Introduction to the Thematic Minireview Series on Intrinsically Disordered Proteins.

In this thematic minireview series, the JBC presents six exciting articles on low complexity or intrinsically disordered proteins (IDPs). The dynamical and fluctuating structures of IDPs or of disordered regions within proteins result in virtually all of their primary sequence being exposed, at least at some time, to potential interacting partners. Their structural versatility underlies their often wide functional repertoires, which is further expanded by post-translational modifications. Given these characteristics, it is not surprising that IDPs serve as important hubs in signaling networks, scaffolding multivalent interactions. They are also important for organizing membrane-less protein organelles. This collection of reviews discusses biophysical approaches for studying IDPs and illuminates their importance to critical functions such as cell cycle control, transcription, and translation, as well as their regulation via cellular input signals.