Fig. 8.

Association of paxillin with the α4 tail.A, Identification of paxillin by Western blotting immunoprecipitates generated using anti-α4, but not using anti-β1 or anti-α5, from biotin-labeled lysates of DRG neurons (top panel). Two paxillin bands were detected, probably representing the α and β isoforms of paxillin. The presence of immunoprecipitated cell-surface proteins in the material used for Western blotting was confirmed by detection with streptavidin peroxidase and ECL (bottom panel). B,Immunoprecipitation of paxillin from the DRG neuron lysates after multiple immunodepletions with anti-α4, anti-α5, or irrelevant IgG (α4, α5, mock depletions). Note the reduction in the level of paxillin in the lysate depleted of α4 integrins. C,Reimmunoprecipitation of α4 (lane 1) but not α5 (lane 2) from immunoprecipitates generated using anti-paxillin antibodies on lysates of DRG neurons. D,Cell lysates from PC12 cell lines expressing α4α4, α4α0, α5α5, α5α0, α5α6, or α5α4 were immunoprecipitated with anti-human α4 (lanes 1, 2) or α5 (lanes 3–6) and then Western blotted with anti-paxillin antibodies. Equal amounts of protein were used. Note that only those cell lines expressing the α4 cytoplasmic domain show coassociation of paxillin.