9316145 Haarer The ability of profilin to block phospholiphase C activity by binding to PIP2 and the observation that overexpression of profilin can suppress defects in yeast CAP (adenylate cyclase-associated protein) suggest that profilin may aid in the conveyance of growth screen has been used to identify five mutations that result in cell death only when combined with an altered profilin. These "synthetic lethal" mutations are likely to define genes whose products interact with profilin, or that provide similar functions. To identify the specific functions of these genes and to define their interactions with profilin, the following genetic and biochemical studies will be performed: 1) Characterization of profilin synthetic lethal (ps1) mutants. 2) Cloning of profilin synthetic lethal genes and analysis of their protein products. 3) Investigation of the PSL1 gene product and associated proteins. %%%% The long-term goals of this project address several basic cell biological questions using yeast as a model experimental organism: i) how does the cell establish polarity; ii)what signals convey this decision-making process to those components of the cell that are responsible for carrying out the necessary morphological changes; and iii) once this message is conveyed, how are morphological changes controlled in an orderly fashion? More specifically, this project strives to identify the role of the actin-binding protein profilin in cell growth. ***
