- Fission yeast pak1+ encodes a protein kinase that interacts with Cdc42p and is involved in the control of cell polarity and mating. Ottilie, S., Miller, P.J., Johnson, D.I., Creasy, C.L., Sells, M.A., Bagrodia, S., Forsburg, S.L., Chernoff, J. EMBO J. (1995)