Paxillin associates with high-affinity α4 integrins isolated from murine spleen cells. (A) The left Western blot compares paxillin coprecipitation with high-affinity α4 integrins isolated from mouse lymph nodes and spleens (1 mg of each lysate was incubated with VCAM-1/Fc). The right blot shows paxillin expression in total cell lysates (20 μg/lane). (B) High-affinity, low-affinity, and both high- and low-affinity α4 integrins were precipitated from murine spleen cell lysates (2 mg total cell lysate per lane) as described in Figure 2. Blots were sequentially probed for phosphorylated Ser988 α4 integrin, paxillin, and α4 integrins. Representative data from 1 of 3 experiments are shown.