JAK2 is required for the SDF-1α–induced phosphorylation of the focal adhesion components FAK, RAFTK, paxillin, CrkII, CrkL, and p130Cas.

CTS cells, pretreated with AG490 (100 μM) (+) or DMSO (−) for 2 hours, were stimulated with 20 nM SDF-1α for 1 minute and lysed. Total cell lysates were immunoprecipitated with anti-FAK (A), anti-RAFTK (B), antipaxillin (C), anti-CrkII (D), anti-CrkL (E), and anti-p130Cas (F) antibodies, and the immunoprecipitates were analyzed by Western blotting with PY99 antibody (pTyr) (upper panels). After stripping, the membranes were reprobed to assure equal protein loading (A-F, lower panels).