Different localizations and cellular behaviors of leiomodin and tropomodulin in mature cardiomyocyte sarcomeres.

ABSTRACT: Leiomodin (Lmod) is a muscle-specific F-actin-nucleating protein that is related to the F-actin pointed-end-capping protein tropomodulin (Tmod). However, Lmod contains a unique ∼150-residue C-terminal extension that is required for its strong nucleating activity. Overexpression or depletion of Lmod compromises sarcomere organization, but the mechanism by which Lmod contributes to myofibril assembly is not well understood. We show that Tmod and Lmod localize through fundamentally different mechanisms to the pointed ends of two distinct subsets of actin filaments in myofibrils. Tmod localizes to two narrow bands immediately adjacent to M-lines, whereas Lmod displays dynamic localization to two broader bands, which are generally more separated from M-lines. Lmod's localization and F-actin nuc

SUBMITTER: Skwarek-Maruszewska A 

PROVIDER: S-EPMC2947471 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature