Transcription Factors and Signal Transduction

In this chapter, we will present transcription factors as the key controllers of gene expression. The activities of these proteins critically influence how a cell functions and responds to environmental perturbations. The most characteristic domain of a transcription factor is its DBD, but the proteins also contain domains for homo- and heterodimerization and for contacts with cofactors and other nuclear proteins. The structural and functional understanding of site-specific transcription factors provides insight how they link to signal transduction and the sensing of intra and extracellular lipophilic molecules via nuclear receptors. Thus, a central characteristic of life, the response to molecules of the extracellular environment, is mediated by signal transduction cascades that mostly start with an extracellular signaling molecule and end with an activated transcription factor, i.e., with a change in gene expression.