Yeast Kre1p is a cell surface O-glycoprotein.
The Saccharomyces cerevisiae KRE1 gene encodes a secretory protein required for the production of the cell wall polymer (1-->6)-beta-glucan. Here we report further characterization of the KRE1 gene product, Kre1p. A functional, epitope-tagged Kre1p is shown to be highly modified in a SEC53-dependent manner. Kre1p is O-glycosylated, but the basis for the majority of its post-translational modification is unknown. Fractionation of Kre1p reveals a cell wall-associated form and a less abundant membrane-associated species. Indirect immunoflurorescence demonstrates that Kre1p localizes to the cell surface, where it becomes concentrated at the surface of mother cells. Such a localization of Kre1p seems to parallel the CAL1/CSD2-dependent cell wall deposition of chitin found in S. cerevisiae, and is consistent with evidence from Schizophyllum commune that (1-->6)-beta-glucan accumulates during maturation of the subapical region of the wall distal to the hyphal tip.
Roemer
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Biology Department, McGill University, Montreal, Quebec, Canada.
Bussey
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H
D000595:Amino Acid Sequence; D001483:Base Sequence; D002473:Cell Wall / Q000378:metabolism; D019084:Fluorescent Antibody Technique, Indirect; D005656:Fungal Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics*; D005800:Genes, Fungal; D005936:Glucans / Q000096:biosynthesis; D008562:Membrane Glycoproteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016324:Sequence Tagged Sites
D005656:Fungal Proteins; D005936:Glucans; C064013:KRE1 protein, S cerevisiae; D008562:Membrane Glycoproteins; D009838:Oligodeoxyribonucleotides; D029701:Saccharomyces cerevisiae Proteins