3rd Conference on Retroviruses and Opportunistic Infections Washington, DC - January 28-February 1, 1996

Conf Retroviruses Opportunistic Infect 1996 Jan 28-Feb 1; 3rd:61 (abstract no. 43)

Holemon HA, Horton RB, Ratner L
Washington University, St.Louis, MO.

Vpx is a viral accessory protein which is packaged within HIV-2 virions in molar quantities equivalent to that of the Gag polyprotein. In order to define packaging requirements within Vpx, several deletion constructs and point-mutation constructs were generated. Studies of the packaging of mutant Vpx proteins encoded by these constructs suggest that the region between residues 73 and 89 of Vpx is important for packaging. However, three conserved cysteines, located at residues 73, 87 and 89, do not contribute to packaging efficacy. To identify regions within HIV-2 Gag Pr55 which are involved in the packaging of Vpx, chimeric HIV-1 /HIV-2 Gag constructs were generated. These studies demonstrated that the p6 portion of HIV-2 Gag is required. Furthermore, it appears that residues 33-49 of HIV-2 p6, which are not present within HIV-I p6, are sufficient for Vpx export. Moreover, Vpx binds directly to Pr55, as demonstrated by co-precipitation experiments performed with viral particles and by a GST-binding assay. In addition, oligomerization of Vpx has been demonstrated with the GST-binding assay and the yeast 2-hybrid system. These findings define multiple protein-protein interactions important for the production of infectious HIV-2 particles, which should provide insights into novel therapeutic approaches.

960128
43

Copyright © 1996 - Foundation for Retrovirology and Human Health . Reproduction of this abstract (other than one copy for personal reference) must be cleared through the Foundation for Retrovirology and Human Health.