FIG. 3.

Knockdown of several candidate proteins or treatment with various control siRNAs fails to reactivate the silent GFP reporter. (A and B) HeLa TI-C cells were treated with the indicated siRNAs and the percentages of GFP-positive cells were determined by FACS at 96 h posttransfection. Single siRNAs were used for H3.3A, H3.3B, and HIRA. Two independent single siRNAs (designated a and b) were tested for HIRA. DF1, DharmaFECT 1 transfection reagent. (C) TI-C cells were treated with 100 nM siRNAs as indicated above the panels and cells were processed for Western blotting after 72 h. (D) Treatment and analysis with the indicated siRNAs was as for panel A. Negative control siRNAs RISC−, RISC+, and GAPDH were analyzed. (E) The HDAC1 siRNA SMARTpool was titrated to determine the lowest effective concentration versus the negative control siRNA RISC⁺. Analysis was as for panel A.