TY - JOUR
T1 - Phase behaviour of disordered proteins underlying low density and high permeability of liquid organelles
AU - Wei, Ming Tzo
AU - Elbaum-Garfinkle, Shana
AU - Holehouse, Alex S.
AU - Chen, Carlos Chih Hsiung
AU - Feric, Marina
AU - Arnold, Craig B.
AU - Priestley, Rodney D.
AU - Pappu, Rohit V.
AU - Brangwynne, Clifford P.
N1 - Funding Information:
We thank H. Zhang and D. M. Mitrea for purifying WHI3 and NPM1, respectively. We acknowledge funding from the Princeton Center for Complex Materials, an MRSEC supported by NSF grant DMR 1420541, and the Eric and Wendy Schmidt Transformative Technology Fund. This work was also supported by an NIH Director’s New Innovator Award (1DP2GM105437-01 to C.P.B.), an NSF CAREER award (1253035 to C.P.B.), NIH grants (1K99NS096217-01 to S.E.G. and 5RO1NS056114 to R.V.P.), and an HFSP Program grant (RGP0007/2012 to C.P.B.). A.S.H. is a Bonnie and Kent Lattig graduate fellow in the Center for Biological Systems Engineering at Washington University in Saint Louis. We thank C. Theriault from TAG Optics for providing the TAG lens used in this study.
Publisher Copyright:
© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.
PY - 2017
Y1 - 2017
N2 - Many intracellular membraneless organelles form via phase separation of intrinsically disordered proteins (IDPs) or regions (IDRs). These include the Caenorhabditis elegans protein LAF-1, which forms P granule-like droplets in vitro. However, the role of protein disorder in phase separation and the macromolecular organization within droplets remain elusive. Here, we utilize a novel technique, ultrafast-scanning fluorescence correlation spectroscopy, to measure the molecular interactions and full coexistence curves (binodals), which quantify the protein concentration within LAF-1 droplets. The binodals of LAF-1 and its IDR display a number of unusual features, including 'high concentration' binodal arms that correspond to remarkably dilute droplets. We find that LAF-1 and other in vitro and intracellular droplets are characterized by an effective mesh size of ∼3-8 nm, which determines the size scale at which droplet properties impact molecular diffusion and permeability. These findings reveal how specific IDPs can phase separate to form permeable, lowdensity (semi-dilute) liquids, whose structural features are likely to strongly impact biological function.
AB - Many intracellular membraneless organelles form via phase separation of intrinsically disordered proteins (IDPs) or regions (IDRs). These include the Caenorhabditis elegans protein LAF-1, which forms P granule-like droplets in vitro. However, the role of protein disorder in phase separation and the macromolecular organization within droplets remain elusive. Here, we utilize a novel technique, ultrafast-scanning fluorescence correlation spectroscopy, to measure the molecular interactions and full coexistence curves (binodals), which quantify the protein concentration within LAF-1 droplets. The binodals of LAF-1 and its IDR display a number of unusual features, including 'high concentration' binodal arms that correspond to remarkably dilute droplets. We find that LAF-1 and other in vitro and intracellular droplets are characterized by an effective mesh size of ∼3-8 nm, which determines the size scale at which droplet properties impact molecular diffusion and permeability. These findings reveal how specific IDPs can phase separate to form permeable, lowdensity (semi-dilute) liquids, whose structural features are likely to strongly impact biological function.
UR - http://www.scopus.com/inward/record.url?scp=85030031088&partnerID=8YFLogxK
U2 - 10.1038/NCHEM.2803
DO - 10.1038/NCHEM.2803
M3 - Article
C2 - 29064502
AN - SCOPUS:85030031088
SN - 1755-4330
VL - 9
JO - Nature Chemistry
JF - Nature Chemistry
IS - 11
M1 - 2803
ER -