title: Herpes simplex virus ICP27 protein directly interacts with the nuclear pore complex through Nup62, inhibiting host nucleocytoplasmic transport pathways.
abstract: The herpes simplex virus ICP27 protein is important for the expression and nuclear export of viral mRNAs. Although several binding sites have been mapped along the ICP27 sequence for various RNA and protein partners, including the transport receptor TAP of the host cell nuclear transport machinery, several aspects of ICP27 trafficking through the nuclear pore complex remain unclear. We investigated if ICP27 could interact directly with the nuclear pore complex itself, finding that ICP27 directly binds the core nucleoporin Nup62. This is confirmed through co-immunoprecipitation and in vitro binding assays with purified components. Mapping with ICP27 deletion and point mutants further shows that the interaction requires sequences in both the N and C termini of ICP27. Expression of wild type ICP27 protein inhibited both classical, importin α/β-dependent and transportin-dependent nuclear import. In contrast, an ICP27 point mutant that does not interact with Nup62 had no such inhibitory effect. We suggest that ICP27 association with Nup62 provides additional binding sites at the nuclear pore for ICP27 shuttling, thus supporting ICP27-mediated transport. We propose that ICP27 competes with some host cell transport receptors for binding, resulting in inhibition of those host transport pathways.
authors.affiliation: Wellcome Trust Centre for Cell Biology and Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom. p.malik@ed.ac.uk
authors.forename: Poonam
authors.initials: P
authors.lastname: Malik
authors.forename: Alijan
authors.initials: A
authors.lastname: Tabarraei
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Kehlenbach
authors.forename: Nadia
authors.initials: N
authors.lastname: Korfali
authors.forename: Ryota
authors.initials: R
authors.lastname: Iwasawa
authors.forename: Sheila V
authors.initials: SV
authors.lastname: Graham
authors.forename: Eric C
authors.initials: EC
authors.lastname: Schirmer
mesh_terms: D021581:Active Transport, Cell Nucleus; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism / Q000821:virology; D006367:HeLa Cells; D018259:Herpesvirus 1, Human / Q000502:physiology*; D019288:Herpesvirus 8, Human / Q000235:genetics; D054884:Host-Pathogen Interactions; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D047468:Immunoprecipitation; D008562:Membrane Glycoproteins / Q000378:metabolism*; D049790:Nuclear Export Signals; D019913:Nuclear Localization Signals; D022022:Nuclear Pore / Q000378:metabolism* / Q000821:virology; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism*; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism; D010449:Peptide Mapping; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D012333:RNA, Messenger / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: C057120:ICP27 protein, human herpesvirus 1; D017874:Immediate-Early Proteins; D008562:Membrane Glycoproteins; C122111:NXF1 protein, human; D049790:Nuclear Export Signals; D019913:Nuclear Localization Signals; D028861:Nuclear Pore Complex Proteins; D029543:Nucleocytoplasmic Transport Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D016601:RNA-Binding Proteins; C049312:nuclear pore protein p62