FIG. 4.

Cell cycle-dependent binding of TRF1 to OriP. (A) Raji cells were arrested in G₀ by serum starvation and assayed by ChIP for association of EBNA1, TRF2, or TRF1 with OriP or control BMRF1 promoter DNA. (B) Raji cells were synchronized by double thymidine block and isolated at various stages of the cell cycle. Asynchronous (A), G₁, S, and G₂/M phase-arrested cells were assayed by ChIP for EBNA1, TRF2, and TRF1 binding to OriP. (C) FACS profile of Raji cells synchronized in panel B as described above. Raji cells were stained with propidium iodide prior to analysis by FACS. IgG, immunoglobulin G.