Fig. 4. TOP1cc enhances dsDNA recognition by cGAS.
a Co-immunoprecipitation analysis of cGAS and TOP1 in control and RAS-induced senescent IMR90 cells. An isotype matched IgG was used as a negative control. b Co-Immunoprecipitation analysis of cGAS and TOP1 in control and RAS-induced senescent IMR90 cells with or without HMGB2 knockdown. Note that addition of (ISD)2 dsDNA into the supernatant rescues the interaction between cGAS and TOP1 in HMGB2 knockdown senescent IMR90 cells. c Electrophoretic mobility shift analysis of TOP1 wild-type and TOP1 Y723F mutant proteins. d Electrophoretic mobility shift analysis shows that wild-type TOP1, but not the mutant TOP1 Y723, enhances the binding of cGAS to dsDNA. e A proposed model as described in the text. Data represent mean ± s.e.m. P-values were calculated using a two-tailed t test. Source data are provided as a Source Data file.