Journal of Muscle Research & Cell Motility

, Volume 26, Issue 4–5, pp 183–189

Fesselin binds to actin and myosin and inhibits actin-activated ATPase activity

Article

DOI: 10.1007/s10974-005-9009-6

Cite this article as:
Schroeter, M.M. & Chalovich, J.M. J Muscle Res Cell Motil (2005) 26: 183. doi:10.1007/s10974-005-9009-6

Abstract

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.

Abbreviations

EDTA

ethylenediaminetetraacetic acid

EGTA

ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid

MOPS

3-(N-Morpholino]-propanesulfonic acid

regulated actin

actin–tropomyosin–troponin

S1

myosin subfragment 1

Copyright information

© Springer Science+Business Media Inc. 2005

Authors and Affiliations

  1. 1.Brody School of Medicine at East Carolina UniversityGreenvilleUSA

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