Altered extent of cross-linking of beta1,6-glucosylated mannoproteins to chitin in Saccharomyces cerevisiae mutants with reduced cell wall beta1,3-glucan content.
The yeast cell wall contains beta1,3-glucanase-extractable and beta1,3-glucanase-resistant mannoproteins. The beta1,3-glucanase-extractable proteins are retained in the cell wall by attachment to a beta1,6-glucan moiety, which in its turn is linked to beta1,3-glucan (J. C. Kapteyn, R. C. Montijn, E. Vink, J. De La Cruz, A. Llobell, J. E. Douwes, H. Shimoi, P. N. Lipke, and F. M. Klis, Glycobiology 6:337-345, 1996). The beta1,3-glucanase-resistant protein fraction could be largely released by exochitinase treatment and contained the same set of beta1,6-glucosylated proteins, including Cwp1p, as the B1,3-glucanase-extractable fraction. Chitin was linked to the proteins in the beta1,3-glucanase-resistant fraction through a beta1,6-glucan moiety. In wild-type cell walls, the beta1,3-glucanase-resistant protein fraction represented only 1 to 2% of the covalently linked cell wall proteins, whereas in cell walls of fks1 and gas1 deletion strains, which contain much less beta1,3-glucan but more chitin, beta1,3-glucanase-resistant proteins represented about 40% of the total. We propose that the increased cross-linking of cell wall proteins via beta1,6-glucan to chitin represents a cell wall repair mechanism in yeast, which is activated in response to cell wall weakening.
Kapteyn
J C
JC
Institute of Molecular Cell Biology, University of Amsterdam, The Netherlands. kapteyn@bio.uva.nl
Ram
A F
AF
Groos
E M
EM
Kollar
R
R
Montijn
R C
RC
Van Den Ende
H
H
Llobell
A
A
Cabib
E
E
Klis
F M
FM
D002473:Cell Wall / Q000378:metabolism*; D002686:Chitin / Q000302:isolation & purification / Q000378:metabolism*; D054714:Echinocandins; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D043326:Glucan 1,3-beta-Glucosidase; D005936:Glucans / Q000378:metabolism*; D005964:Glucosyltransferases; D006026:Glycoside Hydrolases / Q000378:metabolism; D006031:Glycosylation; D006596:Hexosaminidases / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D047071:beta-Glucans; D001617:beta-Glucosidase / Q000378:metabolism
C093810:CWP1 protein, S cerevisiae; D054714:Echinocandins; D005656:Fungal Proteins; C066709:GAS1 protein, S cerevisiae; D005936:Glucans; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D047071:beta-Glucans; C025363:mannoproteins; D002686:Chitin; C064197:beta-1,6-glucan; C033363:beta-1,3-glucan; D005964:Glucosyltransferases; C091618:FKS1 protein, S cerevisiae; D006026:Glycoside Hydrolases; D006596:Hexosaminidases; D001617:beta-Glucosidase; D043326:Glucan 1,3-beta-Glucosidase; C020105:endo-1,6-beta-glucanase