Fig. 2

Bi-phasic effect of AIMP2 and DX2 on PARP-1 activity and parthanatos A After DX2 overexpression, binding between AIMP2 and PARP-1 was determined by Western blotting in SH-SY5Y cells. B DX2 siRNA (DX2) and control siRNA (Con) were transfected into SH-SY5Y cells and incubated for 48 h. Total cell lysates were incubated with protein agarose beads to immunoprecipitate PARP-1 bound AIMP2, which is then analyzed by immunoblot analysis. C and D Cells were transfected with the EV (empty vector), AIMP2, and DX2; after 24 h, transfected cells were incubated with 100 μM H₂O₂ for 24 h. Cleaved PARP-1 levels C and PARylation D are shown. E Flag-tagged EV, AIMP2 and DX2 was transfected in SH-SY5Y cell line. Transfected cells were incubated with 200 μM H₂O₂ for 24 h. HSP70 antibody was used for cytosol marker and Lamin A/C antibody was used for nucleus marker. F and G GFP- or myc-tagged AIMP2 and/or DX2 expressing plasmid were transfected into cells and binding affinity was measured by immunoprecipitation (IP) with a myc antibody F and GFP antibody (G). H Schematic Fig. of AIMP2-induced PARP-1 activation. In the absence of DX2, AIMP2 dimers induce PARP-1 activation and neuronal death. However, in the presence of DX2, DX2 interacts with AIMP2 and inhibits PARP-1 activation