H2O2 induces HSP70 nuclear translocation to interact with HMGB1b.
A and B, H2O2 induces nuclear translocation of HSP70. A, verifying the specificity of the HSP70 Ab. The cell lysate of CIK and RFP-HSP70 stably transfected cells was subjected to IB analysis with HSP70 Ab. B, nucleocytoplasmic accumulation of HSP70 upon H2O2 challenge. Nuclear (Nuc) and cytoplasmic (Cyt) proteins from H2O2-treated or untreated RFP-HSP70–expressing cells were subjected to WB examination by anti-HSP70 Ab, anti-histone H3 Ab as a nuclear protein marker, and anti-β-tubulin as a cytoplasmic protein marker. C, HMGB1b interacts with HSP70 in the nucleus. HMGB1b-GFP was transfected into CIK cells for 16 h and treated with H2O2 for another 24 h. Then nuclear and cytoplasmic proteins were extracted and subjected to IP with GFP trap beads. IB analysis was conducted with anti-HSP70, anti-GFP, anti-histone H3, and anti-β-tubulin Abs.