HIV-1 infection of non-dividing cells: evidence that the amino-terminal basic region of the viral matrix protein is important for Gag processing but not for post-entry nuclear import.
Human immunodeficiency virus type-1 (HIV-1) is able to infect non-dividing cells such as tissue macrophages productively because post-entry viral nucleoprotein complexes are specifically imported into the nucleus in the absence of mitosis. Although it has been proposed that an amino-terminal region of the viral matrix (MA, p17Gag) protein harbors a basic-type nuclear localization sequence (NLS) that contributes to this process, utilization of three distinct nuclear import assays failed to provide any direct supporting evidence. Instead, we found that disruption of this region (26KK-->TT) reduces the rate at which the viral Gag polyprotein (p55Gag) is post-translationally processed by the viral protease. Consistent with the fact that appropriate proteolytic processing is essential for efficient viral growth in all cell types, we also show that the 26KK-->TT MA mutation is equivalently deleterious to the replication of a primary macrophage-tropic viral isolate in cultures of non-dividing and dividing cells. Taken together, these observations suggest that proteins other than MA supply the NLS(s) that enable HIV-1 to infect non-dividing cells.
Fouchier
R A
RA
Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia 19104-6148, USA.
Meyer
B E
BE
Simon
J H
JH
Fischer
U
U
Malim
M H
MH
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D001693:Biological Transport, Active; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism / Q000821:virology; D005260:Female; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism*; D015488:HIV Antigens / Q000235:genetics / Q000378:metabolism; D015658:HIV Infections / Q000378:metabolism / Q000821:virology*; D015497:HIV-1 / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D016297:Mutagenesis, Site-Directed; D009865:Oocytes; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins; D014779:Virus Replication; D014982:Xenopus laevis; D054301:gag Gene Products, Human Immunodeficiency Virus
D015683:Gene Products, gag; D015488:HIV Antigens; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D014763:Viral Matrix Proteins; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1; C059767:p55 gag precursor protein, Human immunodeficiency virus 1