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bioRxiv · 10.1101/2020.08.30.273748

Sequence-encoded and Composition-dependent Protein-RNA Interactions Control Multiphasic Condensate Topologies

Kaur, T.·Raju, M.·Alshareedah, I.·Davis, R. B.·Potoyan, D. A.·Banerjee, P. R.
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Abstract

Multivalent protein-protein and protein-RNA interactions are the drivers of biological phase separation. Biomolecular condensates typically contain a dense network of multiple proteins and RNAs, and their competing molecular interactions play key roles in regulating the condensate composition and structure. Employing a ternary system comprising of a prion-like polypeptide (PLP), arginine-rich polypeptide (RRP), and RNA, we show that competition between the PLP and RNA for a single shared partner, the RRP, leads to RNA-induced demixing of PLP-RRP condensates into stable coexisting phases-homotypic PLP condensates and heterotypic RRP-RNA condensates. The morphology of these biphasic condensates (non-engulfing/ partial engulfing/ complete engulfing) is determined by the RNA-to-RRP stoichiometry and the hierarchy of intermolecular interactions, providing a glimpse of the broad range of multiphasic patterns that are accessible to these condensates. Our findings provide a minimal set of physical rules that govern the composition and spatial organization of multicomponent and multiphasic biomolecular condensates.

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Kaur, T., Raju, M., Alshareedah, I., Davis, R. B., Potoyan, D. A., Banerjee, P. R.. 2020-08-31. Sequence-encoded and Composition-dependent Protein-RNA Interactions Control Multiphasic Condensate Topologies. https://doi.org/10.1101/2020.08.30.273748

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