Role of the gag and pol genes of human immunodeficiency virus in the morphogenesis and maturation of retrovirus-like particles expressed by recombinant vaccinia virus: an ultrastructural study

• Published in: Journal of general virology 1991-10, Vol.72 (10), p.2509-2517
• Main Authors: Hoshikawa, Nariyoshi, Kojima, Asato, Yasuda, Atsushi, Takayashiki, Eiko, Masuko, Sanae, Chiba, Joe, Sata, Tetsutaro, Kurata, Takeshi
• Format: Article
• Language: English
• Subjects: AIDS/HIV; Amino Acid Sequence; Animals; Base Sequence; Biological and medical sciences; Blotting, Western; Cell Line; Cloning, Molecular; DNA, Viral; Fundamental and applied biological sciences. Psychology; Genes, gag; Genes, pol; Genetics; HIV-1 - genetics; HIV-1 - growth & development; HIV-1 - ultrastructure; Humans; Microbiology; Molecular Sequence Data; Morphogenesis; Rabbits; vaccinia virus; Vaccinia virus - genetics; Virion - genetics; Virion - metabolism; Virology
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-72-10-2509

1 Department of Pathology and 2 AIDS Research Center, National Institute of Health, 2-10-35, Kamiosaki, Shinagawa-ku, Tokyo 141 3 Biological Science Laboratory, Nippon Zeon Company Ltd, Yako, Kawasaki-ku, Kawasaki-shi, Kanagawa, and 4 Basic Research Laboratories, Toray Industries Inc., Tebiro, Kamakura, Kanagawa, Japan An ultrastructural study was performed on rabbit epithelial RK-13 cells and CD4 + human T lymphocyte lines infected with various recombinant vaccinia viruses (RVVs) expressing genes of human immunodeficiency virus (HIV): the mature p17 or p24 gag domain alone, the entire or truncated gag gene, the reverse transcriptase domain, or the gag-pol genes with a frameshift mutation. Cells infected with RVVs that produced the gag polyprotein with a predicted M r of more than 48K showed budding and release of HIV-like particles into the extracellular space. These particles were not observed in cells expressing a truncated gag gene (p17 and p24 regions). Mature HIV-like particles were observed extracellularly when the entire gag gene and the protease region of the pol gene were expressed. In contrast, in cells infected with RVVs that contained the gag-pol gene with a frameshift mutation, neither recognizable budding structures nor extracellular HIV-like particles could be detected. These results suggest that the gag gene, particularly its 3' terminus, is necessary for the assembly of HIV particles. In addition, the protease region of the pol gene seems to be required for morphological maturation of HIV particles, but complete proteolytic cleavage of the gag protein may prevent bud formation. Received 4 March 1991; accepted 19 June 1991.