Cyclic AMP was the first chemical to be isolated and identified as a second messenger--a substance produced by a cell when a hormone or other chemical (the first messenger) binds to specific receptor sites on the cell surface. The second messenger, in turn, influences the cell's processes. The discovery was a major step toward understanding how both hormones and cells function. Important new areas of genetic research involve the role of such second messengers in gene regulation and post ranslational gene regulatory proteins. Cyclic AMP receptor protein (CRP) interactions have been demonstrated to induce changes in shape and reactions of DNA (allosteric and conformational changes) that, in turn, influence transcription.

Cyclic AMP has been shown to be an important link in many processes, such as memory and hormonal response. In 1998, scientists at the University of California at San Francisco discovered...