TY - JOUR A1 - Sekulovski, Samoil A1 - Devant, Pascal A1 - Panizza, Silvia A1 - Gogakos, Tasos A1 - Pitiriciu, Anda A1 - Heitmeier, Katharina A1 - Ramsay, Ewan Phillip A1 - Barth, Marie A1 - Schmidt, Carla A1 - Tuschl, Thomas A1 - Baas, Frank A1 - Weitzer, Stefan A1 - Martinez, Javier A1 - Trowitzsch, Simon T1 - Assembly defects of human tRNA splicing endonuclease contribute to impaired pre-tRNA processing in pontocerebellar hypoplasia T2 - Nature Communications N2 - 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. KW - Mechanisms of disease KW - RNA KW - RNA-binding proteins KW - X-ray crystallography Y1 - 2021 UR - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63466 UR - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-634663 SN - 2041-1723 N1 - 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. N1 - Open Access funding enabled and organized by Projekt DEAL. VL - 12 IS - art. 5610 SP - 1 EP - 15 PB - Nature Publishing Group UK CY - [London] ER -