UNC-98 links an integrin-associated complex to thick laments in Caenorhabditis elegans muscle

• Authors: Rachel K. Miller, Emory University; Hiroshi Qadota, Emory University; Megan L. Landsverk, Baylor College of Medicine; Kristina B. Mercer, Emory University; Henry F. Epstein, University of Texas Medical Branch; Guy Benian, Emory University
• Journal Title: Journal of Cell Biology
• Volume: Volume 175, Number 6
• Publisher: Rockefeller University Press | 2006-12-18, Pages 853-859
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1083/jcb.200608043
• Subjects: Biology, Cell; Health Sciences, Pathology
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cell Biology; MYOSIN HEAVY-CHAIN; BODY-WALL MUSCLE; ADHESION COMPLEXES; PROTEIN; PARAMYOSIN; FILAMENTS; GENE; IDENTIFICATION; LOCALIZATION; COSTAMERES

Abstract

Focal adhesions are multiprotein assemblages that link cells to the extracellular matrix. The transmembrane protein, integrin, is a key component of these structures. In vertebrate muscle, focal adhesion-like structures called costameres attach myofibrils at the periphery of muscle cells to the cell membrane. In Caenorhabditis elegans muscle, all the myofibrils are attached to the cell membrane at both dense bodies (Z-disks) and M-lines. Clustered at the base of dense bodies and M-lines, and associated with the cytoplasmic tail of β-integrin, is a complex of many proteins, including UNC-97 (vertebrate PINCH). Previously, we showed that UNC-97 interacts with UNC-98, a 37-kD protein, containing four C2H2 Zn fingers, that localizes to M-lines. We report that UNC-98 also interacts with the C-terminal portion of a myosin heavy chain. Multiple lines of evidence support a model in which UNC-98 links integrin-associated proteins to myosin in thick filaments at M-lines. © The Rockefeller University Press.