Profiling non-lysyl tRNAs in HIV-1

During its assembly, human HIV-1 selectively packages the tRNA Lys isoacceptors, including tRNA Lys3 , the primer for the reverse transcriptase. However, other low molecular weight RNA species are also seen in the virus. We profiled the tRNAs packaged into HIV-1 using microarray analysis and validated our results by two-dimensional gel electrophoresis and RT-PCR. In addition to tRNA Lys isoacceptors, tRNA Asn and the rare isoacceptor of tRNA Ile are also selectively packaged. In Gag viral-like particles missing the GagPol protein, overall tRNA incorporation is reduced by >80%. This reduction is significantly greater than can be accounted for by the reduction in tRNA Lys isoacceptors, tRNA Asn and tRNA Ile , suggesting that incorporation of other tRNAs may also require the GagPol protein. These results demonstrate selective incorporation of non-lysyl tRNAs into HIV-1 and highlight the application of microarrays as a novel method to study tRNA incorporation into viruses.