title: Poly-proline motif in HIV-2 Vpx is critical for its efficient translation.
abstract: Human immunodeficiency virus type 2 (HIV-2) carries an accessory protein Vpx that is important for viral replication in natural target cells. In its C-terminal region, there is a highly conserved poly-proline motif (PPM) consisting of seven consecutive prolines, encoded in a poly-pyrimidine tract. We have previously shown that PPM is critical for Vpx expression and viral infectivity. To elucidate the molecular basis underlying this observation, we analysed the expression of Vpx proteins with various PPM mutations by in vivo and in vitro systems. We found that the number and position of consecutive prolines in PPM are important for Vpx expression, and demonstrated that PPM is essential for efficient Vpx translation. Furthermore, mutational analysis to synonymously disrupt the poly-pyrimidine tract suggested that the context of PPM amino acid sequences is required for efficient translation of Vpx. We similarly analysed HIV-1 and HIV-2 Vpr proteins structurally related to HIV-2 Vpx. Expression level of the two Vpr proteins lacking PPM was shown to be much lower relative to that of Vpx, and not meaningfully enhanced by introduction of PPM at the C terminus. Finally, we examined the Vpx of simian immunodeficiency virus from rhesus monkeys (SIVmac), which also has seven consecutive prolines, for PPM-dependent expression. A multi-substitution mutation in the PPM markedly reduced the expression level of SIVmac Vpx. Taken together, it can be concluded that the notable PPM sequence enhances the expression of Vpx proteins from viruses of the HIV-2/SIVmac group at the translational level.
authors.affiliation: Department of Microbiology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Tokushima, Japan.
authors.forename: Ariko
authors.initials: A
authors.lastname: Miyake
authors.affiliation: Research Institute for Drug Discovery, School of Pharmacy, Kumamoto University, Kumamoto, Kumamoto, Japan.
authors.forename: Mikako
authors.initials: M
authors.lastname: Fujita
authors.affiliation: Department of Bioorganic Medicinal Chemistry, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Fujino
authors.affiliation: Department of Bioorganic Medicinal Chemistry, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Koga
authors.affiliation: Department of Bioorganic Medicinal Chemistry, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
authors.forename: Sogo
authors.initials: S
authors.lastname: Kawamura
authors.affiliation: Department of Bioorganic Medicinal Chemistry, Faculty of Life Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Otsuka
authors.affiliation: Japanese Foundation for AIDS Prevention, Chiyoda-ku, Tokyo, Japan.|Clinical Research Center, National Hospital Organization, Nagoya Medical Center, Nagoya, Aichi, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Ode
authors.affiliation: Clinical Research Center, National Hospital Organization, Nagoya Medical Center, Nagoya, Aichi, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Iwatani
authors.affiliation: Department of Microbiology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Tokushima, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: Japanese Foundation for AIDS Prevention, Chiyoda-ku, Tokyo, Japan.|Department of Microbiology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Tokushima, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Doi
authors.affiliation: Department of Microbiology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Tokushima, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Nomaguchi
authors.affiliation: Department of Microbiology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Tokushima, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Adachi
authors.affiliation: Department of Microbiology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Tokushima, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Miyazaki
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001483:Base Sequence; D002460:Cell Line; D015967:Gene Expression Regulation, Viral; D015658:HIV Infections / Q000821:virology*; D015498:HIV-2 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D011392:Proline / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D054325:vpr Gene Products, Human Immunodeficiency Virus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D054325:vpr Gene Products, Human Immunodeficiency Virus; C514913:vpr protein, Human immunodeficiency virus 2; D011392:Proline