title: Characterization of ERM transactivation domain binding to the ACID/PTOV domain of the Mediator subunit MED25.
abstract: The N-terminal acidic transactivation domain (TAD) of ERM/ETV5 (ERM38-68), a PEA3 group member of Ets-related transcription factors, directly interacts with the ACID/PTOV domain of the Mediator complex subunit MED25. Molecular details of this interaction were investigated using nuclear magnetic resonance (NMR) spectroscopy. The TAD is disordered in solution but has a propensity to adopt local transient secondary structure. We show that it folds upon binding to MED25 and that the resulting ERM-MED25 complex displays characteristics of a fuzzy complex. Mutational analysis further reveals that two aromatic residues in the ERM TAD (F47 and W57) are involved in the binding to MED25 and participate in the ability of ERM TAD to activate transcription. Mutation of a key residue Q451 in the VP16 H1 binding pocket of MED25 affects the binding of ERM. Furthermore, competition experiments show that ERM and VP16 H1 share a common binding interface on MED25. NMR data confirms the occupancy of this binding pocket by ERM TAD. Based on these experimental data, a structural model of a functional interaction is proposed. This study provides mechanistic insights into the Mediator-transactivator interactions.
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France isabelle.landrieu@univ-lille1.fr.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Landrieu
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France.
authors.forename: Alexis
authors.identifier: http://orcid.org/0000-0002-0299-2344
authors.initials: A
authors.lastname: Verger
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Baert
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France.
authors.forename: Prakash
authors.initials: P
authors.lastname: Rucktooa
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Cantrelle
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Dewitte
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ferreira
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France.
authors.forename: Zoé
authors.initials: Z
authors.lastname: Lens
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Villeret
authors.affiliation: CNRS UMR 8576, Université de Lille, Parc CNRS de la Haute Borne, 50 avenue de Halley, B.P. 70478, 59658 Villeneuve d'Ascq Cedex, France didier.monte@iri.univ-lille1.fr.
authors.forename: Didier
authors.initials: D
authors.lastname: Monté
mesh_terms: D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D056892:Mediator Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D009154:Mutation; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D015534:Trans-Activators / Q000737:chemistry* / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C086680:ETV5 protein, human; C483045:MED25 protein, human; D056892:Mediator Complex; D015534:Trans-Activators; D014157:Transcription Factors