UNC-98 links an integrin-associated complex to thick filaments in Caenorhabditis elegans muscle.
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 beta-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.
Miller
Rachel K
RK
Department of Pathology and 2Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, GA 30322, USA.
Qadota
Hiroshi
H
Landsverk
Megan L
ML
Mercer
Kristina B
KB
Epstein
Henry F
HF
Benian
Guy M
GM
D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D016023:Integrins / Q000235:genetics / Q000378:metabolism*; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D009210:Myofibrils; D018995:Myosin Heavy Chains / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D029742:Caenorhabditis elegans Proteins; D016023:Integrins; D009124:Muscle Proteins; C117451:UNC-97 protein, C elegans; C481656:UNC-98 protein, C elegans; D018995:Myosin Heavy Chains