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Kashida, S.

Publications and source records attributed to Kashida, S..

2 recordsLinked to original sources

Nanoparticle-based local translation reveals mRNA as translation-coupled scaffold with anchoring function

Spatial regulations of mRNA translation are central to cellular functions and relies on numerous complex processes. Biomimetic approaches could bypass the endogenous complex processes, improve our comprehension, and allow for controlling local translation regulations and functions. However, the causality between localizing translation and nascent protein function remains elusive. Here, we develop a novel nanoparticle-based strategy to magnetically control mRNA spatial patterns in mammalian cell extracts and investigate how local translation impacts nascent protein localization and function. By monitoring translation on magnetically localized mRNAs, we show that mRNA-nanoparticle operates as a source for the continuous production of proteins from defined positions. By applying magnetic localization of mRNAs coding for Actin Binding Proteins, we trigger the local formation of actin cytoskeleton and identify minimal requirements for spatial control of actin filament network. In addition, our bottom-up approach identifies a novel role of mRNA as translation-coupled scaffold for nascent N-terminal protein domain functions. Our approach will serve as a novel platform for regulating mRNA localization and investigating a functional role of nascent protein domains during translation.

molecular biology

RNA is a critical element for the sizing and the composition of phase-separated RNA-protein condensates

Liquid-liquid phase separation is thought to be a key organizing principle in eukaryotic cells to generate highly concentrated dynamic assemblies, such as the RNP granules. Numerous in vitro approaches have validated this model, yet a missing aspect is to take into consideration the complex molecular mixture and promiscuous interactions found in vivo. Here we report the versatile scaffold \"ArtiG\" to generate concentration-dependent RNA-protein condensates within living cells, as a bottom-up approach to study the impact of co-segregated endogenous components on phase separation. We demonstrate that intracellular RNA seeds the nucleation of the condensates, as it provides molecular cues to locally coordinate the formation of endogenous high order RNP assemblies. Interestingly, the co-segregation of intracellular components ultimately impacts the size of the phase-separated condensates. Thus, RNA arises as an architectural element that can influence the composition and the morphological outcome of the condensate phases in an intracellular context.

cell biology