MAFA (gene)
From Wikipedia, the free encyclopedia
Transcription factor MafA is a protein that in humans is encoded by the MAFA gene.[5] It is a member of the Maf family of transcription factors.[6]
MAFA is phosphorylated sequentially on four serine/threonine residues by GSK-3 kinase.[7] These phosphorylations activate MAFA transcription and trigger its degradation in the proteasome. Altering these post-translationnal modifications leads to severe pathological consequences. Mutation of these residues is perinatally lethal in mice,[8] and mutation of the Ser64Phe priming site was reported to induce familial diabetes mellitus and insulinomatosis in humans.[9]
An in vivo study on mice proved MafA binds to the promoter in an insulin gene to regulate insulin transcription in response to serum glucose levels.[10] MafA is a β cell-specific activator, which differentiates it from other transcription factors involved with insulin gene expression.[11] It helps regulate the β cells involved with insulin secretion primarily by maintaining β cell metabolism.[12] The amount of MafA in the β cells is regulated by levels of glucose and oxidative stress.[6]
