Eukaryotes have evolved elaborate mechanisms to survive periods of adversity. By manipulating genes that control these mechanisms, researchers have found they can generate more stress resistant, longer-lived organisms. One of these is the PNC1 gene of Saccharomyces cerevisiae, a master "longevity regulatory gene" that translates a variety of environmental stresses into lifespan extension by activating the sirtuin family of longevity deacetylases. Master longevity genes such as PNC1 are highly adaptive because they allow organisms to respond in a concerted way to adversity and to rapidly evolve life strategies to compensate for a changing environment. Hence, they should be well conserved. We propose that there is a functional equivalent of PNC1 in mammals called Nampt (a.k.a. PBEF/Visfatin), a stress-responsive gene that would coordinately regulate metabolism, cell defenses, and resistance to diseases of aging.
