Title: | Identification of a G1-type cyclin puc1+ in the fission yeast Schizosaccharomyces pombe |
Address: | "Biochemistry Department, Oxford University, UK" |
ISSN/ISBN: | 0028-0836 (Print) 0028-0836 (Linking) |
Abstract: | "In rapidly growing cells of the budding yeast Saccharomyces cerevisiae, the cell cycle is regulated chiefly at Start, just before the G1-S boundary, whereas in the fission yeast Schizosaccharomyces pombe, the cycle is predominantly regulated at G2-M. Both control points are present in both yeasts, and both require the p34cdc2 protein kinase. At G2-M, p34cdc2 kinase activity in S. pombe requires a B-type cyclin in a complex with p34cdc2; this complex is the same as MPF (maturation promoting factor). The p34cdc2 activity at the G1-S transition in S. cerevisiae may be regulated by a similar cyclin complex, using one of the products of a new class of cyclin genes (CLN1, CLN2 and WHI1 (DAF1/CLN3)). At least one is required for progression through the G1-S phase, and deletion of all three leads to G1 arrest. WHI1 was isolated as a dominant allele causing budding yeast cells to divide at a reduced size and was later independently identified as DAF1, a dominant allele of which rendered the cells refractory to the G1-arrest induced by the mating pheromone alpha-factor. The dominant alleles are truncations thought to yield proteins of increased stability, and the cells are accelerated through G1. Without WHI1 function, the cells are hypersensitive to alpha-factor, enlarged and delayed in G1. Heretofore, this G1-class of cyclins has not been identified in other organisms. We have isolated a G1-type cyclin gene called puc1+ from S. pombe, using a functional assay in S. cerevisiae. Expression of puc1+ in S. pombe indicates that it has a cyclin-like role in the fission yeast distinct from the role of the B-type mitotic cyclin" |
Keywords: | "Amino Acid Sequence Base Sequence Blotting, Northern Cell Division Cyclins/*genetics/physiology Flow Cytometry Gene Expression Molecular Sequence Data Saccharomyces cerevisiae/*genetics Schizosaccharomyces/*genetics Sequence Homology, Nucleic Acid Transfo;" |
Notes: | "MedlineForsburg, S L Nurse, P eng Research Support, Non-U.S. Gov't England 1991/05/16 Nature. 1991 May 16; 351(6323):245-8. doi: 10.1038/351245a0" |