Duplication of the primary encapsidation and dimer linkage region of human immunodeficiency virus type 1 RNA results in the appearance of monomeric RNA in virions.
The dimerization initiation site (DIS) and the dimer linkage sequences (DLS) of human immunodeficiency virus type 1 have been shown to mediate in vitro dimerization of genomic RNA. However, the precise role of the DIS-DLS region in virion assembly and RNA dimerization in virus particles has not been fully elucidated, since deletion or mutation of the DIS-DLS region also abolishes the packaging ability of genomic RNA. To characterize the DIS-DLS region without altering packaging ability, we generated mutant constructs carrying a duplication of approximately 1,000 bases including the encapsidation signal and DIS-DLS (E/DLS) region. We found that duplication of the E/DLS region resulted in the appearance of monomeric RNA in virus particles. No monomers were observed in virions of mutants carrying the E/DLS region only at ectopic positions. Monomers were not observed when pol or env regions were duplicated, indicating an absolute need for two intact E/DLS regions on the same RNA for generating particles with monomeric RNA. These monomeric RNAs were most likely generated by intramolecular interaction between two E/DLS regions on one genome. Moreover, incomplete genome dimerization did not affect RNA packaging and virion formation. Examination of intramolecular interaction between E/DLS regions could be a convenient tool for characterizing the E/DLS region in virion assembly and RNA dimerization within virus particles.
McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA. sakuragi@biken.osaka-u.ac.jp
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Sakuragi
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Shioda
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Panganiban
D015153:Blotting, Western; D002460:Cell Line; D019281:Dimerization; D016679:Genome, Viral; D015497:HIV-1 / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D009154:Mutation; D009690:Nucleic Acid Conformation; D019590:Nucleocapsid Proteins / Q000737:chemistry* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D012367:RNA, Viral / Q000737:chemistry* / Q000378:metabolism; D014162:Transfection; D014771:Virion / Q000235:genetics / Q000378:metabolism*; D019065:Virus Assembly
D019590:Nucleocapsid Proteins; D012367:RNA, Viral