title: Functional, comparative and cell biological analysis of Saccharomyces cerevisiae Kre5p.
abstract: Saccharomyces cerevisiae kre5delta mutants lack beta-1,6-glucan, a polymer required for proper cell wall assembly and architecture. A functional and cell biological analysis of Kre5p was conducted to further elucidate the role of this diverged protein glucosyltransferase-like protein in beta-1,6-glucan synthesis. Kre5p was found to be a primarily soluble N-glycoprotein of approximately 200 kDa, that localizes to the endoplasmic reticulum. The terminal phenotype of Kre5p-deficient cells was observed, and revealed a severe cell wall morphological defect. KRE6, encoding a glucanase-like protein, was identified as a multicopy suppressor of a temperature-sensitive kre5 allele, suggesting that these proteins may participate in a common beta-1,6-biosynthetic pathway. An analysis of truncated versions of Kre5p indicated that all major regions of the protein are required for viability. Finally, Candida albicans KRE5 was shown to partially restore growth to S. cerevisiae kre5delta cells, suggesting that these proteins are functionally related.
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada H3A 1B1.
authors.forename: Joshua N
authors.initials: JN
authors.lastname: Levinson
authors.forename: Serge
authors.initials: S
authors.lastname: Shahinian
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Sdicu
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Tessier
authors.forename: Howard
authors.initials: H
authors.lastname: Bussey
mesh_terms: D000483:Alleles; D002473:Cell Wall / Q000378:metabolism / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000201:enzymology / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D017353:Gene Deletion; D005936:Glucans / Q000096:biosynthesis* / Q000235:genetics; D005964:Glucosyltransferases / Q000032:analysis / Q000172:deficiency / Q000502:physiology*; D006023:Glycoproteins / Q000032:analysis / Q000172:deficiency / Q000502:physiology*; D006031:Glycosylation; D008565:Membrane Proteins / Q000235:genetics; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D013489:Suppression, Genetic; D013696:Temperature; D047071:beta-Glucans
chemical_list: D005936:Glucans; D006023:Glycoproteins; C064198:KRE5 protein, S cerevisiae; C081933:KRE6 protein, S cerevisiae; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D047071:beta-Glucans; C064197:beta-1,6-glucan; D005964:Glucosyltransferases