Xarvcf, Xenopus member of the p120 catenin subfamily associating with cadherin juxtamembrane region

The catenin ARVCF is a member of the p120(ctn) subfamily of Armadillo prote ins. A number of catenins directly bind cadherin cytoplasmic tails, contrib uting to the modulation of cell-cell adhesion and motility processes. Some catenins, such as beta-catenin (and likely p120(ctn)), have additional role s within signaling pathways regulating gene transcription. We have isolated the Xenopus homolog of human ARVCF. Utilizing the cadherin membrane proxim al region known to bind p120(ctn) and delta-catenin, coimmunoprecipitation experiments demonstrate that Xarvcf, likewise, binds cadherin in this regio n and that corresponding point mutations within conserved residues abrogate the Xarvcf cadherin association. Western blot analysis of Xarvcf protein a cross a series of developmental stages reveals changes in protein mobility, likely due to changes in phosphorylation. Xarvcf is a maternally provided transcript and expressed in the embryo throughout all stages of development . Interestingly, Xarvcf mRNA is differentially spliced to produce several i soforms, one of which is developmentally regulated. In common with the puta tive post-translational modifications of the Xarvcf protein, the presence o f alternative splice isoforms suggests that Xarvcf possesses the capacity t o effect developmental functions in a regulatable manner.