Figure 3.

NFIL3/HDAC2 have similar DNA-binding dynamics. (A) Schematic of possible modes of NFIL3-mediated repression. (B) Avidin–biotin complex DNA assays: Lysates from transfected HEK293 cells were incubated with biotinylated TRAIL promoter DNA to purify associated proteins. NFIL3 and HDAC2 associated with DNA that retained the mapped NFIL3-binding site. (C,D) NFIL3 and HDAC2 physically associate. Coimmunoprecipitations were performed with HEK293 cell extracts and antibodies to endogenous NFIL3 and HDAC2, which detected an interaction between these proteins; no interaction was seen between NFIL3 and HDAC1. (E) TRAIL reporter assays with or without exogenous NFIL3 and/or HDAC2. HDAC2 repressed TRAIL reporter activity. (F) Treatment of HEK293 cells with HDAC inhibitors (2 μM SAHA or 1 μM TSA) for 24 h induced endogenous TRAIL gene expression as measured by qRT–PCR.