title: Low external pH induces HOG1-dependent changes in the organization of the Saccharomyces cerevisiae cell wall.
abstract: Low environmental pH strongly affected the organization of the Saccharomyces cerevisiae cell wall, resulting in rapidly induced resistance to beta1,3-glucanase. At a molecular level, we found that a considerable amount of Cwp1p became anchored through a novel type of linkage for glycosylphosphatidylinositol (GPI)-dependent cell wall proteins, namely an alkali-labile linkage to beta1,3-glucan. This novel type of modification for Cwp1p did not require the presence of a GPI-derived structure connecting the protein with beta1,6-glucan. In addition, we found high levels of Cwp1p, which was double-anchored through both the novel alkali-sensitive bond to beta1,3-glucan and the alkali-resistant GPI-derived linkage to beta1,6-glucan. Further cell wall analyses demonstrated that Pir2p/Hsp150 and possibly other Pir cell wall proteins, which were already known to be linked to the beta1,3-glucan framework by an alkali-sensitive linkage, were also more efficiently retained in the cell wall at pH 3.5 than at pH 5.5. Consequently, the alkali-sensitive type of linkage of cell wall proteins to beta1,3-glucan was induced by low pH. The low pH-induced alterations in yeast cell wall architecture were demonstrated to be dependent on a functional HOG1 gene, but not on the Slt2p-mediated MAP kinase pathway. Consistent with this observation, DNA microarray studies revealed transcriptional induction of many known high-osmolarity glycerol (HOG) pathway-dependent genes, including four cell wall-related genes, namely CWP1, HOR7, SPI1 and YGP1.
authors.affiliation: Fungal Research Group, Swammerdam Institute of Life Sciences, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: Kapteyn
authors.forename: B
authors.initials: B
authors.lastname: ter Riet
authors.forename: E
authors.initials: E
authors.lastname: Vink
authors.forename: S
authors.initials: S
authors.lastname: Blad
authors.forename: H
authors.initials: H
authors.lastname: De Nobel
authors.forename: H
authors.initials: H
authors.lastname: Van Den Ende
authors.forename: F M
authors.initials: FM
authors.lastname: Klis
mesh_terms: D002473:Cell Wall / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002686:Chitin / Q000032:analysis; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000235:genetics*; D043326:Glucan 1,3-beta-Glucosidase; D006023:Glycoproteins; D006026:Glycoside Hydrolases / Q000494:pharmacology; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D014158:Transcription, Genetic
chemical_list: C093810:CWP1 protein, S cerevisiae; D005656:Fungal Proteins; D006023:Glycoproteins; C074229:HSP150 protein, S cerevisiae; D006360:Heat-Shock Proteins; D008562:Membrane Glycoproteins; D029701:Saccharomyces cerevisiae Proteins; D002686:Chitin; C088589:HOG1 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases; D006026:Glycoside Hydrolases; D043326:Glucan 1,3-beta-Glucosidase; C117648:beta-1,3-exoglucanase