Fig. 2: The transmembrane domain and extracellular domain of PD-L1 are involved in homodimerization.
From: Homodimerized cytoplasmic domain of PD-L1 regulates its complex glycosylation in living cells
a Transmembrane domain of PD-L1 is involved in its homodimerization. Residues that were replaced by Azi are indicated in the upper row. WT PD-L1 treated with UV was used as a control. HEK293T cells were irradiated with UV before being lysed. Shown are immunoblotting using anti-Flag antibodies. b Structure of drug-free and BMS-induced PD-L1 homodimer. The PDB ID is 3FN3 for drug-free PD-L1 homodimer and 5N2F for BMS-induced PD-L1 homodimer. BMS was colored green. Residues that are important for PD-L1 homodimerization were colored cyan. c Screening of residues in extracellular domain that covalent captured PD-L1 homodimer. Transfected cells expressing PD-L1-XAzi-Flag proteins were treated with UV to induce cross-linking and performed immunoblotting analysis. d, e BMS-1166 reduces Azi-mediated covalent capture of PD-L1 homodimerization dosage dependently. HEK293T cells were transiently transfected with PD-L1-Xtag-Flag and pIRE4-Azi plasmids. d Residues replaced by Azi are indicated in the upper row. 100 nM of BMS-1166 were incubated with cells for 18 h before UV treatment. e Working concentration of BMS-1166 ranged from 0 to 200 nM. All samples were treated with PNGase F to remove the N-glycan.
