| We have previously identified poly ( A ) binding protein 1 ( PABP 1 ) as a ligand for paxillin and shown that the paxillin PABP 1 complex undergoes nucleocytoplasmic shuttling . ^^^ By targeting the paxillin binding subdomain sequences in PABP 1 , we have generated mutants of PABP 1 that do not bind to cellular paxillin . ^^^ Here we report that paxillin association is necessary for efficient nuclear export of PABP 1 and that RNA interference of paxillin drives the nuclear accumulation of PABP 1 . ^^^ Furthermore , ablation of paxillin PABP 1 association impeded a number of indices of cell motility including spreading on fibronectin , cell migration on two dimensional matrices , and transmigration in Boyden chambers . ^^^ These data indicate that PABP 1 must associate with paxillin in order to be efficiently transported from the nucleus to the cytoplasm and that this event is necessary for cells to remodel their focal adhesions during cell migration . . ^^^ |