An intrinsically disordered region mediates RNA-binding selectivity and cellular activities of LARP6

Journal article

Intrinsically disordered regions (IDRs) are prevalent in RNA-binding proteins (RBPs), yet their roles in RNA interactions remain poorly defined. We examined RNA-binding regulation by structured and disordered regions of LARP6, an RBP with a diverse RNA-binding repertoire. Mass spectrometry-based RNA interaction mapping in living cells identified direct LARP6–RNA contacts within the structured La-module and its flanking IDRs. Mutagenesis and individual-nucleotide resolution UV-crosslinking and immunoprecipitation (iCLIP) revealed the La-module, but not the IDRs, as essential for LARP6 RNA binding. Deletion of the N-terminal IDR broadened LARP6 RNA footprints, uncovering a role in RNA-binding selectivity. This is achieved through a composite mechanism of restricting the conformational flexibility of the adjacent La-module, forming auxiliary contacts with the RNA, and modulating RNA access for binding. The IDR-mediated RNA-binding selectivity is critical for LARP6-mediated promotion of cancer cell viability and invasion. Our findings uncover a previously unrecognised critical function for IDRs in promoting selective RBP–RNA recognition, by affecting the binding specificity of their adjacent structured domains.

Authors: Capraro, F; Abis, G; Incocciati, A; Simpson, PJ; Karimzadeh, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Nature Communications
• Volume: 17
• Issue: 1
• Article number: 2939
• Publication date: 2026-02-19
• Acceptance date: 2026-02-09
• DOI: 10.1038/s41467-026-69789-z
• EISSN: 2041-1723
• ISSN: 2041-1723
• Language: English
• Keywords: RNA; Intrinsically disordered proteins; Function (biology); Mutagenesis; Immunoprecipitation; RNA-binding protein; Protein–protein interaction; Binding site; Plasma protein binding