FIG. 9.

PARP enhances Tax-activated transcription in vivo. A mouse embryonic cell line deficient for PARP was transfected with 10 μg of a luciferase reporter plasmid driven by the HTLV-1 promoter (positions −306 to −1) alone or with 15 μg of an HTLV-1 Tax expression vector; 10 μg of PARP expression vector (pcD-12) was added as indicated. Each reaction received additional pUC DNA to a total of 35 μg of DNA. Luciferase activity was normalized to protein concentration and then divided by the activity in the absence of Tax and PARP; the numerical value is indicated above each bar. Experiment 1 is the average of duplicates, while experiment 2 is the average of triplicates. The positive error bar indicates the standard deviation for each average.