Calpain abolishes the effect of filamin on the actomyosin system in platelets.
Platelet filamin was shown to cross-link F-actin and inhibit actomyosin ATPase activity. Filamin was also shown to be degraded by calpain (calcium-activated neutral proteinase; CANP) when the platelet was activated. The consequences of the proteolysis of filamin on the actomyosin system have been investigated. When degraded by calpain in the presence of Ca2+, filamin loses its ability to cross-link F-actin. Under the same conditions, its inhibitory effects on the superprecipitation and ATPase activity of actomyosin are abolished. The result suggests that the degradation of filamin is favorable for contraction of the activated platelets.
D000199:Actins / Q000097:blood; D000205:Actomyosin / Q000097:blood*; D000818:Animals; D001792:Blood Platelets / Q000378:metabolism*; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002154:Calpain / Q000494:pharmacology*; D003285:Contractile Proteins / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D064448:Filamins; D008840:Microfilament Proteins / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D010447:Peptide Hydrolases / Q000378:metabolism; D013552:Swine; D014783:Viscosity
D000199:Actins; D003285:Contractile Proteins; D064448:Filamins; D008840:Microfilament Proteins; D000205:Actomyosin; D010447:Peptide Hydrolases; D002154:Calpain; D017301:Ca(2+) Mg(2+)-ATPase