ISSN:
1617-4623
Keywords:
Key words Saccharomyces cerevisiae
;
Cell cycle
;
LTE1
;
CDC15
;
CDC14
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract LTE1 encodes a homolog of GDP-GTP exchange factors for the Ras superfamily and is required at low temperatures for cell cycle progression at the stage of the termination of M phase in Saccharomyces cerevisiae. We isolated extragenic suppressors which suppress the cold sensitivity of lte1 cells and confer a temperature-sensitive phenotype on cells. Cells mutant for the suppressor alone were arrested at telophase at non-permissive temperatures and the terminal phenotype was almost identical to that of lte1 cells at non-permissive temperatures. Genetic analysis revealed that the suppressor is allelic to CDC15, which encodes a protein kinase. The cdc15 mutations thus isolated were recessive with regard to the temperature-sensitive phenotype and were dominant with respect to suppression of lte1. We isolated CDC14 as a low-copy-number suppressor of cdc15-rlt1. CDC14 encodes a phosphotyrosine phosphatase (PTPase) and is essential for termination of M phase. An extra copy of CDC14 suppressed the temperature sensitivity of cdc15-rlt1 cells, but not that of cdc15-1 cells. In addition, some residues that are essential for the Cdc14 PTPase activity were found to be non-essential for the suppression. These results strongly indicate that Cdc14 possesses dual functions; PTPase activity is needed for one function but not for the other. We postulate that the cooperative action of Cdc14 and Cdc15 plays an essential role in the termination of M phase.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02172916
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