6 1 The SMAD2/3 interactome reveals that TGFβ controls m A 2 mRNA methylation in pluripotency 3 4 Alessandro Bertero1,*,†, Stephanie Brown1,*, Pedro Madrigal1,2, Anna Osnato1, Daniel 5 Ortmann1, Loukia Yiangou1, Juned Kadiwala1, Nina C. Hubner3, Igor Ruiz de los Mozos4, 6 Christoph Sadee4, An-Sofie Lenaerts1, Shota Nakanoh1, Rodrigo Grandy1, Edward Farnell5, 7 Jernej Ule4, Hendrik G. Stunnenberg3, Sasha Mendjan1,‡, and Ludovic Vallier1,2,#. 8 9 1 Wellcome Trust - MRC Cambridge Stem Cell Institute Anne McLaren Laboratory and 10 Department of Surgery, University of Cambridge, UK. 11 2 Wellcome Trust Sanger Institute, Hinxton UK. 12 3 Department of Molecular Biology, Radboud University Nijmegen, The Netherlands. 13 4 Francis Crick Institute and Department of Molecular Neuroscience, University College 14 London, UK. 15 5 Department of Pathology, University of Cambridge, UK. 16 17 * These authors contributed equally to this work. 18 † Current address: Department of Pathology, University of Washington, Seattle, WA, USA. 19 ‡ Current address: Institute of Molecular Biotechnology, Vienna, Austria. 20 # Corresponding author (
[email protected]). 1 21 The TGFβ pathway plays an essential role in embryonic development, organ 22 homeostasis, tissue repair, and disease1,2. This diversity of tasks is achieved through the 23 intracellular effector SMAD2/3, whose canonical function is to control activity of target 24 genes by interacting with transcriptional regulators3. Nevertheless, a complete 25 description of the factors interacting with SMAD2/3 in any given cell type is still lacking. 26 Here we address this limitation by describing the interactome of SMAD2/3 in human 27 pluripotent stem cells (hPSCs). This analysis reveals that SMAD2/3 is involved in 28 multiple molecular processes in addition to its role in transcription.