We study basic mechanisms of gene regulation, primarily in yeast at the moment, but with an eye to understanding many basic aspects of biological regulation.
One recently published book, based on our earlier work, describes the protein-protein and protein-DNA interactions that underlie a complex gene regulatory circuit in phage lambda (A Genetic Switch 3rd ed., Ptashne, 2004); and another (Genes and Signals, Ptashne and Gann 2002), shows how these underlying mechanisms are at work in eukaryotes as well. Moreover, the latter book shows how the principle mechanism of transcriptional regulation — “recruitment” — is also used to regulate the activity of a wide array of enzymes including polymerases, kinases, phosphatases, ubiquitylases, proteases, and so on. The picture that emerges describes how evolution can use the same enzymes to produce a fly and a human. We are now immersed in a study of how gene regulators deal with the fact that genes in eukaryotes are wrapped in nucleosomes, using new techniques for quantitating nucleosome formation. A short recent essay (Ptashne 2007A) shows how thinking about this problem sheds light on current ideas about ’epigenetics.’