1
|
Vicente JB, Guerreiro ACL, Felgueiras B, Chapla D, Tehrani D, Moremen KW, Costa J. Glycosyltransferase 8 domain-containing protein 1 (GLT8D1) is a UDP-dependent galactosyltransferase. Sci Rep 2023; 13:21684. [PMID: 38066107 PMCID: PMC10709319 DOI: 10.1038/s41598-023-48605-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/28/2023] [Indexed: 12/18/2023] Open
Abstract
Glycosyltransferases (GTs) are enzymes that catalyze the formation of glycosidic bonds and hundreds of GTs have been identified so far in humans. Glycosyltransferase 8 domain-containing protein 1 (GLT8D1) has been associated with central nervous system diseases and cancer. However, evidence on its enzymatic properties, including its substrates, has been scarcely described. In this paper, we have produced and purified recombinant secretory GLT8D1. The enzyme was found to be N-glycosylated. Differential scanning fluorimetry was employed to analyze the stabilization of GLT8D1 by Mn2+ and nucleotides, revealing UDP as the most stabilizing nucleotide scaffold. GLT8D1 displayed glycosyltransferase activity from UDP-galactose onto N-acetylgalactosamine but with a low efficiency. Modeling of the structure revealed similarities with other GT-A fold enzymes in CAZy family GT8 and glycosyltransferases in other families with galactosyl-, glucosyl-, and xylosyltransferase activities, each with retaining catalytic mechanisms. Our study provides novel structural and functional insights into the properties of GLT8D1 with implications in pathological processes.
Collapse
Affiliation(s)
- João B Vicente
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Ana Catarina L Guerreiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
| | - Beatriz Felgueiras
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Digantkumar Chapla
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Daniel Tehrani
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Kelley W Moremen
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
| | - Júlia Costa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal.
| |
Collapse
|
2
|
Brauer VS, Pessoni AM, Freitas MS, Cavalcanti-Neto MP, Ries LNA, Almeida F. Chitin Biosynthesis in Aspergillus Species. J Fungi (Basel) 2023; 9:jof9010089. [PMID: 36675910 PMCID: PMC9865612 DOI: 10.3390/jof9010089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 12/14/2022] [Accepted: 12/17/2022] [Indexed: 01/11/2023] Open
Abstract
The fungal cell wall (FCW) is a dynamic structure responsible for the maintenance of cellular homeostasis, and is essential for modulating the interaction of the fungus with its environment. It is composed of proteins, lipids, pigments and polysaccharides, including chitin. Chitin synthesis is catalyzed by chitin synthases (CS), and up to eight CS-encoding genes can be found in Aspergillus species. This review discusses in detail the chitin synthesis and regulation in Aspergillus species, and how manipulation of chitin synthesis pathways can modulate fungal growth, enzyme production, virulence and susceptibility to antifungal agents. More specifically, the metabolic steps involved in chitin biosynthesis are described with an emphasis on how the initiation of chitin biosynthesis remains unknown. A description of the classification, localization and transport of CS was also made. Chitin biosynthesis is shown to underlie a complex regulatory network, with extensive cross-talks existing between the different signaling pathways. Furthermore, pathways and recently identified regulators of chitin biosynthesis during the caspofungin paradoxical effect (CPE) are described. The effect of a chitin on the mammalian immune system is also discussed. Lastly, interference with chitin biosynthesis may also be beneficial for biotechnological applications. Even after more than 30 years of research, chitin biosynthesis remains a topic of current interest in mycology.
Collapse
Affiliation(s)
- Veronica S. Brauer
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo 01000-000, Brazil
| | - André M. Pessoni
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo 01000-000, Brazil
| | - Mateus S. Freitas
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo 01000-000, Brazil
| | - Marinaldo P. Cavalcanti-Neto
- Integrated Laboratory of Morphofunctional Sciences, Institute of Biodiversity and Sustainability (NUPEM), Federal University of Rio de Janeiro, Rio de Janeiro 27965-045, Brazil
| | - Laure N. A. Ries
- MRC Centre for Medical Mycology, University of Exeter, Exeter EX4 4QD, UK
- Correspondence: (L.N.A.R.); (F.A.)
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Sao Paulo 01000-000, Brazil
- Correspondence: (L.N.A.R.); (F.A.)
| |
Collapse
|
3
|
Mechanism of glycogen synthase inactivation and interaction with glycogenin. Nat Commun 2022; 13:3372. [PMID: 35690592 PMCID: PMC9188544 DOI: 10.1038/s41467-022-31109-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/02/2022] [Indexed: 11/08/2022] Open
Abstract
Glycogen is the major glucose reserve in eukaryotes, and defects in glycogen metabolism and structure lead to disease. Glycogenesis involves interaction of glycogenin (GN) with glycogen synthase (GS), where GS is activated by glucose-6-phosphate (G6P) and inactivated by phosphorylation. We describe the 2.6 Å resolution cryo-EM structure of phosphorylated human GS revealing an autoinhibited GS tetramer flanked by two GN dimers. Phosphorylated N- and C-termini from two GS protomers converge near the G6P-binding pocket and buttress against GS regulatory helices. This keeps GS in an inactive conformation mediated by phospho-Ser641 interactions with a composite “arginine cradle”. Structure-guided mutagenesis perturbing interactions with phosphorylated tails led to increased basal/unstimulated GS activity. We propose that multivalent phosphorylation supports GS autoinhibition through interactions from a dynamic “spike” region, allowing a tuneable rheostat for regulating GS activity. This work therefore provides insights into glycogen synthesis regulation and facilitates studies of glycogen-related diseases. Glycogen is a major energy reserve in eukaryotes and is synthesised in part by glycogenin (GN) and glycogen synthase (GS). Here, authors describe the structural basis of GS regulation, specifically the mechanism of inactivation by phosphorylation.
Collapse
|
4
|
Identification and expression analysis of the PtGATL genes under different nitrogen and carbon dioxide treatments in Populus trichocarpa. 3 Biotech 2022; 12:67. [PMID: 35223353 PMCID: PMC8837729 DOI: 10.1007/s13205-022-03129-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 01/23/2022] [Indexed: 11/01/2022] Open
Abstract
Pectin is one of the most important components of the plant cell wall. Galacturonosyltransferase-like (GATL) is an important enzyme involved in forming pectin in Arabidopsis thaliana. In this study, 12 PtGATL genes were identified and characterized based on the Populus trichocarpa genome using bioinformatics methods. The results showed that the PtGATLs contained four typical motifs, including DXD, LPPF, GLG, and HXXGXXKPW. According to phylogenetic analysis, PtGATLs were divided into six groups. Chromosome distribution and genome synteny analysis showed that there were 11 segmental-duplicated gene pairs with repeated fragments on chromosomes 2, 5, 7, 8, 10, and 14. Tissue-specific expression profiles indicated that these PtGATLs had different expression patterns. The transcription level of PtGATLs was regulated by different carbon dioxide and nitrogen concentrations. In conclusion, the identification and analysis of PtGATL genes in poplar provide important information on the gene function. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-022-03129-y.
Collapse
|
5
|
Cimino R, Bhangu SK, Baral A, Ashokkumar M, Cavalieri F. Ultrasound-Assisted Microencapsulation of Soybean Oil and Vitamin D Using Bare Glycogen Nanoparticles. Molecules 2021; 26:molecules26175157. [PMID: 34500590 PMCID: PMC8434121 DOI: 10.3390/molecules26175157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/13/2021] [Accepted: 08/23/2021] [Indexed: 01/27/2023] Open
Abstract
Ultrasonically synthesized core-shell microcapsules can be made of synthetic polymers or natural biopolymers, such as proteins and polysaccharides, and have found applications in food, drug delivery and cosmetics. This study reports on the ultrasonic synthesis of microcapsules using unmodified (natural) and biodegradable glycogen nanoparticles derived from various sources, such as rabbit and bovine liver, oyster and sweet corn, for the encapsulation of soybean oil and vitamin D. Depending on their source, glycogen nanoparticles exhibited differences in size and 'bound' proteins. We optimized various synthetic parameters, such as ultrasonic power, time and concentration of glycogens and the oil phase to obtain stable core-shell microcapsules. Particularly, under ultrasound-induced emulsification conditions (sonication time 45 s and sonication power 160 W), native glycogens formed microcapsules with diameter between 0.3 μm and 8 μm. It was found that the size of glycogen as well as the protein component play an important role in stabilizing the Pickering emulsion and the microcapsules shell. This study highlights that native glycogen nanoparticles without any further tedious chemical modification steps can be successfully used for the encapsulation of nutrients.
Collapse
Affiliation(s)
- Rita Cimino
- Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy;
| | | | - Anshul Baral
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia;
| | - Muthupandian Ashokkumar
- School of Chemistry, University of Melbourne, Melbourne, VIC 3010, Australia;
- Correspondence: (M.A.); (F.C.)
| | - Francesca Cavalieri
- Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy;
- School of Science, RMIT University, Melbourne, VIC 3000, Australia;
- Correspondence: (M.A.); (F.C.)
| |
Collapse
|
6
|
Chlorovirus PBCV-1 Multidomain Protein A111/114R Has Three Glycosyltransferase Functions Involved in the Synthesis of Atypical N-Glycans. Viruses 2021; 13:v13010087. [PMID: 33435207 PMCID: PMC7826918 DOI: 10.3390/v13010087] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/03/2021] [Accepted: 01/08/2021] [Indexed: 12/04/2022] Open
Abstract
The structures of the four N-linked glycans from the prototype chlorovirus PBCV-1 major capsid protein do not resemble any other glycans in the three domains of life. All known chloroviruses and antigenic variants (or mutants) share a unique conserved central glycan core consisting of five sugars, except for antigenic mutant virus P1L6, which has four of the five sugars. A combination of genetic and structural analyses indicates that the protein coded by PBCV-1 gene a111/114r, conserved in all chloroviruses, is a glycosyltransferase with three putative domains of approximately 300 amino acids each. Here, in addition to in silico sequence analysis and protein modeling, we measured the hydrolytic activity of protein A111/114R. The results suggest that domain 1 is a galactosyltransferase, domain 2 is a xylosyltransferase and domain 3 is a fucosyltransferase. Thus, A111/114R is the protein likely responsible for the attachment of three of the five conserved residues of the core region of this complex glycan, and, if biochemically corroborated, it would be the second three-domain protein coded by PBCV-1 that is involved in glycan synthesis. Importantly, these findings provide additional support that the chloroviruses do not use the canonical host endoplasmic reticulum–Golgi glycosylation pathway to glycosylate their glycoproteins; instead, they perform glycosylation independent of cellular organelles using virus-encoded enzymes.
Collapse
|
7
|
Mandalasi M, Kim HW, Thieker D, Sheikh MO, Gas-Pascual E, Rahman K, Zhao P, Daniel NG, van der Wel H, Ichikawa HT, Glushka JN, Wells L, Woods RJ, Wood ZA, West CM. A terminal α3-galactose modification regulates an E3 ubiquitin ligase subunit in Toxoplasma gondii. J Biol Chem 2020; 295:9223-9243. [PMID: 32414843 PMCID: PMC7335778 DOI: 10.1074/jbc.ra120.013792] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/14/2020] [Indexed: 12/29/2022] Open
Abstract
Skp1, a subunit of E3 Skp1/Cullin-1/F-box protein ubiquitin ligases, is modified by a prolyl hydroxylase that mediates O2 regulation of the social amoeba Dictyostelium and the parasite Toxoplasma gondii The full effect of hydroxylation requires modification of the hydroxyproline by a pentasaccharide that, in Dictyostelium, influences Skp1 structure to favor assembly of Skp1/F-box protein subcomplexes. In Toxoplasma, the presence of a contrasting penultimate sugar assembled by a different glycosyltransferase enables testing of the conformational control model. To define the final sugar and its linkage, here we identified the glycosyltransferase that completes the glycan and found that it is closely related to glycogenin, an enzyme that may prime glycogen synthesis in yeast and animals. However, the Toxoplasma enzyme catalyzes formation of a Galα1,3Glcα linkage rather than the Glcα1,4Glcα linkage formed by glycogenin. Kinetic and crystallographic experiments showed that the glycosyltransferase Gat1 is specific for Skp1 in Toxoplasma and also in another protist, the crop pathogen Pythium ultimum The fifth sugar is important for glycan function as indicated by the slow-growth phenotype of gat1Δ parasites. Computational analyses indicated that, despite the sequence difference, the Toxoplasma glycan still assumes an ordered conformation that controls Skp1 structure and revealed the importance of nonpolar packing interactions of the fifth sugar. The substitution of glycosyltransferases in Toxoplasma and Pythium by an unrelated bifunctional enzyme that assembles a distinct but structurally compatible glycan in Dictyostelium is a remarkable case of convergent evolution, which emphasizes the importance of the terminal α-galactose and establishes the phylogenetic breadth of Skp1 glycoregulation.
Collapse
Affiliation(s)
- Msano Mandalasi
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Hyun W Kim
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - David Thieker
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - M Osman Sheikh
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Elisabet Gas-Pascual
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Kazi Rahman
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Peng Zhao
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Nitin G Daniel
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Hanke van der Wel
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - H Travis Ichikawa
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - John N Glushka
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Lance Wells
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA; Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Robert J Woods
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA; Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA
| | - Zachary A Wood
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Christopher M West
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA; Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA.
| |
Collapse
|
8
|
Besford QA, Cavalieri F, Caruso F. Glycogen as a Building Block for Advanced Biological Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904625. [PMID: 31617264 DOI: 10.1002/adma.201904625] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/15/2019] [Indexed: 06/10/2023]
Abstract
Biological nanoparticles found in living systems possess distinct molecular architectures and diverse functions. Glycogen is a unique biological polysaccharide nanoparticle fabricated by nature through a bottom-up approach. The biocatalytic synthesis of glycogen has evolved over time to form a nanometer-sized dendrimer-like structure (20-150 nm) with a highly branched surface and a dense core. This makes glycogen markedly different from other natural linear or branched polysaccharides and particularly attractive as a platform for biomedical applications. Glycogen is inherently biodegradable, nontoxic, and can be functionalized with diverse surface and internal motifs for enhanced biofunctional properties. Recently, there has been growing interest in glycogen as a natural alternative to synthetic polymers and nanoparticles in a range of applications. Herein, the recent literature on glycogen in the material-based sciences, including its use as a constituent in biodegradable hydrogels and fibers, drug delivery vectors, tumor targeting and penetrating nanoparticles, immunomodulators, vaccine adjuvants, and contrast agents, is reviewed. The various methods of chemical functionalization and physical assembly of glycogen nanoparticles into multicomponent nanodevices, which advance glycogen toward a functional therapeutic nanoparticle from nature and back again, are discussed in detail.
Collapse
Affiliation(s)
- Quinn A Besford
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Francesca Cavalieri
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
- Dipartimento di Scienze e Tecnologie Chimiche, Università degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - Frank Caruso
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
| |
Collapse
|
9
|
From the seminal discovery of proteoglycogen and glycogenin to emerging knowledge and research on glycogen biology. Biochem J 2019; 476:3109-3124. [DOI: 10.1042/bcj20190441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/10/2019] [Accepted: 10/14/2019] [Indexed: 11/17/2022]
Abstract
AbstractAlthough the discovery of glycogen in the liver, attributed to Claude Bernard, happened more than 160 years ago, the mechanism involved in the initiation of glucose polymerization remained unknown. The discovery of glycogenin at the core of glycogen's structure and the initiation of its glucopolymerization is among one of the most exciting and relatively recent findings in Biochemistry. This review focuses on the initial steps leading to the seminal discoveries of proteoglycogen and glycogenin at the beginning of the 1980s, which paved the way for subsequent foundational breakthroughs that propelled forward this new research field. We also explore the current, as well as potential, impact this research field is having on human health and disease from the perspective of glycogen storage diseases. Important new questions arising from recent studies, their links to basic mechanisms involved in the de novo glycogen biogenesis, and the pervading presence of glycogenin across the evolutionary scale, fueled by high throughput -omics technologies, are also addressed.
Collapse
|
10
|
Structural basis of glycogen metabolism in bacteria. Biochem J 2019; 476:2059-2092. [PMID: 31366571 DOI: 10.1042/bcj20170558] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/11/2019] [Accepted: 07/15/2019] [Indexed: 01/25/2023]
Abstract
The evolution of metabolic pathways is a major force behind natural selection. In the spotlight of such process lies the structural evolution of the enzymatic machinery responsible for the central energy metabolism. Specifically, glycogen metabolism has emerged to allow organisms to save available environmental surplus of carbon and energy, using dedicated glucose polymers as a storage compartment that can be mobilized at future demand. The origins of such adaptive advantage rely on the acquisition of an enzymatic system for the biosynthesis and degradation of glycogen, along with mechanisms to balance the assembly and disassembly rate of this polysaccharide, in order to store and recover glucose according to cell energy needs. The first step in the classical bacterial glycogen biosynthetic pathway is carried out by the adenosine 5'-diphosphate (ADP)-glucose pyrophosphorylase. This allosteric enzyme synthesizes ADP-glucose and acts as a point of regulation. The second step is carried out by the glycogen synthase, an enzyme that generates linear α-(1→4)-linked glucose chains, whereas the third step catalyzed by the branching enzyme produces α-(1→6)-linked glucan branches in the polymer. Two enzymes facilitate glycogen degradation: glycogen phosphorylase, which functions as an α-(1→4)-depolymerizing enzyme, and the debranching enzyme that catalyzes the removal of α-(1→6)-linked ramifications. In this work, we rationalize the structural basis of glycogen metabolism in bacteria to the light of the current knowledge. We describe and discuss the remarkable progress made in the understanding of the molecular mechanisms of substrate recognition and product release, allosteric regulation and catalysis of all those enzymes.
Collapse
|
11
|
Pederson BA. Structure and Regulation of Glycogen Synthase in the Brain. ADVANCES IN NEUROBIOLOGY 2019; 23:83-123. [PMID: 31667806 DOI: 10.1007/978-3-030-27480-1_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Brain glycogen synthesis is a regulated, multi-step process that begins with glucose transport across the blood brain barrier and culminates with the actions of glycogen synthase and the glycogen branching enzyme to elongate glucose chains and introduce branch points in a growing glycogen molecule. This review focuses on the synthesis of glycogen in the brain, with an emphasis on glycogen synthase, but draws on salient studies in mammalian muscle and liver as well as baker's yeast, with the goal of providing a more comprehensive view of glycogen synthesis and highlighting potential areas for further study in the brain. In addition, deficiencies in the glycogen biosynthetic enzymes which lead to glycogen storage diseases in humans are discussed, highlighting effects on the brain and discussing findings in genetically modified animal models that recapitulate these diseases. Finally, implications of glycogen synthesis in neurodegenerative and other diseases that impact the brain are presented.
Collapse
|
12
|
Brewer MK, Gentry MS. Brain Glycogen Structure and Its Associated Proteins: Past, Present and Future. ADVANCES IN NEUROBIOLOGY 2019; 23:17-81. [PMID: 31667805 PMCID: PMC7239500 DOI: 10.1007/978-3-030-27480-1_2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This chapter reviews the history of glycogen-related research and discusses in detail the structure, regulation, chemical properties and subcellular distribution of glycogen and its associated proteins, with particular focus on these aspects in brain tissue.
Collapse
Affiliation(s)
- M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry, Epilepsy and Brain Metabolism Center, Lafora Epilepsy Cure Initiative, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, Epilepsy and Brain Metabolism Center, Lafora Epilepsy Cure Initiative, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, USA.
| |
Collapse
|
13
|
Amos RA, Mohnen D. Critical Review of Plant Cell Wall Matrix Polysaccharide Glycosyltransferase Activities Verified by Heterologous Protein Expression. FRONTIERS IN PLANT SCIENCE 2019; 10:915. [PMID: 31379900 PMCID: PMC6646851 DOI: 10.3389/fpls.2019.00915] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 06/27/2019] [Indexed: 05/02/2023]
Abstract
The life cycle and development of plants requires the biosynthesis, deposition, and degradation of cell wall matrix polysaccharides. The structures of the diverse cell wall matrix polysaccharides influence commercially important properties of plant cells, including growth, biomass recalcitrance, organ abscission, and the shelf life of fruits. This review is a comprehensive summary of the matrix polysaccharide glycosyltransferase (GT) activities that have been verified using in vitro assays following heterologous GT protein expression. Plant cell wall (PCW) biosynthetic GTs are primarily integral transmembrane proteins localized to the endoplasmic reticulum and Golgi of the plant secretory system. The low abundance of these enzymes in plant tissues makes them particularly difficult to purify from native plant membranes in quantities sufficient for enzymatic characterization, which is essential to study the functions of the different GTs. Numerous activities in the synthesis of the major cell wall matrix glycans, including pectins, xylans, xyloglucan, mannans, mixed-linkage glucans (MLGs), and arabinogalactan components of AGP proteoglycans have been mapped to specific genes and multi-gene families. Cell wall GTs include those that synthesize the polymer backbones, those that elongate side branches with extended glycosyl chains, and those that add single monosaccharide linkages onto polysaccharide backbones and/or side branches. Three main strategies have been used to identify genes encoding GTs that synthesize cell wall linkages: analysis of membrane fractions enriched for cell wall biosynthetic activities, mutational genetics approaches investigating cell wall compositional phenotypes, and omics-directed identification of putative GTs from sequenced plant genomes. Here we compare the heterologous expression systems used to produce, purify, and study the enzyme activities of PCW GTs, with an emphasis on the eukaryotic systems Nicotiana benthamiana, Pichia pastoris, and human embryonic kidney (HEK293) cells. We discuss the enzymatic properties of GTs including kinetic rates, the chain lengths of polysaccharide products, acceptor oligosaccharide preferences, elongation mechanisms for the synthesis of long-chain polymers, and the formation of GT complexes. Future directions in the study of matrix polysaccharide biosynthesis are proposed.
Collapse
Affiliation(s)
- Robert A. Amos
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - Debra Mohnen
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
- *Correspondence: Debra Mohnen
| |
Collapse
|
14
|
Bilyard MK, Bailey HJ, Raich L, Gafitescu MA, Machida T, Iglésias-Fernández J, Lee SS, Spicer CD, Rovira C, Yue WW, Davis BG. Palladium-mediated enzyme activation suggests multiphase initiation of glycogenesis. Nature 2018; 563:235-240. [PMID: 30356213 DOI: 10.1038/s41586-018-0644-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 08/31/2018] [Indexed: 11/09/2022]
Abstract
Biosynthesis of glycogen, the essential glucose (and hence energy) storage molecule in humans, animals and fungi1, is initiated by the glycosyltransferase enzyme, glycogenin (GYG). Deficiencies in glycogen formation cause neurodegenerative and metabolic disease2-4, and mouse knockout5 and inherited human mutations6 of GYG impair glycogen synthesis. GYG acts as a 'seed core' for the formation of the glycogen particle by catalysing its own stepwise autoglucosylation to form a covalently bound gluco-oligosaccharide chain at initiation site Tyr 195. Precise mechanistic studies have so far been prevented by an inability to access homogeneous glycoforms of this protein, which unusually acts as both catalyst and substrate. Here we show that unprecedented direct access to different, homogeneously glucosylated states of GYG can be accomplished through a palladium-mediated enzyme activation 'shunt' process using on-protein C-C bond formation. Careful mimicry of GYG intermediates recapitulates catalytic activity at distinct stages, which in turn allows discovery of triphasic kinetics and substrate plasticity in GYG's use of sugar substrates. This reveals a tolerant but 'proof-read' mechanism that underlies the precision of this metabolic process. The present demonstration of direct, chemically controlled access to intermediate states of active enzymes suggests that such ligation-dependent activation could be a powerful tool in the study of mechanism.
Collapse
Affiliation(s)
| | - Henry J Bailey
- Structural Genomics Consortium, University of Oxford, Oxford, UK
| | - Lluís Raich
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) and Institut de Química Teòrica i Computacional (IQTC), Universitat de Barcelona, Barcelona, Spain
| | | | - Takuya Machida
- Department of Chemistry, University of Oxford, Oxford, UK
| | - Javier Iglésias-Fernández
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) and Institut de Química Teòrica i Computacional (IQTC), Universitat de Barcelona, Barcelona, Spain.,Institut de Química Computacional i Catalisi and Departament de Química, Universitat de Girona, Girona, Spain
| | - Seung Seo Lee
- Department of Chemistry, University of Oxford, Oxford, UK.,School of Chemistry, University of Southampton, Southampton, UK
| | | | - Carme Rovira
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) and Institut de Química Teòrica i Computacional (IQTC), Universitat de Barcelona, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Wyatt W Yue
- Structural Genomics Consortium, University of Oxford, Oxford, UK.
| | | |
Collapse
|
15
|
Amos RA, Pattathil S, Yang JY, Atmodjo MA, Urbanowicz BR, Moremen KW, Mohnen D. A two-phase model for the non-processive biosynthesis of homogalacturonan polysaccharides by the GAUT1:GAUT7 complex. J Biol Chem 2018; 293:19047-19063. [PMID: 30327429 DOI: 10.1074/jbc.ra118.004463] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/08/2018] [Indexed: 11/06/2022] Open
Abstract
Homogalacturonan (HG) is a pectic glycan in the plant cell wall that contributes to plant growth and development and cell wall structure and function, and interacts with other glycans and proteoglycans in the wall. HG is synthesized by the galacturonosyltransferase (GAUT) gene family. Two members of this family, GAUT1 and GAUT7, form a heteromeric enzyme complex in Arabidopsis thaliana Here, we established a heterologous GAUT expression system in HEK293 cells and show that co-expression of recombinant GAUT1 with GAUT7 results in the production of a soluble GAUT1:GAUT7 complex that catalyzes elongation of HG products in vitro The reaction rates, progress curves, and product distributions exhibited major differences dependent upon small changes in the degree of polymerization (DP) of the oligosaccharide acceptor. GAUT1:GAUT7 displayed >45-fold increased catalytic efficiency with DP11 acceptors relative to DP7 acceptors. Although GAUT1:GAUT7 synthesized high-molecular-weight polymeric HG (>100 kDa) in a substrate concentration-dependent manner typical of distributive (nonprocessive) glycosyltransferases with DP11 acceptors, reactions primed with short-chain acceptors resulted in a bimodal product distribution of glycan products that has previously been reported as evidence for a processive model of GT elongation. As an alternative to the processive glycosyltransfer model, a two-phase distributive elongation model is proposed in which a slow phase, which includes the de novo initiation of HG and elongation of short-chain acceptors, is distinguished from a phase of rapid elongation of intermediate- and long-chain acceptors. Upon reaching a critical chain length of DP11, GAUT1:GAUT7 elongates HG to high-molecular-weight products.
Collapse
Affiliation(s)
- Robert A Amos
- From the Complex Carbohydrate Research Center and.,the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
| | | | | | - Melani A Atmodjo
- From the Complex Carbohydrate Research Center and.,the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
| | | | - Kelley W Moremen
- From the Complex Carbohydrate Research Center and.,the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
| | - Debra Mohnen
- From the Complex Carbohydrate Research Center and .,the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602
| |
Collapse
|
16
|
Tan X, Sullivan MA, Nada SS, Deng B, Schulz BL, Gilbert RG. Proteomic Investigation of the Binding Agent between Liver Glycogen β Particles. ACS OMEGA 2018; 3:3640-3645. [PMID: 30023874 PMCID: PMC6045358 DOI: 10.1021/acsomega.8b00119] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 03/22/2018] [Indexed: 06/08/2023]
Abstract
Glycogen is a highly branched glucose polymer which plays an important role in glucose storage and the maintenance of blood sugar homeostasis. The dimeric protein glycogenin can self-glucosylate to act as a primer for glycogen synthesis, eventually resulting in small (∼20 nm diameter) glycogen β particles with a dimer of glycogenin at their core. In the liver, glycogen is also found in the form of α particles: large bound composites of many β particles. Here, we provide evidence using qualitative and quantitative proteomics and size-exclusion chromatography from healthy rat, mouse, and human liver glycogen that glycogenin is the binding agent linking β particles together into α particles.
Collapse
Affiliation(s)
- Xinle Tan
- Joint
International Research Laboratory of Agriculture and Agri-Product
Safety, College of Agriculture, Yangzhou
University, Yangzhou 225009, Jiangsu Province, China
- School of Chemistry and Molecular
Biosciences and Centre for Nutrition and Food Sciences,
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
- Tongji
School of Pharmacy and Department of Pharmacy, Union Hospital, Tongji Medical
College, Huazhong University of Science
and Technology, Wuhan, Hubei 430030, China
| | - Mitchell A. Sullivan
- Glycation
and Diabetes, Mater Research Institute, Translational Research Institute, The University of Queensland, Brisbane, Queensland 4102, Australia
| | - Sharif S. Nada
- School of Chemistry and Molecular
Biosciences and Centre for Nutrition and Food Sciences,
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bin Deng
- Tongji
School of Pharmacy and Department of Pharmacy, Union Hospital, Tongji Medical
College, Huazhong University of Science
and Technology, Wuhan, Hubei 430030, China
| | - Benjamin L. Schulz
- School of Chemistry and Molecular
Biosciences and Centre for Nutrition and Food Sciences,
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Robert G. Gilbert
- Joint
International Research Laboratory of Agriculture and Agri-Product
Safety, College of Agriculture, Yangzhou
University, Yangzhou 225009, Jiangsu Province, China
- School of Chemistry and Molecular
Biosciences and Centre for Nutrition and Food Sciences,
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| |
Collapse
|
17
|
Bian B, Kageshima S, Yano K, Fujiwara T, Kamiya T. Screening Arabidopsis thaliana mutants for low sensitivity to manganese identifies novel alleles of NRAMP1 and PGSIP6. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1795-1803. [PMID: 29365153 PMCID: PMC5888932 DOI: 10.1093/jxb/ery018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 01/11/2018] [Indexed: 05/09/2023]
Abstract
Manganese (Mn) is an essential micronutrient; however, few genes required for growth under low-Mn conditions have been identified. In this study, we isolated Arabidopsis thaliana mutants sensitive to low-Mn conditions from ethyl methanesulfonate-mutagenized seeds. Among them, we identified the causal genes of two mutants. One mutant (35-34) exhibited a short root phenotype and low Mn concentration in the shoots. The other mutant (30-11) exhibited a small shoot phenotype with Mn concentrations similar to the control. Genetic mapping, allelism tests, and gene complementation tests identified the causal genes as At1g80830 (NRAMP1) for 35-34 and At5g18480 (PGSIP6) for 30-11. NRAMP1 was previously reported to be essential for Mn uptake under low-Mn conditions, thus validating our screening method. PGSIP6 encodes inositol phosphorylceramide glucuronosyltransferase, which is involved in glycosyl inositol phosphorylceramide sphingolipid glycosylation. PGSIP6-green fluorescent protein was localized to the Golgi apparatus, which is consistent with its function in the glycosylation of sphingolipids. Our screening identified a novel gene required for low-Mn tolerance, and we also provide new insights towards understanding the physiological function of PGSIP6.
Collapse
Affiliation(s)
- Bian Bian
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Sae Kageshima
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Kenji Yano
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Toru Fujiwara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
| | - Takehiro Kamiya
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, Saitama, Japan
| |
Collapse
|
18
|
Harrus D, Kellokumpu S, Glumoff T. Crystal structures of eukaryote glycosyltransferases reveal biologically relevant enzyme homooligomers. Cell Mol Life Sci 2018; 75:833-848. [PMID: 28932871 PMCID: PMC11105277 DOI: 10.1007/s00018-017-2659-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/24/2017] [Accepted: 09/13/2017] [Indexed: 12/31/2022]
Abstract
Glycosyltransferases (GTases) transfer sugar moieties to proteins, lipids or existing glycan or polysaccharide molecules. GTases form an important group of enzymes in the Golgi, where the synthesis and modification of glycoproteins and glycolipids take place. Golgi GTases are almost invariably type II integral membrane proteins, with the C-terminal globular catalytic domain residing in the Golgi lumen. The enzymes themselves are divided into 103 families based on their sequence homology. There is an abundance of published crystal structures of GTase catalytic domains deposited in the Protein Data Bank (PDB). All of these represent either of the two main characteristic structural folds, GT-A or GT-B, or present a variation thereof. Since GTases can function as homomeric or heteromeric complexes in vivo, we have summarized the structural features of the dimerization interfaces in crystal structures of GTases, as well as considered the biochemical data available for these enzymes. For this review, we have considered all 898 GTase crystal structures in the Protein Data Bank and highlight the dimer formation characteristics of various GTases based on 24 selected structures.
Collapse
Affiliation(s)
- Deborah Harrus
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, 90014, Oulu, Finland
| | - Sakari Kellokumpu
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, 90014, Oulu, Finland
| | - Tuomo Glumoff
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, PO Box 5400, 90014, Oulu, Finland.
| |
Collapse
|
19
|
Fan Y, Yu M, Liu M, Zhang R, Sun W, Qian M, Duan H, Chang W, Ma J, Qu C, Zhang K, Lei B, Lu K. Genome-Wide Identification, Evolutionary and Expression Analyses of the GALACTINOL SYNTHASE Gene Family in Rapeseed and Tobacco. Int J Mol Sci 2017; 18:E2768. [PMID: 29261107 PMCID: PMC5751367 DOI: 10.3390/ijms18122768] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/16/2017] [Accepted: 12/17/2017] [Indexed: 11/16/2022] Open
Abstract
Galactinol synthase (GolS) is a key enzyme in raffinose family oligosaccharide (RFO) biosynthesis. The finding that GolS accumulates in plants exposed to abiotic stresses indicates RFOs function in environmental adaptation. However, the evolutionary relationships and biological functions of GolS family in rapeseed (Brassica napus) and tobacco (Nicotiana tabacum) remain unclear. In this study, we identified 20 BnGolS and 9 NtGolS genes. Subcellular localization predictions showed that most of the proteins are localized to the cytoplasm. Phylogenetic analysis identified a lost event of an ancient GolS copy in the Solanaceae and an ancient duplication event leading to evolution of GolS4/7 in the Brassicaceae. The three-dimensional structures of two GolS proteins were conserved, with an important DxD motif for binding to UDP-galactose (uridine diphosphate-galactose) and inositol. Expression profile analysis indicated that BnGolS and NtGolS genes were expressed in most tissues and highly expressed in one or two specific tissues. Hormone treatments strongly induced the expression of most BnGolS genes and homologous genes in the same subfamilies exhibited divergent-induced expression. Our study provides a comprehensive evolutionary analysis of GolS genes among the Brassicaceae and Solanaceae as well as an insight into the biological function of GolS genes in hormone response in plants.
Collapse
Affiliation(s)
- Yonghai Fan
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Mengna Yu
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Miao Liu
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Rui Zhang
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Wei Sun
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Mingchao Qian
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Huichun Duan
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Wei Chang
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Jinqi Ma
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Cunmin Qu
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| | - Kai Zhang
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
| | - Bo Lei
- Key Laboratory of Molecular Genetics, China National Tobacco Corporation, Guizhou Academy of Tobacco Science, Guiyang 550081, China.
- Upland Flue-Cured Tobacco Quality and Ecology Key Laboratory of China Tobacco, Guizhou Academy of Tobacco Science, Guiyang 550081, China.
| | - Kun Lu
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China.
- Academy of Agricultural Sciences, Southwest University, Chongqing 400715, China.
| |
Collapse
|
20
|
Glycosyltransferase MDR1 assembles a dividing ring for mitochondrial proliferation comprising polyglucan nanofilaments. Proc Natl Acad Sci U S A 2017; 114:13284-13289. [PMID: 29180407 DOI: 10.1073/pnas.1715008114] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitochondria, which evolved from a free-living bacterial ancestor, contain their own genomes and genetic systems and are produced from preexisting mitochondria by binary division. The mitochondrion-dividing (MD) ring is the main skeletal structure of the mitochondrial division machinery. However, the assembly mechanism and molecular identity of the MD ring are unknown. Multi-omics analysis of isolated mitochondrial division machinery from the unicellular alga Cyanidioschyzon merolae revealed an uncharacterized glycosyltransferase, MITOCHONDRION-DIVIDING RING1 (MDR1), which is specifically expressed during mitochondrial division and forms a single ring at the mitochondrial division site. Nanoscale imaging using immunoelectron microscopy and componential analysis demonstrated that MDR1 is involved in MD ring formation and that the MD ring filaments are composed of glycosylated MDR1 and polymeric glucose nanofilaments. Down-regulation of MDR1 strongly interrupted mitochondrial division and obstructed MD ring assembly. Taken together, our results suggest that MDR1 mediates the synthesis of polyglucan nanofilaments that assemble to form the MD ring. Given that a homolog of MDR1 performs similar functions in chloroplast division, the establishment of MDR1 family proteins appears to have been a singular, crucial event for the emergence of endosymbiotic organelles.
Collapse
|
21
|
Camiruaga A, Usabiaga I, Insausti A, León I, Fernández JA. Sugar-peptidic bond interactions: spectroscopic characterization of a model system. Phys Chem Chem Phys 2017; 19:12013-12021. [PMID: 28443888 DOI: 10.1039/c7cp00615b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Sugars are small carbohydrates which play numerous roles in living organisms such as storage of energy or as structural components. Modifications of specific sites within the glycan chain can modulate a carbohydrate's overall biological function as it happens with nucleic acids and proteins. Hence, identifying discrete carbohydrate modifications and understanding their biological effects is essential. A study of such processes requires of a deep knowledge of the interaction mechanism at the molecular level. Here, we use a combination of laser spectroscopy in jets and quantum mechanical calculations to characterize the interaction between phenyl-β-d-glucopyranoside and N-methylacetamide as a model to understand the interaction between a sugar and a peptide bond. The most stable structure of the molecular aggregate shows that the main interaction between the peptide fragment and the sugar proceeds via a C[double bond, length as m-dash]OH-O2 hydrogen bond. A second conformer was also found, in which the peptide establishes a C[double bond, length as m-dash]OH-O6 hydrogen bond with the hydroxymethyl substituent of the sugar unit. All the conformers present an additional interaction point with the aromatic ring. This particular preference of the peptide for the hydroxyl close to the aromatic ring could explain why glycogenin uses tyrosine in order to convert glucose into glycogen by exposing the O4H hydroxyl group for the other glucoses for the polymerization to take place.
Collapse
Affiliation(s)
- Ander Camiruaga
- Dpto. de Química Física, Facultad de Ciencia y Tecnología, Universidad del País Vasco-UPV/EHU, Bo Sarriena s/n, Leioa 48940, Spain.
| | | | | | | | | |
Collapse
|
22
|
Comino N, Cifuente JO, Marina A, Orrantia A, Eguskiza A, Guerin ME. Mechanistic insights into the allosteric regulation of bacterial ADP-glucose pyrophosphorylases. J Biol Chem 2017; 292:6255-6268. [PMID: 28223362 DOI: 10.1074/jbc.m116.773408] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/17/2017] [Indexed: 11/06/2022] Open
Abstract
ADP-glucose pyrophosphorylase (AGPase) controls bacterial glycogen and plant starch biosynthetic pathways, the most common carbon storage polysaccharides in nature. AGPase activity is allosterically regulated by a series of metabolites in the energetic flux within the cell. Very recently, we reported the first crystal structures of the paradigmatic AGPase from Escherichia coli (EcAGPase) in complex with its preferred physiological negative and positive allosteric regulators, adenosine 5'-monophosphate (AMP) and fructose 1,6-bisphosphate (FBP), respectively. However, understanding the molecular mechanism by which AMP and FBP allosterically modulates EcAGPase enzymatic activity still remains enigmatic. Here we found that single point mutations of key residues in the AMP-binding site decrease its inhibitory effect but also clearly abolish the overall AMP-mediated stabilization effect in wild-type EcAGPase. Single point mutations of key residues for FBP binding did not revert the AMP-mediated stabilization. Strikingly, an EcAGPase-R130A mutant displayed a dramatic increase in activity when compared with wild-type EcAGPase, and this increase correlated with a significant increment of glycogen content in vivo The crystal structure of EcAGPase-R130A revealed unprecedented conformational changes in structural elements involved in the allosteric signal transmission. Altogether, we propose a model in which the positive and negative energy reporters regulate AGPase catalytic activity via intra- and interprotomer cross-talk, with a "sensory motif" and two loops, RL1 and RL2, flanking the ATP-binding site playing a significant role. The information reported herein provides exciting possibilities for industrial/biotechnological applications.
Collapse
Affiliation(s)
- Natalia Comino
- From the Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Javier O Cifuente
- From the Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Alberto Marina
- From the Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Ane Orrantia
- From the Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Ander Eguskiza
- From the Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain
| | - Marcelo E Guerin
- From the Structural Biology Unit, CIC bioGUNE, Bizkaia Technology Park, 48160 Derio, Spain, .,Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, 48940 Bizkaia, Spain.,Departamento de Bioquímica, Universidad del País Vasco, Leioa, 48940 Bizkaia, Spain, and.,IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
| |
Collapse
|
23
|
Camiruaga A, Usabiaga I, Insausti A, Cocinero EJ, León I, Fernández JA. Understanding the role of tyrosine in glycogenin. MOLECULAR BIOSYSTEMS 2017; 13:1709-1712. [DOI: 10.1039/c7mb00293a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
α-/β-Glucose shows a particular affinity for the O3H and O4H moieties of β-PhGlc in the synthesis of glucogen.
Collapse
Affiliation(s)
- Ander Camiruaga
- Dpto. de Química Física
- Facultad de Ciencia y Tecnología
- Universidad del País Vasco-UPV/EHU
- Leioa
- Spain
| | - Imanol Usabiaga
- Dpto. de Química Física
- Facultad de Ciencia y Tecnología
- Universidad del País Vasco-UPV/EHU
- Leioa
- Spain
| | - Aran Insausti
- Dpto. de Química Física
- Facultad de Ciencia y Tecnología
- Universidad del País Vasco-UPV/EHU
- Leioa
- Spain
| | - Emilio J. Cocinero
- Dpto. de Química Física
- Facultad de Ciencia y Tecnología
- Universidad del País Vasco-UPV/EHU
- Leioa
- Spain
| | - Iker León
- Dpto. de Química Física
- Facultad de Ciencia y Tecnología
- Universidad del País Vasco-UPV/EHU
- Leioa
- Spain
| | - José A. Fernández
- Dpto. de Química Física
- Facultad de Ciencia y Tecnología
- Universidad del País Vasco-UPV/EHU
- Leioa
- Spain
| |
Collapse
|
24
|
Hedberg-Oldfors C, Glamuzina E, Ruygrok P, Anderson LJ, Elliott P, Watkinson O, Occleshaw C, Abernathy M, Turner C, Kingston N, Murphy E, Oldfors A. Cardiomyopathy as presenting sign of glycogenin-1 deficiency-report of three cases and review of the literature. J Inherit Metab Dis 2017; 40:139-149. [PMID: 27718144 PMCID: PMC5203857 DOI: 10.1007/s10545-016-9978-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 09/01/2016] [Accepted: 09/12/2016] [Indexed: 01/19/2023]
Abstract
We describe a new type of cardiomyopathy caused by a mutation in the glycogenin-1 gene (GYG1). Three unrelated male patients aged 34 to 52 years with cardiomyopathy and abnormal glycogen storage on endomyocardial biopsy were homozygous for the missense mutation p.Asp102His in GYG1. The mutated glycogenin-1 protein was expressed in cardiac tissue but had lost its ability to autoglucosylate as demonstrated by an in vitro assay and western blot analysis. It was therefore unable to form the primer for normal glycogen synthesis. Two of the patients showed similar patterns of heart dilatation, reduced ejection fraction and extensive late gadolinium enhancement on cardiac magnetic resonance imaging. These two patients were severely affected, necessitating cardiac transplantation. The cardiomyocyte storage material was characterized by large inclusions of periodic acid and Schiff positive material that was partly resistant to alpha-amylase treatment consistent with polyglucosan. The storage material had, unlike normal glycogen, a partly fibrillar structure by electron microscopy. None of the patients showed signs or symptoms of muscle weakness but a skeletal muscle biopsy in one case revealed muscle fibres with abnormal glycogen storage. Glycogenin-1 deficiency is known as a rare cause of skeletal muscle glycogen storage disease, usually without cardiomyopathy. We demonstrate that it may also be the cause of severe cardiomyopathy and cardiac failure without skeletal muscle weakness. GYG1 should be included in cardiomyopathy gene panels.
Collapse
Affiliation(s)
| | - Emma Glamuzina
- National Metabolic Service, Starship Children’s Hospital, Auckland, New Zealand
| | - Peter Ruygrok
- Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand
| | | | | | | | - Chris Occleshaw
- Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand
| | | | - Clinton Turner
- Anatomical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Nicola Kingston
- Anatomical Pathology, LabPlus, Auckland City Hospital, Auckland, New Zealand
| | - Elaine Murphy
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Anders Oldfors
- Department of Pathology and Genetics, University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
25
|
Hamada Y, Kanematsu Y, Tachikawa M. Quantum Mechanics/Molecular Mechanics Study of the Sialyltransferase Reaction Mechanism. Biochemistry 2016; 55:5764-5771. [PMID: 27644888 DOI: 10.1021/acs.biochem.6b00267] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The sialyltransferase is an enzyme that transfers the sialic acid moiety from cytidine 5'-monophospho-N-acetyl-neuraminic acid (CMP-NeuAc) to the terminal position of glycans. To elucidate the catalytic mechanism of sialyltransferase, we explored the potential energy surface along the sialic acid transfer reaction coordinates by the hybrid quantum mechanics/molecular mechanics method on the basis of the crystal structure of sialyltransferase CstII. Our calculation demonstrated that CstII employed an SN1-like reaction mechanism via the formation of a short-lived oxocarbenium ion intermediate. The computational barrier height was 19.5 kcal/mol, which reasonably corresponded with the experimental reaction rate. We also found that two tyrosine residues (Tyr156 and Tyr162) played a vital role in stabilizing the intermediate and the transition states by quantum mechanical interaction with CMP.
Collapse
Affiliation(s)
- Yojiro Hamada
- Division of Materials Science, Graduate School of Nanobioscience, Yokohama City University , Seto 22-2, Kanazawa-ku, Yokohama 236-0027, Japan
| | - Yusuke Kanematsu
- Division of Materials Science, Graduate School of Nanobioscience, Yokohama City University , Seto 22-2, Kanazawa-ku, Yokohama 236-0027, Japan.,Graduate School of Information Sciences, Hiroshima City University , Ozuka-Higashi 3-4-1, Asa-Minami-Ku, Hiroshima 731-3194, Japan
| | - Masanori Tachikawa
- Division of Materials Science, Graduate School of Nanobioscience, Yokohama City University , Seto 22-2, Kanazawa-ku, Yokohama 236-0027, Japan
| |
Collapse
|
26
|
Giant mimivirus R707 encodes a glycogenin paralogue polymerizing glucose through α- and β-glycosidic linkages. Biochem J 2016; 473:3451-3462. [PMID: 27433018 DOI: 10.1042/bcj20160280] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 07/18/2016] [Indexed: 11/17/2022]
Abstract
Acanthamoeba polyphaga mimivirus is a giant virus encoding 1262 genes among which many were previously thought to be exclusive to cellular life. For example, mimivirus genes encode enzymes involved in the biosynthesis of nucleotide sugars and putative glycosyltransferases. We identified in mimivirus a glycogenin-1 homologous gene encoded by the open reading frame R707. The R707 protein was found to be active as a polymerizing glucosyltransferase enzyme. Like glycogenin-1, R707 activity was divalent-metal-ion-dependent and relied on an intact DXD motif. In contrast with glycogenin-1, R707 was, however, not self-glucosylating. Interestingly, the product of R707 catalysis featured α1-6, β1-6 and α1-4 glycosidic linkages. Mimivirus R707 is the first reported glycosyltransferase able to catalyse the formation of both α and β linkages. Mimivirus-encoded glycans play a role in the infection of host amoebae. Co-infection of Acanthamoeba with mimivirus and amylose and chitin hydrolysate reduced the number of infected amoebae, thus supporting the importance of polysaccharide chains in the uptake of mimivirus by amoebae. The identification of a glycosyltransferase capable of forming α and β linkages underlines the peculiarity of mimivirus and enforces the concept of a host-independent glycosylation machinery in mimivirus.
Collapse
|
27
|
Adeva-Andany MM, González-Lucán M, Donapetry-García C, Fernández-Fernández C, Ameneiros-Rodríguez E. Glycogen metabolism in humans. BBA CLINICAL 2016; 5:85-100. [PMID: 27051594 PMCID: PMC4802397 DOI: 10.1016/j.bbacli.2016.02.001] [Citation(s) in RCA: 264] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/10/2016] [Accepted: 02/16/2016] [Indexed: 12/31/2022]
Abstract
In the human body, glycogen is a branched polymer of glucose stored mainly in the liver and the skeletal muscle that supplies glucose to the blood stream during fasting periods and to the muscle cells during muscle contraction. Glycogen has been identified in other tissues such as brain, heart, kidney, adipose tissue, and erythrocytes, but glycogen function in these tissues is mostly unknown. Glycogen synthesis requires a series of reactions that include glucose entrance into the cell through transporters, phosphorylation of glucose to glucose 6-phosphate, isomerization to glucose 1-phosphate, and formation of uridine 5'-diphosphate-glucose, which is the direct glucose donor for glycogen synthesis. Glycogenin catalyzes the formation of a short glucose polymer that is extended by the action of glycogen synthase. Glycogen branching enzyme introduces branch points in the glycogen particle at even intervals. Laforin and malin are proteins involved in glycogen assembly but their specific function remains elusive in humans. Glycogen is accumulated in the liver primarily during the postprandial period and in the skeletal muscle predominantly after exercise. In the cytosol, glycogen breakdown or glycogenolysis is carried out by two enzymes, glycogen phosphorylase which releases glucose 1-phosphate from the linear chains of glycogen, and glycogen debranching enzyme which untangles the branch points. In the lysosomes, glycogen degradation is catalyzed by α-glucosidase. The glucose 6-phosphatase system catalyzes the dephosphorylation of glucose 6-phosphate to glucose, a necessary step for free glucose to leave the cell. Mutations in the genes encoding the enzymes involved in glycogen metabolism cause glycogen storage diseases.
Collapse
Affiliation(s)
- María M. Adeva-Andany
- Nephrology Division, Hospital General Juan Cardona, c/ Pardo Bazán s/n, 15406 Ferrol, Spain
| | | | | | | | | |
Collapse
|
28
|
Culbertson AT, Tietze AA, Tietze D, Chou YH, Smith AL, Young ZT, Zabotina OA. A homology model of Xyloglucan Xylosyltransferase 2 reveals critical amino acids involved in substrate binding. Glycobiology 2016; 26:961-972. [DOI: 10.1093/glycob/cww050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 04/14/2016] [Indexed: 11/14/2022] Open
|
29
|
Zeqiraj E, Sicheri F. Getting a handle on glycogen synthase - Its interaction with glycogenin. Mol Aspects Med 2015; 46:63-9. [PMID: 26278983 DOI: 10.1016/j.mam.2015.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 08/04/2015] [Indexed: 02/08/2023]
Abstract
Glycogen is a polymer of glucose that serves as a major energy reserve in eukaryotes. It is synthesized through the cooperative action of glycogen synthase (GS), glycogenin (GN) and glycogen branching enzyme. GN initiates the first enzymatic step in the glycogen synthesis process by self glucosylation of a short 8-12 glucose residue primer. After interacting with GN, GS then extends this sugar primer to form glycogen particles of different sizes. We discuss recent developments in the structural biology characterization of GS and GN enzymes, which have contributed to a better understanding of how the two proteins interact and how they collaborate to synthesize glycogen particles.
Collapse
Affiliation(s)
- Elton Zeqiraj
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Room 1090, Toronto, ON M5G 1X5, Canada; Departments of Biochemistry and Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.
| | - Frank Sicheri
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Room 1090, Toronto, ON M5G 1X5, Canada; Departments of Biochemistry and Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada.
| |
Collapse
|
30
|
Luo S, Zhu W, Yue D, Lin J, Wang Y, Zhu Z, Qiu W, Lu J, Hedberg-Oldfors C, Oldfors A, Zhao C. Muscle pathology and whole-body MRI in a polyglucosan myopathy associated with a novel glycogenin-1 mutation. Neuromuscul Disord 2015; 25:780-5. [PMID: 26255073 DOI: 10.1016/j.nmd.2015.07.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 06/22/2015] [Accepted: 07/10/2015] [Indexed: 11/24/2022]
Abstract
We report a 46-year-old female with late-onset skeletal myopathy affecting proximal limb muscles. Muscle biopsy revealed a polyglucosan myopathy with PAS-positive inclusions predominantly in glycogen-depleted fibers, which were demonstrated as type I fibers by ATPase staining. Whole-body magnetic imaging disclosed that the paravertebral, scapular, and pelvic girdle muscles, the anterior compartment of the arms, and the posterior compartment of the thighs were preferentially involved. Genetic analysis revealed a homozygous novel mutation in exon 6 of the glycogenin-1 gene (GYG1) (c.634C>T, p.His212Tyr). Protein analysis revealed normal levels of glycogenin-1 even before alpha-amylase digestion indicating preserved protein expression but impaired glucosylation. In vitro functional assay demonstrated that this variant impaired the autoglucosylating ability resulting in a non-functional protein. We report a glycogenin-1 related myopathy with a distinct histopathology and unique muscle imaging pattern.
Collapse
Affiliation(s)
- Sushan Luo
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Wenhua Zhu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo, Japan
| | - Dongyue Yue
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jie Lin
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Yin Wang
- Department of Neuropathology, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhen Zhu
- Department of Radiology, Children's Hospital of Shanghai, Jiaotong University, Shanghai, China
| | - Wenjuan Qiu
- Department of Pediatric Endocrinology, Genetic and Metabolic Diseases, Shanghai Institute for Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University, Shanghai, China
| | - Jiahong Lu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Carola Hedberg-Oldfors
- Department of Pathology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Anders Oldfors
- Department of Pathology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China; Department of Neurology, Jing'an District Center Hospital of Shanghai, Shanghai, China.
| |
Collapse
|
31
|
Abdulbari HA, Shabirin A, Abdurrahman H. Bio-polymers for improving liquid flow in pipelines—A review and future work opportunities. J IND ENG CHEM 2014. [DOI: 10.1016/j.jiec.2013.07.050] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
32
|
Structural basis for the recruitment of glycogen synthase by glycogenin. Proc Natl Acad Sci U S A 2014; 111:E2831-40. [PMID: 24982189 DOI: 10.1073/pnas.1402926111] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Glycogen is a primary form of energy storage in eukaryotes that is essential for glucose homeostasis. The glycogen polymer is synthesized from glucose through the cooperative action of glycogen synthase (GS), glycogenin (GN), and glycogen branching enzyme and forms particles that range in size from 10 to 290 nm. GS is regulated by allosteric activation upon glucose-6-phosphate binding and inactivation by phosphorylation on its N- and C-terminal regulatory tails. GS alone is incapable of starting synthesis of a glycogen particle de novo, but instead it extends preexisting chains initiated by glycogenin. The molecular determinants by which GS recognizes self-glucosylated GN, the first step in glycogenesis, are unknown. We describe the crystal structure of Caenorhabditis elegans GS in complex with a minimal GS targeting sequence in GN and show that a 34-residue region of GN binds to a conserved surface on GS that is distinct from previously characterized allosteric and binding surfaces on the enzyme. The interaction identified in the GS-GN costructure is required for GS-GN interaction and for glycogen synthesis in a cell-free system and in intact cells. The interaction of full-length GS-GN proteins is enhanced by an avidity effect imparted by a dimeric state of GN and a tetrameric state of GS. Finally, the structure of the N- and C-terminal regulatory tails of GS provide a basis for understanding phosphoregulation of glycogen synthesis. These results uncover a central molecular mechanism that governs glycogen metabolism.
Collapse
|
33
|
A hemizygous GYG2 mutation and Leigh syndrome: a possible link? Hum Genet 2013; 133:225-34. [DOI: 10.1007/s00439-013-1372-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 09/29/2013] [Indexed: 11/26/2022]
|
34
|
Abstract
Recent progress in the identification and characterization of pectin biosynthetic proteins and the discovery of pectin domain-containing proteoglycans are changing our view of how pectin, the most complex family of plant cell wall polysaccharides, is synthesized. The functional confirmation of four types of pectin biosynthetic glycosyltransferases, the identification of multiple putative pectin glycosyl- and methyltransferases, and the characteristics of the GAUT1:GAUT7 homogalacturonan biosynthetic complex with its novel mechanism for retaining catalytic subunits in the Golgi apparatus and its 12 putative interacting proteins are beginning to provide a framework for the pectin biosynthetic process. We propose two partially overlapping hypothetical and testable models for pectin synthesis: the consecutive glycosyltransferase model and the domain synthesis model.
Collapse
Affiliation(s)
- Melani A Atmodjo
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602-4712, USA.
| | | | | |
Collapse
|
35
|
Sullivan MA, O'Connor MJ, Umana F, Roura E, Jack K, Stapleton DI, Gilbert RG. Molecular insights into glycogen α-particle formation. Biomacromolecules 2012; 13:3805-13. [PMID: 23004915 DOI: 10.1021/bm3012727] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glycogen, a hyperbranched complex glucose polymer, is an intracellular glucose store that provides energy for cellular functions, with liver glycogen involved in blood-glucose regulation. Liver glycogen comprises complex α particles made up of smaller β particles. The recent discovery that these α particles are smaller and fewer in diabetic, compared with healthy, mice highlights the need to elucidate the nature of α-particle formation; this paper tests various possibilities for binding within α particles. Acid hydrolysis effects, examined using dynamic light scattering and size exclusion chromatography, showed that the binding is not simple α-(1→4) or α-(1→6) glycosidic linkages. There was no significant change in α particle size after the addition of various reagents, which disrupt disulfide, protein, and hydrogen bonds and hydrophobic interactions. The results are consistent with proteinaceous binding between β particles in α particles, with the inability of protease to break apart particles being attributed to steric hindrance.
Collapse
Affiliation(s)
- Mitchell A Sullivan
- Centre for Nutrition & Food Sciences (Building 83/S434), Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Qld 4072, Australia
| | | | | | | | | | | | | |
Collapse
|
36
|
Rennie EA, Hansen SF, Baidoo EE, Hadi MZ, Keasling JD, Scheller HV. Three members of the Arabidopsis glycosyltransferase family 8 are xylan glucuronosyltransferases. PLANT PHYSIOLOGY 2012; 159:1408-17. [PMID: 22706449 PMCID: PMC3428776 DOI: 10.1104/pp.112.200964] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 06/14/2012] [Indexed: 05/17/2023]
Abstract
Xylan is a major component of the plant cell wall and the most abundant noncellulosic component in the secondary cell walls that constitute the largest part of plant biomass. Dicot glucuronoxylan consists of a linear backbone of β(1,4)-linked xylose residues substituted with α(1,2)-linked glucuronic acid (GlcA). Although several genes have been implicated in xylan synthesis through mutant analyses, the biochemical mechanisms responsible for synthesizing xylan are largely unknown. Here, we show evidence for biochemical activity of GUX1 (for GlcA substitution of xylan 1), a member of Glycosyltransferase Family 8 in Arabidopsis (Arabidopsis thaliana) that is responsible for adding the glucuronosyl substitutions onto the xylan backbone. GUX1 has characteristics typical of Golgi-localized glycosyltransferases and a K(m) for UDP-GlcA of 165 μm. GUX1 strongly favors xylohexaose as an acceptor over shorter xylooligosaccharides, and with xylohexaose as an acceptor, GlcA is almost exclusively added to the fifth xylose residue from the nonreducing end. We also show that several related proteins, GUX2 to GUX5 and Plant Glycogenin-like Starch Initiation Protein6, are Golgi localized and that only two of these proteins, GUX2 and GUX4, have activity as xylan α-glucuronosyltransferases.
Collapse
Affiliation(s)
- Emilie A. Rennie
- Feedstocks Division (E.A.R., S.F.H., H.V.S.) and Fuels Synthesis Division (E.E.K.B., J.D.K.), Joint BioEnergy Institute, Emeryville, California 94608; Biomass Science and Conversion Technologies Department, Sandia National Laboratories, Livermore, California 94551 (M.Z.H.)
- Department of Plant and Microbial Biology (E.A.R., H.V.S.) and Department of Chemical and Biomolecular Engineering and Department of Bioengineering (J.D.K.), University of California, Berkeley, California 94720
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (J.D.K., H.V.S.)
| | - Sara Fasmer Hansen
- Feedstocks Division (E.A.R., S.F.H., H.V.S.) and Fuels Synthesis Division (E.E.K.B., J.D.K.), Joint BioEnergy Institute, Emeryville, California 94608; Biomass Science and Conversion Technologies Department, Sandia National Laboratories, Livermore, California 94551 (M.Z.H.)
- Department of Plant and Microbial Biology (E.A.R., H.V.S.) and Department of Chemical and Biomolecular Engineering and Department of Bioengineering (J.D.K.), University of California, Berkeley, California 94720
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (J.D.K., H.V.S.)
| | - Edward E.K. Baidoo
- Feedstocks Division (E.A.R., S.F.H., H.V.S.) and Fuels Synthesis Division (E.E.K.B., J.D.K.), Joint BioEnergy Institute, Emeryville, California 94608; Biomass Science and Conversion Technologies Department, Sandia National Laboratories, Livermore, California 94551 (M.Z.H.)
- Department of Plant and Microbial Biology (E.A.R., H.V.S.) and Department of Chemical and Biomolecular Engineering and Department of Bioengineering (J.D.K.), University of California, Berkeley, California 94720
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (J.D.K., H.V.S.)
| | - Masood Z. Hadi
- Feedstocks Division (E.A.R., S.F.H., H.V.S.) and Fuels Synthesis Division (E.E.K.B., J.D.K.), Joint BioEnergy Institute, Emeryville, California 94608; Biomass Science and Conversion Technologies Department, Sandia National Laboratories, Livermore, California 94551 (M.Z.H.)
- Department of Plant and Microbial Biology (E.A.R., H.V.S.) and Department of Chemical and Biomolecular Engineering and Department of Bioengineering (J.D.K.), University of California, Berkeley, California 94720
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (J.D.K., H.V.S.)
| | - Jay D. Keasling
- Feedstocks Division (E.A.R., S.F.H., H.V.S.) and Fuels Synthesis Division (E.E.K.B., J.D.K.), Joint BioEnergy Institute, Emeryville, California 94608; Biomass Science and Conversion Technologies Department, Sandia National Laboratories, Livermore, California 94551 (M.Z.H.)
- Department of Plant and Microbial Biology (E.A.R., H.V.S.) and Department of Chemical and Biomolecular Engineering and Department of Bioengineering (J.D.K.), University of California, Berkeley, California 94720
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (J.D.K., H.V.S.)
| | | |
Collapse
|
37
|
Abstract
Glycogen is a branched polymer of glucose that acts as a store of energy in times of nutritional sufficiency for utilization in times of need. Its metabolism has been the subject of extensive investigation and much is known about its regulation by hormones such as insulin, glucagon and adrenaline (epinephrine). There has been debate over the relative importance of allosteric compared with covalent control of the key biosynthetic enzyme, glycogen synthase, as well as the relative importance of glucose entry into cells compared with glycogen synthase regulation in determining glycogen accumulation. Significant new developments in eukaryotic glycogen metabolism over the last decade or so include: (i) three-dimensional structures of the biosynthetic enzymes glycogenin and glycogen synthase, with associated implications for mechanism and control; (ii) analyses of several genetically engineered mice with altered glycogen metabolism that shed light on the mechanism of control; (iii) greater appreciation of the spatial aspects of glycogen metabolism, including more focus on the lysosomal degradation of glycogen; and (iv) glycogen phosphorylation and advances in the study of Lafora disease, which is emerging as a glycogen storage disease.
Collapse
|
38
|
Li HM, Chen H, Yang ZN, Gong JM. Cdigene is required for pollen germination and tube growth in Arabidopsis. FEBS Lett 2012; 586:1027-31. [DOI: 10.1016/j.febslet.2012.02.046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 02/24/2012] [Accepted: 02/24/2012] [Indexed: 02/04/2023]
|
39
|
Carrizo ME, Romero JM, Issoglio FM, Curtino JA. Structural and biochemical insight into glycogenin inactivation by the glycogenosis-causing T82M mutation. FEBS Lett 2012; 586:254-7. [PMID: 22226635 DOI: 10.1016/j.febslet.2011.12.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 12/14/2011] [Accepted: 12/21/2011] [Indexed: 10/14/2022]
Abstract
The X-ray structure of rabbit glycogenin containing the T82M (T83M according to previous authors amino acid numbering) mutation causing glycogenosis showed the loss of Thr82 hydrogen bond to Asp162, the residue involved in the activation step of the glucose transfer reaction mechanism. Autoglucosylation, maltoside transglucosylation and UDP-glucose hydrolyzing activities were abolished even though affinity and interactions with UDP-glucose and positioning of Tyr194 acceptor were conserved. Substitution of Thr82 for serine but not for valine restored the maximum extent of autoglucosylation as well as transglucosylation and UDP-glucose hydrolysis rate. Results provided evidence sustaining the essential role of the lost single hydrogen bond for UDP-glucose activation leading to glycogenin-bound glycogen primer synthesis.
Collapse
Affiliation(s)
- María E Carrizo
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC, UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
| | | | | | | |
Collapse
|
40
|
Lee SC, Kang NY, Park SJ, Yun SW, Chandran Y, Chang YT. Development of a fluorescent chalcone library and its application in the discovery of a mouse embryonic stem cell probe. Chem Commun (Camb) 2012; 48:6681-3. [DOI: 10.1039/c2cc31662e] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
41
|
Conformational plasticity of glycogenin and its maltosaccharide substrate during glycogen biogenesis. Proc Natl Acad Sci U S A 2011; 108:21028-33. [PMID: 22160680 DOI: 10.1073/pnas.1113921108] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glycogenin initiates the synthesis of a maltosaccharide chain covalently attached to itself on Tyr195 via a stepwise glucosylation reaction, priming glycogen synthesis. We have captured crystallographic snapshots of human glycogenin during its reaction cycle, revealing a dynamic conformational switch between ground and active states mediated by the sugar donor UDP-glucose. This switch includes the ordering of a polypeptide stretch containing Tyr195, and major movement of an approximately 30-residue "lid" segment covering the active site. The rearranged lid guides the nascent maltosaccharide chain into the active site in either an intra- or intersubunit mode dependent upon chain length and steric factors and positions the donor and acceptor sugar groups for catalysis. The Thr83Met mutation, which causes glycogen storage disease XV, is conformationally locked in the ground state and catalytically inactive. Our data highlight the conformational plasticity of glycogenin and coexistence of two modes of glucosylation as integral to its catalytic mechanism.
Collapse
|
42
|
Nilsson J, Halim A, Moslemi AR, Pedersen A, Nilsson J, Larson G, Oldfors A. Molecular pathogenesis of a new glycogenosis caused by a glycogenin-1 mutation. Biochim Biophys Acta Mol Basis Dis 2011; 1822:493-9. [PMID: 22198226 DOI: 10.1016/j.bbadis.2011.11.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 11/07/2011] [Accepted: 11/28/2011] [Indexed: 11/29/2022]
Abstract
Glycogenin-1 initiates the glycogen synthesis in skeletal muscle by the autocatalytic formation of a short oligosaccharide at tyrosine 195. Glycogenin-1 catalyzes both the glucose-O-tyrosine linkage and the α1,4 glucosidic bonds linking the glucose molecules in the oligosaccharide. We recently described a patient with glycogen depletion in skeletal muscle as a result of a non-functional glycogenin-1. The patient carried a Thr83Met substitution in glycogenin-1. In this study we have investigated the importance of threonine 83 for the catalytic activity of glycogenin-1. Non-glucosylated glycogenin-1 constructs, with various amino acid substitutions in position 83 and 195, were expressed in a cell-free expression system and autoglucosylated in vitro. The autoglucosylation was analyzed by gel-shift on western blot, incorporation of radiolabeled UDP-(14)C-glucose and nano-liquid chromatography with tandem mass spectrometry (LC/MS/MS). We demonstrate that glycogenin-1 with the Thr83Met substitution is unable to form the glucose-O-tyrosine linkage at tyrosine 195 unless co-expressed with the catalytically active Tyr195Phe glycogenin-1. Our results explain the glycogen depletion in the patient expressing only Thr83Met glycogenin-1 and why heterozygous carriers without clinical symptoms show a small proportion of unglucosylated glycogenin-1.
Collapse
Affiliation(s)
- Johanna Nilsson
- Department of Pathology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
| | | | | | | | | | | | | |
Collapse
|
43
|
Issoglio FM, Carrizo ME, Romero JM, Curtino JA. Mechanisms of monomeric and dimeric glycogenin autoglucosylation. J Biol Chem 2011; 287:1955-61. [PMID: 22128147 DOI: 10.1074/jbc.m111.287813] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Initiation of glucose polymerization by glycogenin autoglucosylation at Tyr-194 is required to prime de novo biosynthesis of glycogen. It has been proposed that the synthesis of the primer proceeds by intersubunit glucosylation of dimeric glycogenin, even though it has not been demonstrated that this mechanism is responsible for the described polymerization extent of 12 glucoses produced by the dimer. We reported previously the intramonomer glucosylation capability of glycogenin without determining the extent of autoglucopolymerization. Here, we show that the maximum specific autoglucosylation extent (MSAE) produced by the non-glucosylated glycogenin monomer is 13.3 ± 1.9 glucose units, similar to the 12.5 ± 1.4 glucose units measured for the dimer. The mechanism and capacity of the dimeric enzyme to carry out full glucopolymerization were also evaluated by construction of heterodimers able to glucosylate exclusively by intrasubunit or intersubunit reaction mechanisms. The MSAE of non-glucosylated glycogenin produced by dimer intrasubunit glucosylation was 16% of that produced by the monomer. However, partially glucosylated glycogenin was able to almost complete its autoglucosylation by the dimer intrasubunit mechanism. The MSAE produced by heterodimer intersubunit glucosylation was 60% of that produced by the wild-type dimer. We conclude that both intrasubunit and intersubunit reaction mechanisms are necessary for the dimeric enzyme to acquire maximum autoglucosylation. The full glucopolymerization capacity of monomeric glycogenin indicates that the enzyme is able to synthesize the glycogen primer without the need for prior dimerization.
Collapse
Affiliation(s)
- Federico M Issoglio
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC, Universidad Nacional de Córdoba-Consejo Nacional de Investigaciones Científicas y Técnicas (UNC-CONICET)), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina
| | | | | | | |
Collapse
|
44
|
Freire MA. Polymer phosphorylases: clues to the emergence of non-replicative and replicative polymers. Theory Biosci 2011; 130:279-87. [PMID: 21785867 DOI: 10.1007/s12064-011-0131-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 07/01/2011] [Indexed: 10/18/2022]
Abstract
Polymer formation is arguably one of the essential factors that allowed the emergence, stabilisation and spread of life on Earth. Consequently, studies concerning biopolymers could shed light on the origins of life itself. Of particular interest are RNA and polysaccharide polymers, the archetypes of the contrasting proposed evolutionary scenarios and their respective polymerases. Nucleic acid polymerases were hypothesised, before their discovery, to have a functional similarity with glycogen phosphorylase. Further identification and characterisation of nucleic acid polymerases; particularly of polynucleotide phosphorylase (PNPase), provided experimental evidence for the initial premise. Once discovered, frequent similarities were found between PNPase and glycogen phosphorylase, in terms of catalytic features and biochemical properties. As a result, PNPase was seen as a model of primitive polymerase and used in laboratory precellular systems. Paradoxically, however, these similarities were not sufficient as an argument in favour of an ancestral common polymerisation mechanism prior to polysaccharides and polyribonucleotides. Here we present an overview of the common features shared by polymer phosphorylases, with new proposals for the emergence of polysaccharide and RNA polymers.
Collapse
Affiliation(s)
- Miguel Angel Freire
- Instituto Multidisciplinario de Biología Vegetal, CONICET, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, segundo piso, 5000, Córdoba, Argentina.
| |
Collapse
|
45
|
The cellular basis of chitin synthesis in fungi and insects: common principles and differences. Eur J Cell Biol 2011; 90:759-69. [PMID: 21700357 DOI: 10.1016/j.ejcb.2011.04.014] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Chitin is a polymer of N-acetylglucosamine, which assembles into microfibrils of about 20 sugar chains. These microfibrils serve as a structural component of natural biocomposites found in cell walls and specialized extracellular matrices such as cuticles and peritrophic membranes. Chitin synthesis is performed by a wide range of organisms including fungi and insects. The underlying biosynthetic machinery is highly conserved and involves several enzymes, of which the chitin synthase is the key enzyme. This membrane integral glycosyltransferase catalyzes the polymerization reaction. Most of what we know about chitin synthesis derives from studies of fungal and insect systems. In this review, common principles and differences will be worked out at the levels of gene organization, enzymatic properties, cellular localization and regulation.
Collapse
|
46
|
Wilson WA, Roach PJ, Montero M, Baroja-Fernández E, Muñoz FJ, Eydallin G, Viale AM, Pozueta-Romero J. Regulation of glycogen metabolism in yeast and bacteria. FEMS Microbiol Rev 2011; 34:952-85. [PMID: 20412306 DOI: 10.1111/j.1574-6976.2010.00220.x] [Citation(s) in RCA: 253] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Microorganisms have the capacity to utilize a variety of nutrients and adapt to continuously changing environmental conditions. Many microorganisms, including yeast and bacteria, accumulate carbon and energy reserves to cope with the starvation conditions temporarily present in the environment. Glycogen biosynthesis is a main strategy for such metabolic storage, and a variety of sensing and signaling mechanisms have evolved in evolutionarily distant species to ensure the production of this homopolysaccharide. At the most fundamental level, the processes of glycogen synthesis and degradation in yeast and bacteria share certain broad similarities. However, the regulation of these processes is sometimes quite distinct, indicating that they have evolved separately to respond optimally to the habitat conditions of each species. This review aims to highlight the mechanisms, both at the transcriptional and at the post-transcriptional level, that regulate glycogen metabolism in yeast and bacteria, focusing on selected areas where the greatest increase in knowledge has occurred during the last few years. In the yeast system, we focus particularly on the various signaling pathways that control the activity of the enzymes of glycogen storage. We also discuss our recent understanding of the important role played by the vacuole in glycogen metabolism. In the case of bacterial glycogen, special emphasis is placed on aspects related to the genetic regulation of glycogen metabolism and its connection with other biological processes.
Collapse
Affiliation(s)
- Wayne A Wilson
- Biochemistry and Nutrition Department, Des Moines University, Des Moines, IA, USA
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Yin Y, Chen H, Hahn MG, Mohnen D, Xu Y. Evolution and function of the plant cell wall synthesis-related glycosyltransferase family 8. PLANT PHYSIOLOGY 2010; 153:1729-46. [PMID: 20522722 PMCID: PMC2923890 DOI: 10.1104/pp.110.154229] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 06/01/2010] [Indexed: 05/17/2023]
Abstract
Carbohydrate-active enzyme glycosyltransferase family 8 (GT8) includes the plant galacturonosyltransferase1-related gene family of proven and putative alpha-galacturonosyltransferase (GAUT) and GAUT-like (GATL) genes. We computationally identified and investigated this family in 15 fully sequenced plant and green algal genomes and in the National Center for Biotechnology Information nonredundant protein database to determine the phylogenetic relatedness of the GAUTs and GATLs to other GT8 family members. The GT8 proteins fall into three well-delineated major classes. In addition to GAUTs and GATLs, known or predicted to be involved in plant cell wall biosynthesis, class I also includes a lower plant-specific GAUT and GATL-related (GATR) subfamily, two metazoan subfamilies, and proteins from other eukaryotes and cyanobacteria. Class II includes galactinol synthases and plant glycogenin-like starch initiation proteins that are not known to be directly involved in cell wall synthesis, as well as proteins from fungi, metazoans, viruses, and bacteria. Class III consists almost entirely of bacterial proteins that are lipooligo/polysaccharide alpha-galactosyltransferases and alpha-glucosyltransferases. Sequence motifs conserved across all GT8 subfamilies and those specific to plant cell wall-related GT8 subfamilies were identified and mapped onto a predicted GAUT1 protein structure. The tertiary structure prediction identified sequence motifs likely to represent key amino acids involved in catalysis, substrate binding, protein-protein interactions, and structural elements required for GAUT1 function. The results show that the GAUTs, GATLs, and GATRs have a different evolutionary origin than other plant GT8 genes, were likely acquired from an ancient cyanobacterium (Synechococcus) progenitor, and separate into unique subclades that may indicate functional specialization.
Collapse
Affiliation(s)
| | | | | | - Debra Mohnen
- Computational Systems Biology Laboratory and Institute of Bioinformatics (Y.Y., H.C., Y.X.), BioEnergy Science Center (Y.Y., M.G.H., D.M., Y.X.), Department of Plant Biology (M.G.H.), Complex Carbohydrate Research Center (M.G.H., D.M.), and Department of Biochemistry and Molecular Biology (D.M., Y.X.), University of Georgia, Athens, Georgia 30602
| | | |
Collapse
|
48
|
Graham TE, Yuan Z, Hill AK, Wilson RJ. The regulation of muscle glycogen: the granule and its proteins. Acta Physiol (Oxf) 2010; 199:489-98. [PMID: 20353490 DOI: 10.1111/j.1748-1716.2010.02131.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Despite decades of studying muscle glycogen in many metabolic situations, surprisingly little is known regarding its regulation. Glycogen is a dynamic and vital metabolic fuel that has very limited energetic capacity. Thus its regulation is highly complex and multifaceted. The stores in muscle are not homogeneous and there appear to be various metabolic pools. Each granule is capable of independent regulation and fundamental aspects of the regulation appear to be associated with a complex set of proteins (some are enzymes and others serve scaffolding roles) that associate both with the granule and with each other in a dynamic fashion. The regulation includes altered phosphorylation status and often translocation as well. The understanding of the roles and the regulation of glycogenin, protein phosphatase 1, glycogen targeting proteins, laforin and malin are in their infancy. These various processes appear to be the mechanisms that give the glycogen granule precise, yet dynamic regulation.
Collapse
Affiliation(s)
- T E Graham
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada.
| | | | | | | |
Collapse
|
49
|
Gonçalves S, Borges N, Esteves AM, Victor BL, Soares CM, Santos H, Matias PM. Structural analysis of Thermus thermophilus HB27 mannosyl-3-phosphoglycerate synthase provides evidence for a second catalytic metal ion and new insight into the retaining mechanism of glycosyltransferases. J Biol Chem 2010; 285:17857-68. [PMID: 20356840 PMCID: PMC2878549 DOI: 10.1074/jbc.m109.095976] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 03/17/2010] [Indexed: 11/06/2022] Open
Abstract
Mannosyl-3-phosphoglycerate synthase is a glycosyltransferase involved in the two-step synthetic pathway of mannosylglycerate, a compatible solute that accumulates in response to salt and/or heat stresses in many microorganisms thriving in hot environments. The three-dimensional structure of mannosyl-3-phosphoglycerate synthase from Thermus thermophilus HB27 in its binary complex form, with GDP-alpha-D-mannose and Mg(2+), shows a second metal binding site, about 6 A away from the mannose moiety. Kinetic and mutagenesis studies have shown that this metal site plays a role in catalysis. Additionally, Asp(167) in the DXD motif is found within van der Waals contact distance of the C1' atom in the mannopyranose ring, suggesting its action as a catalytic nucleophile, either in the formation of a glycosyl-enzyme intermediate according to the double-displacement S(N)2 reaction mechanism or in the stabilization of the oxocarbenium ion-like intermediate according to the D(N)*A(Nss) (S(N)i-like) reaction mechanism. We propose that either mechanism may occur in retaining glycosyltransferases with a GT-A fold, and, based on the gathered structural information, we identified an extended structural signature toward a common scaffold between the inverting and retaining glycosyltransferases.
Collapse
Affiliation(s)
- Susana Gonçalves
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Nuno Borges
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Ana M. Esteves
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Bruno L. Victor
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Cláudio M. Soares
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Helena Santos
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| | - Pedro M. Matias
- From the Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal
| |
Collapse
|
50
|
Moslemi AR, Lindberg C, Nilsson J, Tajsharghi H, Andersson B, Oldfors A. Glycogenin-1 deficiency and inactivated priming of glycogen synthesis. N Engl J Med 2010; 362:1203-10. [PMID: 20357282 DOI: 10.1056/nejmoa0900661] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Glycogen, which serves as a major energy reserve in cells, is a large, branched polymer of glucose molecules. We describe a patient who had muscle weakness, associated with the depletion of glycogen in skeletal muscle, and cardiac arrhythmia, associated with the accumulation of abnormal storage material in the heart. The skeletal muscle showed a marked predominance of slow-twitch, oxidative muscle fibers and mitochondrial proliferation. Western blotting showed the presence of unglucosylated glycogenin-1 in the muscle and heart. Sequencing of the glycogenin-1 gene, GYG1, revealed a nonsense mutation in one allele and a missense mutation, Thr83Met, in the other. The missense mutation resulted in inactivation of the autoglucosylation of glycogenin-1 that is necessary for the priming of glycogen synthesis in muscle.
Collapse
Affiliation(s)
- Ali-Reza Moslemi
- Department of Pathology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | | | | | | | | | | |
Collapse
|