Hashimoto H, Yoda K
Department of Biotechnology, University of Tokyo, Japan.
Biochem Biophys Res Commun. 1997 Dec 29;241(3):682-6. doi: 10.1006/bbrc.1997.7888.
Three type II membrane proteins Anp1, Van1 and Mnn9 of Saccharomyces cerevisiae share significant sequence homology. Their precise biochemical activity has long been unknown though the mutant phenotype indicates their participation in protein glycosylation in the Golgi apparatus. To shed light on their molecular characteristics, interactions of these proteins were studied by immunoprecipitation after solubilizing the membrane by nonionic detergent. Our results indicated that there are at least two submembrane complexes containing these proteins: one contains Van1 and Mnn9 proteins and the other contains Anp1 and Mnn9 proteins. In addition, Hoc1 protein which has significant homology to Och1 protein colocalized with Anp1 and Mnn9 proteins. These complexes with similar but partially different constituents may represent essential parts of glycosylation machinery in the yeast Golgi compartments.
酿酒酵母的三种II型膜蛋白Anp1、Van1和Mnn9具有显著的序列同源性。尽管突变体表型表明它们参与了高尔基体中的蛋白质糖基化，但它们确切的生化活性长期以来一直未知。为了阐明它们的分子特征，在用非离子去污剂溶解膜后，通过免疫沉淀研究了这些蛋白质的相互作用。我们的结果表明，至少有两个包含这些蛋白质的膜下复合物：一个包含Van1和Mnn9蛋白，另一个包含Anp1和Mnn9蛋白。此外，与Och1蛋白具有显著同源性的Hoc1蛋白与Anp1和Mnn9蛋白共定位。这些具有相似但部分不同组成成分的复合物可能代表了酵母高尔基体区室中糖基化机制的重要部分。
