Profiling non-lysyl tRNAs in HIV-1

Abstract

During its assembly, human HIV-1 selectively packages the tRNALys isoacceptors, including tRNALys3, 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 tRNALys isoacceptors, tRNAAsn and the rare isoacceptor of tRNAIle 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 tRNALys isoacceptors, tRNAAsn and tRNAIle, 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.