TY - JOUR
T1 - RNA-Based Coacervates as a Model for Membraneless Organelles
T2 - Formation, Properties, and Interfacial Liposome Assembly
AU - Aumiller, William M.
AU - Pir Cakmak, Fatma
AU - Davis, Bradley W.
AU - Keating, Christine D.
N1 - Funding Information:
This work was supported by the National Science Foundation, grant MCB-1244180 (coacervate preparation, temperature dependence, partitioning, liposome interactions), and the NASA Exobiology program, grant NNX13AI01G (FRAP measurements). We thank Philip Bevilacqua for helpful discussions on polyU structure and Erica Frankel for assistance with polyU characterization.
Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/10/4
Y1 - 2016/10/4
N2 - Liquid-liquid phase separation is responsible for formation of P granules, nucleoli, and other membraneless subcellular organelles composed of RNA and proteins. Efforts to understand the physical basis of liquid organelle formation have thus far focused on intrinsically disordered proteins (IDPs) as major components that dictate occurrence and properties. Here, we show that complex coacervates composed of low complexity RNA (polyuridylic acid, polyU) and short polyamines (spermine and spermidine) share many features of IDP-based coacervates. PolyU/polyamine coacervates compartmentalize biomolecules (peptides, oligonucleotides) in a sequence- and length-dependent manner. These solutes retain mobility within the coacervate droplets, as demonstrated by rapid recovery from photobleaching. Coacervation is reversible with changes in solution temperature due to changes in the polyU structure that impact its interactions with polyamines. We further demonstrate that lipid vesicles assemble at the droplet interface without impeding RNA entry/egress. These vesicles remain intact at the interface and can be released upon temperature-induced droplet dissolution.
AB - Liquid-liquid phase separation is responsible for formation of P granules, nucleoli, and other membraneless subcellular organelles composed of RNA and proteins. Efforts to understand the physical basis of liquid organelle formation have thus far focused on intrinsically disordered proteins (IDPs) as major components that dictate occurrence and properties. Here, we show that complex coacervates composed of low complexity RNA (polyuridylic acid, polyU) and short polyamines (spermine and spermidine) share many features of IDP-based coacervates. PolyU/polyamine coacervates compartmentalize biomolecules (peptides, oligonucleotides) in a sequence- and length-dependent manner. These solutes retain mobility within the coacervate droplets, as demonstrated by rapid recovery from photobleaching. Coacervation is reversible with changes in solution temperature due to changes in the polyU structure that impact its interactions with polyamines. We further demonstrate that lipid vesicles assemble at the droplet interface without impeding RNA entry/egress. These vesicles remain intact at the interface and can be released upon temperature-induced droplet dissolution.
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U2 - 10.1021/acs.langmuir.6b02499
DO - 10.1021/acs.langmuir.6b02499
M3 - Article
C2 - 27599198
AN - SCOPUS:84989875593
VL - 32
SP - 10042
EP - 10053
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 39
ER -