Fig. 5: GSK3α-mediated phosphorylation of PD-L1 promotes PD-L1-ARIH1 interaction and ARIH1-induced degradation.
From: ARIH1 signaling promotes anti-tumor immunity by targeting PD-L1 for proteasomal degradation
a Co-IP analysis for the interaction of K48-ubiquitin, ARIH1 (HA), and PD-L1 in HEK293T cells transfected with HA-ARIH1 and Flag-PD-L1 (WT, S279A, S283A, or 2SA), treated with MG132 (10 μM) for 6 h; HA-tagged empty vector (HA-EV) was transfected as a negative control. b Co-IP analysis for the interaction of ARIH1 and PD-L1 in HEK293T cells transfected with HA-ARIH1 and Flag-PD-L1 (WT or 2SA), treated with 10 μM ES-072 for 24 h, Flag-tagged empty vector (Flag-EV) was transfected as a negative control. c HEK293T cells were transfected with Flag-PD-L1. Co-IP analysis for the interaction of ubiquitin and PD-L1 in HEK293T cells transfected with ARIH1-siRNAs or HA-GSK3α and treated with MG132 (10 μM) for 6 h; non-targeting siRNA (si-CTRL) was transfected as a negative control. d Immunoblots of PD-L1 and ARIH1 (HA) in H1975 cells transfected with HA-ARIH1, treated with or without 5 μM LY for 6 h. e, f MFI (e) and relative quantification (f) of PD-L1 in HA-ARIH1-overexpressed H1975 cells, treated with or without 5 μM LY for 6 h. Data represent means ± SEM, n = 9, 3 independent repeats, ****P < 0.0001. g HEK293T cells were transfected with Flag-PD-L1. Co-IP analysis for the interaction of K48-ubiquitin, ARIH1 (HA), and PD-L1 in HEK293T cells transfected with HA-ARIH1, treated with or without 5 μM LY for 12 h and treated with MG132 (10 μM) for 6 h. Source data are provided as a Source Data file.
