A new cdc gene required for S phase entry of Schizosaccharomyces pombe encodes a protein similar to the cdc 10+ and SWI4 gene products.
We have isolated a new cell division cycle gene (res1+) required for entry into S phase, as a multicopy dual suppressor of the pat1 and cdc10 mutants of the fission yeast Schizosaccharomyces pombe. The res1+ gene specifies a 72 kDa protein with two copies of the cdc10/SWI6 motif. A disruptant of res1+ grows poorly at 30 degrees C with severe heat- and cold-sensitivities, and completely arrests in G1 at 36 degrees C and 23 degrees C. The arrested disruptant retains a full conjugation ability. In addition to the cdc10/SWI6 motif, Res1 and SWI4 proteins share a remarkable homology in their amino-terminal region, whereas Cdc10 and SWI6 do so in their carboxy-terminal region. Moreover, the amino-terminal region is essential for the function of Res1 as it is for the function of SWI4. Furthermore, analogous to the relationship of SWI4 to SWI6, the res1+ gene effectively rescues cdc10 mutants, but the cdc10+ gene cannot rescue the res1- phenotype. Thus, striking similarities exist in both structural and functional relationships between Res1 and SWI4, and between Cdc10 and SWI6. In view of the fact that SWI4 and SWI6 form a transcription factor complex and activate promoters containing the SWI4/SWI6 dependent cell-cycle box, Res1 might be a putative association partner of Cdc10 which appears to be involved at least in the activation of promoters containing a MluI cell-cycle box.
Tanaka
K
K
Department of Molecular Genetics, Osaka University, Japan.
Okazaki
K
K
Okazaki
N
N
Ueda
T
T
Sugiyama
A
A
Nojima
H
H
Okayama
H
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D005434:Flow Cytometry; D005656:Fungal Proteins / Q000235:genetics*; D016193:G1 Phase / Q000235:genetics; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D010641:Phenotype; D015183:Restriction Mapping; D016196:S Phase / Q000235:genetics*; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D005656:Fungal Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C061178:cdc10 protein, S pombe; C078732:res1 protein, S pombe