Figure 3.

Alf promoter is up-regulated by RFX2 expression. (A) Sequence of the minimal -117 to -5 Alf promoter with the X-box underlined. Alterations used to make the mutant X-box are indicated. (B) Demonstration that carboxyl deletion greatly enhances transactivation potential of RFX2. Transient transfections, using pEP4-Luc (with 4 repeats of the hepatitis B virus enhancer X-box) as a reporter, were done plus or minus expression vectors for full length RFX2 or the d353 construct missing amino acids 353 to 653. (C) RFX2 stimulation of the Alf promoter. Transient transfections were carried out using the minimal Alf promoter or a variant with a mutant X-box, plus or minus the RFX2 d353 expression vector. Note different scales for the Y axes. (D) ChIP assay shows in vivo Alf promoter occupancy by RFX2. Left: Amplification of Alf promoter following chromatin capture by anti-RFX2 or IgG control. Right: Amplification of unrelated Tcrd (T cell receptor delta) gene following chromatin capture.