FIG. 3.
Stable Tax expression in T cells interferes with PIR complex formation on the proximal PCNA promoter TRE. (A) Western blot of whole-cell extracts from Jurkat (lane 1), CEM (lane 2), MS-9 (lane 3), and MT-2 (lane 4) T cells, using antibodies to Tax or actin as indicated. (B) EMSA using 32P-labeled proximal probe (lanes 1 to 5) incubated with whole-cell extract from Jurkat (lane 2), CEM (lane 3), MS-9 (lanes 4), or MT-2 (lane 5) T cells. The position of the specific complex is indicated on the left. (C) Densitometric volume analyses of the samples from panel B quantitated with ImageQuant software. Each reaction signal from the specific complex was divided by the total signal and normalized to that of Jurkat T cells. Error bars represent the standard errors of the means for two independent experiments. *, significant difference in specific complex formation between Tax-negative and Tax-positive cells (Student t test; P < 0.05).