The 45K molecular weight actin-modulating protein from sea urchin eggs forms a complex with actin in the presence of calcium ions.
The 45K protein from sea urchin eggs forms a complex with actin in the presence of Ca2+. The fraction was not readily dissociated on depletion of Ca2+ by gel filtration, but was dissociated on dialysis against an EGTA-containing solution. The free 45K protein and the 45K protein-actin complex affect F-actin in different manners in the presence of Ca2+. The former severs F-actin in the presence of Ca2+ but not in its absence, while the latter caps the barbed end of F-actin in a Ca2+-independent manner thereby lowering the viscosity of F-actin slowly.
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002850:Chromatography, Gel; D003598:Cytoskeletal Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D010063:Ovum / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D012617:Sea Urchins; D014783:Viscosity
D000199:Actins; D003598:Cytoskeletal Proteins; D011506:Proteins; C028514:actin-modulating proteins; D002118:Calcium