Cellular Adaptation Relies on Regulatory Proteins Having Episodic Memory

The ability to memorize changes in the environment is present at all biological levels, from social groups and individuals, down to single cells. Trans‐generational memory is embedded subcellularly through genetic and epigenetic mechanisms. Evidence that cells process and remember features of the immediate environment using protein sensors is reviewed. It is argued that this mnemonic ability is encapsulated within the protein conformational space and lasts throughout its lifetime, which can overlap with the lifespan of the organism. Means to determine diachronic changes in protein activity are presented. Formation of protein memory following initial stimulation of naive protein leads to changes in its subsequent activity upon re‐stimulation: habituation (above) or sensitization (below).