Dr. Chaoping Chen

Abstract: The HIV-1 Gag protein is encoded by the viral genome and is initially synthesized as a 55 kD polypeptide in the infected cell.  It carries essential determinants that mediate its association with cellular membranes and Gag-Gag interactions leading to assembly and production of progeny virions that contain about 1500 copies of Gag protein.  The mechanisms by which Gag proteins are transported from the sites of synthesis to the places where they assemble in the infected cell remain illusive. Our long-term hypothesis is that the cellular trafficking machinery is recruited and utilized to facilitate transportation and assembly of Gag proteins.  Using fluorescently labeled HIV Gag proteins, we studied intracellular distribution and migration trajectory of HIV Gag in fixed and living cells.   Interestingly, we found that there are two distinct populations of Gag proteins, relatively stationary and fast migrating particles.  Motility of the latter population is not consistent; rather these particles appear to have a general pattern that a restricted local wobbling is followed by a long range rapid migration.  These data will be fundamental for the development of mathematical models to simulate intracellular trafficking behaviors of HIV Gag proteins.