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Characterization of SKM1, a Saccharomyces cerevisiae gene encoding a novel Ste20/PAK-like protein kinase.
- Source :
- Molecular Microbiology; Feb1997, Vol. 23 Issue 4, p431-444, 14p, 5 Diagrams, 2 Charts
- Publication Year :
- 1997
-
Abstract
- Ste20/PAK serine/threonine protein kinases have been suggested as playing essential roles in cell signalling and morphogenesis as potential targets of Cdc42 and Rac GTPases. We have isolated and characterized the <em>Saccharomyces cerevisiae SKM1</em> gene, which codes for a novel member of this family of protein kinases. The amino acid sequence analysis of Skm1p revealed the presence of a PH domain and a putative p21-binding domain near its amino terminus, suggesting its involvement in cellular signalling or cytoskeletal functions. However, deletion of <em>SKM1</em> produced no detectable phenotype under standard laboratory conditions. Moreover, disruption of each of the two other <em>S. cerevisiae</em> Ste20/PAK-like kinase-encoding genes, <em>STE20</em> and <em>CLA4</em>, in <em>skm1</em> backgrounds, showed that Skm1p is not redundant with Ste20p or Cla4p. Interestingly, overexpression of <em>SKM1</em> led to morphological alterations, indicating a possible role for this protein in morphogenetic control. Furthermore, overproduction of Skm1 p lacking its N-terminus caused growth arrest. This effect was also seen when similarly truncated versions of Ste20p or Cta4p were overexpressed. We further observed that overproduction of this C-terminal fragment of Skm1p complements the mating defect of a <em>sfe20</em> mutant strain. These results suggest that the N-terminal domains of <em>S. cerevisiae</em> Ste20/ PAK-like protein kinases share a negative regulatory function and play a role in substrate specificity. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0950382X
- Volume :
- 23
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Molecular Microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 21318075