Recombinational analysis of a natural noncytopathic human immunodeficiency virus type 1 (HIV-1) isolate: role of the vif gene in HIV-1 infection kinetics and cytopathicity.
Two molecularly cloned coisolates of human immunodeficiency virus type 1 (HIV-1) have been found to exhibit different phenotypes of viral expression, either rapid and cytopathic (N1T-A virus) or delayed and noncytopathic (N1T-E virus [X. Ma, K. Sakai, F. Sinangil, E. Golub, and D. J. Volsky, Virology 176:184-194, 1990]). To identify the viral genetic elements responsible for these phenotypes, we prepared reciprocal recombinants in different regions of N1T-A and N1T-E viral genomes. Infectivity experiments with the recombinant viruses revealed that the rapid/cytopathic (N1T-A-like) phenotype assorted cleanly with the V1f-coding region and Vif expression. The smallest HIV-1 DNA region that conferred the complete phenotypic switch was a 284-bp NdeI-StuI fragment within the vif open reading frame. Nucleotide sequence analysis revealed a 35-bp deletion starting at nucleotide 218 in the N1T-E vif gene. A 23-kDa Vif protein was detected by immunoblotting using Vif-specific antiserum in extracts of cells infected with N1T-A but not N1T-E virus. No detectable vif protein was found in association with sedimented particles of either virus. Cotransfection of a eucaryotic vif expression plasmid with N1T-E DNA complemented the N1T-E defect; rapid/cytopathic infection similar to that in N1T-A-transfected cells was observed. We conclude that Vif controls the rate, and consequently the cytopathic outcome, of HIV-1 infection.
Molecular Virology Laboratory, St. Luke's Roosevelt Hospital Center, New York, New York.
K
K
Sakai
X Y
XY
Ma
I
I
Gordienko
D J
DJ
Volsky
D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D015153:Blotting, Western; D002460:Cell Line; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics*; D015870:Gene Expression; D016346:Gene Products, vif / Q000032:analysis / Q000235:genetics*; D016341:Genes, vif; D005816:Genetic Complementation Test; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010641:Phenotype; D011533:Proviruses / Q000235:genetics; D011995:Recombination, Genetic; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection; D054320:vif Gene Products, Human Immunodeficiency Virus
D004279:DNA, Viral; D016346:Gene Products, vif; D054320:vif Gene Products, Human Immunodeficiency Virus