MHC class II regulatory factor RFX1 (RFX1)

MHC class II regulatory factor RFX1 (RFX1) is a member of the regulatory factor X (RFX) family of transcription factors characterized by a winged-helix DNA-binding domain and distinct activation and repression domains[1][4][2]. RFX1 binds the X-boxes of MHC class II gene promoters, acting as an essential transcriptional regulator necessary for the expression of MHC class II molecules, which are critical for immune system function[1][5][2][10]. It can also bind DNA as a monomer or as a heterodimer with other RFX family members (excluding RFX4), and is involved in regulating a range of genes with roles in immunity and potentially in cancer progression. Aberrant expression of RFX1 is observed in certain diseases, including glioblastoma and systemic lupus erythematosus, highlighting its importance in immune homeostasis and possible disease association[4]. RFX1 can also bind elements required for the expression of hepatitis B virus genes[1][5]. There are currently no known drugs clinically targeting RFX1, and it is not generally considered a direct therapeutic target.

Other names

Regulatory factor X1EF-CEnhancer factor CRFXRegulatory factor X1 (influences HLA class II expression)Trans-acting regulatory factor 1MHC class II regulatory factor RFXEFC