Lucid Belmudes, Guillaume Communie, Dayana C. Farhat, Thierry Lagrange, Alexandre Bougdour, Dominique Pontier, Yohann Couté, Matthew W. Bowler, Charlotte Corrao, Christopher Swale, Mohamed-Ali Hakimi, Caroline Mas, Institute for Advanced Biosciences / Institut pour l'Avancée des Biosciences (Grenoble) (IAB), Etablissement français du sang - Auvergne-Rhône-Alpes (EFS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre Hospitalier Universitaire [Grenoble] (CHU)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire européen de biologie moléculaire - European Molecular Biology Laboratory (EMBL Grenoble), European Molecular Biology Laboratory [Grenoble] (EMBL), Institut Laue-Langevin (ILL), ILL, Laboratoire Génome et développement des plantes (LGDP), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Etude de la dynamique des protéomes (EDyP), BioSanté (UMR BioSanté), Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Integrated Structural Biology Grenoble (ISBG - UMS 3518 ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-European Molecular Biology Laboratory [Grenoble] (EMBL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ANR-10-INSB-0801 ProFI ANR-10-INSB-0801, ANR-11-LABX-0024,ParaFrap,Alliance française contre les maladies parasitaires(2011), ANR-18-CE15-0023,HostQuest,Stratégies de Persistence de Toxoplasma gondii : Conquérir la Cellule Hôte et Echapper à la Réponse Immune Innée(2018), ANR-10-LABX-0041,TULIP,Towards a Unified theory of biotic Interactions: the roLe of environmental(2010), ANR-18-EURE-0019,TULIP-GSR,The Toulouse-Perpignan(2018), Centre Hospitalier Universitaire [Grenoble] (CHU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Etablissement français du sang - Auvergne-Rhône-Alpes (EFS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Integrated Structural Biology Grenoble (ISBG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-European Molecular Biology Laboratory [Grenoble] (EMBL)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Rosalie, Martin, Laboratoires d'excellence - Alliance française contre les maladies parasitaires - - ParaFrap2011 - ANR-11-LABX-0024 - LABX - VALID, APPEL À PROJETS GÉNÉRIQUE 2018 - Stratégies de Persistence de Toxoplasma gondii : Conquérir la Cellule Hôte et Echapper à la Réponse Immune Innée - - HostQuest2018 - ANR-18-CE15-0023 - AAPG2018 - VALID, Towards a Unified theory of biotic Interactions: the roLe of environmental - - TULIP2010 - ANR-10-LABX-0041 - LABX - VALID, and The Toulouse-Perpignan - - TULIP-GSR2018 - ANR-18-EURE-0019 - EURE - VALID
Correct 3’end processing of mRNAs is one of the regulatory cornerstones of gene expression. In a parasite that must adapt to the regulatory requirements of its multi-host life style, there is a need to adopt additional means to partition the distinct transcriptional signatures of the closely and tandemly arranged stage-specific genes. In this study, we report our findings in T. gondii of an m6A-dependent 3’end polyadenylation serving as a transcriptional barrier at these loci. We identify the core polyadenylation complex within T. gondii and establish CPSF4 as a reader for m6A-modified mRNAs, via a YTH domain within its C-terminus, a feature which is shared with plants. We bring evidence of the specificity of this interaction both biochemically, and by determining the crystal structure at high resolution of the T. gondii CPSF4-YTH in complex with an m6A-modified RNA. We show that the loss of m6A, both at the level of its deposition or its recognition is associated with an increase in aberrantly elongated chimeric mRNAs emanating from impaired transcriptional termination, a phenotype previously noticed in the plant model Arabidopsis thaliana. Nanopore direct RNA sequencing shows the occurrence of transcriptional read-through breaching into downstream repressed stage-specific genes, in the absence of either CPSF4 or the m6A RNA methylase components in both T. gondii and A. thaliana. Taken together, our results shed light on an essential regulatory mechanism coupling the pathways of m6A metabolism directly to the cleavage and polyadenylation processes, one that interestingly seem to serve, in both T. gondii and A. thaliana, as a guardian against aberrant transcriptional read-throughs.