Cell Signaling ReagentsAll biological processes result from integrated and concerted molecular events. For example, enzyme catalysis is not defined solely by kinetic activity; it is the culmination of a series of events, including activation of the enzyme, substrate synthesis and availability, direct and indirect product and substrate feedback control, and interactions with inhibitors or stimulators. In essence the entire process of protein activation is a cascade of events, each serving as a signal to another: hence the term signal cascades. Intracellular signaling cascades are found in practically all forms of life--bacteria, plants, and animals--and are molecular triggers initiating and/or controlling events spanning time scales from milliseconds to days. In addition, signal cascades are involved in practically all aspects of biological function, including metabolism, cell division, developmental regulation, response to environmental stimuli and stress, muscular contraction, vision, and thought.
E.G. Krebs and colleagues proposed one of the first enzyme activation ...
