The UNC-112 gene in Caenorhabditis elegans encodes a novel component of cell-matrix adhesion structures required for integrin localization in the muscle cell membrane.
Embryos homozygous for mutations in the unc-52, pat-2, pat-3, and unc-112 genes of C. elegans exhibit a similar Pat phenotype. Myosin and actin are not organized into sarcomeres in the body wall muscle cells of these mutants, and dense body and M-line components fail to assemble. The unc-52 (perlecan), pat-2 (alpha-integrin), and pat-3 (beta-integrin) genes encode ECM or transmembrane proteins found at the cell-matrix adhesion sites of both dense bodies and M-lines. This study describes the identification of the unc-112 gene product, a novel, membrane-associated, intracellular protein that colocalizes with integrin at cell-matrix adhesion complexes. The 720-amino acid UNC-112 protein is homologous to Mig-2, a human protein of unknown function. These two proteins share a region of homology with talin and members of the FERM superfamily of proteins. We have determined that a functional UNC-112::GFP fusion protein colocalizes with PAT-3/beta-integrin in both adult and embryonic body wall muscle. We also have determined that UNC-112 is required to organize PAT-3/beta-integrin after it is integrated into the basal cell membrane, but is not required to organize UNC-52/perlecan in the basement membrane, nor for DEB-1/vinculin to localize with PAT-3/beta-integrin. Furthermore, UNC-112 requires the presence of UNC-52/perlecan and PAT-3/beta-integrin, but not DEB-1/vinculin to become localized to the muscle cell membrane.
Rogalski
T M
TM
Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Mullen
G P
GP
Gilbert
M M
MM
Williams
B D
BD
Moerman
D G
DG
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D015801:Helminth Proteins / Q000235:genetics / Q000378:metabolism; D016023:Integrins / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D011509:Proteoglycans / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D029742:Caenorhabditis elegans Proteins; D015815:Cell Adhesion Molecules; D015801:Helminth Proteins; D016023:Integrins; D008164:Luminescent Proteins; D008565:Membrane Proteins; D011509:Proteoglycans; D011993:Recombinant Fusion Proteins; C411729:UNC-112 protein, C elegans; C082396:unc-52 protein, C elegans; D049452:Green Fluorescent Proteins