Effect of Altering the tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document}Concentration in Human Immunodeficiency Virus Type 1 upon Its Annealing to Viral RNA, GagPol Incorporation, and Viral Infectivity

Human immunodeficiency virus type 1 (HIV-1) uses tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document} as a primer for reverse transcription and, during viral assembly, this tRNA is selectively packaged into the virus along with the other major tRNA Lys , tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(1,2Lys\) {document} . Increasing the cytoplasmic concentration of tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document} through transfection of cells with a plasmid containing both HIV-1 proviral DNA and a tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document} gene results in a greater incorporation of tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document} into virions, which is accompanied by increased annealing of tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document} to the viral genome and increased infectivity of the viral population. Increased viral tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document} is accompanied by decreased viral tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(1,2Lys\) {document} , with the total tRNA Lys /virion and the GagPol/Gag ratios remaining unchanged. Viral tRNA Lys can be doubled, with increases in both tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document} and tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(1,2Lys\) {document} concentrations, by overexpressing lysyl tRNA synthetase. This also results in increased tRNA [fleqn,10pt,legalpaper]{article} {amssymb} {amsfonts} {amsmath} {empty} {document} \(₃Lys\) {document} annealing to the viral RNA and increased viral infectivity but, again, no change in the GagPol/Gag ratio was observed. This result indicates that GagPol, whose interaction is required during packaging, is not a limiting factor during tRNA Lys incorporation into HIV-1, whereas LysRS is.