Pseudouridine selects RNAs for extracellular transport

Area of Science:

• Molecular Biology
• Cell Biology
• Neuroscience

Background:

• Extracellular RNAs (exRNAs) mediate intercellular communication, particularly in the nervous system.
• Mechanisms governing the specific loading and transport of RNAs into extracellular vesicles (EVs) remain largely unknown.

Purpose of the Study:

• To identify molecular factors regulating the export of RNAs into extracellular vesicles from neuronal cells.
• To elucidate the role of RNA modification in extracellular RNA trafficking.

Main Methods:

• Genome-wide CRISPR screening in a neuronal cell line.
• Proteomics and high-sensitivity transcriptomics.
• Biochemical assays to assess RNA modification and protein-RNA interactions.

Main Results:

• Identified domesticated retroviral proteins and RNA-modifying enzymes involved in EV-mediated RNA transport.
• Pseudouridine synthase 1 (PUS1) and its product, pseudouridine, are critical for extracellular RNA export.
• Myosin light chain 6 (MYL6) acts as a pseudouridine-binding protein essential for RNA secretion.

Conclusions:

• RNA chemical modification, specifically pseudouridylation, is a key determinant of extracellular RNA export.
• A novel biochemical code links RNA modification to transport via EVs.
• Established a framework for investigating exRNA function in the nervous system and other tissues.