FIG 2.

HIV-1 Env trafficking, recycling, and egress. (1) Env trafficking to plasma membrane after synthesis and transit through endoplasmic reticulum and Golgi apparatus. Both fully processed and unprocessed forms of Env can transit to the cell surface. (2) Env endocytosis is initiated by AP2-dependent recruitment of the clathrin endocytosis pathway at the plasma membrane. Early endosomes traffic to recycling endosomes mediated by an interaction of the gp41 cytoplasmic tail with Rab11-FIP1C and Rab14. Alternative pathways for lysosomal degradation of a fraction of endocytosed Env are proposed, but not well documented. (3) Endocytosed Env sorted for outward trafficking or hypothetically could travel to retrograde transport pathways to Golgi apparatus for further proteolytic processing and/or glycosylation. (4) Virus particles are enriched for fully processed Env, which is targeted to the viral assembly site at the plasma membrane. Figure created with Biorender.com.