FIG. 6.

p28^II associates with the HTLV-2 promoter, as well as downstream DNA sequences. (A) ChIP analysis reveals that p28^II associates with the HTLV-2 promoter (LTR-2) but only in the presence of the transcription activator Tax-2, indicating that p28^II associates only with a transcriptionally active promoter. Input, 10% of DNA prior to immunoprecipitation. (B) Schematic diagram of the HTLV-2 provirus with primer pairs used in the following ChIP are indicated. For exact location of primers, refer to Materials and Methods. TRE, three 21-bp repeats representing Tax response elements in the viral promoter. The ChIP assay was performed as described in the legend to panel A with antibodies specific for p28^II, HTLV-1 p30^II, or RNA polymerase II. PCR conditions for each primer pair were optimized to amplify a product in the linear range. Lanes 1 and 4, lysates from mock-transfected cells; lanes 2, 5, 7, and 9, lysates from cells expressing wtHTLV-2; lanes 3, 6, and 10, lysates from cells expressing wtHTLV-2 and p28^II; lane 8, lysate from cells expressing wtHTLV-2 and p30^II. Antibodies used in ChIP are indicated (top).