Transcriptional activator; DNA-binding protein that specifically recognize the sequence 5'-YAAC[GT]G-3'. Plays an important role in the control of proliferation and differentiation of hematopoietic progenitor cells. Binds MYBBP1A. Interacts with HIPK2, MAF and NLK (By similarity). Binds to HIPK1. Negatively regulated by microRNA-155 (miR-155). Comprised of 3 domains; an N-terminal DNA-binding domain, a centrally located transcriptional activation domain and a C-terminal domain involved in transcriptional repression. Ubiquitinated; mediated by SIAH1 and leading to its subsequent proteasomal degradation. Phosphorylated by NLK on multiple sites, which induces proteasomal degradation. Phosphorylated by HIPK1. This phosphorylation reduces MYB transcription factor activity but not MYB protein levels. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay.