title: Loss of Sarcomere-associated Formins Disrupts Z-line Organization, but does not Prevent Thin Filament Assembly inCaenorhabditis elegansMuscle.
abstract: Members of the formin family of actin filament nucleation factors have been implicated in sarcomere formation, but precisely how these proteins affect sarcomere structure remains poorly understood. Of six formins in the simple nematodeCaenorhabditis elegans, only FHOD-1 and CYK-1 contribute to sarcomere assembly in the worm's obliquely striated body-wall muscles. We analyze here the ultrastructure of body-wall muscle sarcomeres in worms with putative nullfhod-1andcyk-1gene mutations. Contrary to a simple model that formins nucleate actin for thin filament assembly, formin mutant sarcomeres contain thin filaments. Rather, formin mutant sarcomeres are narrower and have deformed thin filament-anchoring Z-line structures. Thus, formins affect multiple aspects of sarcomere structure.
authors.affiliation: Department of Cell and Developmental Biology, State University of New York Upstate Medical University, 766 Irving Avenue, Syracuse, NY 13210, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Mi-Mi
authors.affiliation: Department of Cell and Developmental Biology, State University of New York Upstate Medical University, 766 Irving Avenue, Syracuse, NY 13210, USA.
authors.forename: David
authors.initials: D
authors.lastname: Pruyne
keywords: C. elegans; Formin; Muscle; Sarcomere; Thin filament; Z-line