Figure 4: Regulatory consequences of GtaC and GtaC^C-S promoter-binding events on gene regulation.

(a,b) Venn diagrams showing the overlap between genes bound by GtaC and differentially expressed between gtaC-null cells complemented with ectopic GtaC–GFP (CM) and gtaC-null (KO) cells (purple circle) and, genes bound by GtaC^C-S and differentially expressed between gtaC-null cells ectopically expressing GtaC^C-S-GFP (CS) and KO cells (yellow circle) during early (a) and late (b) aggregation. (c) Plots showing the cumulative proportions of genes (y axis) at a given binding score (ranked; x axis) of GtaC or GtaC^C-S at early aggregation (E; (i), (ii)) and late aggregation (L; (iii), (iv)). All genes are categorized as upregulated (UP, red lines), downregulated (DOWN, green lines) or NDE (black dashed lines) in CM (first column) or CS (second column) compared with KO cells. The UP and DOWN cumulative distributions are compared with the corresponding NDE distribution using the Kolmogorov–Smirnov test (P values<0.001 indicated by * in (i) and (iii)). (d) The heatmaps represent GtaC-binding scores (log₂-transformed; scale indicated, left panel) and standardized mRNA abundance (scale indicated, right panel) of genes bound only by GtaC at early aggregation (E; clusters i–ii) or late aggregation (L; clusters ii–iii). Each row represents a gene and genes were grouped by their binding patterns. Each column represents a strain (coloured panels on top, purple: CM, green: KO) and time point (S: starvation-sensing, E: early aggregation and L: late aggregation).