Differential actin organization by vinculin isoforms: implications for cell type-specific microfilament anchorage.
Vinculin is found in all adherens junctions, while metavinculin, a larger splice variant, is coexpressed with vinculin only in smooth and cardiac muscle. To understand the significance of metavinculin expression, we compared ligand binding between turkey vinculin and metavinculin. Residues 1-258 were found essential for head-tail interactions in both proteins. The tail domains (VT and MVT, respectively) both bind to F-actin. However, while VT bundles F-actin, MVT generates highly viscous F-actin webs. In transfected PtK2 cells, VT causes F-actin needles or coils, while MVT-expressing cells display a diffuse F-actin distribution. Thus, the MVT-specific insert induces an F-actin supraorganization different from the VT-based form, suggesting that metavinculin has a specific role in muscle.
Cell Biology, Zoological Institute, Technical University Braunschweig, Germany.
M
M
Rüdiger
N
N
Korneeva
C
C
Schwienbacher
E E
EE
Weiss
B M
BM
Jockusch
D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D004926:Escherichia coli; D008969:Molecular Sequence Data; D011485:Protein Binding; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D014162:Transfection; D014422:Turkeys; D016596:Vinculin / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism*; D014783:Viscosity
D000199:Actins; D011994:Recombinant Proteins; C103334:metavinculin; D016596:Vinculin