title: Phase separation in biology; functional organization of a higher order.
abstract: Inside eukaryotic cells, macromolecules are partitioned into membrane-bounded compartments and, within these, some are further organized into non-membrane-bounded structures termed membrane-less organelles. The latter structures are comprised of heterogeneous mixtures of proteins and nucleic acids and assemble through a phase separation phenomenon similar to polymer condensation. Membrane-less organelles are dynamic structures maintained through multivalent interactions that mediate diverse biological processes, many involved in RNA metabolism. They rapidly exchange components with the cellular milieu and their properties are readily altered in response to environmental cues, often implicating membrane-less organelles in responses to stress signaling. In this review, we discuss: (1) the functional roles of membrane-less organelles, (2) unifying structural and mechanistic principles that underlie their assembly and disassembly, and (3) established and emerging methods used in structural investigations of membrane-less organelles.
authors.affiliation: Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA. diana.mitrea@stjude.org.
authors.forename: Diana M
authors.initials: DM
authors.lastname: Mitrea
authors.affiliation: Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA. richard.kriwacki@stjude.org.|Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center, Memphis, TN, 38163, USA. richard.kriwacki@stjude.org.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Kriwacki
mesh_terms: D000818:Animals; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D044367:Phase Transition; D011506:Proteins / Q000378:metabolism*; D012313:RNA / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D011506:Proteins; D012313:RNA