title: The intrinsically disordered distal face of nucleoplasmin recognizes distinct oligomerization states of histones.
abstract: The role of Nucleoplasmin (NP) as a H2A-H2B histone chaperone has been extensively characterized. To understand its putative interaction with other histone ligands, we have characterized its ability to bind H3-H4 and histone octamers. We find that the chaperone forms distinct complexes with histones, which differ in the number of molecules that build the assembly and in their spatial distribution. When complexed with H3-H4 tetramers or histone octamers, two NP pentamers form an ellipsoidal particle with the histones located at the center of the assembly, in stark contrast with the NP/H2A-H2B complex that contains up to five histone dimers bound to one chaperone pentamer. This particular assembly relies on the ability of H3-H4 to form tetramers either in solution or as part of the octamer, and it is not observed when a variant of H3 (H3C110E), unable to form stable tetramers, is used instead of the wild-type protein. Our data also suggest that the distal face of the chaperone is involved in the interaction with distinct types of histones, as supported by electron microscopy analysis of the different NP/histone complexes. The use of the same structural region to accommodate all type of histones could favor histone exchange and nucleosome dynamics.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencia y Tecnología, Universidad del PaísVasco, P. O. Box 644, 48080 Bilbao, Spain, Unidad de Biofísica (Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea), Barrio Sarriena s/n, 48080 Leioa Spain, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain and Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada.
authors.forename: Isbaal
authors.initials: I
authors.lastname: Ramos
authors.forename: Noelia
authors.initials: N
authors.lastname: Fernández-Rivero
authors.forename: Rocío
authors.initials: R
authors.lastname: Arranz
authors.forename: Kerman
authors.initials: K
authors.lastname: Aloria
authors.forename: Ron
authors.initials: R
authors.lastname: Finn
authors.forename: Jesús M
authors.initials: JM
authors.lastname: Arizmendi
authors.forename: Juan
authors.initials: J
authors.lastname: Ausió
authors.forename: José María
authors.initials: JM
authors.lastname: Valpuesta
authors.forename: Arturo
authors.initials: A
authors.lastname: Muga
authors.forename: Adelina
authors.initials: A
authors.lastname: Prado
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006657:Histones / Q000737:chemistry* / Q000378:metabolism; D064267:Intrinsically Disordered Proteins / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D056489:Nucleoplasmins / Q000737:chemistry* / Q000378:metabolism; D055503:Protein Multimerization; D059748:Proteolysis; D014982:Xenopus laevis
chemical_list: D006657:Histones; D064267:Intrinsically Disordered Proteins; D056489:Nucleoplasmins