Receptor‐mediated stimulation induces massive actin polymerization and cyto‐skeletal reorganization. The activity of a potent actin‐modulating protein, gelsolin, is regulated both by Ca2+ and polyphos‐phoinositides, and it may have a pivotal role in restructuring the actin cytoskeleton in response to agonist stimulation. Structure‐function analysis of gelsolin has (1) indicated that its NH2‐terminal half is primarily responsible for modulating actin filament length and polymerization; and (2) elucidated mechanisms by which Ca2+ and phospholipids may regulate such functions. Gelsolin is functionally and structurally similar to villin, another Ca2+‐activated actin‐severing protein found in microvilli, suggesting that gelsolin may be a prototype of this family of actin‐modulating proteins. A molecular variant of gelsolin is secreted and may be involved in the clearance of actin filaments released during tissue damage. The two forms of gelsolin are encoded by a single gene, and distinct messages are derived by alternative message splicing.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)