DNA-binding protein that regulates the transcription of several genes and is involved in heart development and limb pattern formation. Binds to the core DNA motif of NPPA promoter. Monomer. Homodimer (via the T-box); binds DNA as homodimer. Interacts (via the T-box) with NKX2-5 (via the homeobox); this complex binds DNA. Interacts with GATA4. Interacts with KAT2A and KAT2B. Shuttles between the cytoplasm and the nucleus. Acetylation at Lys-338 promotes nuclear retention. The T-Box domain binds to double-stranded DNA. Acetylation at Lys-338 by KAT2A and KAT2B promotes nuclear retention.