Certain components of the cytoskeleton play a role in yeast fluid-phas
e endocytosis as well as in endocytosis of the alpha-factor when this
pheromone is bound to its 7-transmembrane segment receptor. The yeast
maltose transporter is a 12-transmembrane segment protein that, under
certain physiological conditions, is degraded in the vacuole after int
ernalization by endocytosis. In this work, the possible role of the cy
toskeleton in endocytosis of this transporter has been investigated. U
sing mutants defective in beta-tubulin, actin and the actin-binding pr
oteins Sac6 and Abp85, as well as nocodazole, which inhibits formation
of microtubules, we have shown that actin microfilaments are involved
in endocytosis of the maltose transporter whereas microtubules are no
t. (C) 1997 by John Wiley & Sons, Ltd.