Fig. 2: DNAJA2 deficiency delays UV-induced CSB degradation.
a Western blotting analysis showing the CSB protein stability after UV irradiation (10 J/m2) in WT, DJ2−/− and CSA knockdown (CSAKD) HeLa cells. b Quantification of the CSB protein levels in WT, DJ2−/− and CSAKD HeLa cells, as shown in a. Data from five independent experiments were used for the quantification and statistical analysis. c Representative images showing the protein levels of ectopically expressed myc-tagged CSB (myc-CSB) in WT and DJ2−/− HeLa cells pre- or 1 h post-UV treatment (10 J/m2). d Quantifications of CSB intensities from 30–40 cells as shown in c by ImageJ. e Western blotting analysis showing the CSB protein stability in HeLa cells treated with or without UV in the presence or absence of a lysosome inhibitor CQ. Cells were pre-treated with 50 μM CQ for 4 h before UV irradiation (20 J/m2), and cultured for another 4 h before harvest in the presence of 50 μM CQ. f Representative images showing the myc-CSB intensity in HeLa cells treated with UV in the presence or absence of CQ. Cells were pre-treated with 50 μM CQ for 4 h before UV irradiation (10 J/m2), and cultured for another 2 h in the presence of CQ. g Quantifications of the CSB intensity, as shown in f by ImageJ. h Western blotting analysis showing the CSB protein stability after UV irradiation (10 J/m2) in the presence or absence of lysosomal protease inhibitors ammonium chloride and leupeptin (combined as NL), in WT and DJ2−/− HeLa cells. Cells were pre-treated with 20 mM ammonium chloride and 100 μM leupeptin for 4 h before UV irradiation (10 J/m2), and cultured for another 2 h in the presence of NL. i Quantification of the relative CSB protein levels as shown in (h). Data from four independent experiments were used for the quantification and statistical analysis. Scale bar, 10 μm. P values were determined by two-tailed unpaired t-test. ns, P > 0.05; *P < 0.05; **P < 0.01; ****P < 0.0001.
