The uvomorulin-anchorage protein alpha catenin is a vinculin homologue.
The cytoplasmic region of the Ca(2+)-dependent cell-adhesion molecule (CAM) uvomorulin associates with distinct cytoplasmic proteins with molecular masses of 102, 88, and 80 kDa termed alpha, beta, and gamma catenin, respectively. This complex formation links uvomorulin to the actin filament network, which seems to be of primary importance for its cell-adhesion properties. We show here that antibodies against alpha catenin also immunoprecipitate complexes that contain human N-cadherin, mouse P-cadherin, chicken A-CAM (adherens junction-specific CAM; also called N-cadherin) or Xenopus U-cadherin, demonstrating that alpha catenin is complexed with other cadherins. In immunofluorescence tests, alpha catenin is colocalized with cadherins at the plasma membrane. However, in cadherin-negative Ltk- cells, alpha catenin is found uniformly distributed in the cytoplasm, suggesting some additional biological function(s). Expression of uvomorulin in these cells results in a concentration of alpha catenin at membrane areas of cell contacts. We also have cloned and sequenced murine alpha catenin. The deduced amino acid sequence reveals a significant homology to vinculin. Our results suggest the possibility of a new vinculin-related protein family involved in the cytoplasmic anchorage of cell-cell and cell-substrate adhesion molecules.
Max-Planck-Institut für Immunbiologie, FG Molekulare Embryologie, Freiburg, Federal Republic of Germany.
K
K
Herrenknecht
M
M
Ozawa
C
C
Eckerskorn
F
F
Lottspeich
M
M
Lenter
R
R
Kemler
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015820:Cadherins / Q000235:genetics* / Q000378:metabolism*; D002460:Cell Line; D002642:Chick Embryo; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D007739:L Cells / Q000166:cytology; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D013724:Teratoma; D014162:Transfection; D016596:Vinculin / Q000235:genetics*; D051178:alpha Catenin
C495273:CTNNA1 protein, human; D015820:Cadherins; C495272:Ctnna1 protein, mouse; D003598:Cytoskeletal Proteins; D051178:alpha Catenin; D016596:Vinculin; D004247:DNA