Svp26 facilitates ER exit of mannosyltransferases Mnt2 and Mnt3 in Saccharomyces cerevisiae.

Svp26 facilitates ER exit of mannosyltransferases Mnt2 and Mnt3 in Saccharomyces cerevisiae.
J Gen Appl Microbiol. 2019 Jan 31;:
Authors: Tanabe Y, Arai S, Wada I, Adachi H, Kamakura T, Yoda K, Noda Y
Abstract
After being translocated into the ER lumen, membrane and secretory proteins are transported from the ER to the early Golgi by COPII vesicles. Incorporation of these cargo proteins into COPII vesicles are facilitated either by direct interaction of cargo proteins with COPII coat proteins or by ER exit adaptor proteins which mediate the interaction of cargo proteins with COPII coat proteins. Svp26 is one of the ER exit adaptor proteins in yeast Saccharomyces cerevisiae. ER exit of several type II membrane proteins have been reported to be facilitated by Svp26. We demonstrate here that efficient incorporation of Mnt2 and Mnt3 into COPII vesicles is also dependent on the function of Svp26. Mnt2 and Mnt3 are Golgi-localized α-1,3-mannosyltransferases with type II membrane topology involved in protein O-glycosylation. Immunoisolation of the yeast Golgi subcompartments quantitatively showed that Mnt2 and Mnt3 are more abundant in the early Golgi fraction than in the late Golgi fraction. Subcellular fractionation and fluorescence microscopy showed that deletion of the SVP26 gene results in the accumulation of Mnt2 and Mnt3 in ER. Using an in vitro COPII vesicle formation assay, we further demonstrate that Svp26 facilitates incorporati...

Source: Journal of General and Applied Microbiology - February 1, 2019 Category: Microbiology Tags: J Gen Appl Microbiol Source Type: research