Assembly defects of human tRNA splicing endonuclease contribute to impaired pre-tRNA processing in pontocerebellar hypoplasia

  • Introns of human transfer RNA precursors (pre-tRNAs) are excised by the tRNA splicing endonuclease TSEN in complex with the RNA kinase CLP1. Mutations in TSEN/CLP1 occur in patients with pontocerebellar hypoplasia (PCH), however, their role in the disease is unclear. Here, we show that intron excision is catalyzed by tetrameric TSEN assembled from inactive heterodimers independently of CLP1. Splice site recognition involves the mature domain and the anticodon-intron base pair of pre-tRNAs. The 2.1-Å resolution X-ray crystal structure of a TSEN15–34 heterodimer and differential scanning fluorimetry analyses show that PCH mutations cause thermal destabilization. While endonuclease activity in recombinant mutant TSEN is unaltered, we observe assembly defects and reduced pre-tRNA cleavage activity resulting in an imbalanced pre-tRNA pool in PCH patient-derived fibroblasts. Our work defines the molecular principles of intron excision in humans and provides evidence that modulation of TSEN stability may contribute to PCH phenotypes.
Author:Samoil SekulovskiORCiD, Pascal DevantORCiD, Silvia PanizzaORCiD, Tasos GogakosORCiD, Anda Pitiriciu, Katharina HeitmeierORCiD, Ewan Phillip RamsayORCiD, Marie BarthORCiDGND, Carla SchmidtORCiDGND, Thomas TuschlORCiDGND, Frank BaasORCiD, Stefan WeitzerORCiD, Javier MartinezORCiD, Simon TrowitzschORCiDGND
Parent Title (English):Nature Communications
Publisher:Nature Publishing Group UK
Place of publication:[London]
Document Type:Article
Date of Publication (online):2021/09/28
Date of first Publication:2021/09/28
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2022/02/09
Tag:Mechanisms of disease; RNA; RNA-binding proteins; X-ray crystallography
Issue:art. 5610
Page Number:15
First Page:1
Last Page:15
M.B. and C.S. acknowledge funding from the Federal Ministry for Education and Research (BMBF, ZIK program, 03Z22HN22), the European Regional Development Funds (EFRE, ZS/2016/04/ 78115) and the MLU Halle-Wittenberg. This study was furthermore supported by grants of the German Research Foundation (grant number TR 1711/1-7) to S.T., the Austrian Science Fund (grant number FWF P29888) to J.M. and S.T., the CRC 902 Molecular Principles of RNA-based Regulation (S.S. and S.T.), and a Boehringer Ingelheim Fonds fellowship to S.S.
Open Access funding enabled and organized by Projekt DEAL.
Institutes:Biochemie, Chemie und Pharmazie
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - Namensnennung 4.0