title: Sequence Determinants of Intracellular Phase Separation by Complex Coacervation of a Disordered Protein.
abstract: Liquid-liquid phase separation, driven by collective interactions among multivalent and intrinsically disordered proteins, is thought to mediate the formation of membrane-less organelles in cells. Using parallel cellular and in vitro assays, we show that the Nephrin intracellular domain (NICD), a disordered protein, drives intracellular phase separation via complex coacervation, whereby the negatively charged NICD co-assembles with positively charged partners to form protein-rich dense liquid droplets. Mutagenesis reveals that the driving force for phase separation depends on the overall amino acid composition and not the precise sequence of NICD. Instead, phase separation is promoted by one or more regions of high negative charge density and aromatic/hydrophobic residues that are distributed across the protein. Many disordered proteins share similar sequence characteristics with NICD, suggesting that complex coacervation may be a widely used mechanism to promote intracellular phase separation.
authors.affiliation: Department of Biophysics and Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Chi W
authors.initials: CW
authors.lastname: Pak
authors.affiliation: Department of Biophysics and Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Martyna
authors.initials: M
authors.lastname: Kosno
authors.affiliation: Computational and Molecular Biophysics Graduate Program, Washington University in St. Louis, St. Louis, MO 63130, USA; Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
authors.forename: Alex S
authors.initials: AS
authors.lastname: Holehouse
authors.affiliation: Department of Biophysics and Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Shae B
authors.initials: SB
authors.lastname: Padrick
authors.affiliation: Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Mittal
authors.affiliation: Department of Biophysics and Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Rustam
authors.initials: R
authors.lastname: Ali
authors.affiliation: Department of Biophysics and Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA.
authors.forename: Ali A
authors.initials: AA
authors.lastname: Yunus
authors.affiliation: Department of Chemistry and Chemical Biology and Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Liu
authors.affiliation: Department of Biomedical Engineering and Center for Biological Systems Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA. Electronic address: pappu@wustl.edu.
authors.forename: Rohit V
authors.initials: RV
authors.lastname: Pappu
authors.affiliation: Department of Biophysics and Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX 75390, USA. Electronic address: michael.rosen@utsouthwestern.edu.
authors.forename: Michael K
authors.initials: MK
authors.lastname: Rosen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism; D003198:Computer Simulation; D006367:HeLa Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D064267:Intrinsically Disordered Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008958:Models, Molecular; D009154:Mutation; D015388:Organelles / Q000737:chemistry* / Q000378:metabolism; D000072417:Protein Domains; D040901:Proteomics / Q000379:methods; D055672:Static Electricity; D013329:Structure-Activity Relationship; D013499:Surface Properties; D013997:Time Factors; D014162:Transfection
chemical_list: D064267:Intrinsically Disordered Proteins; D008565:Membrane Proteins; C113267:nephrin