MafA Background Information Members of the bZIP containing Maf transcription factor family play important roles in cellular differentiation and regulation. MafA, originally identified in mammals as the pancreatic b-cell specific RIPE3b1 factor, is a transcriptional activator expressed specifically in insulin-producing cells, where it functions by binding to the critical insulin enhancer element RIPE3b. MafA is critical for generating and regulating glucose-reponsive insulin expression in b cells. The size of MafA in mammalian cell lines varies, due to posttranslational modification of the protein.
