title: The glucanase-soluble mannoproteins limit cell wall porosity in Saccharomyces cerevisiae.
abstract: The cell wall porosity of batch-grown Saccharomyces cerevisiae was maximal in the early exponential phase and fell off rapidly to lower levels in later growth phases. Treatment of stationary-phase cells with alpha-mannosidase restored wall porosity to the level of cells in early exponential phase. When cells in the early exponential phase were treated with alpha-mannosidase, or tunicamycin, an inhibitor of N-glycosylation, even higher porosities were obtained. Mutants with truncated mannan side-chains in their wall proteins also had very porous walls. The importance of the mannan side-chains for wall porosity was also seen during sexual induction. Treatment with alpha pheromone, which leads to the formation of wall proteins with shorter mannan side-chains, enhanced wall porosity. Disulphide bridges also affect cell wall porosity. They were predominantly found in the glucanase-soluble wall proteins. Because the main part of the mannan side-chains is also found in this family of wall proteins, our results demonstrate that the glucanase-soluble mannoproteins limit cell wall porosity in yeast.
authors.affiliation: Department of Molecular Cell Biology, University of Amsterdam, The Netherlands.
authors.forename: J G
authors.initials: JG
authors.lastname: de Nobel
authors.forename: F M
authors.initials: FM
authors.lastname: Klis
authors.forename: J
authors.initials: J
authors.lastname: Priem
authors.forename: T
authors.initials: T
authors.lastname: Munnik
authors.forename: H
authors.initials: H
authors.lastname: van den Ende
mesh_terms: D001557:Benzenesulfonates / Q000494:pharmacology; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D003637:DEAE-Dextran / Q000494:pharmacology; D004220:Disulfides / Q000378:metabolism; D006867:Hydrolases / Q000494:pharmacology; D008361:Mannosidases / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D016062:Porosity; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D014415:Tunicamycin / Q000378:metabolism*; D043323:alpha-Mannosidase
chemical_list: D001557:Benzenesulfonates; D004220:Disulfides; D008562:Membrane Glycoproteins; C025363:mannoproteins; D014415:Tunicamycin; C037833:zymolyase; C007061:C.I. Fluorescent Brightening Agent 28; D003637:DEAE-Dextran; D006867:Hydrolases; D008361:Mannosidases; D043323:alpha-Mannosidase