FIG. 3.

Cell cycle-dependent association of CTCF and cohesins with the KSHV latency control region. BCBL1 cells elutriated over the cell cycle were assayed by ChIP, with antibodies specific to RAD21, SMC1, SMC3, CTCF, or control IgG. Resultant ChIP products were analyzed by real-time PCR, with primers for the KSHV CTCF binding site (ORF73/72/71 control region; KSHV 127556-127631), a negative control region (KSHV 54721-55080), and a CTCF binding site in the human c-myc P2 promoter (42). Both CTCF and cohesins colocalized at CTCF binding sites and were most enriched at mid-S phase of the BCBL1 cell cycle.