Activates insulin and somatostatin gene transcription. Key regulator of islet peptide hormone expression but also responsible for the development of the pancreas, most probably by determining maturation and differentiation of common pancreatic precursor cells in the developing gut. Binds the DNA sequence 5'-CC[CT]TAATGGG-3' (By similarity).
Subcellular locations: Nucleus, Cytoplasm, Cytosol