title: Synthesis and secretion of serum gelsolin by smooth muscle tissue.
abstract: Gelsolin is one of many actin binding proteins which regulate the structure of intracellular microfilaments. A secretory form of gelsolin, a protein also known as "actin depolymerizing factor" or "brevin," is present in animal sera. In the present studies, we: demonstrate that a 90-kDa secretory protein produced by chicken gizzard smooth muscle is serum gelsolin; show that chicken serum gelsolin, as compared with its mammalian counterparts, lacks 26 amino acid residues at its NH2-terminal end; show that gizzard smooth muscle devotes on the order of 100 times more of its total protein synthetic effort (about 1% of the total) to the production of serum gelsolin than does liver, a previously speculated major source of this protein; and give evidence that rat tissues which are rich in smooth muscle cells (blood vessels, uterine muscle) also produce serum gelsolin. Our work suggests that, in vivo, smooth muscle-containing tissues may be major producers of the serum form of this actin binding protein.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002135:Calcium-Binding Proteins / Q000096:biosynthesis* / Q000378:metabolism; D002645:Chickens; D018260:Gelsolin; D005895:Gizzard, Avian / Q000378:metabolism; D008840:Microfilament Proteins / Q000096:biosynthesis* / Q000378:metabolism; D009130:Muscle, Smooth / Q000378:metabolism*
chemical_list: D002135:Calcium-Binding Proteins; D018260:Gelsolin; D008840:Microfilament Proteins