title: Human nonsense-mediated mRNA decay factor UPF2 interacts directly with eRF3 and the SURF complex.
abstract: Nonsense-mediated mRNA decay (NMD) is an mRNA degradation pathway that regulates gene expression and mRNA quality. A complex network of macromolecular interactions regulates NMD initiation, which is only partially understood. According to prevailing models, NMD begins by the assembly of the SURF (SMG1-UPF1-eRF1-eRF3) complex at the ribosome, followed by UPF1 activation by additional factors such as UPF2 and UPF3. Elucidating the interactions between NMD factors is essential to comprehend NMD, and here we demonstrate biochemically and structurally the interaction between human UPF2 and eukaryotic release factor 3 (eRF3). In addition, we find that UPF2 associates with SURF and ribosomes in cells, in an UPF3-independent manner. Binding assays using a collection of UPF2 truncated variants reveal that eRF3 binds to the C-terminal part of UPF2. This region of UPF2 is partially coincident with the UPF3-binding site as revealed by electron microscopy of the UPF2-eRF3 complex. Accordingly, we find that the interaction of UPF2 with UPF3b interferes with the assembly of the UPF2-eRF3 complex, and that UPF2 binds UPF3b more strongly than eRF3. Together, our results highlight the role of UPF2 as a platform for the transient interactions of several NMD factors, including several components of SURF.
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (Spanish National Research Council), Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: López-Perrote
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (Spanish National Research Council), Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Castaño
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (Spanish National Research Council), Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Melero
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (Spanish National Research Council), Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Zamarro
authors.affiliation: Department of Molecular Biology, Yokohama City University School of Medicine, 3-9, Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kurosawa
authors.affiliation: Department of Molecular Biology, Yokohama City University School of Medicine, 3-9, Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ohnishi
authors.affiliation: Department of Molecular Biology, Yokohama City University School of Medicine, 3-9, Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Uchiyama
authors.affiliation: Department of Molecular Biology, Yokohama City University School of Medicine, 3-9, Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Aoyagi
authors.affiliation: Max Planck Institute of Biochemistry, Department of Structural Cell Biology, Am Klopferspitz 18, D-82152 Martinsried, Germany.
authors.forename: Gretel
authors.initials: G
authors.lastname: Buchwald
authors.affiliation: Medical Innovation Center, Laboratory for Malignancy Control Research, Kyoto University Graduate School of Medicine, 53, Shogoin Kawaharacho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Kataoka
authors.affiliation: Department of Molecular Biology, Yokohama City University School of Medicine, 3-9, Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan yamasita@yokohama-cu.ac.jp.
authors.forename: Akio
authors.initials: A
authors.lastname: Yamashita
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (Spanish National Research Council), Ramiro de Maeztu 9, 28040 Madrid, Spain ollorca@cib.csic.es.
authors.forename: Oscar
authors.initials: O
authors.lastname: Llorca
mesh_terms: D018389:Codon, Nonsense / Q000235:genetics; D056890:Eukaryota / Q000235:genetics; D005091:Exons; D006801:Humans; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D059365:Nonsense Mediated mRNA Decay / Q000235:genetics*; D010454:Peptide Termination Factors / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D016601:RNA-Binding Proteins; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D018389:Codon, Nonsense; D046912:Multiprotein Complexes; D010454:Peptide Termination Factors; D016601:RNA-Binding Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C468286:UPF2 protein, human; C087971:peptide-chain-release factor 3