DNA-binding protein that regulates the transcription of several genes and is involved in heart development and limb pattern formation (PubMed:25725155, PubMed:25963046, PubMed:29174768, PubMed:26917986, PubMed:27035640, PubMed:8988164). Binds to the core DNA motif of NPPA promoter (PubMed:26926761). Monomer (PubMed:20450920). Homodimer (via the T-box); binds DNA as homodimer (PubMed:26926761). Interacts (via the T-box) with NKX2-5 (via the homeobox); this complex binds DNA (PubMed:26926761). Interacts with GATA4 (PubMed:24000169). Interacts with KAT2A and KAT2B (PubMed:29174768). Shuttles between the cytoplasm and the nucleus. Acetylation at Lys-339 promotes nuclear retention. The T-Box domain binds to double-stranded DNA (PubMed:26926761). Acetylation at Lys-339 by KAT2A and KAT2B promotes nuclear retention. The disease is caused by variants affecting the gene represented in this entry. Defects in TBX5 are associated with susceptibility to heart disorders including dilated cardiomyopathy (DCM) and atrial fibrillation (AF). DCM is characterized by ventricular and impaired systolic function, resulting in heart failure and arrhythmia. Patient are at risk of premature death. AF is a common sustained cardiac rhythm disturbance. AF is characterized by disorganized atrial electrical activity and ineffective atrial contraction promoting blood stasis in the atria and reduces ventricular filling. It can result in palpitations, syncope, thromboembolic stroke, and congestive heart failure.