A Drosophila gene encoding a DEAD box RNA helicase can suppress loss of wee1/mik1 function in Schizosaccharomyces pombe.
We describe a screen to isolate cDNAs encoding Drosophila mitosis inhibitors capable of suppressing the mitotic catastrophe phenotype resulting in Schizosaccharomyces pombe from the combination of the wee1-50 mutation with either a deletion allele of mik1, or with overexpression of cdc25+. One plasmid was isolated which could suppress the temperature sensitive lethality of both these strains. The cDNA in this plasmid encodes a protein highly homologous to the DEAD-box family of ATP-dependent RNA helicases, rather than to protein kinases as might be expected. It is possible that the RNA helicase described here may regulate entry into mitosis by down regulating the expression of other genes whose activity may be rate-limiting for entry into mitosis.
Warbrick
E
E
Department of Anatomy and Physiology, University of Dundee, Scotland.
Glover
D
D
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018797:Cell Cycle Proteins; D004330:Drosophila / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D011494:Protein Kinases / Q000235:genetics*; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D020365:RNA Helicases; D012316:RNA Nucleotidyltransferases / Q000235:genetics*; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid; D013489:Suppression, Genetic; D020666:ras-GRF1
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D009687:Nuclear Proteins; D029702:Schizosaccharomyces pombe Proteins; D020666:ras-GRF1; D011494:Protein Kinases; C090679:mik1 protein, S pombe; C068689:wee1 protein, S pombe; D011505:Protein-Tyrosine Kinases; D012316:RNA Nucleotidyltransferases; D020365:RNA Helicases