The cofactor nicotinamide adenine dinucleotide (NAD) – once consigned to the oblivion of metabolic pathway wall charts – has recently attained celebrity status as the link between metabolic activity, cellular resistance to stress or injury, and longevity.
NAD influences many cell fate decisions – for example NAD-dependent enzymes such as poly (ADP-ribose) polymerase (PARP) are important for the DNA damage response, and NAD-dependent protein deacetylases (Sirtuins) are involved in transcriptional regulation, the stress response, and cellular differention.
Neuroscience. Bedalov, A & Simon, J.A. 13 August 2004. Vol 305 954-955.