Core promoters and transcriptional control.

Many biological processes are controlled, spatially and temporally, at the level of transcription. Thus, understanding the mechanisms of transcriptional regulation of gene expression is critical in deciphering the molecular modes of differentiation and development of a eukaryotic cell. Transcriptional control is mediated largely through interactions of regulatory transcription factors with their cognate enhancer elements. The regulatory signals generated at enhancer elements are communicated to the general transcription machinery formed at the core promoter elements of all genes. Recent observations suggest that the general transcription machinery can also generate regulatory signals independent of enhancer-generated interactions. Thus, the transcriptional regulation of gene expression, both in time and in space, may result from appropriate interfacing of independent signals generated at the core promoter and at the enhancer.