Transcription factor that activates insulin gene expression (PubMed:15993959, PubMed:12011435). Acts synergistically with NEUROD1/BETA2 and PDX1 (PubMed:15993959). Binds the insulin enhancer C1/RIPE3b element (PubMed:12011435). Binds to consensus TRE-type MARE 5'-TGCTGACTCAGCA-3' DNA sequence (PubMed:23148532, PubMed:29339498). Forms homodimers or heterodimers (PubMed:12011435, PubMed:23148532). Monomers and dimers are able to bind DNA, but the off-rate is faster for monomers (PubMed:23148532). Interacts with NEUROD1 and PDX1 (By similarity). May interact with MAFB, FOS, JUN and PCAF (By similarity). Expressed in the islets of Langerhans (at protein level). Ubiquitinated, leading to its degradation by the proteasome. Phosphorylated at tyrosines. The disease is caused by variants affecting the gene represented in this entry. Belongs to the bZIP family. Maf subfamily.