title: Virion-incorporated alpha-enolase suppresses the early stage of HIV-1 reverse transcription.
abstract: Human immunodeficiency virus type-1 (HIV-1) particles contain not only viral-encoded but also host-encoded proteins. Interestingly, several studies showed that host proteins play a critical role in viral infectivity, replication and/or immunoreactivity in the next target cells. Here, we show that alpha-enolase (ENO1) is incorporated into HIV-1 virions and the virion-incorporated ENO1 prevents the early stage of HIV-1 reverse transcription. We found that viral particles contain two isoforms of ENO1 with different isoelectric points by two-dimensional electrophoresis. Suppression of ENO1 expression by RNA interference in the HIV-1 producer cells decreased ENO1 incorporation into virions without altering the packaging of viral structural proteins and viral production but increased viral infectivity. Although the low-level-ENO1-packaging virus maintained comparable levels of reverse transcriptase activity, viral genomic RNA and tRNALys3packaging to the control virus, its levels of early cDNA products of reverse transcription were higher than those of the control virus. In contrast, the high-level-ENO1-packaging virus, which was produced from ENO1-overexpressing cells, showed decreased infectivity and the levels of early cDNA products. Taken together, these findings reveal a novel function of ENO1 as a negative regulation factor targeting HIV-1 reverse transcription.
authors.affiliation: Department of Environmental and Molecular Health Sciences, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kishimoto
authors.affiliation: Department of Environmental and Molecular Health Sciences, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Iga
authors.affiliation: Department of Environmental and Molecular Health Sciences, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: Innovative Collaboration Organization, Kumamoto University, Kumamoto 860-8555, Japan.
authors.forename: Nobutoki
authors.initials: N
authors.lastname: Takamune
authors.affiliation: Department of Environmental and Molecular Health Sciences, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan. Electronic address: misumi@gpo.kumamoto-u.ac.jp.
authors.forename: Shogo
authors.initials: S
authors.lastname: Misumi
mesh_terms: D002460:Cell Line; D015497:HIV-1 / Q000201:enzymology / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D010751:Phosphopyruvate Hydratase / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D048348:Reverse Transcription; D014771:Virion / Q000201:enzymology / Q000502:physiology*; D019065:Virus Assembly
chemical_list: D010751:Phosphopyruvate Hydratase
keywords: Alpha-enolase; Human immunodeficiency virus type 1; Reverse transcription