HOX11 constructs and protein expression. (A) Schematic diagram of expression constructs for FLAG-tagged HOX11 WT and mutant proteins. FLAG peptide, Gly/Pro-rich region (Gly/Pro), homeodomain (HD), Gln-rich region (Gln), and PBX interaction motif (PIM; FPWME) are indicated. (B) FLAG-tagged HOX11 proteins were detected in lysates from HeLa cells transiently transfected with pFLAG-HOX11 constructs using immunoprecipitation and Western blotting with an anti–FLAG-M5 antibody (top row, middle row) or by direct Western blotting of lysates from stably transduced NIH3T3 cells using an anti-HOX11 antibody (bottom row). C indicates control.