Fesselin binds to actin and myosin and inhibits actin-activated ATPase activity
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Fesselin is an actin binding protein that bundles actin filaments and accelerates nucleation of actin polymerization. The effect of fesselin on actin polymerization is regulated by Ca++-calmodulin. Because actin filaments serve both structural and contractile functions we also examined the effect of fesselin on activation of myosin S1 ATPase activity. Fesselin inhibited the activation of S1-catalyzed ATP hydrolysis in a similar manner in both the presence and absence of tropomyosin. This inhibition was unaffected by Ca++-calmodulin. Fesselin inhibited the binding of myosin-S1 to actin during steady-state ATP hydrolysis. Fesselin also displaced caldesmon from actin. S1 displaced fesselin from actin in the absence of nucleotide when the affinity of S1 for actin was much greater than the affinity of fesselin for actin. It is likely that fesselin and S1 share common binding sites on F-actin. We also observed that fesselin could bind to smooth muscle myosin with μM affinity. Fesselin shares some similarities to caldesmon in binding to several other proteins and having multiple potential functions.
KeywordsATPase Activity Actin Polymerization Actin Monomer Smooth Muscle Myosin Actin Concentration
ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid
- regulated actin
myosin subfragment 1
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This work was supported by Grant (AR035216 from the National Institutes of Health.
- Asanuma K, Kim K, Oh J, Giardino L, Chabanis S, Faul C, Reiser J and Mundel P (2005) Synaptopodin regulates the actin-bundling activity of (alpha)-actinin in an isoform-specific manner. J Clin Invest 115: 1188–1198Google Scholar
- Eisenberg E, Kielley WW, (1972) Evidence for a refractory state of heavy meromyosin and subfragment-1 unable to bind to actin in the presence of ATP Cold Spring Harbor Symp Quant Biol 37:145–152Google Scholar
- Perry SV, Cole HA, Head JF, Wilson FJ, (1972) Localization and mode of action of the inhibitory protein component of the tropomyosin complex Cold Spring Harbor Symp Quant Biol 37:251–262Google Scholar
- Pollard TD and Earnshaw WC (2002) Actin and actin-binding proteins. In Cell Biology, 1st edn. (pp. 557–577). WB Saunder, New YorkGoogle Scholar
- Sobue K, Morimoto K, Inui M, Kanda K, Kakiuchi S, (1982a) Control of actin-myosin interaction of gizzard smooth muscle by calmodulin-and caldesmon-linked flip-flop mechanism Biomed Res 3:188–196Google Scholar
- Sobue K, Morimoto K, Kanda K, Fukunaga K, Miyamoto E, Kakiuchi S, (1982b) Interaction of 135000-Mw calmodulin-binding protein (myosin kinase) and F-actin: another Ca2+- and calmodulin-dependent flip-flop switch Biochem Int 5:503–510Google Scholar