title: Structure of a herpesvirus nuclear egress complex subunit reveals an interaction groove that is essential for viral replication.
abstract: Herpesviruses require a nuclear egress complex (NEC) for efficient transit of nucleocapsids from the nucleus to the cytoplasm. The NEC orchestrates multiple steps during herpesvirus nuclear egress, including disruption of nuclear lamina and particle budding through the inner nuclear membrane. In the important human pathogen human cytomegalovirus (HCMV), this complex consists of nuclear membrane protein UL50, and nucleoplasmic protein UL53, which is recruited to the nuclear membrane through its interaction with UL50. Here, we present an NMR-determined solution-state structure of the murine CMV homolog of UL50 (M50; residues 1-168) with a strikingly intricate protein fold that is matched by no other known protein folds in its entirety. Using NMR methods, we mapped the interaction of M50 with a highly conserved UL53-derived peptide, corresponding to a segment that is required for heterodimerization. The UL53 peptide binding site mapped onto an M50 surface groove, which harbors a large cavity. Point mutations of UL50 residues corresponding to surface residues in the characterized M50 heterodimerization interface substantially decreased UL50-UL53 binding in vitro, eliminated UL50-UL53 colocalization, prevented disruption of nuclear lamina, and halted productive virus replication in HCMV-infected cells. Our results provide detailed structural information on a key protein-protein interaction involved in nuclear egress and suggest that NEC subunit interactions can be an attractive drug target.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
authors.forename: Kendra E
authors.initials: KE
authors.lastname: Leigh
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
authors.forename: Mayuri
authors.initials: M
authors.lastname: Sharma
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
authors.forename: My Sam
authors.initials: MS
authors.lastname: Mansueto
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
authors.forename: Andras
authors.initials: A
authors.lastname: Boeszoermenyi
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
authors.forename: David J
authors.initials: DJ
authors.lastname: Filman
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
authors.forename: James M
authors.initials: JM
authors.lastname: Hogle
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 gerhard_wagner@hms.harvard.edu hari_arthanari@hms.harvard.edu.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wagner
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115.
authors.forename: Donald M
authors.initials: DM
authors.lastname: Coen
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115 gerhard_wagner@hms.harvard.edu hari_arthanari@hms.harvard.edu.
authors.forename: Haribabu
authors.initials: H
authors.lastname: Arthanari
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites; D002151:Calorimetry; D002467:Cell Nucleus / Q000378:metabolism*; D030562:Databases, Protein; D055808:Drug Discovery; D006564:Herpesviridae / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018146:Muromegalovirus; D009154:Mutation / Q000235:genetics; D034881:Nuclear Lamina / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D021122:Protein Subunits / Q000737:chemistry* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012996:Solutions; D013329:Structure-Activity Relationship; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D010455:Peptides; D021122:Protein Subunits; D012996:Solutions; D014764:Viral Proteins
keywords: NMR; cytomegalovirus; drug target; herpesvirus; protein–protein interactions