FIG. 5.

Association of RECQ1 and RECQ4 with beta-globin replication origin as a function of origin timing. (A) Genomic region containing the beta-globin replication origin, together with the locations of sets of primers (converging arrow pairs) used for quantitative real-time PCR analysis. (B) Flow cytometry profiling of synchronized K562 cells that had been cultured with mimosine for 24 h and then sampled 3 (early S) and 9 (late S) h after the removal of the drug is shown at the top. The histograms below quantify cross-linked lamin B2 and beta-globin origin DNAs immunoprecipitated by ChIP from early- and late-S-phase-synchronized K562 cells. (C) Flow cytometry profiling of synchronized HeLa cells that had been cultured with mimosine for 24 h and then sampled 3 (early S) and 9 (late S) h after the removal of the drug is shown at the top. The histograms below quantify cross-linked lamin B2 and beta-globin origin DNAs immunoprecipitated by ChIP from early- and late-S-phase-synchronized HeLa cells. Histograms report the means ± SEM for at least three independent experiments, where fold enrichment of lamin B2 and beta-globin origin region DNAs was determined as described in the legends to Fig. 1 and 2.