Fig. 3
From: Membrane protein trafficking in the anti-tumor immune response: work of endosomal-lysosomal system
The synthesis and antigen-presentation processes of MHC molecular. MHC-I loads the polypeptide of endogenous antigens treated by proteasome in the endoplasmic reticulum under the action of TPN molecules; PCSK9 induced MHC-I to lysosome degradation; In the absence of PCSK9 cell, MHC-I is recycled to the cell surface after endocytosis in the clathrin-independent, Arf6-dependent pathways. MHC-II binds to the Ii chain in the endoplasmic reticulum, and Ii chain dissolves in the MIIC, then Ii-free MHC-II loads the exogenous antigens treated by lysosomes under the action of DM molecules; MARCH1 ubiquitinates β chain down-regulating the membrane MHC-II; SWAP-70 increases the membrane MHC-II through negatively regulating GTPases