Li Meng, Eipers Peter G, Ni Na, Morrow Casey D
Department of Cell Biology, University of Alabama at Birmingham, AL 35294-0024, USA.
Virol J. 2006 Sep 26;3:80. doi: 10.1186/1743-422X-3-80.
Previous studies have shown that infection with human immunodeficiency virus type 1 (HIV-1) causes acceleration of the synthesis of glutamine tRNA (tRNAGln) in infected cells. To investigate whether this might influence HIV-1 to utilize tRNAGln 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 tRNAGln,1 or tRNAGln,3 and 3' terminal 18 nucleotides of each isoacceptor of tRNAGln.
Viruses in which the PBS was altered to be complementary to tRNAGln,1 or tRNAGln,3 with or without the A-loop all exhibited a lower infectivity than the wild type virus. Viruses with only the PBS complementary to tRNAGln,1 or tRNAGln,3 reverted to wild type following culture in SupT1 cells. Surprisingly, viruses in which the PBS and A-loop were complementary to tRNAGln,1 did not grow in SupT1 cells, while viruses in which the PBS and A-loop were made complementary to tRNAGln,3 grew slowly in SupT1 cells. Analysis of the PBS of this virus revealed that it had reverted to select tRNAThr as the primer, which shares complementarity in 15 of 18 nucleotides with the PBS complementary to tRNAGln,3.
The results of these studies support the concept that the HIV-1 has preferred tRNAs that can be selected as primers for replication.
先前的研究表明，感染1型人类免疫缺陷病毒（HIV-1）会导致受感染细胞中谷氨酰胺tRNA（tRNAGln）的合成加速。为了研究这是否会影响HIV-1利用tRNAGln作为逆转录起始的引物，我们构建了HIV-1前病毒基因组，其中引物结合位点（PBS）和PBS上游的A环区域已与tRNAGln,1或tRNAGln,3的反密码子区域以及tRNAGln每个同功受体的3'末端18个核苷酸互补。
PBS被改变为与tRNAGln,1或tRNAGln,3互补的病毒，无论有无A环，其感染性均低于野生型病毒。仅PBS与tRNAGln,1或tRNAGln,3互补的病毒在SupT1细胞中培养后恢复为野生型。令人惊讶的是，PBS和A环与tRNAGln,1互补的病毒在SupT1细胞中无法生长，而PBS和A环与tRNAGln,3互补的病毒在SupT1细胞中生长缓慢。对这种病毒的PBS分析表明，它已恢复选择苏氨酸tRNA作为引物，该引物与与tRNAGln,3互补的PBS在18个核苷酸中的15个具有互补性。
这些研究结果支持了HIV-1具有可被选作复制引物的偏好tRNA这一概念。
