title: Severin is a gelsolin prototype.
abstract: A number of Ca2(+)-activated actin filament severing proteins have been identified in eukaryotic cells of diverse lineages. Gelsolin and villin, with molecular mass of about 80-90 kDa, and severin and fragmin, with molecular mass of about 40 kDa, have been isolated from vertebrates and invertebrates, respectively. We report here a direct comparison of the functional properties of gelsolin and severin, and the finding that the actin filament severing activity of severin, like that of gelsolin, is inhibited by polyphosphoinositides. However, severin does not nucleate actin filament assembly as well as gelsolin. These characteristics are very similar to those ascribed to the NH2-terminal half of gelsolin, supporting the idea that they are evolutionarily related. Regulation of severin by polyphospholipids raises the possibility that it may participate in agonist-stimulated regulation of the actin cytoskeleton in Dictyostelium discoideum.
authors.affiliation: Department of Physiology, University of Texas Southwestern Medical Center, Dallas.
authors.forename: H L
authors.initials: HL
authors.lastname: Yin
authors.forename: P A
authors.initials: PA
authors.lastname: Janmey
authors.forename: M
authors.initials: M
authors.lastname: Schleicher
mesh_terms: D000199:Actins / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000097:blood / Q000302:isolation & purification / Q000494:pharmacology*; D005656:Fungal Proteins / Q000097:blood / Q000302:isolation & purification / Q000494:pharmacology*; D018260:Gelsolin; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008840:Microfilament Proteins / Q000097:blood / Q000302:isolation & purification / Q000494:pharmacology*; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000494:pharmacology; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000494:pharmacology; D015800:Protozoan Proteins
chemical_list: D000199:Actins; D002135:Calcium-Binding Proteins; D005656:Fungal Proteins; D018260:Gelsolin; D046911:Macromolecular Substances; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; D015800:Protozoan Proteins; C036571:severin protein, Dictyostelium