VARIABLE TRANSFER-RNA CONTENT IN HIV-1(IIIB)

Low molecular weight RNA in HIV-1 is found in three size classes resembling 7S RNA, 5S RNA, and tRNA. The 2-dimensional polyacrylamide gel electrophoresis (2D PAGE) patterns of tRNA found in HIV-1 have been determined in virus produced in five different cell types: H9, UHC1 (a U937-derived clone), UHC8 (an RT(-) derivative of U937), HeLa, and COS. The presence of the putative primer tRNA for reverse transcriptase, tRNALys,3, has also been determined either by hybridization with a tRNALys,3-specific DNA probe or by a comparison of the electrophoretic mobility of viral tRNA species with purified human tRNALys,3. Our results indicate the following: 1) The number of tRNA species found in infectious HIV-1IIIB produced in different cell types varies, according to cell type, from >20 to 4, indicating that only 4 or less tRNA species are required for the viral infectious life cycle. 2) There are 1-3 tRNA species tightly associated to the viral genomic RNA, depending upon the cell type producing the virus. 3) The putative primer tRNA, tRNALys,3, is detected with the tRNALys,3-specific hybridization probe in the tRNA of HIV-1 produced in H9 cells, and the tightly associated tRNA species in this virus has the same electrophoretic mobility in 1-D PAGE as purified tRNALys,3. On the other hand, we cannot detect tRNALys,3 in the tRNA of HIV-1 produced in HeLa cells, and the tightly associated tRNA found in this virus does not migrate with the same electrophoretic mobility as tRNALys,3. © 1992.