       Document 0646
 DOCN  M9640646
 TI    The envelope glycoprotein of human immunodeficiency virus type 2
       enhances viral particle release: a Vpu-like factor?
 DT    9604
 AU    Bour S; Schubert U; Peden K; Strebel K; Laboratory of Molecular
       Microbiology, National Institute of; Allergy and Infectious Diseases,
       Bethesda, Maryland 20892, USA.
 SO    J Virol. 1996 Feb;70(2):820-9. Unique Identifier : AIDSLINE MED/96135191
 AB    The Vpu protein is a human immunodeficiency virus type 1
       (HIV-1)-specific accessory protein that is required for the efficient
       release of viral particles from infected cells. Even though HIV-2 does
       not encode Vpu, we found that this virus is nevertheless capable of
       efficiently releasing virus particles. In fact, the rate of virus
       release from HeLa cells transfected with a full-length molecular clone
       of HIV-2, ROD10, was comparable to that observed for the vpu+ HIV-1
       NL4-3 isolate and was not further enhanced by expression of Vpu in
       trans. However, consistent with previous observations showing that HIV-2
       particle release is Vpu responsive in the context of HIV-1/HIV-2
       chimeric constructs; exchanging the gag-pol region of NL4-3 with the
       corresponding region from pROD10 rendered the resulting chimeric virus
       Vpu responsive. Our finding that the responsiveness of HIV-2 particle
       release to Vpu is context dependent suggested the presence of a Vpu-like
       factor(s) encoded by HIV-2. Using chimeric proviruses encoding HIV-2 gag
       and pol in the context of the HIV-1 provirus that were coexpressed with
       subgenomic HIV-2 constructs, we found that the HIV-2 envelope
       glycoprotein had the ability to enhance HIV-2 particle release with an
       efficiency comparable to that of the HIV-1 Vpu protein. Conversely,
       inactivation of the HIV-2 env gene in the original ROD10 clone resulted
       in a decrease in the rate of viral particle release to a level that was
       comparable to that of Vpu-deficient HIV-1 isolates. Providing the
       wild-type envelope in trans rescued the particle release defect of the
       ROD10 envelope mutant. Thus, unlike HIV-1, which encodes two separate
       proteins to regulate virus release or to mediate viral entry, the HIV-2
       Env protein has evolved to perform both functions.
 DE    Cyclopentanes/PHARMACOLOGY  Gene Products, nef/METABOLISM  Gene
       Products, vif/METABOLISM  Gene Products, vpr/METABOLISM  Gene Products,
       vpu/DRUG EFFECTS/*METABOLISM  Genes, Viral  Glycoproteins/DRUG
       EFFECTS/GENETICS/*METABOLISM  Human  HIV Seropositivity/BLOOD/IMMUNOLOGY
       HIV-2/*METABOLISM  Mutation  Support, Non-U.S. Gov't  Support, U.S.
       Gov't, P.H.S.  Viral Envelope Proteins/DRUG EFFECTS/GENETICS/*METABOLISM
       Viral Regulatory Proteins/METABOLISM  Virion/METABOLISM  JOURNAL ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

