Fig. 4. WAVE2 and Abi1 are found in the same complex and are enriched at CSF-1-induced membrane protrusions. (A) FLAG-tagged WAVE2-expressing RAW/LR5 cells were lysed and lysates were sequentially incubated with control IgG and specific antibodies against FLAG for immunoprecipitation (IP). Immunoprecipitates were then subjected to western blotting using the indicated antibodies. Signals corresponding to IgG heavy chain are shown as a proof of equal loading. (B) RAW/LR5 cells were either left untreated (–) or were treated (+) with 20 ng/ml CSF-1 for 5 minutes prior to lysis and immunoprecipitation of Abi1 followed by WAVE2 and Abi1 western blotting. (C) BMM and RAW/LR5 cells were treated with CSF-1, then fixed and stained for WAVE2 and Abi1 as described in Materials in Methods. Bars, 10 µm.