Mutational analysis of yeast profilin.

• DOI: 10.1128/mcb.13.12.7864
• Publication Date: 2015-10-06T00:37:17Z
• Authors: B K Haarer; A S Petzold; S S Brown
• Keywords: Profilin; Polyproline helix; Actin-binding protein; MDia1; Actin remodeling

We have mutated two regions within the yeast profilin gene in an effort to functionally dissect roles of actin and phosphatidylinositol 4,5-bisphosphate (PIP2) binding function. A series truncations was carried out at C terminus profilin, a region that has been implicated binding. Removal last three amino acids nearly eliminated ability bind polyproline vitro but had no dramatic vivo effects. Thus, extreme is binding, physiological relevance this interaction called into question. More extensive truncation, up eight acids, effects increasing severity resulted changes conformation expression level mutant profilins. However, these mutants not eliminated, suggesting cannot be solely responsible for also mutagenized we hypothesized might involved PIP2 Alteration basic produced profilins functioned well vivo. Many mutants, however, were unable suppress loss adenylate cyclase-associated protein (Cap/Srv2p [A. Vojtek, B. Haarer, J. Field, Gerst, T. D. Pollard, S. Brown, M. Wigler, Cell 66:497-505, 1991]), indicating defect could demonstrated In assays inability Cap/Srv2p correlated with actin, independently whether reduced. Since our earlier studies Acanthamoeba suggested importance suppression, conclude both activities are interplay between may important