Identification of a Gl-type cyclin puc1 + in the fission yeast Schizosaccharomyces pombe

摘要: IN rapidly growing cells of the budding yeast Saccharomyces cerevisiae, cell cycle is regulated chiefly at Start, just before G1–S boundary1, whereas in fission Schizosaccharomyces pombe, predominantly G2–M (ref. 2). Both control points are present both yeasts, and require p34cdc2 protein kinase3–5. At G2–M, kinase activity S. pombe requires a B-type cyclin complex with dc2 j. tnjs same as MPF (maturation promoting factor15,16). The p34cdcj2 transition cerevisiae may be by similar complex, using one products new class genes (CLN1, CLN2 WHI1 (DAF1/CLN3)) (refs 17–22). least required for progression through phase, deletion all three leads to Gl arrest19. was isolated dominant allele causing divide reduced size21 later independently identified DAF1, which rendered refractory -arrest induced mating pheromone α -factor22. alleles trunca-tions thought yield proteins increased stability, accelerated 20, 22). Without function, hypersensitive α-factor22, enlarged delayed Heretofore, this G1-class cyclins has not been other organisms. We have Gl-type gene called puc1+ from functional assay cerevisiae. Expression pucl+ indicates that it cyclin-like role distinct mitotic cyclin.