Cellular distribution and karyophilic properties of matrix, integrase, and Vpr proteins from the human and simian immunodeficiency viruses.
Infections by human and simian immunodeficiency viruses (HIV and SIV) are independent of host cell division since the preintegration complex (PIC), containing the viral DNA, is able to undergo active nuclear import after viral entry. In order to clarify the mechanisms responsible for nuclear import of the PIC, we have analyzed the subcellular distribution and the karyophilic properties of its viral components, matrix protein (MA), integrase (IN), Vpr, and Vpx. Although MA has been reported to contain a nuclear localization signal, the MA/GFP fusions are excluded from the nucleus and associated with cellular membranes. In contrast, both HIV-1 and SIV IN and Vpr localize in the nucleus of transfected cells. Interestingly, only Vpx from SIVsm virus accumulate in the nucleus while SIVsm Vpr is uniformly distributed throughout nucleus and cytoplasm. Coexpression of MA, Vpr, and IN does not induce any change in their respective intracellular localizations. Finally, we confirm the karyophilic properties of HIV-1 IN and Vpr using an in vitro nuclear import assay. These results indicate that the viral proteins IN and Vpr, which are strongly associated with the viral DNA within PIC, may participate in the nuclear import of the HIV PIC.
Depienne
C
C
CEA, Service de Neurovirologie, 60-68 avenue de la Division Leclerc, Fontenay-aux-Roses, 92 265, France.
Roques
P
P
Créminon
C
C
Fritsch
L
L
Casseron
R
R
Dormont
D
D
Dargemont
C
C
Benichou
S
S
D000818:Animals; D001692:Biological Transport; D002467:Cell Nucleus / Q000378:metabolism; D015870:Gene Expression; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism*; D016336:Gene Products, vpr / Q000235:genetics / Q000378:metabolism*; D015488:HIV Antigens / Q000235:genetics / Q000378:metabolism*; D019427:HIV Integrase / Q000235:genetics / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D019426:Integrases / Q000235:genetics / Q000378:metabolism*; D007424:Intracellular Fluid / Q000378:metabolism; D010539:Permeability; D015302:Simian Immunodeficiency Virus / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; D054325:vpr Gene Products, Human Immunodeficiency Virus
D015683:Gene Products, gag; D016336:Gene Products, vpr; D015488:HIV Antigens; D014763:Viral Matrix Proteins; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1; C077410:simian immunodeficiency virus matrix protein p17; D054325:vpr Gene Products, Human Immunodeficiency Virus; D019427:HIV Integrase; D019426:Integrases