title: Structural basis for PHDVC5HCHNSD1-C2HRNizp1 interaction: implications for Sotos syndrome.
abstract: Sotos syndrome is an overgrowth syndrome caused by mutations within the functional domains ofNSD1 gene coding for NSD1, a multidomain protein regulating chromatin structure and gene expression. In particular, PHDVC5HCHNSD1 tandem domain, composed by a classical (PHDV) and an atypical (C5HCH) plant homeo-domain (PHD) finger, is target of several pathological missense-mutations. PHDVC5HCHNSD1 is also crucial for NSD1-dependent transcriptional regulation and interacts with the C2HR domain of transcriptional repressor Nizp1 (C2HRNizp1)in vitro To get molecular insights into the mechanisms dictating the patho-physiological relevance of the PHD finger tandem domain, we solved its solution structure and provided a structural rationale for the effects of seven Sotos syndrome point-mutations. To investigate PHDVC5HCHNSD1 role as structural platform for multiple interactions, we characterized its binding to histone H3 peptides and to C2HRNizp1 by ITC and NMR. We observed only very weak electrostatic interactions with histone H3 N-terminal tails, conversely we proved specific binding to C2HRNizp1 We solved C2HRNizp1 solution structure and generated a 3D model of the complex, corroborated by site-directed mutagenesis. We suggest a mechanistic scenario where NSD1 interactions with cofactors such as Nizp1 are impaired by PHDVC5HCHNSD1 pathological mutations, thus impacting on the repression of growth-promoting genes, leading to overgrowth conditions.
authors.affiliation: Biomolecular NMR Unit, Division of Genetics and Cell Biology, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy Università degli Studi di Milano, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Berardi
authors.affiliation: Biomolecular NMR Unit, Division of Genetics and Cell Biology, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Quilici
authors.affiliation: Biomolecular NMR Unit, Division of Genetics and Cell Biology, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy Università Vita e Salute San Raffaele, Milano 21032, Italy.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Spiliotopoulos
authors.affiliation: Biomolecular NMR Unit, Division of Genetics and Cell Biology, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy Università Vita e Salute San Raffaele, Milano 21032, Italy.
authors.forename: Maria Angeles
authors.initials: MA
authors.lastname: Corral-Rodriguez
authors.affiliation: Biomolecular NMR Unit, Division of Genetics and Cell Biology, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy.
authors.forename: Fernando
authors.initials: F
authors.lastname: Martin-Garcia
authors.affiliation: Biocrystallography Unit, Division of Immunology, Transplantation, and Infectious Diseases, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Degano
authors.affiliation: Functional genomics of cancer, Division of Experimental Oncology, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy.
authors.forename: Giovanni
authors.identifier: http://orcid.org/0000-0003-2973-5038
authors.initials: G
authors.lastname: Tonon
authors.affiliation: Biomolecular NMR Unit, Division of Genetics and Cell Biology, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Ghitti
authors.affiliation: Biomolecular NMR Unit, Division of Genetics and Cell Biology, IRCCS S. Raffaele Scientific Institute, Milan 20132, Italy musco.giovanna@hsr.it.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Musco
mesh_terms: D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D011495:Histone-Lysine N-Methyltransferase; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D058495:Sotos Syndrome / Q000235:genetics*
chemical_list: D002352:Carrier Proteins; D006657:Histones; C487408:Nizp1 protein, mouse; D009687:Nuclear Proteins; D011495:Histone-Lysine N-Methyltransferase; C491867:Nsd1 protein, mouse