P21 is derived from CREB-binding protein (CBP) and directly enhances CREB-mediated gene transcription, a master regulator of long-term memory formation and synaptic plasticity. It increases dendritic complexity and promotes the expression of plasticity-related genes.
Studies at the Salk Institute demonstrate P21 rescues age-related CREB dysfunction and restores youthful patterns of gene expression in aged neurons.