The linkage of (1-3)-beta-glucan to chitin during cell wall assembly in Saccharomyces cerevisiae.
Pulse-chase experiments with [14C]glucose demonstrated that in the cell wall of wild-type Saccharomyces cerevisiae alkali-soluble (1-3)-beta-glucan serves as a precursor for alkali-insoluble (1-3)-beta-glucan. The following observations support the notion that the insolubilization of the glucan is caused by linkage to chitin: (i) degradation of chitin by chitinase completely dissolved the glucan, and (ii) disruption of the gene for chitin synthase 3 prevented the formation of alkali-insoluble glucan. These cells, unable to form a glucan-chitin complex, were highly vulnerable to hypo-osmotic shock indicating that the linkage of the two polymers significantly contributes to the mechanical strength of the cell wall. Conversion of alkali-soluble glucan into alkali-insoluble glucan occurred both early and late during budding and also in the ts-mutant cdc24-1 in the absence of bud formation.
Hartland
R P
RP
Department of Plant Biology, University of Groningen, Haren, The Netherlands.
Vermeulen
C A
CA
Klis
F M
FM
Sietsma
J H
JH
Wessels
J G
JG
D002473:Cell Wall / Q000737:chemistry; D002686:Chitin / Q000032:analysis*; D005936:Glucans / Q000032:analysis*; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D047071:beta-Glucans
D005936:Glucans; D047071:beta-Glucans; D002686:Chitin; C033363:beta-1,3-glucan