, Faculty of Engineering, Soka University, Hachioji, Tokyo, Japan
| | - Satoshi Goto
- Department of Life Science, Rikkyo University, Toshima-ku, Tokyo, Japan.,Core Research for Evolutional Science and Technology (CREST) of Japan Science and Technology Agency (JST), Kawaguchi, Saitama, Japan
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18
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Dynamic regulation of innate immune responses in Drosophila by Senju-mediated glycosylation. Proc Natl Acad Sci U S A 2015; 112:5809-14. [PMID: 25901322 DOI: 10.1073/pnas.1424514112] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The innate immune system is the first line of defense encountered by invading pathogens. Delayed and/or inadequate innate immune responses can result in failure to combat pathogens, whereas excessive and/or inappropriate responses cause runaway inflammation. Therefore, immune responses are tightly regulated from initiation to resolution and are repressed during the steady state. It is well known that glycans presented on pathogens play important roles in pathogen recognition and the interactions between host molecules and microbes; however, the function of glycans of host organisms in innate immune responses is less well known. Here, we show that innate immune quiescence and strength of the immune response are controlled by host glycosylation involving a novel UDP-galactose transporter called Senju. In senju mutants, reduced expression of galactose-containing glycans resulted in hyperactivation of the Toll signaling pathway in the absence of immune challenges. Genetic epistasis and biochemical analyses revealed that Senju regulates the Toll signaling pathway at a step that converts Toll ligand Spatzle to its active form. Interestingly, Toll activation in immune-challenged wild type (WT) flies reduced the expression of galactose-containing glycans. Suppression of the degalactosylation by senju overexpression resulted in reduced induction of Toll-dependent expression of an antimicrobial peptide, Drosomycin, and increased susceptibility to infection with Gram-positive bacteria. These data suggest that Senju-mediated galactosylation suppresses undesirable Toll signaling activation during the steady state; however, Toll activation in response to infection leads to degalactosylation, which raises the immune response to an adequate level and contributes to the prompt elimination of pathogens.
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19
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Riches Z, Collier AC. Posttranscriptional regulation of uridine diphosphate glucuronosyltransferases. Expert Opin Drug Metab Toxicol 2015; 11:949-65. [PMID: 25797307 DOI: 10.1517/17425255.2015.1028355] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION The uridine diphosphate (UDP)-glucuronosyltransferase (UGT) superfamily of enzymes (EC 2.4.1.17) conjugates glucuronic acid to an aglycone substrate to make them more polar and readily excreted. In general, this reaction terminates the activities of chemicals, drugs and toxins, although occasionally a more active or toxic species is produced. AREAS COVERED In addition to their well-known transcriptional responsiveness, UGTs are also regulated by posttranscriptional mechanisms. Here, the authors review these mechanisms, including latency, modulation of co-substrate accessibility and binding, dimerization and oligomerization, protein-protein interactions, allosteric inhibition and activation, posttranslational structural and functional modifications and developmental switching for UGTs. EXPERT OPINION Posttranscriptional regulation of UGTs has traditionally received less attention than nuclear regulation, in part because mechanisms involving ribosomes and endoplasmic reticula are challenging to investigate. Most promising of the posttranscriptional mechanisms reviewed are likely to be effects on co-substrate (UDP-glucuronic acid) transport and availability and structure-function changes to UGT proteins through, for example, glycosylation and phosphorylation. Although classical biochemistry continues to illuminate many aspects of UGT function, advances in proteomics and structural biology are beginning to assist in the determination of posttranscriptional regulation mechanisms for UGTs.
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Affiliation(s)
- Zoe Riches
- University of British Columbia, Faculty of Pharmaceutical Sciences , 2405 Wesbrook Mall, Vancouver, BC V6T 1Z3 , Canada +1 604 827 2380 ;
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20
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Collier AC, Yamauchi Y, Sato BLM, Rougée LRA, Ward MA. UDP-glucuronosyltransferase 1a enzymes are present and active in the mouse blastocyst. Drug Metab Dispos 2014; 42:1921-5. [PMID: 25200869 DOI: 10.1124/dmd.114.059766] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The UDP-glucuronosyltransferase (UGT) enzymes are critical for regulating nutrients, hormones, and endobiotics, as well as for detoxifying xenobiotics. Human and murine fetuses are known to express glucuronidation enzymes, but there are currently no data prior to implantation. Here we addressed this gap in knowledge and tested whether Ugt enzymes are already present in preimplantation-stage embryos. Blastocysts were obtained after in vitro fertilization with gametes from B6D2F1 hybrid mice and from embryo culture. Protein expression and localization were determined using pan-specific UGT1A and UGT2B, as well as anti-human isoform-specific antibodies. Immunofluorescence analysis showed that blastocysts expressed Ugt1a globally, in the cytoplasm and nuclei of all of the cells. Western blots demonstrated the presence of Ugt1a6 but not Ugt1a1, Ugt1a3, Ugt1a4, or Ugt1a9. The Ugt2b proteins were not detected by either assay. The level of Ugt activity in murine blastocysts was comparable with that of the adult human liver (per milligram of protein), but the activity of β-glucuronidase, an Ugt-partnering enzyme responsible for substrate regeneration, was lower. Altogether, these data confirm that Ugt1a proteins are present and active in preimplantation murine embryos and point to a potential role for these proteins in implantation and early embryonic and fetal development.
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Affiliation(s)
- Abby C Collier
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.C.C.); Department of Tropical Medicine, Medical Microbiology, and Pharmacology (A.C.C., B.L.M.S., L.R.A.R.), and Institute for Biogenesis Research (Y.Y., M.A.W.), John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii; and Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii (B.L.M.S.)
| | - Yasuhiro Yamauchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.C.C.); Department of Tropical Medicine, Medical Microbiology, and Pharmacology (A.C.C., B.L.M.S., L.R.A.R.), and Institute for Biogenesis Research (Y.Y., M.A.W.), John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii; and Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii (B.L.M.S.)
| | - Brittany L M Sato
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.C.C.); Department of Tropical Medicine, Medical Microbiology, and Pharmacology (A.C.C., B.L.M.S., L.R.A.R.), and Institute for Biogenesis Research (Y.Y., M.A.W.), John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii; and Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii (B.L.M.S.)
| | - Luc R A Rougée
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.C.C.); Department of Tropical Medicine, Medical Microbiology, and Pharmacology (A.C.C., B.L.M.S., L.R.A.R.), and Institute for Biogenesis Research (Y.Y., M.A.W.), John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii; and Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii (B.L.M.S.)
| | - Monika A Ward
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada (A.C.C.); Department of Tropical Medicine, Medical Microbiology, and Pharmacology (A.C.C., B.L.M.S., L.R.A.R.), and Institute for Biogenesis Research (Y.Y., M.A.W.), John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii; and Natural Sciences and Mathematics, Chaminade University of Honolulu, Honolulu, Hawaii (B.L.M.S.)
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21
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Peterson NA, Anderson TK, Wu XJ, Yoshino TP. In silico analysis of the fucosylation-associated genome of the human blood fluke Schistosoma mansoni: cloning and characterization of the enzymes involved in GDP-L-fucose synthesis and Golgi import. Parasit Vectors 2013; 6:201. [PMID: 23835114 PMCID: PMC3718619 DOI: 10.1186/1756-3305-6-201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 06/15/2013] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Carbohydrate structures of surface-expressed and secreted/excreted glycoconjugates of the human blood fluke Schistosoma mansoni are key determinants that mediate host-parasite interactions in both snail and mammalian hosts. Fucose is a major constituent of these immunologically important glycans, and recent studies have sought to characterize fucosylation-associated enzymes, including the Golgi-localized fucosyltransferases that catalyze the transfer of L-fucose from a GDP-L-fucose donor to an oligosaccharide acceptor. Importantly, GDP-L-fucose is the only nucleotide-sugar donor used by fucosyltransferases and its availability represents a bottleneck in fucosyl-glycotope expression. METHODS A homology-based genome-wide bioinformatics approach was used to identify and molecularly characterize the enzymes that contribute to GDP-L-fucose synthesis and Golgi import in S. mansoni. Putative functions were further investigated through molecular phylogenetic and immunocytochemical analyses. RESULTS We identified homologs of GDP-D-mannose-4,6-dehydratase (GMD) and GDP-4-keto-6-deoxy-D-mannose-3,5-epimerase-4-reductase (GMER), which constitute a de novo pathway for GDP-L-fucose synthesis, in addition to a GDP-L-fucose transporter (GFT) that putatively imports cytosolic GDP-L-fucose into the Golgi. In silico primary sequence analyses identified characteristic Rossman loop and short-chain dehydrogenase/reductase motifs in GMD and GMER as well as 10 transmembrane domains in GFT. All genes are alternatively spliced, generating variants of unknown function. Observed quantitative differences in steady-state transcript levels between miracidia and primary sporocysts may contribute to differential glycotope expression in early larval development. Additionally, analyses of protein expression suggest the occurrence of cytosolic GMD and GMER in the ciliated epidermal plates and tegument of miracidia and primary sporocysts, respectively, which is consistent with previous localization of highly fucosylated glycotopes. CONCLUSIONS This study is the first to identify and characterize three key genes that are putatively involved in the synthesis and Golgi import of GDP-L-fucose in S. mansoni and provides fundamental information regarding their genomic organization, genetic variation, molecular phylogenetics, and developmental expression in intramolluscan larval stages.
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Affiliation(s)
- Nathan A Peterson
- Current address: Department of Entomology, College of Agricultural and Life Sciences, University of Wisconsin, 1630 Linden Drive, Madison, WI 53706, USA
| | - Tavis K Anderson
- Current address: Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, 1920 Dayton Ave, Ames, IA 50010, USA
| | - Xiao-Jun Wu
- Current address: Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, 2115 Observatory Drive, Madison, WI 53706, USA
| | - Timothy P Yoshino
- Current address: Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, 2115 Observatory Drive, Madison, WI 53706, USA
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Sekine SU, Haraguchi S, Chao K, Kato T, Luo L, Miura M, Chihara T. Meigo governs dendrite targeting specificity by modulating ephrin level and N-glycosylation. Nat Neurosci 2013; 16:683-91. [PMID: 23624514 DOI: 10.1038/nn.3389] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/01/2013] [Indexed: 11/09/2022]
Abstract
Neural circuit assembly requires precise dendrite and axon targeting. We identified an evolutionarily conserved endoplasmic reticulum (ER) protein, Meigo, from a mosaic genetic screen in Drosophila melanogaster. Meigo was cell-autonomously required in olfactory receptor neurons and projection neurons to target their axons and dendrites to the lateral antennal lobe and to refine projection neuron dendrites into individual glomeruli. Loss of Meigo induced an unfolded protein response and reduced the amount of neuronal cell surface proteins, including Ephrin. Ephrin overexpression specifically suppressed the projection neuron dendrite refinement defect present in meigo mutant flies, and ephrin knockdown caused a similar projection neuron dendrite refinement defect. Meigo positively regulated the level of Ephrin N-glycosylation, which was required for its optimal function in vivo. Thus, Meigo, an ER-resident protein, governs neuronal targeting specificity by regulating ER folding capacity and protein N-glycosylation. Furthermore, Ephrin appears to be an important substrate that mediates Meigo's function in refinement of glomerular targeting.
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Affiliation(s)
- Sayaka U Sekine
- Department of Genetics, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan
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23
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Molecular cloning, phylogenetic analysis, and expression profiling of a grape CMP-sialic acid transporter-like gene induced by phytohormone and abiotic stress. Genes Genomics 2013. [DOI: 10.1007/s13258-013-0074-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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24
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Handford M, Rodríguez-Furlán C, Marchant L, Segura M, Gómez D, Alvarez-Buylla E, Xiong GY, Pauly M, Orellana A. Arabidopsis thaliana AtUTr7 encodes a golgi-localized UDP-glucose/UDP-galactose transporter that affects lateral root emergence. MOLECULAR PLANT 2012; 5:1263-80. [PMID: 22933714 DOI: 10.1093/mp/sss074] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Nucleotide sugar transporters (NSTs) are antiporters comprising a gene family that plays a fundamental role in the biosynthesis of complex cell wall polysaccharides and glycoproteins in plants. However, due to the limited number of related mutants that have observable phenotypes, the biological function(s) of most NSTs in cell wall biosynthesis and assembly have remained elusive. Here, we report the characterization of AtUTr7 from Arabidopsis (Arabidopsis thaliana (L.) Heynh.), which is homologous to multi-specific UDP-sugar transporters from Drosophila melanogaster, humans, and Caenorhabditis elegans. We show that AtUTr7 possesses the common structural characteristics conserved among NSTs. Using a green fluorescent protein (GFP) tagged version, we demonstrate that AtUTr7 is localized in the Golgi apparatus. We also show that AtUTr7 is widely expressed, especially in the roots and in specific floral organs. Additionally, the results of an in vitro nucleotide sugar transport assay carried out with a tobacco and a yeast expression system suggest that AtUTr7 is capable of transferring UDP-Gal and UDP-Glc, but not a range of other UDP- and GDP-sugars, into the Golgi lumen. Mutants lacking expression of AtUTr7 exhibited an early proliferation of lateral roots as well as distorted root hairs when cultivated at high sucrose concentrations. Furthermore, the distribution of homogalacturonan with a low degree of methyl esterification differed in lateral root tips of the mutant compared to wild-type plants, although additional analytical procedures revealed no further differences in the composition of the root cell walls. This evidence suggests that the transport of UDP-Gal and UDP-Glc into the Golgi under conditions of high root biomass production plays a role in lateral root and root hair development.
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25
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Liu L, Hirschberg CB. Developmental diseases caused by impaired nucleotide sugar transporters. Glycoconj J 2012; 30:5-10. [PMID: 22527830 DOI: 10.1007/s10719-012-9375-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 03/28/2012] [Indexed: 01/24/2023]
Abstract
Nucleotide sugar transporters play critical roles in glycosylation of proteins, lipids and proteoglycans, which are essential for organogenesis, development, mammalian cellular immunity and pathogenicity of human pathogenic agents. Functional deficiencies of these transporters result in global defects of glycoconjugates, which in turn lead to a diversity of biochemical, physiological and pathological phenotypes. In this short review, we will highlight human and bovine diseases caused by mutations of these transporters.
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Affiliation(s)
- Li Liu
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Evans-E438, 72 East Concord Street, Boston, MA 02118, USA
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26
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Carbohydrate synthesis and biosynthesis technologies for cracking of the glycan code: recent advances. Biotechnol Adv 2012; 31:17-37. [PMID: 22484115 DOI: 10.1016/j.biotechadv.2012.03.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Revised: 03/06/2012] [Accepted: 03/20/2012] [Indexed: 12/22/2022]
Abstract
The glycan code of glycoproteins can be conceptually defined at molecular level by the sequence of well characterized glycans attached to evolutionarily predetermined amino acids along the polypeptide chain. Functional consequences of protein glycosylation are numerous, and include a hierarchy of properties from general physicochemical characteristics such as solubility, stability and protection of the polypeptide from the environment up to specific glycan interactions. Definition of the glycan code for glycoproteins has been so far hampered by the lack of chemically defined glycoprotein glycoforms that proved to be extremely difficult to purify from natural sources, and the total chemical synthesis of which has been hitherto possible only for very small molecular species. This review summarizes the recent progress in chemical and chemoenzymatic synthesis of complex glycans and their protein conjugates. Progress in our understanding of the ways in which a particular glycoprotein glycoform gives rise to a unique set of functional properties is now having far reaching implications for the biotechnology of important glycodrugs such as therapeutical monoclonal antibodies, glycoprotein hormones, carbohydrate conjugates used for vaccination and other practically important protein-carbohydrate conjugates.
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27
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Yamamoto-Hino M, Abe M, Shibano T, Setoguchi Y, Awano W, Ueda R, Okano H, Goto S. Cisterna-specific localization of glycosylation-related proteins to the Golgi apparatus. Cell Struct Funct 2012; 37:55-63. [PMID: 22251795 DOI: 10.1247/csf.11037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The Golgi apparatus is an intracellular organelle playing central roles in post-translational modification and in the secretion of membrane and secretory proteins. These proteins are synthesized in the endoplasmic reticulum (ER) and transported to the cis-, medial-and trans-cisternae of the Golgi. While trafficking through the Golgi, proteins are sequentially modified with glycan moieties by different glycosyltransferases. Therefore, it is important to analyze the glycosylation function of the Golgi at the level of cisternae. Markers widely used for cis-, medial- and trans-cisternae/trans Golgi network (TGN) in Drosophila are GM130, 120 kDa and Syntaxin16 (Syx16); however the anti-120 kDa antibody is no longer available. In the present study, Drosophila Golgi complex-localized glycoprotein-1 (dGLG1) was identified as an antigen recognized by the anti-120 kDa antibody. A monoclonal anti-dGLG1 antibody suitable for immunohistochemistry was raised in rat. Using these markers, the localization of glycosyltransferases and nucleotide-sugar transporters (NSTs) was studied at the cisternal level. Results showed that glycosyltransferases and NSTs involved in the same sugar modification are localized to the same cisternae. Furthermore, valuable functional information was obtained on the localization of novel NSTs with as yet incompletely characterized biochemical properties.
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Affiliation(s)
- Miki Yamamoto-Hino
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
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28
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Ambegaokar SS, Jackson GR. Functional genomic screen and network analysis reveal novel modifiers of tauopathy dissociated from tau phosphorylation. Hum Mol Genet 2011; 20:4947-77. [PMID: 21949350 PMCID: PMC3221533 DOI: 10.1093/hmg/ddr432] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A functional genetic screen using loss-of-function and gain-of-function alleles was performed to identify modifiers of tau-induced neurotoxicity using the 2N/4R (full-length) isoform of wild-type human tau expressed in the fly retina. We previously reported eye pigment mutations, which create dysfunctional lysosomes, as potent modifiers; here, we report 37 additional genes identified from ∼1900 genes screened, including the kinases shaggy/GSK-3beta, par-1/MARK, CamKI and Mekk1. Tau acts synergistically with Mekk1 and p38 to down-regulate extracellular regulated kinase activity, with a corresponding decrease in AT8 immunoreactivity (pS202/T205), suggesting that tau can participate in signaling pathways to regulate its own kinases. Modifiers showed poor correlation with tau phosphorylation (using the AT8, 12E8 and AT270 epitopes); moreover, tested suppressors of wild-type tau were equally effective in suppressing toxicity of a phosphorylation-resistant S11A tau construct, demonstrating that changes in tau phosphorylation state are not required to suppress or enhance its toxicity. Genes related to autophagy, the cell cycle, RNA-associated proteins and chromatin-binding proteins constitute a large percentage of identified modifiers. Other functional categories identified include mitochondrial proteins, lipid trafficking, Golgi proteins, kinesins and dynein and the Hsp70/Hsp90-organizing protein (Hop). Network analysis uncovered several other genes highly associated with the functional modifiers, including genes related to the PI3K, Notch, BMP/TGF-β and Hedgehog pathways, and nuclear trafficking. Activity of GSK-3β is strongly upregulated due to TDP-43 expression, and reduced GSK-3β dosage is also a common suppressor of Aβ42 and TDP-43 toxicity. These findings suggest therapeutic targets other than mitigation of tau phosphorylation.
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Affiliation(s)
- Surendra S Ambegaokar
- Department of Neurology, University of Texas Medical Branch, 301 University Blvd., MRB 10.138, Galveston, TX 77555, USA
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29
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Maszczak-Seneczko D, Olczak T, Wunderlich L, Olczak M. Comparative analysis of involvement of UGT1 and UGT2 splice variants of UDP-galactose transporter in glycosylation of macromolecules in MDCK and CHO cell lines. Glycoconj J 2011; 28:481-92. [PMID: 21894462 PMCID: PMC3180625 DOI: 10.1007/s10719-011-9348-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 08/18/2011] [Accepted: 08/19/2011] [Indexed: 12/02/2022]
Abstract
Nucleotide sugar transporters deliver nucleotide sugars into the Golgi apparatus and endoplasmic reticulum. This study aimed to further characterize mammalian UDP-galactose transporter (UGT) in MDCK and CHO cell lines. MDCK-RCAr and CHO-Lec8 mutant cell lines are defective in UGT transporter, although they exhibit some level of galactosylation. Previously, only single forms of UGT were identified in both cell lines, UGT1 in MDCK cells and UGT2 in CHO cells. We have identified the second UGT splice variants in CHO (UGT1) and MDCK (UGT2) cells. Compared to UGT1, UGT2 is more abundant in nearly all examined mammalian tissues and cell lines, but MDCK cells exhibit different relative distribution of both splice variants. Complementation analysis demonstrated that both UGT splice variants are necessary for N- and O-glycosylation of proteins. Both mutant cell lines produce chondroitin-4-sulfate at only a slightly lower level compared to wild-type cells. This defect is corrected by overexpression of both UGT splice variants. MDCK-RCAr mutant cells do not produce keratan sulfate and this effect is not corrected by either UGT splice variant, overexpressed either singly or in combination. Here we demonstrate that both UGT splice variants are important for glycosylation of proteins. In contrast to MDCK cells, MDCK-RCAr mutant cells may possess an additional defect within the keratan sulfate biosynthesis pathway.
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Affiliation(s)
- Dorota Maszczak-Seneczko
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Tamka 2, 50-137 Wroclaw, Poland
| | - Teresa Olczak
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Tamka 2, 50-137 Wroclaw, Poland
| | - Livius Wunderlich
- Laboratory of Biochemistry and Molecular Biology, Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, 1521 Budapest, P.O. Box 91, Hungary
| | - Mariusz Olczak
- Laboratory of Biochemistry, Faculty of Biotechnology, University of Wroclaw, Tamka 2, 50-137 Wroclaw, Poland
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30
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Frank MJ, Fossella JA. Neurogenetics and pharmacology of learning, motivation, and cognition. Neuropsychopharmacology 2011; 36:133-52. [PMID: 20631684 PMCID: PMC3055524 DOI: 10.1038/npp.2010.96] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 06/09/2010] [Accepted: 06/10/2010] [Indexed: 02/07/2023]
Abstract
Many of the individual differences in cognition, motivation, and learning-and the disruption of these processes in neurological conditions-are influenced by genetic factors. We provide an integrative synthesis across human and animal studies, focusing on a recent spate of evidence implicating a role for genes controlling dopaminergic function in frontostriatal circuitry, including COMT, DARPP-32, DAT1, DRD2, and DRD4. These genetic effects are interpreted within theoretical frameworks developed in the context of the broader cognitive and computational neuroscience literature, constrained by data from pharmacological, neuroimaging, electrophysiological, and patient studies. In this framework, genes modulate the efficacy of particular neural computations, and effects of genetic variation are revealed by assays designed to be maximally sensitive to these computations. We discuss the merits and caveats of this approach and outline a number of novel candidate genes of interest for future study.
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Affiliation(s)
- Michael J Frank
- Department of Cognitive, Linguistic and Psychological Sciences, Brown Institute for Brain Science, Brown University, Providence, RI 02912-1978, USA.
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31
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Mo JS, Ann EJ, Yoon JH, Jung J, Choi YH, Kim HY, Ahn JS, Kim SM, Kim MY, Hong JA, Seo MS, Lang F, Choi EJ, Park HS. Serum- and glucocorticoid-inducible kinase 1 (SGK1) controls Notch1 signaling by downregulation of protein stability through Fbw7 ubiquitin ligase. J Cell Sci 2010; 124:100-12. [PMID: 21147854 DOI: 10.1242/jcs.073924] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Notch is a transmembrane protein that acts as a transcriptional factor in the Notch signaling pathway for cell survival, cell death and cell differentiation. Notch1 and Fbw7 mutations both lead the activation of the Notch1 pathway and are found in the majority of patients with the leukemia T-ALL. However, little is known about the mechanisms and regulators that are responsible for attenuating the Notch signaling pathway through Fbw7. Here, we report that the serum- and glucocorticoid-inducible protein kinase SGK1 remarkably reduced the protein stability of the active form of Notch1 through Fbw7. The protein level and transcriptional activity of the Notch1 intracellular domain (Notch1-IC) were higher in SGK1-deficient cells than in SGK1 wild-type cells. Notch1-IC was able to form a trimeric complex with Fbw7 and SGK1, thereby SGK1 enhanced the protein degradation of Notch1-IC via a Fbw7-dependent proteasomal pathway. Furthermore, activated SGK1 phosphorylated Fbw7 at serine 227, an effect inducing Notch1-IC protein degradation and ubiquitylation. Moreover, accumulated dexamethasone-induced SGK1 facilitated the degradation of Notch1-IC through phosphorylation of Fbw7. Together our results suggest that SGK1 inhibits the Notch1 signaling pathway via phosphorylation of Fbw7.
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Affiliation(s)
- Jung-Soon Mo
- Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
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32
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Richards RC, Short CE, Driedzic WR, Ewart KV. Seasonal changes in hepatic gene expression reveal modulation of multiple processes in rainbow smelt (Osmerus mordax). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2010; 12:650-663. [PMID: 20107851 DOI: 10.1007/s10126-009-9252-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 11/23/2009] [Indexed: 05/28/2023]
Abstract
Rainbow smelt (Osmerus mordax) are freeze-resistant fish that accumulate glycerol and produce an antifreeze protein during winter. Quantitative reverse transcription PCR (qPCR) and subtractive hybridization studies have previously revealed five genes in rainbow smelt liver to be differentially regulated in winter in comparison with the fall when water temperatures are warmer. In order to further define the suite of processes that are regulated seasonally, we undertook a large-scale analysis of gene expression by hybridization of smelt cDNA to the salmonid 16K cGRASP microarray. In total, 69 genes were identified as up-regulated and 14 genes as down-regulated under winter conditions. A subset of these genes was examined for differential regulation by qPCR in the individual cDNA samples that were pooled for microarray analysis. Ten of the 15 genes tested showed significant change in the same direction as microarray results, whereas one showed significant change in the opposite direction. Fructose-bisphosphate aldolase B and the cytosolic NAD-dependent glycerol-3-phosphate dehydrogenase were among the most highly up-regulated genes, a result supporting a metabolic focus on glycerol synthesis during winter. Modulation of other processes, including endoplasmic reticulum stress, lipid metabolism and transport, and protein synthesis, was also suggested by the qPCR analysis of array-identified genes. The 15 genes were subsequently examined by qPCR for seasonal variation in expression over five sampling times between October and March, and ten showed significant variation in expression over the sampling period. Taken together, these results provide new understanding of the biochemical adaptations of vertebrates to an extremely low seasonal temperature.
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Affiliation(s)
- Robert C Richards
- Institute for Marine Biosciences, National Research Council, Halifax, NS, Canada
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33
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Kharat KR, Sawant MV, Peter S, Hardikar BP. Development and characterization of new cell line BPH22 from midgut epithelial cells of Poekilocerus pictus (Fabricius, 1775). In Vitro Cell Dev Biol Anim 2010; 46:824-7. [DOI: 10.1007/s11626-010-9349-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 09/03/2010] [Indexed: 11/30/2022]
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Jafar-Nejad H, Leonardi J, Fernandez-Valdivia R. Role of glycans and glycosyltransferases in the regulation of Notch signaling. Glycobiology 2010; 20:931-49. [PMID: 20368670 DOI: 10.1093/glycob/cwq053] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The evolutionarily conserved Notch signaling pathway plays broad and important roles during embryonic development and in adult tissue homeostasis. Unlike most other pathways used during animal development, Notch signaling does not rely on second messengers and intracellular signaling cascades. Instead, pathway activation results in the cleavage of the Notch intracellular domain and its translocation into the nucleus, where it functions as a transcriptional co-activator of the Notch target genes. To ensure tight spatial and temporal regulation of a pathway with such an unusually direct signaling transduction, animal cells have devised a variety of specialized modulatory mechanisms. One such mechanism takes advantage of decorating the Notch extracellular domain with rare types of O-linked glycans. In this review, we will discuss the genetic and biochemical data supporting the notion that carbohydrate modification is essential for Notch signaling and attempt to provide a brief historical overview of how we have learned what we know about the glycobiology of Notch. We will also summarize what is known about the contribution of specific nucleotide-sugar transporters to Notch biology and the roles-enzymatic and non-enzymatic-played by specific glycosyltransferases in the regulation of this pathway. Mutations in the Notch pathway components cause a variety of human diseases, and manipulation of Notch signaling is emerging as a powerful tool in regenerative medicine. Therefore, studying how sugar modification modulates Notch signaling provides a framework for better understanding the role of glycosylation in animal development and might offer new tools to manipulate Notch signaling for therapeutic purposes.
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35
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The role of nucleotide sugar transporters in development of eukaryotes. Semin Cell Dev Biol 2010; 21:600-8. [PMID: 20144721 DOI: 10.1016/j.semcdb.2010.02.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 01/25/2010] [Accepted: 02/01/2010] [Indexed: 01/23/2023]
Abstract
The Golgi apparatus membrane of all eukaryotes has nucleotide sugar transporters which play essential roles in the glycosylation of glycoproteins, proteoglycans and glycolipids. Mutations of these transporters have broad developmental phenotypes across many species including diseases in humans and cattle.
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36
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Abstract
Notch and the DSL Notch ligands Delta and Serrate/Jagged are glycoproteins with a single transmembrane domain. The extracellular domain (ECD) of both Notch receptors and Notch ligands contains numerous epidermal growth factor (EGF)-like repeats which are post-translationally modified by a variety of glycans. Inactivation of a subset of genes that encode glycosyltransferases which initiate and elongate these glycans inhibits Notch signaling. In the formation of developmental boundaries in Drosophila and mammals, in mouse T-cell and marginal zone B-cell development, and in co-culture Notch signaling assays, the regulation of Notch signaling by glycans is to date a cell-autonomous effect of the Notch-expressing cell. The regulation of Notch signaling by glycans represents a new paradigm of signal transduction. O-fucose glycans modulate the strength of Notch binding to DSL Notch ligands, while O-glucose glycans facilitate juxta-membrane cleavage of Notch, generating the substrate for intramembrane cleavage and Notch activation. Identifying precisely how the addition of particular sugars at specific locations on Notch modifies Notch signaling is a challenge for the future.
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Affiliation(s)
- Pamela Stanley
- Department of Cell Biology, Albert Einstein College Medicine, New York, USA
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37
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Nishihara S. Glycosyltransferases and Transporters that Contribute to Proteoglycan Synthesis in Drosophila. Methods Enzymol 2010; 480:323-51. [DOI: 10.1016/s0076-6879(10)80015-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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38
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Engel J, Schmalhorst PS, Dörk-Bousset T, Ferrières V, Routier FH. A single UDP-galactofuranose transporter is required for galactofuranosylation in Aspergillus fumigatus. J Biol Chem 2009; 284:33859-68. [PMID: 19840949 DOI: 10.1074/jbc.m109.070219] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Galactofuranose (Galf) containing molecules have been described at the cell surface of several eukaryotes and shown to contribute to the virulence of the parasite Leishmania major and the fungus Aspergillus fumigatus. It is anticipated that a number of the surface glycoconjugates such as N-glycans or glycolipids are galactofuranosylated in the Golgi apparatus. This raises the question of how the substrate for galactofuranosylation reactions, UDP-Galf, which is synthesized in the cytosol, translocates into the organelles of the secretory pathway. Here we report the first identification of a Golgi-localized nucleotide sugar transporter, named GlfB, with specificity for a UDP-Galf. In vitro transport assays established binding of UDP-Galf to GlfB and excluded transport of several other nucleotide sugars. Furthermore, the implication of glfB in the galactofuranosylation of A. fumigatus glycoconjugates and galactomannan was demonstrated by a targeted gene deletion approach. Our data reveal a direct connection between galactomannan and the organelles of the secretory pathway that strongly suggests that the cell wall-bound polysaccharide originates from its glycosylphosphatidylinositol-anchored form.
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Affiliation(s)
- Jakob Engel
- Institute for Cellular Chemistry, Hannover Medical School, 30625 Hannover, Germany
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Molecular profiling of striatonigral and striatopallidal medium spiny neurons past, present, and future. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2009; 89:1-35. [PMID: 19900613 DOI: 10.1016/s0074-7742(09)89001-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Defining distinct molecular properties of the two striatal medium spiny neurons (MSNs) has been a challenging task for basal ganglia (BG) neuroscientists. Identifying differential molecular components in each MSN subtype is crucial for BG researchers to understand functional properties of these two neurons. The two MSN populations are morphologically identical except in their projections through the direct verses indirect BG pathways and they are heterogeneously dispersed throughout the dorsal striatum (dStr) and nucleus accumbens (NAc). These characteristics have made it difficult for researchers to distinguish and isolate these two neuronal populations thereby hindering progress toward a more comprehensive understanding of their differential molecular properties. Researchers began to investigate molecular differences in the striatonigral and striatopallidal neurons using in situ hybridization (ISH) techniques and single cell reverse transcription-polymerase chain reaction (scRT-PCR). Currently the field is utilizing more advanced techniques for large-scale gene expression studies including fluorescence activated cell sorting (FACS) of MSNs, from which RNA is purified, from fluorescent reporter transgenic mice or use of transgenic mice in which ribosomes from each MSN are tagged and can be immunoprecipitated followed by RNA isolation, a technique termed translating ribosomal affinity purification (TRAP). Additionally, the availability of fluorescent reporter mice for each MSN subtype is allowing, scientists to perform more accurate histology studies evaluating differential protein expression and signaling changes in each cell subtype. Finally, researchers are able to evaluate the role of specific genes in vivo by utilizing cell type-specific mouse models including Cre driver lines that can be crossed with conditional overexpression or knockout systems. This is a very exciting time in the BG field because researchers are well equipped with the most progressive tools to comprehensively evaluate molecular components in the two MSNs and their consequence on BG functional output in the normal, diseased, and developing brain.
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40
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Tuxworth RI, Vivancos V, O'Hare MB, Tear G. Interactions between the juvenile Batten disease gene, CLN3, and the Notch and JNK signalling pathways. Hum Mol Genet 2008; 18:667-78. [PMID: 19028667 PMCID: PMC2638826 DOI: 10.1093/hmg/ddn396] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Mutations in the gene CLN3 are responsible for the neurodegenerative disorder juvenile neuronal ceroid lipofuscinosis or Batten disease. CLN3 encodes a multi-spanning and hydrophobic transmembrane protein whose function is unclear. As a consequence, the cell biology that underlies the pathology of the disease is not well understood. We have developed a genetic gain-of-function system in Drosophila to identify functional pathways and interactions for CLN3. We have identified previously unknown interactions between CLN3 and the Notch and Jun N-terminal kinase signalling pathways and have uncovered a potential role for the RNA splicing and localization machinery in regulating CLN3 function.
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Affiliation(s)
- Richard I Tuxworth
- MRC Centre for Developmental Neurobiology, New Hunt's House, Guy's Hospital Campus, King's College London, London, UK
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41
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Matsuura A, Ito M, Sakaidani Y, Kondo T, Murakami K, Furukawa K, Nadano D, Matsuda T, Okajima T. O-linked N-acetylglucosamine is present on the extracellular domain of notch receptors. J Biol Chem 2008; 283:35486-95. [PMID: 18948267 DOI: 10.1074/jbc.m806202200] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rare types of glycosylation often occur in a domain-specific manner and are involved in specific biological processes. In particular, O-fucose glycans are reported to regulate the functions of EGF domain-containing proteins such as Notch receptors. In the course of mass spectrometric analysis of O-glycans displayed on Drosophila Notch receptors expressed in S2 cells, we found an unusual O-linked N-acetylhexosamine (HexNAc) modification which occurs at a site distinct from those of O-fucose and O-glucose glycosylations. Modification site mapping by mass spectrometry and amino acid substitution studies revealed that O-HexNAc modification occurs on a serine or threonine located between the fifth and sixth cysteines within the EGF domain. This modification occurs simultaneously along with other closely positioned O-glycosylations. This modification was determined to be O-beta-GlcNAc by galactosyltransferase labeling and beta-N-acetyl-hexosaminidase digestion experiments and by immunoblotting with a specific antibody. O-GlcNAc modification occurs at multiple sites on Notch epidermal growth factor repeats. O-GlcNAc modification was also found on the extracellular domain of Delta, a ligand for Notch receptors. Although the O-GlcNAc modification is known to regulate a wide range of cellular processes, the list of known modified proteins has previously been limited to intracellular proteins in animals. Thus, the finding of O-GlcNAc modification in extracellular environments predicts a distinct glycosylation process that might be associated with a novel regulatory mechanism for Notch receptor activity.
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Affiliation(s)
- Aiko Matsuura
- Department of Applied Molecular Biosciences, Nagoya University Graduate School of Bioagricultural Sciences, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
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ten Hagen KG, Zhang L, Tian E, Zhang Y. Glycobiology on the fly: developmental and mechanistic insights from Drosophila. Glycobiology 2008; 19:102-11. [PMID: 18824561 DOI: 10.1093/glycob/cwn096] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Drosophila melanogaster offers many unique advantages for deciphering the complexities of glycan biosynthesis and function. The completion of the Drosophila genome sequencing project as well as the comprehensive catalogue of existing mutations and phenotypes have lead to a prolific database where many of the genes involved in glycan synthesis, assembly, modification, and recognition have been identified and characterized. Recent biochemical and molecular studies have elucidated the structure of the glycans present in Drosophila. Powerful genetic approaches have uncovered a number of critical biological roles for glycans during development that impact on our understanding of their function during mammalian development. Here, we summarize key recent findings and provide evidence for the usefulness of this model organism in unraveling the complexities of glycobiology across many species.
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Affiliation(s)
- Kelly G ten Hagen
- Developmental Glycobiology Unit, NIDCR, National Institutes of Health, Building 30, 30 Convent Drive, MSC 4370, Bethesda, MD 20892-4370, USA.
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Abstract
Notch is a key signaling protein mediating cell-fate decisions during development. In this issue, Acar et al. (2008) describe a new gene called rumi that is required for Notch signaling in Drosophila. This gene encodes an O-glucosyltransferase that attaches glucose sugars to serine residues in the multiple EGF domains of the extracellular region of Notch. This modification by Rumi likely influences Notch folding and trafficking.
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Caffaro CE, Luhn K, Bakker H, Vestweber D, Samuelson J, Berninsone P, Hirschberg CB. A single Caenorhabditis elegans Golgi apparatus-type transporter of UDP-glucose, UDP-galactose, UDP-N-acetylglucosamine, and UDP-N-acetylgalactosamine. Biochemistry 2008; 47:4337-44. [PMID: 18341292 DOI: 10.1021/bi702468g] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The genome of Caenorhabditis elegans encodes for 18 putative nucleotide sugar transporters even though its glycome only contains 7 different monosaccharides. To understand the biological significance of this phenomenon, we have begun a systematic substrate characterization of the above putative transporters and have determined that the gene ZK896.9 encodes a Golgi apparatus transporter for UDP-glucose, UDP-galactose, UDP- N-acetylglucosamine, and UDP- N-acetylgalactosamine. This is the first tetrasubstrate nucleotide sugar transporter characterized for any organism and is also the first nonplant transporter for UDP-glucose. Evidence for the above substrate specificity and substrate transport saturation kinetics was obtained by expression of ZK896.9 in Saccharomyces cerevisiae followed by Golgi enriched vesicle isolation and assays in vitro. Further evidence for UDP-glucose transport was obtained by expression of ZK 896.9 in Giardia lamblia, an organism recently characterized as having endogenous transport activity for only UDP- N-acetylglucosamine. Expression of ZK896.9 was also able to correct the phenotype of a mutant Chinese ovary cell line specifically defective in the transport of UDP-galactose into the Golgi apparatus and of a mutant of the yeast Kluyveromyces lactis specifically defective in the transport of UDP- N-acetylglucosamine into its Golgi apparatus. Because up to now all three other characterized nucleotide sugar transporters of C. elegans have been found to transport two or three substrates, the substrate specificity of ZK896.9 raises questions as to the evolutionary ancestry of this group of proteins in this nematode.
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Affiliation(s)
- Carolina E Caffaro
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USA
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Okajima T, Matsuura A, Matsuda T. Biological functions of glycosyltransferase genes involved in O-fucose glycan synthesis. J Biochem 2008; 144:1-6. [PMID: 18272537 DOI: 10.1093/jb/mvn016] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Rare types of glycosylation often occur in a domain-specific manner and are involved in specific biological processes. Well-known examples of such modification are O-linked fucose (O-fucose) and O-linked glucose (O-glucose) glycans on epidermal growth factor (EGF) domains. In particular, O-fucose glycans are reported to regulate the functions of EGF domain-containing proteins such as urinary-type plasminogen activator and Notch receptors. Two glycosyltransferases catalyze the initiation and elongation of O-fucose glycans. The initiation process is catalyzed by O-fucosyltransferase 1, which is essential for Notch signalling in both Drosophila and mice. O-fucosyltransferase 1 can affect the folding, ligand interaction and endocytosis of Notch receptors, and both the glycosyltransferase and non-catalytic activities of O-fucosyltransferase 1 have been reported. The elongation of O-fucose monosaccharide is catalyzed by Fringe-related genes, which differentially modulate the interaction between Notch and two classes of ligands, namely, Delta and Serrate/Jagged. In this article, we have reviewed the recent reports addressing the distinctive features of the glycosyltransferases and O-glycans present on the EGF domains.
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Affiliation(s)
- Tetsuya Okajima
- Nagoya University Graduate School of Bioagricultural Sciences, Department of Applied Molecular Biosciences, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
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46
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Bornemann DJ, Park S, Phin S, Warrior R. A translational block to HSPG synthesis permits BMP signaling in the early Drosophila embryo. Development 2008; 135:1039-47. [PMID: 18256192 DOI: 10.1242/dev.017061] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Heparan sulfate proteoglycans (HSPGs) are extracellular macromolecules found on virtually every cell type in eumetazoans. HSPGs are composed of a core protein covalently linked to glycosaminoglycan (GAG) sugar chains that bind and modulate the signaling efficiency of many ligands, including Hedgehog (Hh), Wingless (Wg) and Bone morphogenetic proteins (BMPs). Here, we show that, in Drosophila, loss of HSPGs differentially affects embryonic Hh, Wg and BMP signaling. We find that a stage-specific block to GAG synthesis prevents HSPG expression during establishment of the BMP activity gradient that is crucial for dorsal embryonic patterning. Subsequently, GAG synthesis is initiated coincident with the onset of Hh and Wg signaling which require HSPGs. This temporal regulation is achieved by the translational control of HSPG synthetic enzymes through internal ribosome entry sites (IRESs). IRES-like features are conserved in GAG enzyme transcripts from diverse organisms, suggesting that this represents a novel evolutionarily conserved mechanism for regulating GAG synthesis and modulating growth factor activity.
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Affiliation(s)
- Douglas J Bornemann
- Developmental and Cell Biology and Developmental Biology Center, University of California Irvine, Irvine, CA, USA
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47
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Zhao W, Colley KJ. Nucleotide sugar transporters of the Golgi apparatus. THE GOLGI APPARATUS 2008. [PMCID: PMC7119966 DOI: 10.1007/978-3-211-76310-0_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The Golgi apparatus is the major site of protein, lipid and proteoglycan glycosylation. The glycosylation enzymes, as well as kinases and sulfatases that catalyze phosphorylation and sulfation, are localized within the Golgi cisternae in characteristic distributions that frequently reflect their order in a particular pathway (Kornfeld and Kornfeld 1985; Colley 1997). The glycosyl-transferases, sulfotransferases and kinases are “transferases” that require activated donor molecules for the reactions they catalyze. For eukaryotic, fungal and protozoan glycosyltransferases these are the nucleotide sugars UDP-N-acetylglucosamine (UDP-GlcNAc), UDP-galactose (UDP-Gal), GDP-fucose (GDP-Fuc), CMP-sialicacid (CMP-Sia), UDP-glucuronicacid (UDP-GlcA), GDP-mannose (GDP-Man), and UDP-xylose (UDP-Xyl) (Hirschberg et al. 1998). For the kinases, ATP functions as the donor, while for the sulfotransferases, adenosine 3′-phosphate 5′-phosphate (PAPS) acts as the donor (Hirschberg et al. 1998). The active sites of all these enzymes are oriented towards the lumen of the Golgi cisternae. This necessitates the translocation of their donors from the cytosol into the lumenal Golgi compartments. In this chapter we will focus on the structure, function and localization of the Golgi nucleotide sugar transporters (NSTs), and highlight the diseases and developmental defects associated with defective transporters. We direct the reader to several excellent reviews on Golgi transporters for additional details and references (Hirschberg et al. 1998; Berninsone and Hirschberg 2000; Gerardy-Schahn et al. 2001; Handford et al. 2006; Caffaro and Hirschberg 2006).
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Ueyama M, Takemae H, Ohmae Y, Yoshida H, Toyoda H, Ueda R, Nishihara S. Functional analysis of proteoglycan galactosyltransferase II RNA interference mutant flies. J Biol Chem 2007; 283:6076-84. [PMID: 18165227 DOI: 10.1074/jbc.m709189200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Heparan sulfate proteoglycan plays an important role in developmental processes by modulating the distribution and stability of the morphogens Wingless, Hedgehog, and Decapentaplegic. Heparan and chondroitin sulfates share a common linkage tetrasaccharide structure, GlcAbeta1,3Galbeta1,3Galbeta1,4Xylbeta-O-Ser. In the present study, we identified Drosophila proteoglycan galactosyltransferase II (dbeta3GalTII), determined its substrate specificity, and performed its functional analysis by using RNA interference (RNAi) mutant flies. The enzyme transferred a galactose to Galbeta1,4Xyl-pMph, confirming that it is the Drosophila ortholog of human proteoglycan galactosyltransferase II. Real-time PCR analyses revealed that dbeta3GalTII is expressed in various tissues and throughout development. The dbeta3GalTII RNAi mutant flies showed decreased amounts of heparan sulfate proteoglycans. A genetic interaction of dbeta3GalTII with Drosophila beta1,4-galactoslyltransferase 7 (dbeta4GalT7) or with six genes that encode enzymes contributing to the synthesis of glycosaminoglycans indicated that dbeta3GalTII is involved in heparan sulfate synthesis for wing and eye development. Moreover, dbeta3GalTII knock-down caused a decrease in extracellular Wingless in the wing imaginal disc of the third instar larvae. These results demonstrated that dbeta3GalTII contributes to heparan sulfate proteoglycan synthesis in vitro and in vivo and also modulates Wingless distribution.
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Affiliation(s)
- Morio Ueyama
- Laboratory of Cell Biology, Department of Bioinformatics, Faculty of Engineering, Soka University, 1-236 Tangi-cho, Hachioji, Tokyo
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49
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Caffaro CE, Hirschberg CB, Berninsone PM. Functional redundancy between two Caenorhabditis elegans nucleotide sugar transporters with a novel transport mechanism. J Biol Chem 2007; 282:27970-5. [PMID: 17652078 DOI: 10.1074/jbc.m704485200] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transporters of nucleotide sugars regulate the availability of these substrates required for glycosylation reactions in the lumen of the Golgi apparatus and play an important role in the development of multicellular organisms. Caenorhabditis elegans has seven different sugars in its glycoconjugates, although 18 putative nucleotide sugar transporters are encoded in the genome. Among these, SQV-7, SRF-3, and CO3H5.2 exhibit partially overlapping substrate specificity and expression patterns. We now report evidence of functional redundancy between transporters CO3H5.2 and SRF-3. Reducing the activity of the CO3H5.2 gene product by RNA interference (RNAi) in SRF-3 mutants results in oocyte accumulation and abnormal gonad morphology, whereas comparable RNAi treatment of wild type or RNAi hypersensitive C. elegans strains does not cause detectable defects. We hypothesize this genetic enhancement to be a mechanism to ensure adequate glycoconjugate biosynthesis required for normal tissue development in multicellular organisms. Furthermore, we show that transporters SRF-3 and CO3H5.2, which are closely related in the phylogenetic tree, share a simultaneous and independent substrate transport mechanism that is different from the competitive one previously demonstrated for transporter SQV-7, which shares a lower amino acid sequence identity with CO3H5.2 and SRF-3. Therefore, different mechanisms for transporting multiple nucleotide sugars may have evolved parallel to transporter amino acid divergence.
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Affiliation(s)
- Carolina E Caffaro
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts 02118, USA
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50
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Kim MY, Ann EJ, Kim JY, Mo JS, Park JH, Kim SY, Seo MS, Park HS. Tip60 histone acetyltransferase acts as a negative regulator of Notch1 signaling by means of acetylation. Mol Cell Biol 2007; 27:6506-19. [PMID: 17636029 PMCID: PMC2099611 DOI: 10.1128/mcb.01515-06] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The Notch signaling pathway appears to perform an important function in a wide variety of organisms and cell types. In our present study, we provide evidence that UV irradiation-induced Tip60 proteins reduced Notch1 activity to a marked degree. Accumulated UV irradiation-induced Tip60 suppresses Notch1 transcriptional activity via the dissociation of the Notch1-IC-CSL complex. The binding between endogenous Tip60 and Notch1-IC in UV radiation-exposed cells was verified in this study by coimmunoprecipitation. Interestingly, the physical interaction of Tip60 with Notch1-IC occurs to a more profound degree in the presence of CSL but does not exist in a trimeric complex. Using Notch1-IC and Tip60 deletion mutants, we also determined that the N terminus, which harbors the RAM domain and seven ankyrin repeats of Notch1-IC, interacts with the zinc finger and acetyl coenzyme A domains of Tip60. Furthermore, here we report that Notch1-IC is a direct target of the acetyltransferase activity of Tip60. Collectively, our data suggest that Tip60 is an inhibitor of the Notch1 signaling pathway and that Tip60-dependent acetylation of Notch1-IC may be relevant to the mechanism by which Tip60 suppresses Notch1 signaling.
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Affiliation(s)
- Mi-Yeon Kim
- Hormonre Research Center, School of Biological Sciences and Technology, Chonnam National University, Yongbong-dong, Buk-ku, Gwangju 500-757, South Korea
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