Analysis of Transcriptional Control Mechanisms II Techniques for Characterization of trans-Acting Factors

cis- Acting DNA control elements, enhancers and promoters, function to control gene expression by acting as targets for specific DNA-binding proteins (trans-acting factors). trans-acting factors are sequence-specific DNA-binding proteins that recognize specific signatures in base composition of the DNA, and upon binding, are able to influence transcriptional activity of the core promoter by multiple diverse mechanisms. These mechanisms include direct interaction with the preinitiation complex, recruitment of additional bridging proteins (coactivators), or induction of chromatin remodeling (such as altering nucleosomal phasing). These mechanisms are coordinated to result in changes in gene expression that control critical events in cellular differentiation and responses to extracellular signals or stressors.