Conservation and evolution of transcriptional mechanisms in eukaryotes.

Eukaryotic transcriptional activators play key roles in controlling cell growth and specifying embryonic development. These activators can stimulate promoters from distances up to tens of kilobases by a mechanism that is remarkably conserved in eukaryotes ranging from yeast to humans. Although the primary sequence of certain activators has also been conserved in widely divergent organisms, the regulatory roles that these factors play have been altered over evolution to fit the specific needs of the host.