The yeast Rvs161 and Rvs167 proteins are involved in secretory vesicles targeting the plasma membrane and in cell integrity

The Rvs161 and Rvs167 proteins are known to play a role in actin cytokeleto n organization and endocytosis. Moreover, Rvs167p functionally interacts wi th the myosin Myo2p. Therefore, we explored the involvement of the Rvs prot eins in vesicle traffic and in cell integrity. The rvs mutants accumulate l ate secretory vesicles at sites of membrane and cell wall construction. The y are synthetic-lethal with the slt/mpk1 mutation, which affects the MAP ki nase cascade controlled by Pkc1p and is required for cell integrity. The ph enotype of the double mutants is close to that described for the pkc1 mutan t. Synthetic defects for growth are also observed with mutation in KRE6, a gene coding for a glucan synthase, required for cell wall construction. The se data support the idea that the Rvs proteins are involved in the late tar geting of vesicles whose cargoes are required for cell wall construction. C opyright (C) 2001 John Wiley & Sons, Ltd.