Fig. 5

PTBP1 interacts with NICD to activate Notch1 expression. a RIP assay was shown the interaction between PTBP1 and Notch1. b Co-localization of PTBP1 and Notch1 protein in A549 cells post radiation was determined by immunofluorescence. Scale bars = 50 μm. c Co-localization of PTBP1 and Notch1 protein in A549 cells with or without knockdown SNHG17 expression post radiation was determined by immunofluorescence. Scale bars = 50 μm. d The Notch1 protein expression was measured after overexpression SNHG17 or PTBP1, or after knockdown of SNHG17 or PTBP1 was determined by Western blotting. e Representative images of the Western blotting results of the Notch1 protein in si NC and si PTBP1-transfected A549 cells after indicated CHX(cicloheximide) treated timepoints (0, 0.5, 1, 2, 4, 8 h). f Immunoprecipitation analysis of ubiquitinated Notch1 in si NC and si SNHG17-transfected A549 cells pretreated with the proteasome inhibitor MG132. g Immunoprecipitation analysis of PTBP1 and NICD interaction. h The nuclear NICD and PTBP1 expression was examined in A549 cells after overexpression of SNHG17 by western blotting. i Representative blots of NICD protein expression in knockdown of PTBP1 in A549 cells post 6 Gy radiation by Western blotting assay. j Rescue assay was shown NICD protein expression in overexpression of PTBP1 following knockdown of PTBP1 in A549 cells post 6 Gy radiation by Western blotting assay. Data are means ± SD (standard deviation). n = 3 independent experiments, Student’s two-tailed unpaired t test was used to compare differences between two groups. *p < 0.05