Distinct roles of profilin in cell morphological changes: microspikes, membrane ruffles, stress fibers, and cytokinesis

Here we report the functional importance of profilin in various actin-mediated morphological changes using H119E mutant profilin I, which is deficient only in actin binding. In the case of actin-protrusive structures from the plasma membrane, H119E-profilin was shown to suppress the formation of Cdc42-induced actin microspikes and Rac-induced membrane ruffles. Conversely, Rho-induced stress fiber formation seemed to occur independently of H119E-profilin introduction, Furthermore, H119E-protilin blocked cleavage furrow ingression and subsequent adhesion to the substratum during cell division, a process in which actin plays indispensable roles. (C) 1999 Federation of European Biochemical Societies.