title: Like-acetylglucosaminyltransferase (LARGE)-dependent modification of dystroglycan at Thr-317/319 is required for laminin binding and arenavirus infection.
abstract: α-dystroglycan is a highly O-glycosylated extracellular matrix receptor that is required for anchoring of the basement membrane to the cell surface and for the entry of Old World arenaviruses into cells. Like-acetylglucosaminyltransferase (LARGE) is a key molecule that binds to the N-terminal domain of α-dystroglycan and attaches ligand-binding moieties to phosphorylated O-mannose on α-dystroglycan. Here we show that the LARGE modification required for laminin- and virus-binding occurs on specific Thr residues located at the extreme N terminus of the mucin-like domain of α-dystroglycan. Deletion and mutation analyses demonstrate that the ligand-binding activity of α-dystroglycan is conferred primarily by LARGE modification at Thr-317 and -319, within the highly conserved first 18 amino acids of the mucin-like domain. The importance of these paired residues in laminin-binding and clustering activity on myoblasts and in arenavirus cell entry is confirmed by mutational analysis with full-length dystroglycan. We further demonstrate that a sequence of five amino acids, Thr(317)ProThr(319)ProVal, contains phosphorylated O-glycosylation and, when modified by LARGE is sufficient for laminin-binding. Because the N-terminal region adjacent to the paired Thr residues is removed during posttranslational maturation of dystroglycan, our results demonstrate that the ligand-binding activity resides at the extreme N terminus of mature α-dystroglycan and is crucial for α-dystroglycan to coordinate the assembly of extracellular matrix proteins and to bind arenaviruses on the cell surface.
authors: The Howard Hughes Medical Institute, The Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
authors: Yuji
authors: Y
authors: Hara
authors: Motoi
authors: M
authors: Kanagawa
authors: Stefan
authors: S
authors: Kunz
authors: Takako
authors: T
authors: Yoshida-Moriguchi
authors: Jakob S
authors: JS
authors: Satz
authors: Yvonne M
authors: YM
authors: Kobayashi
authors: Zihan
authors: Z
authors: Zhu
authors: Steven J
authors: SJ
authors: Burden
authors: Michael B A
authors: MB
authors: Oldstone
authors: Kevin P
authors: KP
authors: Campbell
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001117:Arenaviridae Infections / Q000209:etiology* / Q000378:metabolism*; D001665:Binding Sites; D002460:Cell Line; D049030:Dystroglycans / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D057809:HEK293 Cells; D006801:Humans; D007797:Laminin / Q000378:metabolism*; D008217:Lymphocytic choriomeningitis virus / Q000472:pathogenicity; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D016296:Mutagenesis; D032446:Myoblasts / Q000378:metabolism; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013912:Threonine / Q000737:chemistry; D053586:Virus Internalization
chemical_list: C483081:DAG1 protein, human; D007797:Laminin; D011994:Recombinant Proteins; D049030:Dystroglycans; D013912:Threonine; C117674:LARGE1 protein, human; D017351:N-Acetylglucosaminyltransferases