ISSN:
1617-4623
Keywords:
Xenopus ovary
;
cDNA expression library Yeast transformation
;
Weel kinase
;
Cell cycle
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract In fission yeast the Weel kinase and the functionally redundant Mikl kinase provide a regulatory mechanism to ensure that mitosis is initiated only after the completion of DNA synthesis. Yeast in which both Weel and Mik1 kinases are defective exhibit a mitotic catastrophe phenotype, presumably due to premature entry into mitosis. Because of the functional conservation of cell cycle control elements, the expression of a vertebrate weel or mikl homolog would be expected to rescue such lethal mutations in yeast. A Xenopus total ovary cDNA library was constructed in a fission yeast expression vector and used to transform a yeast temperature-dependent mitotic catastrophe mutant defective in both weel and mikl. Here we report the identification of a Xenopus cDNA clone that can rescue several different yeast mitotic catastrophe mutants defective in Weel kinase function. The expression of this clone in a weel/mikl-deficient mutant causes an elongated cell phenotype under non-permissive growth conditions. The 2.0 kb cDNA clone contains an open reading frame of 1263 nucleotides, encoding a predicted 47 kDa protein. Bacterially expressed recombinant protein was used to raise a polyclonal antibody, which specifically recognizes a 47 kDa protein from Xenopus oocyte nuclei, suggesting the gene encodes a nuclear protein in Xenopus. The ability of this cDNA to complement mitotic catastrophe mutations is independent of Weel kinase activity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00288613
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