First Author | Xiong H | Year | 2006 |
Journal | Biochem Biophys Res Commun | Volume | 350 |
Issue | 4 | Pages | 935-41 |
PubMed ID | 17034757 | Mgi Jnum | J:114512 |
Mgi Id | MGI:3689255 | Doi | 10.1016/j.bbrc.2006.09.129 |
Citation | Xiong H, et al. (2006) Molecular interaction between fukutin and POMGnT1 in the glycosylation pathway of alpha-dystroglycan. Biochem Biophys Res Commun 350(4):935-41 |
abstractText | The recent identification of mutations in genes encoding demonstrated or putative glycosyltransferases has revealed a novel mechanism for congenital muscular dystrophy. Hypoglycosylated alpha-dystroglycan (alpha-DG) is commonly seen in Fukuyama-type congenital muscular dystrophy (FCMD), muscle-eye-brain disease (MEB), Walker-Warburg syndrome (WWS), and Large(myd) mice. POMGnT1 and POMTs, the gene products responsible for MEB and WWS, respectively, synthesize unique O-mannose sugar chains on alpha-DG. The function of fukutin, the gene product responsible for FCMD, remains undetermined. Here we show that fukutin co-localizes with POMGnT1 in the Golgi apparatus. Direct interaction between fukutin and POMGnT1 was confirmed by co-immunoprecipitation and two-hybrid analyses. The transmembrane region of fukutin mediates its localization to the Golgi and participates in the interaction with POMGnT1. Y371C, a missense mutation found in FCMD, retains fukutin in the ER and also redirects POMGnT1 to the ER. Finally, we demonstrate reduced POMGnT1 enzymatic activity in transgenic knock-in mice carrying the retrotransposal insertion in the fukutin gene, the prevalent mutation in FCMD. From these findings, we propose that fukutin forms a complex with POMGnT1 and may modulate its enzymatic activity. |