KL stimulation results in tyrosine phosphorylation of WASP, WIP, and Arp2. M-07e cells were stimulated with KL (250 ng/mL) for the times indicated, and WASP and WIP were immunoprecipitated. Bound fractions of the immunoprecipitations (IPs) were analyzed for tyrosine phosphorylation (PY) and protein amounts of the primary and associated proteins by immunoblot (IB). WASP IPs (A) were analyzed for PY (top panel) and protein amounts of WASP (bottom panel). WIP IPs (B) were analyzed for PY (top panel; short exposure showing phospho [p] WIP), protein amounts of WIP (second panel), PY (third panel; long exposure showing pWASP), and protein amounts of WASP (fourth panel). Please note that both WASP and WIP are tyrosine phosphorylated and form a complex as phosphoproteins. In the longer exposure showing pWASP in complex with pWIP, the chemoluminescence signals from pWIP and Ig are not separated due to close migration on sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Both WASP and WIP IPs (C) were analyzed for PY of Arp2 (top panel) and protein amounts of Arp2 (bottom panel). Experiments were performed twice, and comparable results were obtained.