MyoD family inhibitor (MDFI)

MyoD family inhibitor (MDFI) is a transcription factor encoded by the MDFI gene in humans. MDFI acts as a negative regulator of myogenic basic-helix-loop-helix transcription factors—such as MyoD and myogenin—by binding these proteins in the cytoplasm, masking their nuclear localization signals, and thereby preventing their DNA binding and activity. This mechanism inhibits skeletal muscle differentiation. In mouse models, MDFI deficiency leads to malformations of the vertebrae and ribs, indicating roles in cartilage and skeletal development. MDFI also modulates cellular and developmental signaling, including calcium signaling pathways via interaction with proteins such as TRPC1, and regulates the activity and localization of other transcription factors. In cancer biology—especially colorectal cancer—MDFI is often upregulated, contributing to tumor cell proliferation and chemoresistance by activating the AKT pathway in conjunction with binding partners such as ITGB4 and LAMB3. Aberrant methylation of the MDFI gene is observed in oncology and can serve as a biomarker for early colorectal cancer detection. MDFI deregulation has also been implicated in fibrotic skin disorders (keloid lesions) and in the modulation of oncogenic E2F signaling via interactions with SERTA domain proteins[1][3][5][6][7].

Other names

I-mfaI-MFmyogenic repressor I-mfinhibitor of MyoD family aI-MFA

Negative regulation of myogenic transcription factors by binding and masking their nuclear localization signals (preventing DNA binding), Suppression of myogenesis, Promotion of tumor cell proliferation via AKT signaling activation, Attenuation of store-operated calcium currents