UNC-97/PINCH is involved in the assembly of integrin cell adhesion complexes in Caenorhabditis elegans body wall muscle.
UNC-97/PINCH is an evolutionarily conserved protein that contains five LIM domains and is located at cell-extracellular matrix attachment sites known as cell adhesion complexes. To understand the role of UNC-97/PINCH in cell adhesion, we undertook a combined genetic and cell biological approach to identify the steps required to assemble cell adhesion complexes in Caenorhabditis elegans. First, we have generated a complete loss of function mutation in the unc-97 coding region. unc-97 null mutants arrest development during embryogenesis and reveal that the myofilament lattice and its attachment structures, which include PAT-4/ILK (integrin-linked kinase) and integrin fail to assemble into properly organized arrays. Although in the absence of UNC-97/PINCH, PAT-4/ILK and integrin fail to organize normally, they are capable of colocalizing together at the muscle cell membrane. Alternatively, in integrin and pat-4 mutants, UNC-97/PINCH fails to localize to the muscle cell membrane and instead is found diffusely throughout the muscle cell cytoplasm. In agreement with mammalian studies, we show that LIM domain 1 of UNC-97/PINCH is required for its interaction with PAT-4/ILK in yeast two-hybrid assays. Additionally, we find, by LIM domain deletion analysis, that LIM1 is required for the localization of UNC-97/PINCH to cell adhesion complexes. Our results provide evidence that UNC-97/PINCH is required for the development of C. elegans and is required for the formation of integrin based adhesion structures.
Norman
Kenneth R
KR
Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada V6T 1Z4.
Cordes
Shaun
S
Qadota
Hiroshi
H
Rahmani
Poupak
P
Moerman
Donald G
DG
D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002448:Cell Adhesion / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism*; D016023:Integrins / Q000378:metabolism*; D009124:Muscle Proteins / Q000235:genetics / Q000502:physiology*; D009132:Muscles / Q000378:metabolism; D009154:Mutation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000378:metabolism; D000099200:Scaffold Protein ILK
D029742:Caenorhabditis elegans Proteins; D016023:Integrins; D009124:Muscle Proteins; D017346:Protein Serine-Threonine Kinases; D014157:Transcription Factors; C117451:UNC-97 protein, C elegans; C466238:PAT-4 protein, C elegans; D000099200:Scaffold Protein ILK