Figure 7.

Model of Env trafficking pathways that support Env accumulation at the VS. (1) Env is transported to the cell surface following synthesis through the ER/Golgi pathways. (2) Clathrin-mediated endocytosis is initiated by recognition of the Env cytoplasmic tail by adapter protein complex, AP-2, which recognizes the membrane proximal tyrosine motif in Env. (3) Following internalization Env is recycled back to the cell surface, selectively trafficking to the VS where it can be incorporated into nascent virus particles. (4) Env at the VS continues to recycle while Gag does not exchange.