       Document 0106
 DOCN  M9630106
 TI    Cytoskeleton association and virion incorporation of the human
       immunodeficiency virus type 1 Vif protein.
 DT    9603
 AU    Karczewski MK; Strebel K; Laboratory of Molecular Microbiology, National
       Institute of; Allergy and Infectious Diseases, Bethesda, Maryland
       20892-0460,; USA.
 SO    J Virol. 1996 Jan;70(1):494-507. Unique Identifier : AIDSLINE
       MED/96099464
 AB    The human immunodeficiency virus type 1 (HIV-1) Vif protein has an
       important role in the regulation of virus infectivity. This function of
       Vif is cell type specific, and virions produced in the absence of Vif in
       restrictive cells have greatly reduced infectivity. We show here that
       the intracellular localization of Vif is dependent on the presence of
       the intermediate filament vimentin. Fractionation of acutely infected T
       cells or transiently transfected HeLa cells demonstrates the existence
       of a soluble and a cytoskeletal form and to a lesser extent the presence
       of a detergent-extractable form of Vif. Confocal microscopy suggests
       that in HeLa cells, Vif is predominantly present in the cytoplasm and
       closely colocalizes with the intermediate filament vimentin. Treatment
       of cells with drugs affecting the structure of vimentin filaments affect
       the localization of Vif accordingly, indicating a close association of
       Vif with this cytoskeletal component. The association of Vif with
       vimentin can cause the collapse of the intermediate filament network
       into a perinuclear aggregate. In contrast, analysis of Vif in
       vimentin-negative cells reveals significant staining of the nucleus and
       the nuclear membrane in addition to diffuse cytoplasmic staining. In
       addition to the association of Vif with intermediate filaments, analyses
       of virion preparations demonstrate that Vif is incorporated into virus
       particles. In sucrose density gradients, Vif cosediments with capsid
       proteins even after detergent treatment of virus preparations,
       suggesting that Vif is associated with the inner core of HIV particles.
       We propose a model in which Vif has a crucial function as a virion
       component either by regulating virus maturation or following virus entry
       into a host cell possibly involving an interaction with the cellular
       cytoskeletal network.
 DE    Animal  Base Sequence  Cell Line  Cytoskeleton/METABOLISM/*VIROLOGY
       DNA, Viral  Gene Products, vif/*METABOLISM  Hela Cells  Human  HIV
       Seropositivity/BLOOD/IMMUNOLOGY  HIV-1/*METABOLISM  Molecular Sequence
       Data  Support, Non-U.S. Gov't  Support, U.S. Gov't, P.H.S.  Tumor Cells,
       Cultured  Vimentin/*METABOLISM  Virion/METABOLISM  JOURNAL ARTICLE

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

