Cross-regulation between CDK and MAPK control cellular fate

Commitment to a new cell cycle is controlled by a number of cellular signals. Mitogen-Activated Protein Kinase pathways, which transduce multiple extracellular cues, have been shown to be interconnected with the cell cycle. Using budding yeast as a model system, we have quantified in live single cells the interplay between the MAPK regulating the mating and the Cyclin-Dependent Kinase controlling cell cycle progression. Four patterns of MAPK activity dynamics could be identified by clustering cells based on their CDK activity, denoting the tight relationship between these two cellular signals. Indeed, inhibiting the CDK activity provides a direct control over the MAPK activity. Conversely, regulating the MAPK activity allows to modulate the number of cells that will enter the cell cycle. During mating, we have verified that the interplay between CDK and MAPK activities allows cells to select their fate, preventing them to be stuck in an undesirable cellular program.