Regulatory factor X, a bare lymphocyte syndrome transcription factor, is a multimeric phosphoprotein complex

Abstract excerpt

Regulatory factor X (RFX) is a transcription factor that binds the conserved X1 box of MHC class II promoters and is essential for transcription of class II genes. The subunit structure of the native RFX complex was examined by coimmunoprecipitation using polyclonal antisera to the 75-kDa subunit of RFX, RFX5. Two polypeptides with apparent masses of 41 and 36 kDa coimmunoprecipitated with RFX5 and appear to be...