title: Interaction between basic residues of Epstein-Barr virus EBNA1 protein and cellular chromatin mediates viral plasmid maintenance.
abstract: The Epstein-Barr virus (EBV) genome is episomally maintained in latently infected cells. The viral protein EBNA1 is a bridging molecule that tethers EBV episomes to host mitotic chromosomes as well as to interphase chromatin. EBNA1 localizes to cellular chromosomes (chromatin) via its chromosome binding domains (CBDs), which are rich in glycine and arginine residues. However, the molecular mechanism by which the CBDs of EBNA1 attach to cellular chromatin is still under debate. Mutation analyses revealed that stepwise substitution of arginine residues within the CBD1 (amino acids 40-54) and CBD2 (amino acids 328-377) regions with alanines progressively impaired chromosome binding activity of EBNA1. The complete arginine-to-alanine substitutions within the CBD1 and -2 regions abolished the ability of EBNA1 to stably maintain EBV-derived oriP plasmids in dividing cells. Importantly, replacing the same arginines with lysines had minimal effect, if any, on chromosome binding of EBNA1 as well as on its ability to stably maintain oriP plasmids. Furthermore, a glycine-arginine-rich peptide derived from the CBD1 region bound to reconstituted nucleosome core particles in vitro, as did a glycine-lysine rich peptide, whereas a glycine-alanine rich peptide did not. These results support the idea that the chromosome binding of EBNA1 is mediated by electrostatic interactions between the basic amino acids within the CBDs and negatively charged cellular chromatin.
authors.affiliation: Division of Virology, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan. tkanda@aichi-cc.jp
authors.forename: Teru
authors.initials: T
authors.lastname: Kanda
authors.forename: Naoki
authors.initials: N
authors.lastname: Horikoshi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Murata
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kawashima
authors.forename: Atsuko
authors.initials: A
authors.lastname: Sugimoto
authors.forename: Yohei
authors.initials: Y
authors.lastname: Narita
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kurumizaka
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Tsurumi
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D024361:Amino Acids, Basic / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D002877:Chromosomes, Human / Q000378:metabolism; D019309:Epstein-Barr Virus Nuclear Antigens / Q000737:chemistry* / Q000378:metabolism*; D006367:HeLa Cells; D004854:Herpesvirus 4, Human / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009707:Nucleosomes / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D024361:Amino Acids, Basic; D002843:Chromatin; D019309:Epstein-Barr Virus Nuclear Antigens; D050505:Mutant Proteins; D009707:Nucleosomes; D010455:Peptides; D011993:Recombinant Fusion Proteins; C417029:EBV-encoded nuclear antigen 1
keywords: Amino Acid; Chromosomes; Confocal Microscopy; DNA Viruses; EBNA1; Episome; Epstein-Barr Virus; Fluorescence; Nucleosome; Site-directed Mutagenesis