Hosted by the School of Cellular and Molecular Medicine

The lecture will be hosted by the Head of School and will be followed by a drinks reception in the D-floor social space. 

Both S-phase and M-phase are common to both mitotic and meiotic cell cycles and are necessary for newly divided cells to receive a full complement of genes. In fission yeast the onset of S-phase and M-phase during both mitosis and meiosis can be brought about by a single cyclin dependent kinase replacing the 4 mitotic and 6 meiotic CDKs. In vivo protein kinase assays have shown that the substrate specificity is very similar for G1/S and G2/M CDKs. Increasing levels of CDK activity bring about progression through the major events of cell cycles in an orderly fashion.

Using phosphoproteomics we show that a low CDK activity is sufficient to bring about S-phase whilst a high activity is needed for onset of mitosis. A G2 cell can be programmed to undergo either S-phase or M-phase simply by modifying CDK activity indicating there is no inherent arrow of time in the cell cycle. In vivo protein kinase assays show protein kinase activity increases 50-fold during the cell cycle, and part of this span of activity is related to cellular localisation. The accumulation of G2/M cyclin through the cell cycle could act as a measure of cell size, followed by a bistable switch of tyrosine phosphorylation control of CDK to bring about irreversible entry into mitosis.

Full details and registration link on the EventBrite page, This event is free and open to all.