Power-law behavior of transcriptional bursting regulated by enhancer–promoter communication

Effect of the E-P communication strength on transcriptional bursting kinetics. (A) Schematic illustration of the augment of E-P communication strength k_EP. (B) Example traces of binarized transcriptional activity for three different values of k_EP, where red points represent the mRNA generation events, and the corresponding 3D chromatin structures are shown on the bottom. (C) Log–log plot for the relationship between mean burst size and strength k_EP. The green dashed line represents the theoretical result, whereas blue circles show numerical simulations. The red solid line indicates a power-law approximation (Equation 3) with a scaling exponent, S_BS = 0.23. (D) Log–log plot for the relationship between burst frequency and k_EP. Meanings of symbols are the same as those in C, but the scaling exponent is S_BF = 0.33. (E,F) Log–log plot of experimental data from Fukaya et al. (2016). The x-axis shows the E-P communication strengths of different enhancers, obtained by theoretical inferring based on the burst frequency data (converted the unit into sec⁻¹). The red points in F represent the theoretical result of mRNA level (converting its trend of change into a fold change), whereas the blue dashed line shows the experimental data (fluorescence intensity is a relative value, converting its trend of change into a fold change).