KEG1/YFR042w encodes a novel Kre6-binding endoplasmic reticulum membrane protein responsible for beta-1,6-glucan synthesis in Saccharomyces cerevisiae.
KEG1/YFR042w of Saccharomyces cerevisiae is an essential gene that encodes a 200-amino acid polypeptide with four predicted transmembrane domains. The green fluorescent protein- or Myc(6)-tagged Keg1 protein showed the typical characteristics of an integral membrane protein and was found in the endoplasmic reticulum by fluorescence imaging. Immunoprecipitation from the Triton X-100-solubilized cell lysate revealed that Keg1 binds to Kre6, which has been known to participate in beta-1,6-glucan synthesis. To analyze the essential function of Keg1 in more detail, we constructed temperature-sensitive mutant alleles by error-prone polymerase chain reaction. The keg1-1 mutant cells showed a common phenotype with Deltakre6 mutant including hypersensitivity to Calcofluor white, reduced sensitivity to the K1 killer toxin, and reduced content of beta-1,6-glucan in the cell wall. These results suggest that Keg1 and Kre6 have a cooperative role in beta-1,6-glucan synthesis in S. cerevisiae.
Nakamata
Kosuke
K
Department of Biotechnology, University of Tokyo, Yayoi, Bunkyo-Ku, Tokyo, Japan.
Kurita
Tomokazu
T
Bhuiyan
M Shah Alam
MS
Sato
Keisuke
K
Noda
Yoichi
Y
Yoda
Koji
K
D001557:Benzenesulfonates / Q000494:pharmacology; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism*; D025141:Drug Resistance, Fungal / Q000187:drug effects / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000494:pharmacology; D055646:Killer Factors, Yeast; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009183:Mycotoxins / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D047071:beta-Glucans / Q000378:metabolism*
D001557:Benzenesulfonates; D005456:Fluorescent Dyes; C089359:K1 killer toxin; C525808:KEG1 protein, S cerevisiae; C081933:KRE6 protein, S cerevisiae; D055646:Killer Factors, Yeast; D008565:Membrane Proteins; D009183:Mycotoxins; D029701:Saccharomyces cerevisiae Proteins; D047071:beta-Glucans; C064197:beta-1,6-glucan; C007061:C.I. Fluorescent Brightening Agent 28