Research Paper Volume 5, Issue 1 pp 3—17

Figure 5. AR is a component of telomeres. (A, B), AR-ChIP contains telomere DNA. LNCaP cell chromatin was subjected to immunoprecipitation with antibodies to AR, TRF2, Rap1, or normal IgG (negative control). (A), DNA was purified from the ChIP and analyzed for the presence of AR binding sequences in the PSA gene (ARE III in PSA promoter/enhancer) [91]. (B), DNA purified from ChIP was loaded onto a nylon membrane using a dot blot apparatus and probed with a DIG-labeled telomere DNA repeat [wt-(ccctaa)₁₀] or mutant DNA repeat [m-(gcctaa)₁₀]. Input DNA represents 10% of total DNA, before immunoprecipitation. (C, D), Telomeric chromatin contains AR. The PICh protocol was used to isolate telomeric chromatin from total chromatin of 293T cells (C) or LNCaP cells (D), using a telomere-specific probe (Tel) or a scrambled sequence probe (SC). Isolates were analyzed by Western blot (WB) for the presence of Rap1, TRF2, TIN2, HIS3, or AR. Input (%) represents starting material.