REACTION OF P55 AND P48GAG POLYPROTEIN PR ECURSORS WITH P160GAG-POL DURING FORMATION OF HIV-1 VIRUS-LIKE PARTICLES BY RECOMBINANT VACCINIA VIRUS-STRAINS

The polypeptide composition of HIV-1 virus-like particles produced by CV-1 cells during mono- and coinfection with recombinant vaccinia viru s (rVV) strains containing the whole (p55) and carboxyterminal truncat ed (p48) gag genes and gag-pol sequence is studied. In monoinfection b oth the gag-strains actively produced virus-like particles consisting of non-processed p55Gag and p48Gag polyprotein without p6 domain. In c ase of a coinfection of the cells with one of these strains and the rV V producing p160Gag-Pol polyprotein the virus-like particles consisted of p24 protein and a negligible amount of non-processed Gag precursor s. The share of p24 protein increased in proportion to the duration of coinfection and decreased with a reduction of multiplicity of infecti on with rVV carrying p160Gag-Pol. Hence, the absence of p6 domain does not influence the processing of Gag proteins during virus-like partic les assembly and budding. In contrast to the natural systems of HIV-I development, in the rVV expression system the p6Gag domain virtually d oes not contribute to reactions between Gag and Gag-Pol precursors and to the particles' morphogenesis.