DIM-1, a novel immunoglobulin superfamily protein in Caenorhabditis elegans, is necessary for maintaining bodywall muscle integrity.
The UNC-112 protein is required during initial muscle assembly in C. elegans to form dense bodies and M-lines. Loss of this protein results in arrest at the twofold stage of embryogenesis. In contrast, a missense mutation in unc-112 results in viable animals that have disorganized bodywall muscle and are paralyzed as adults. Loss or reduction of dim-1 gene function can suppress the severe muscle disruption and paralysis exhibited by these mutant hermaphrodites. The overall muscle structure in hermaphrodites lacking a functional dim-1 gene is slightly disorganized, and the myofilament lattice is not as strongly anchored to the muscle cell membrane as it is in wild-type muscle. The dim-1 gene encodes two polypeptides that contain three Ig-like repeats. The short DIM-1 protein isoform consists entirely of three Ig repeats and is sufficient for wild-type bodywall muscle structure and stability. DIM-1(S) localizes to the region of the muscle cell membrane around and between the dense bodies, which are the structures that anchor the actin filaments and may play a role in stabilizing the thin rather than the thick filament components of the sarcomere.
Rogalski
Teresa M
TM
Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Gilbert
Mary M
MM
Devenport
Danelle
D
Norman
Kenneth R
KR
Moerman
Donald G
DG
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000276:immunology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics*; D015815:Cell Adhesion Molecules / Q000235:genetics; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D007136:Immunoglobulins / Q000235:genetics*; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000276:immunology*; D010957:Plasmids; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D029742:Caenorhabditis elegans Proteins; D015815:Cell Adhesion Molecules; C480418:DIM-1 protein, C elegans; D007136:Immunoglobulins; C411729:UNC-112 protein, C elegans