GC-MRs regulating >100 targets. Left side of the plot shows the distribution of the positively (red) and negatively (blue) correlated targets of the MR on the gene list ranked by differential mRNA expression in centroblast compared with naive samples. The right side of the plot shows a heatmap of the mRNA expression level of the MRs in naive (N) and centroblast (CB) samples. Source data is available for this figure at www.nature.com/msb.

FOXM1/MYB network. (A) FOXM1/MYB subnetwork from the HBCI. (B) Distribution of the MYB/FOXM1 regulon against a list of genes ranked by their differentially expression in centroblast compared with naive B cells. Source data is available for this figure at www.nature.com/msb.

MYB directly regulates the transcription of FOXM1. (A) Western blot analysis of ST486 total cell lysates obtained at 24, 48, and 72 h after lentiviral-mediated transduction of control, FOXM1, or MYB shRNA. Viral load was set for complete silencing of FOXM1 at 24 h but only partial (>50%) silencing of MYB, as complete silencing induced >80% apoptosis at 48 h (data from previous experiment). GAPDH was used as a loading control. (B) Percentage of FOXM1 protein level on MYB silencing were calculated by densitometric analysis (in ImageJ) and normalized to GAPDH protein level. (C) qPCR analysis showing the mRNA expression level of FOXM1 and MYB at 24 h. Similar results were observed at 48 and 72 h (data not shown). (D) qChIP with control IgG or anti-MYB antibody at FOXM1-binding site. Data shown in (A, C) are representative of one of three independent experiments. Error bars were calculated (C) from samples run in duplicate or (D) from two sets of three independent real-time PCR reactions. (E) qChIP with control IgG, anti-FOXM1, and anti-MYB antibodies performed in the nuclear extract of ST486 cells. Samples from two independent experiments were pooled together and real-time PCR reactions were run in duplicate. Error bars represent the standard error.

TCM showing GC-MRs controlled by MYB and FOXM1 and their targets. The figure describes the relationship between MYB and FOXM1 and three other MRs downregulated after silencing the two TFs independently (see qPCR results in Supplementary Figure S11). We used hierarchical clustering to cluster the five MRs according to their common targets. The distance between each MR was computed using their percentage of common targets and we used the ward agglomeration method. Gene Ontology enrichment was computed for common MRs targets as well as specific targets of each MR.

FOXM1 and MYB are required for cell proliferation and viability of ST486 cells. (A) Proliferating ST486 cells were quantified by BrdU labeling of cells transduced with control, FOXM1, or MYB shRNA, and collected at 24 h. Error bars represent standard error calculated from the samples run in triplicate. (B) The percentage of apoptotic ST486 cells was assessed by Annexin V staining of cells transduced with control, FOXM1, or MYB shRNA and collected at 24, 48, and 72 h post-infection.

MCM3 and MCM6 interact with BUBR1 and AURKA. (A) MCM3 co-immunoprecipitates with BUBR1 and AURKA. Cell lysates of Ramos cell line were immunoprecipitated with control IgG or anti-MCM3 antibodies and probed with anti-BUBR1 and anti-AURKA antibodies. (B) MCM6 binds to BUBR1 and AURKA in Xenopus cell-free extracts. Interphase extracts from Xenopus cytosolic fraction were immunoprecipitated with anti-XMCM6 or control IgG antibodies and probed with anti-XMCM6, anti-XBUBR1, and anti-XAURKA antibodies. (C) Co-localization of MCM3 with BUBR1 and AURKA in Ramos cells shown by confocal dual-color indirect immunofluorescence with (a) anti-MCM3 and anti-BUBR1 antibodies or (b) anti-MCM3 and anti-AURKA antibodies. DNA was stained with DAPI. Data shown are representative of one of three independent experiments.