Both Svp26 and Mnn6 are required for the efficient ER exit of Mnn4 in Saccharomyces cerevisiae.

Both Svp26 and Mnn6 are required for the efficient ER exit of Mnn4 in Saccharomyces cerevisiae.
J Gen Appl Microbiol. 2019 Mar 06;:
Authors: Noda Y, Arai S, Wada I, Yoda K
Abstract
Incorporation of membrane and secretory proteins into COPII vesicles are facilitated either by the 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 the yeast Saccharomyces cerevisiae. The ER exit of several type II membrane proteins have been reported to be facilitated by Svp26. We demonstrate here that the efficient incorporation of Mnn4, a type II membrane protein required for mannosyl phosphate transfer to glycoprotein-linked oligosaccharides, into COPII vesicles is also dependent on the function of Svp26. We show that Mnn4 is localized to the Golgi. In addition to Mnn4, Mnn6 is known to be also required for the transfer of mannosyl phosphate to the glycans. We show, by indirect immunofluorescence, that Mnn6 localizes to the ER. As in the case with Svp26, deletion of the MNN6 gene results in the accumulation of Mnn4 in ER. In vitro COPII vesicle budding assays show that Svp26 and Mnn6 facilitate the incorporation of Mnn4 into COPII vesicles. In contrast to Svp26, which is itself efficiently captured into the COPII vesicles, Mnn6 was not incorporated into the COPII vesicles. Mnn4 and Mnn6 h...

Source: Journal of General and Applied Microbiology - March 9, 2019 Category: Microbiology Tags: J Gen Appl Microbiol Source Type: research