Fig. 4. SRC64B and DRL and their mammalian orthologs physically associate. (A) Drosophila Kc cells were transfected with the indicated expression constructs, lysates were immunoprecipitated (IP) with antibodies specific to DRL (anti-HA) or SRC64B (anti-MYC) and then immunoblotted (WB) with the reciprocal antibody to detect co-immunoprecipitation. The expression of DRL and SRC64B was confirmed by immunoblotting of the whole-cell extract (WCE). DRL and SRC64B specifically co-immunoprecipitate in the presence or absence of WNT5 protein. (B) The mammalian orthologs of DRL and SRC64B, RYK and c-SRC, physically interact as assayed by their co-immunoprecipitation from transfected human 293T cell lysates. The expression of RYK-HA and untagged c-SRC was confirmed by WCE immunoblot. RYK derived from c-SRC-overexpressing cells migrates faster than control RYK species, presumably owing to altered post-translational processing. Endogenous c-SRC protein is visible in lanes 1 and 2 of the lowermost blot.