title: N-linked glycosylation of mouse adiponectin.
abstract: Adiponectin is an insulin-sensitizing adipokine with antidiabetic, anti-atherogenic, anti-inflammatory, and cardioprotective properties. Previously, some types of posttranslational modification on adiponectin have been reported. In this study, we demonstrate that mouse adiponectin protein migrated as 2 bands on SDS-PAGE gel. Slower migrating band of adiponectin was reduced by PNGase treatment. PNGase is known as N-glycosidase, and is able to change the mobility of N-glycosylated protein on SDS-PAGE gel. This result indicates the possibility that slower band shifted and overlapped with faster band by cleavage of N-glycan. To further clarify the N-glycosylation of adiponectin, we investigated the effect of N-glycosylation inhibitor tunicamycin on 3T3-L1 adipocytes. Tunicamycin significantly reduced the ratio of slower band to faster band in culture medium from 3T3-L1 adipocytes. This result also indicates the possibility that slower band of adiponectin is N-glycosylated. Lastly, to identify glycosylated asparagine residues, we established 3T3-L1 cell lines stably expressing wild type and mutant adiponectin in N-glycosylation sites. Wild-type adiponectin protein migrated as double bands, and mutant adiponectin in either asparagine at position 53 or threonine at 55 lacked slower band. These results suggest that a part of mouse adiponectin is modified by N-linked glycosylation at asparagine 53.
authors.affiliation: Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Osaka , Japan. mas_tanaka@research.otsuka.co.jp
authors.forename: M
authors.initials: M
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: Fukuhara
authors.forename: I
authors.initials: I
authors.lastname: Shimomura
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D052242:Adiponectin / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D017077:Culture Media, Conditioned / Q000494:pharmacology; D006031:Glycosylation / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D014415:Tunicamycin / Q000494:pharmacology
chemical_list: D052242:Adiponectin; C499919:Adipoq protein, mouse; D017077:Culture Media, Conditioned; D014415:Tunicamycin