Implicated in the genesis of hemopoietic malignancies. It may play an important role in hemopoietic differentiation. Serves as a positive regulator of erythroid differentiation. Efficient DNA binding requires dimerization with another bHLH protein. Forms heterodimers with TCF3. Binds to the LIM domain containing protein LMO2 and to DRG1. Can assemble in a complex with LDB1 and LMO2. Component of a TAL-1 complex composed at least of CBFA2T3, LDB1, TAL1 and TCF3 (PubMed:9391090). Interacts with SBNO2; this interaction inhibits TAL1 occupancy of the DCSTAMP promoter, leading to the activation of the DCSTAMP promoter by the transcription factor MITF (PubMed:23980096). Erythroid and myeloid cells. The helix-loop-helix domain is necessary and sufficient for the interaction with DRG1. Phosphorylated on serine residues. Phosphorylation of Ser-122 by MAPK is strongly stimulated by hypoxia. Ubiquitinated; subsequent to hypoxia-dependent phosphorylation of Ser-122, ubiquitination targets the protein for rapid degradation via the ubiquitin system. This process may be characteristic for microvascular endothelial cells, since it could not be observed in large vessel endothelial cells.