Title: | "Involvement of protein N-glycosyl chain glucosylation and processing in the biosynthesis of cell wall beta-1,6-glucan of Saccharomyces cerevisiae" |
Author(s): | Shahinian S; Dijkgraaf GJ; Sdicu AM; Thomas DY; Jakob CA; Aebi M; Bussey H; |
Address: | "Department of Biology, McGill University, Montreal, Quebec, Canada, H3A 1B1" |
DOI: | 10.1093/genetics/149.2.843 |
ISSN/ISBN: | 0016-6731 (Print) 0016-6731 (Linking) |
Abstract: | "beta-1,6-Glucan plays a key structural role in the yeast cell wall. Of the genes involved in its biosynthesis, the activity of Cwh41p is known, i.e., the glucosidase I enzyme of protein N-chain glucose processing. We therefore examined the effects of N-chain glucosylation and processing mutants on beta-1,6-glucan biosynthesis and show that incomplete N-chain glucose processing results in a loss of beta-1,6-glucan, demonstrating a relationship between N-chain glucosylation/processing and beta-1,6-glucan biosynthesis. To explore the involvement of other N-chain-dependent events with beta-1,6-glucan synthesis, we investigated the Saccharomyces cerevisiae KRE5 and CNE1 genes, which encode homologs of the 'quality control' components UDP-Glc:glycoprotein glucosyltransferase and calnexin, respectively. We show that the essential activity of Kre5p is separate from its possible role as a UDP-Glc:glycoprotein glucosyltransferase. We also observe a approximately 30% decrease in beta-1,6-glucan upon disruption of the CNE1 gene, a phenotype that is additive with other beta-1,6-glucan synthetic mutants. Analysis of the cell wall anchorage of the mannoprotein alpha-agglutinin suggests the existence of two beta-1,6-glucan biosynthetic pathways, one N-chain dependent, the other involving protein glycosylphosphatidylinositol modification" |
Keywords: | "Calnexin Cell Wall/enzymology/genetics/metabolism Fungal Proteins/genetics/physiology Glucans/*biosynthesis/genetics Glucose/genetics/*metabolism Glycoproteins/genetics/physiology Glycosylation Mating Factor *Membrane Proteins Mutagenesis, Site-Directed P;" |
Notes: | "MedlineShahinian, S Dijkgraaf, G J Sdicu, A M Thomas, D Y Jakob, C A Aebi, M Bussey, H eng Research Support, Non-U.S. Gov't 1998/06/11 Genetics. 1998 Jun; 149(2):843-56. doi: 10.1093/genetics/149.2.843" |