In vivo reconstitution finds multivalent RNA-RNA interactions as drivers of mesh-like condensates
Abstract
Liquid-like condensates have been thought to be sphere-like. Recently, various condensates with filamentous morphology have been observed in cells. One such condensate is the TIS granule network that shares a large surface area with the rough endoplasmic reticulum and is important for membrane protein trafficking. It has been unclear how condensates with mesh-like shapes, but dynamic protein components are formed. In vitro and in vivo reconstitution experiments revealed that the minimal components are a multivalent RNA-binding protein that concentrates RNAs that are able to form extensive intermolecular mRNA-mRNA interactions. mRNAs with large unstructured regions have a high propensity to form a pervasive intermolecular interaction network that acts as condensate skeleton. The underlying RNA matrix prevents full fusion of spherical liquid-like condensates, thus driving the formation of irregularly shaped membraneless organelles. The resulting large surface area may promote interactions at the condensate surface and at the interface with other organelles.
Data availability
All raw data are included as supplementary Excel files in the manuscript.
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POSTAR2: deciphering the post-transcriptional regulatory logicshttp://lulab.life.tsinghua.edu.cn/postar/index.php.
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Author details
Funding
NIH Office of the Director (DP1-GM123454)
- Christine Mayr
National Cancer Institute (P30 CA008748)
- Christine Mayr
Pershing Square Sohn Cancer Research Alliance
- Christine Mayr
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Ma et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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