Fig. 4: BAHCC1 interacts with MCM complex and ORC1.

a BioID-based identification of BAHCC1-associated proteins in HeLa and U2OS cells. BioID/Control shows ratio of results from biotin-treated versus vehicle-treated cells, with cut-off set to the log2-transformed value of fold change (FC) above 1. MCM and HDAC complex subunits are highlighted in red and blue, respectively. b Co-IP for Flag-BAHCC1 interaction with HA-MCM3 or HA-ORC1 in HeLa cells, without (left) or with benzonase treatment (right). c ChIP-qPCR for GAL4^DBD-BAHCC1-Flag (α-Flag) and MCM2 binding at the 5×GAL4-binding sites in MEFs, after the GAL4^DBD-BAHCC1-Flag expression induction by doxycycline (dox) treatment (+) versus mock (-). Mock-treated cells and a negative control (NC) locus serve as cell and locus controls, respectively. ChIP signals, presented as means ± SD, were normalized to those of 1% of input (n = 3 replicated experiments). Two-tailed unpaired t-test was conducted. Exact P-values are labeled. d, e Heatmaps (top) and box plots (bottom) showing CUT&Tag signals of MCM2 (d) and CUT&RUN signals of HA-MCM3 (e), ± 5 kb from the peak centers in HeLa cells with BAHCC1 KO or BAHCC1^TTD-dead mutation, compared to WT (after normalization to spike-in control signals). Color scale was quantified using the median of FPKM at peaks, with blue and yellow indicating high and low signals, respectively. f Venn diagram showing overlap between the BAHCC1 and HA-tagged ORC1 peaks in HeLa cells. g–j Box plots showing the binding signals of BAHCC1 (g), H4K20me1 (h), HA-MCM3 (i) and MCM2 (j) at genomic regions bound by BAHCC1 only or HA-ORC1 only or co-bound by both in HeLa cells with WT BAHCC1 (left) or the TTD-dead/Y1993A mutation (right). k Integrated Genomics Viewer (IGV) views of BAHCC1, HA-ORC1, MCM2, HA-MCM3 and H4K20me1/2/3 at MYC in HeLa cells with WT BAHCC1 or BAHCC1^TTD-dead mutation. For (d, e) and (g−j) P-values are analyzed by two-tailed Wilcoxon test for paired comparison or two-tailed Mann-Whitney U test for unpaired comparison. Center lines represent the medians, edges of the box indicate the 25th and 75th percentiles, and whiskers indicate the 5% minima and 95% maxima. Source data are provided as a Source Data file.