| Immunocytochemistry , sucrose density gradient sedimentation , co immunoprecipitation analyses and in vitro binding assays have shown that polycystin 1 associates with the focal adhesion proteins talin , vinculin , p130Cas , FAK , alpha actinin , paxillin and pp60c src in subconfluent normal human fetal collecting tubule ( HFCT ) epithelia when cell matrix interactions predominate . ^^^ Although inhibition of tyrosine phosphorylation by tyrphostin inhibits polycystin 1 FAK interactions , E cadherin interactions are enhanced . ^^^ |