Research Perspective Volume 4, Issue 4 pp 247—255

Figure 2. The “coactivator-poor and coactivator-rich” model showing that increased recruitment of distinct classes of coactivators (HATs CBP/p300, and non-HATs CRTC) at promoters with more bound transcription factor (CREB bound to cAMP response elements) may increase transcriptional resilience at certain endogenous target genes. Broadness of the curved arrows indicates the amount of different types (colored) of transactivating “biochemical flux” that stimulate transcription. In certain endogenous promoter contexts the increased flux though one mechanism (e.g. CRTC) may overcome the lack of a different mechanism (e.g. CBP/p300) [41]. Other types of coactivators (“x”) that might be present and participate in gene activation are shown.