Suchergebnisse

Although human nucleoporin Tpr is frequently deregulated in cancer, its roles are poorly understood. Here we show that Tpr depletion generates transcription-dependent replication stress, DNA breaks, and genomic instability. DNA fiber assays and electron microscopy visualization of replication intermediates show that Tpr deficient cells exhibit slow and asymmetric replication forks under replication stress. Tpr deficiency evokes enhanced levels of DNA-RNA hybrids. Additionally, complementary proteomic strategies identify a network of Tpr-interacting proteins mediating RNA processing, such as MATR3 and SUGP2, and functional experiments confirm that their depletion trigger cellular phenotypes shared with Tpr deficiency. Mechanistic studies reveal the interplay of Tpr with GANP, a component of the TREX-2 complex. The Tpr-GANP interaction is supported by their shared protein level alterations in a cohort of ovarian carcinomas. Our results reveal links between nucleoporins, DNA transcription and replication, and the existence of a network physically connecting replication forks with transcription, splicing, and mRNA export machinery. ; The research was funded by the grants from the Fondazione AIRC per la Ricerca sul Cancro to M.F.; grants from Danish Cancer Society, Novo Nordisk Foundation, Danish National Research Foundation (project CARD), Swedish Research Council, Grant Agency of the Czech Republic (GACR 19-21325S), and Lundbeck Foundation to J.B.; and grants from the European Research Council (ERC2014 AdG669898 TARLOOP), the Spanish Ministry of Economy and Competitiveness (BFU2016-75058-P), and European Union Regional Funds (FEDER) to A.A. Author F.G-B. was a recipient of a predoctoral training fellowship of the Spanish Ministry of Education, Culture and Sports. Work of V.C. has been supported by Associazione Italiana per la Ricerca sul Cancro, AIRC-IG Ref: 21824 and by AIRC-FIRC fellowship assigned to M.A.R.-O., Ref: 2531. M.K. has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 707600, and from the Fondazione Umberto Veronesi (Milano, Italy), Post-doctoral Fellowships 2019 and 2020.