Alteration of tropomyosin-binding properties of tropomodulin-1 affects its capping ability and localization in skeletal myocytes

Abstract

Background: Tropomodulin is a tropomyosin-dependent actin-capping protein. Results: Mutations intropomodulin-1 that reduce its affinity for tropomyosin (R11K, D12N, Q144K) reduced inhibition of actin pointed-end polymerization in vitro and decreased assembly of tropomodulin-1 in skeletal myocytes. Conclusion: The tropomyosin-binding ability of tropomodulin-1 directly influences its actin filament regulatory activity. Significance: Creating a tool for studying the roles of different tropomodulin isoforms in living cells.© 2013 by The American Society for Biochemistry and Molecular Biology, Inc.