Two novel protein kinase C-related genes of fission yeast are essential for cell viability and implicated in cell shape control.
Two novel protein kinase C (PKC)-like genes, pck1+ and pck2+ were isolated from fission yeast by PCR. Both contain common domains of PKC-related molecules, but lack a putative Ca(2+)-binding domain so that they may belong to the nPKC group. Gene disruption of pck1+ and pck2+ establishes that they share an overlapping essential function for cell viability. Cells of a single pck2 deletion display severe defects in cell shape; they are irregular and sometimes pear-like instead of cylindrical. In contrast, the induced overexpression of pck2+ is lethal, producing multiseptated and branched cells. These results suggest that fission yeast PKC-like genes are involved in the polarity of cell growth control. We show that pck2 is allelic to sts6, a locus we have previously identified by its supersensitivity to staurosporine, a potent protein kinase inhibitor [Toda et al. (1991) Genes Dev., 5, 60-73]. In addition, the lethal overexpression of pck2+ can be suppressed by staurosporine, indicating that fission yeast pck1 and pck2 are molecular targets of this inhibitor.
Department of Biophysics, Faculty of Science, Kyoto University, Japan.
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Toda
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Shimanuki
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Yanagida
D000470:Alkaloids / Q000494:pharmacology; D000595:Amino Acid Sequence; D001483:Base Sequence; D004271:DNA, Fungal; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009154:Mutation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000235:genetics*; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics* / Q000254:growth & development; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D019311:Staurosporine
D000470:Alkaloids; D004271:DNA, Fungal; D011493:Protein Kinase C; D019311:Staurosporine