Generic nature of the condensed states of proteins

Proteins undergoing liquid-liquid phase separation are being discovered at an increasing rate. Since at the high concentrations present in the cell most proteins would be expected to form a liquid condensed state, this state should be considered to be a fundamental state of proteins along with the native state and the amyloid state. Here we discuss the generic nature of the liquid-like and solid-like condensed states, and describe a wide variety of biological functions conferred by these condensed states. In this Perspective, Fuxreiter and Vendruscolo discuss the fundamental nature of the droplet and amyloid states of proteins, the regulatory mechanisms controlling their formation, and the cellular functions associated with these condensed states.