FIG. 2.

Effects of mutations of the U₆ track on CAT expression. Human 293 kidney cells were transfected with four protein expression plasmids (pGT-h-PB1, pGT-h-PB2, pGT-h-PA, and pGT-h-NP) and pPOL-I-CAT-RT with a wild-type polyadenylation signal (lanes 1 to 4), a U₆→A₆ mutation (lanes 5 and 6), or a U₆→UCUACG mutation (lanes 7 and 8). The CAT activities of the cell lysates were analyzed as described in Materials and Methods. Dilution factors of the cell lysates are indicated. Lane 9, mock transfection.