A critical role for the polarization of membrane recycling in cell motility

This paper is concerned with the proposition that the insertion of membrane mass into the leading edge of a motile cell plays a critical role in directed cell migration. We show by immunofluorescence, with cells transfected with a cloned cDNA encoding the G-protein of a temperature-sensitive mutant of vesicular stomatitis virus, that the first cell surface appearance of the G-protein is indeed at the leading edge of the motile cell. Two drugs capable of inhibiting directed cell migration, cytochalasin D and monensin, appear to function independently, the former by affecting the actin cytoskeleton without affecting the polarized insertion of membrane mass into the cell surface and the latter by abrogating membrane mass insertion without affecting the actin cytoskeleton.