PD-L1(CD274) glycosylation and translocation to plasma membrane

PD-L1 (CD274) glycosylation plays a critical role in determining the protein function and stability. PD-L1 is N-glycosylated at N192, N200 and N219 by the OST complex in the ER lumen. This process is important for PD-L1 stability and inhibits its targeting for proteasomal degradation by GSK3B. Also, JAK1 activated by IL6 pathway positively regulates the glycosylation process by aiding in the process of recruiting endoplasmic reticulum-associated N-glycosyltransferase STT3A (part of the OST complex) to catalyse PD-L1 glycosylation. PD-L1 is phosphorylated by IL6-activated JAK1 at Tyr112 (Y112). This process aids in stabilizing the PD-L1 protein. PD-L1, once glycosylated in the ER lumen, get translocated to the Golgi complex for further glycosylation by B3GNT3 and K63-ubiquitination by MIB2. Post Golgi, PD-L1 gets transported to the plasma membrane where it can bind with its receptor and induce immune tolerance.

Summary from Reactome (R-HSA-9931295), read 2026-09-23.