Furthermore, increases in p-tyr for some proteins lasted even shorter than 5 min. There were also proteins, the p-tyr of which progressively decreased in response to the calcium transient. Immunofluorescence staining also showed that p-tyr signals were significantly increased or redistributed by the calcium transient. In cells grown on homogenous FBN substrates, the increased p-tyr was located over most of the extending lamella, while in cells grown on FBN paths, more p-tyr were found to have accumulated at the leading lamella that was crawling along the FBN path than elsewhere. The accumulation of p-tyr was most evident at 2 min after calcium uncaging, but had diminished greatly after 20 min. Interestingly, DTT treatment did not cause any significant increase or accumulation of p-tyr staining as compared to the control cells. In leukocytes, the Beclamide actin-binding protein paxilin has been shown to connect integrin receptors to actin cytoskeleton through protein phosphorylation control. Therefore, we next examined the phosphorylated paxillin content of the cells after calcium uncaging. As shown in Fig. 3G, we found that although the amount of paxillin protein did not significantly change, the protein��s phosphorylation level strongly increased in the first 5 min after the calcium transient, but had diminished after 20 min. Immunofluorescence staining of p-pax also revealed an apparent increase/redistribution of p-pax at 5 min after calcium uncaging. Accumulation of p-pax at the leading lamella that guided the cell movement along the FBN path was noted, as compared to the dim and homogenously distributed ppax across the entire lamella in the control cell receiving mock photolysis. The next question to ask was whether the phenotype of calcium uncaging described here might be extended to the physiological control of cell motility by native calcium signaling. To explore this question, we carefully examined the pattern of cell motion and Ceftizoxime sodium correlated the dynamics of cell movement with the occurrences of spontaneous calcium transients. Typical examples of this series of study are shown in Fig. 4.