IMPOSING SPECIFICITY BY LOCALIZATION - MECHANISM AND EVOLVABILITY

Cells detect extracellular signals by allostery and then give those si gnals meaning by 'regulated localization'. We suggest that this formul ation applies to many biological processes and is particularly well il lustrated by the mechanisms of gene regulation. Analysis of these mech anisms reveals that regulated localization requires simple molecular i nteractions that are readily used combinatorially. This system of regu lation is highly 'evolvable', and its use accounts, at least in part, for the nature of the complexities observed in biological systems.