The role of matrix in HIV-1 envelope glycoprotein incorporation

• Matrix and gp41 cytoplasmic tail are the key factors in HIV-1 envelope incorporation.
• Gp41 cytoplasmic tail interacts with cellular trafficking factors.
• Matrix adopts a hexamer-of-trimers structure that accommodates the gp41 cytoplasmic tail.

Incorporation of the viral envelope (Env) glycoprotein is a critical requirement for the production of infectious HIV-1 particles. It has long been appreciated that the matrix (MA) domain of the Gag polyprotein and the cytoplasmic tail of Env are central players in the process of Env incorporation, but the precise mechanisms have been elusive. Several recent developments have thrown light on the contributions of both proteins, prompting a re-evaluation of the role of MA during Env incorporation. The two domains appear to play distinct but complementary roles, with the cytoplasmic tail of Env responsible for directing Env to the site of assembly and the matrix domain accommodating the cytoplasmic tail of Env in the Gag lattice.