The HIV-1
assembly and release pathway. Virus particle production takes place
as a series of steps driven by the Gag precursor protein, Pr55Gag. Gag rapidly
and specifically targets raft-rich regions of the plasma membrane. Gag multimerization
proceeds at the membrane, giving rise to budding structures that eventually pinch
off from the cell surface as nascent virions. The viral Env glycoproteins
are incorporated during the budding process. Virus release requires the
host factor TSG101 and other components of the cellular endosomal sorting pathway.
Insets show by electron microscopy the inhibition of virus release upon coexpression
of HIV-1 with a transdominant form of TSG101 (left inset; note the particles tethered
to the plasma membrane) and wild-type virions released from the cell surface (right
inset).
Last
modified: 11 August 2008 |