STT10, a novel class-D VPS yeast gene required for osmotic integrity related to the PKC1/STT1 protein kinase pathway.
We report the genetic and biochemical properties of a staurosporine (ST)- and temperature-sensitive mutant, stt10, of Saccharomyces cerevisiae. The stt10 mutant shows an osmoremedial phenotype in a medium with 1 M sorbitol. ST sensitivity of the stt10 mutant was suppressed by overexpression of PKC1/STT1, showing the genetic interactions of STT10 with the PKC1/STT1 pathway. The nucleotide sequence of STT10 predicts a hydrophilic protein composed of 577 amino acids that possesses 20-25% sequence similarity with yeast Slp1/Vam5p, Sec1p and Sly1p, and nematode Unc-18. The stt10 deletion mutant is viable and shows a typical class-D vacuolar protein sorting defective (vps) phenotype. Vacuoles from stt10 cells have a normal vacuolar H(+)-ATPase activity, but are defective in vacuolar acidification. Genetic studies of yeast mutants carrying delta stt10, delta bck1, stt1/pkc1 or stt4 have revealed that their functions are phenotypically related to maintenance of cellular osmotic integrity.
Yoshida
S
S
Department of Plant Sciences, University of Tokyo, Japan.
Ohya
Y
Y
Hirose
R
R
Nakano
A
A
Anraku
Y
Y
D000470:Alkaloids / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics*; D005800:Genes, Fungal; D006358:Hot Temperature; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D019311:Staurosporine; D014617:Vacuoles / Q000201:enzymology; D033921:Vesicular Transport Proteins
D000470:Alkaloids; D005656:Fungal Proteins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C092934:VPS45 protein, S cerevisiae; D033921:Vesicular Transport Proteins; D011493:Protein Kinase C; D006180:Proton-Translocating ATPases; D019311:Staurosporine