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Isolation of a CDC25 family gene, MSI2/LTE1 , as a multicopy suppressor of ira1
Author(s) -
Shirayama Masaki,
Matsui Yasushi,
Tanaka Kazuma,
TohE Akio
Publication year - 1994
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.320100404
Subject(s) - biology , gene product , gene , genetics , microbiology and biotechnology , mutation , cdc25 , saccharomyces cerevisiae , cell cycle , cyclin dependent kinase 1 , gene expression
We have identified MS12 as a gene of Saccharomyces cerevisiae which, when on a multicopy vector, suppresses the heat shock sensitivity caused by the loss of the IRA1 product, a negative regulator of the RAS protein. The multicopy MSI2 also suppresses the heat shock sensitivity of cells with the RAS2 val19 mutation but not those with the bcy1 mutation, suggesting that the MSI2 protein may interfere with the activity of the RAS protein. The sequence analysis of MSI2 reveals that it is identical to LTE1 belonging to the CDC25 family: CDC25 , SCD25 and BUD5 , each of which encodes a guanine nucleotide exchange factor for the ras superfamily gene products. Deletion of the entire MSI2 coding region reveals that MSI2 is not essential but the disruptant shows a cold‐sensitive phenotype. Under the non‐permissive conditions, more than 70% of the msi2 disruptants arrested at telophase as large budded cells with two nuclei divided completely and elongated spindles, indicating that the msi2 deletion is a cell division cycle mutation. These results suggest that MSI2 is involved in the termination of M phase and that this process is regulated by a ras superfamily gene product.