Figure 2. Metazoan regulatory modules controlling transcription.

Shown is a diagram of a typical metazoan gene illustrating the complex interactions among cis-acting modules and trans-acting factors regulating gene expression. Note that both positive and negative control regions are interspersed with promoter modules, all of which can be further influenced by distal regions regulating chromatin configuration, such as insulators. (Used with permission Levine and Tjian, 2003; PMID 12853946)