| Title: | Fission yeast pheromone blocks S-phase by inhibiting the G1 cyclin B-p34cdc2 kinase |
| Address: | "Cell Cycle Laboratory, Imperial Cancer Research Fund, London, UK" |
| ISSN/ISBN: | 0261-4189 (Print) 1460-2075 (Electronic) 0261-4189 (Linking) |
| Abstract: | "Yeast pheromones block cell cycle progression in G1 in order to prepare mating partners for conjugation. We have investigated the mechanism underlying pheromone-induced G1 arrest in the fission yeast Schizosaccharomyces pombe. We find that the G1-specific transcription factor p65cdc10-p72res1/sct1 which controls the expression of S-phase genes is fully activated in pheromone, unlike the analogous control in budding yeast. In contrast, the G1 function of p34cdc2 acting after activation of the G1-specific transcription is blocked. Pheromone inhibits the p34cdc2 kinase associated with both the G1-specific B-type cyclin p45cig2 and the B-type cyclin p56cdc13 and overexpression of p45cig2 or p47cdc13delta90 overcomes the pheromone-induced G1 arrest. G1 arrest is compromised in enlarged cells. We suggest that onset of S-phase is controlled by pheromone inhibiting the B-cyclin-associated kinase in G1, and that increasing cell size contributes to the mechanism for pheromone adaptation. Thus, pheromone in fission and budding yeast acts similarly in inhibiting the G1 cyclin-dependent kinase (CDK), but differs in its effects on the G1/S transcriptional control, suggesting that inhibition of CDKs may be a more general mechanism for the control of G1 progression compared with G1/S transcriptional control" |
| Keywords: | "Blotting, Northern CDC2 Protein Kinase/*metabolism Cell Count/drug effects Cell Cycle/drug effects/physiology Cell Size/drug effects Cyclin B Cyclin-Dependent Kinases/*antagonists & inhibitors/metabolism Cyclins/*metabolism DNA/analysis Enzyme Inhibitors/;" |
| Notes: | "MedlineStern, B Nurse, P eng Research Support, Non-U.S. Gov't England 1997/02/03 EMBO J. 1997 Feb 3; 16(3):534-44. doi: 10.1093/emboj/16.3.534" |
