HIV-1 designed to use different tRNA(Gln )isoacceptors prefers to select tRNA(Thr )for replication

BACKGROUND: Previous studies have shown that infection with human immunodeficiency virus type 1 (HIV-1) causes acceleration of the synthesis of glutamine tRNA (tRNA(Gln)) in infected cells. To investigate whether this might influence HIV-1 to utilize tRNA(Gln )as a primer for initiation of reverse transcription, we have constructed HIV-1 proviral genomes in which the PBS and the A-loop region upstream of the PBS have been made complementary to either the anticodon region of tRNA(Gln,1 )or tRNA(Gln,3 )and 3' terminal 18 nucleotides of each isoacceptor of tRNA(Gln). RESULTS: Viruses in which the PBS was altered to be complementary to tRNA(Gln,1 )or tRNA(Gln,3 )with or without the A-loop all exhibited a lower infectivity than the wild type virus. Viruses with only the PBS complementary to tRNA(Gln,1 )or tRNA(Gln,3 )reverted to wild type following culture in SupT1 cells. Surprisingly, viruses in which the PBS and A-loop were complementary to tRNA(Gln,1 )did not grow in SupT1 cells, while viruses in which the PBS and A-loop were made complementary to tRNA(Gln,3 )grew slowly in SupT1 cells. Analysis of the PBS of this virus revealed that it had reverted to select tRNA(Thr )as the primer, which shares complementarity in 15 of 18 nucleotides with the PBS complementary to tRNA(Gln,3). CONCLUSION: The results of these studies support the concept that the HIV-1 has preferred tRNAs that can be selected as primers for replication.