FIGURE 8.

Recruitment of P-TEFb to the LTR promoter by Tip110. A, 293T cells were transfected with pLTR-Luc and pTip110.HA, pTat.Myc, or both. Chromatin from these cells was cross-linked, sheared, and immunoprecipitated with α-HA, α-Myc, α-CycT1, α-CDK9, α-CTDa, α-CTDo2, and α-CTDo5. After reverse cross-linking, the purified DNA was purified and analyzed by PCR with the primer set for the HIV-1 LTR promoter. PCR products were quantitated by densitometry and expressed as -fold increases over the input control. An isotype-matched IgG was included as a control. pcDNA3 was added to equalize the total amount of plasmid DNA transfected. B, 293T cells were first transfected with psh-Tip110 at day 0 and then transfected with pLTR-Luc and pTat.Myc plasmids at day 4. Cells were cultured for an additional 3 days and harvested for the ChIP assay as described above with the exception that α-Tip110 antibody was used in place of α-HA antibody for immunoprecipitation. pSIREN, the backbone vector for psh-Tip110, was included as a control for psh-Tip110. The quantitative data were derived from multiple independent experiments. Error bars, S.D.