Anti histone 3

For precipitation of RNA-protein complexes, 1x10⁷ cells were homogenized using EZ Magna RIP kit per manufacturer’s protocol (Millipore). Supernatants were incubated with 1–2 μg of anti- RBM5 (Active motif) or mouse IgG (Invitrogen) for 1 hour at 4°C followed by precipitation with protein A/G agarose (Pierce).
IB was performed according to standard protocols as described previously.^{20 (link),21 (link)} Proteins were detected by IB with anti-RBM5, anti-EZH2, anti-histone-3 (Santa Cruz Biotechnology), anti-PARP, anti-cleaved capase-3, and anti-caspase-8 (Cell Signaling Technologies) primary antibodies (1:1000 dilution in 5% nonfat milk), followed by the corresponding HRP-conjugated secondary goat anti-mouse or anti-rabbit antibodies (Jackson ImmunoResearch). Equal loading was verified by blotting with anti-β-actin-HRP antibody (1:10,000; Sigma Aldrich). Visualization was achieved by Supersignal West Pico chemiluminescent substrate (Pierce).