Katanosaka K, Tokunaga F, Kawamura S, Ozaki K
Department of Biology, Graduate School of Science, Osaka University, Toyonaka, Japan.
FEBS Lett. 1998 Mar 13;424(3):149-54. doi: 10.1016/s0014-5793(98)00160-4.
Immature Drosophila rhodopsin is N-glycosylated, but undergoes complete deglycosylation during the process of protein maturation. In order to elucidate the site of glycosylation and its role in rhodopsin synthesis, we investigated the in vitro and in vivo synthesis of rhodopsin whose putative N-glycosylation sites (Asn-20 and Asn-196) were replaced by isoleucine. The results demonstrated that immature rhodopsin binds a single oligosaccharide chain exclusively at Asn-20 in the N-terminal extracellular domain. Furthermore, the results gave the first evidence directly indicating that deletion of the oligosaccharide chain markedly impedes rhodopsin maturation.
未成熟的果蝇视紫红质是N-糖基化的，但在蛋白质成熟过程中会经历完全去糖基化。为了阐明糖基化位点及其在视紫红质合成中的作用，我们研究了将假定的N-糖基化位点（天冬酰胺-20和天冬酰胺-196）替换为异亮氨酸的视紫红质的体外和体内合成。结果表明，未成熟的视紫红质仅在N端细胞外结构域的天冬酰胺-20处结合一条寡糖链。此外，结果首次直接证明了寡糖链的缺失显著阻碍视紫红质的成熟。
