MAX Dimerization Protein 3 (MXD3)

MXD3 is a member of the Myc superfamily of basic helix-loop-helix leucine zipper transcriptional regulators. The encoded protein forms a heterodimer with the cofactor MAX which binds specific E-box DNA motifs in the promoters of target genes and regulates their transcription. Disruption of the MAX-MXD3 complex is associated with uncontrolled cell proliferation and tumorigenesis. Transcript variants of this gene encoding different isoforms have been described. In the developing embryo, Mxd3 RNA was detected from 9.5 to 12.5 days postcoitus, especially in the ventricular zone of the neuroepithelia, in the progression zone of the limb buds, and in the aortic arches and liver. In situ hybridization and double labeling for BrdU incorporation suggested that Mxd3 was expressed during the last S phase prior to terminal differentiation.