title: The KNH1 gene of Saccharomyces cerevisiae is a functional homolog of KRE9.
abstract: The KNH1 gene from Saccharomyces cerevisiae was identified as an open reading frame on the right arm of chromosome IV. The product encoded by the KNH1 gene, Knhlp, shares 46% overall identity with Kre9p, a protein required for cell surface beta 1,6-glucan synthesis. While disruption of the KNH1 locus had no effect on cell growth, killer toxin sensitivity or beta 1,6-glucan levels, overexpression of KNH1 was found to suppress the severe growth defect of a kre9 delta mutant and restored the level of alkali-insoluble beta 1,6-glucan to almost wild-type levels. Knhlp, like Kre9p, can be found in the extracellular culture medium as an O-glycoprotein, with a molecular mass of 45-61 kDa. Disruption of both KNH1 and KRE9 is lethal, and unlike single kre9 delta mutants, could not be rescued by overproducing SKN7, a putative transcription factor involved in the regulation of extracellular matrix assembly. Transcription of KNH1 was found to be carbon-source and kre9 delta dependent, but SKN7 independent, suggesting that KNH1 is subject to alternative transcriptional control.
authors.affiliation: McGill University, Department of Biology, Montreal, Quebec, Canada.
authors.forename: G J
authors.initials: GJ
authors.lastname: Dijkgraaf
authors.forename: J L
authors.initials: JL
authors.lastname: Brown
authors.forename: H
authors.initials: H
authors.lastname: Bussey
mesh_terms: D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics*; D005800:Genes, Fungal; D005936:Glucans / Q000096:biosynthesis; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D016366:Open Reading Frames; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D047071:beta-Glucans
chemical_list: D005656:Fungal Proteins; D005936:Glucans; D006023:Glycoproteins; C103935:KNH1 protein, S cerevisiae; C083328:KRE9 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D047071:beta-Glucans; C064197:beta-1,6-glucan