Revertants and pseudo-revertants of human immunodeficiency virus type 1 viruses mutated in the long terminal repeat promoter region.
The TAR domain is an RNA secondary structure element within the leader transcript of the human immunodeficiency virus type 1 (HIV-1) virus. TAR RNA forms the binding site for the viral trans-activator protein Tat and cellular co-factors that are involved in induction of the LTR transcriptional promoter. Here, we report that mutations in the single-stranded bulge- and loop-domains of TAR RNA impair the ability of the virus to replicate in T cell lines. Revertant viruses were isolated upon prolonged culturing and analysed through sequencing. The reversion data confirm the importance of both bulge and loop as sequence-specific recognition motifs. We also analysed the replication phenotype of a mutant HIV-1 virus with a substitution in the -19/-3 promoter region. This mutant displayed delayed infection kinetics compared to the wild-type virus, and revertants with increased replication potential could be isolated. Interestingly, all revertants had acquired an additional mutation at position -2. Primer extension analyses revealed that an upstream shift in transcription start site usage was induced by the -19/-3 substitution. This effect was compensated for by the nucleotide substitution near the RNA start site.
Berkhout
B
B
Department of Virology, University of Amsterdam Academic Medical Centre, The Netherlands.
Klaver
B
B
D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002460:Cell Line; D002478:Cells, Cultured; D004279:DNA, Viral; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics* / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D013601:T-Lymphocytes / Q000166:cytology / Q000821:virology; D014779:Virus Replication
D004279:DNA, Viral