title: Inhibition of IKKα by BAY61-3606 Reveals IKKα-Dependent Histone H3 Phosphorylation in Human Cytomegalovirus Infected Cells.
abstract: Protein kinase inhibitors can be used as tools to identify proteins and pathways required for virus replication. Using virus replication assays and western blotting we found that the widely used protein kinase inhibitor BAY61-3606 inhibits replication of human cytomegalovirus (HCMV) strain AD169 and the accumulation of HCMV immediate-early proteins in AD169 infected cells, but has no effect on replication of HCMV strain Merlin. Using in vitro kinase assays we found that BAY61-3606 is a potent inhibitor of the cellular kinase IKKα. Infection of cells treated with siRNA targeting IKKα indicated IKKα was required for efficient AD169 replication and immediate-early protein production. We hypothesized that IKKα was required for AD169 immediate-early protein production as part of the canonical NF-κB signaling pathway. However, although BAY61-3606 inhibited phosphorylation of the IKKα substrate IκBα, we found no canonical or non-canonical NF-κB signaling in AD169 infected cells. Rather, we observed that treatment of cells with BAY61-3606 or siRNA targeting IKKα decreased phosphorylation of histone H3 at serine 10 (H3S10p) in western blotting assays. Furthermore, we found treatment of cells with BAY61-3606, but not siRNA targeting IKKα, inhibited the accumulation of histone H3 acetylation (H3K9ac, H3K18ac and H3K27ac) and tri-methylation (H3K27me3 and H3K36me3) modifications. Therefore, the requirement for IKKα in HCMV replication was strain-dependent and during replication of an HCMV strain requiring IKKα, IKKα-dependent H3S10 phosphorylation was associated with efficient HCMV replication and immediate-early protein production. Plus, inhibition of HCMV replication by BAY61-3606 is associated with acetylation and tri-methylation modifications of histone H3 that do not involve IKKα.
authors.affiliation: Institute of Infection & Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, United Kingdom.
authors.forename: Catherine M K
authors.initials: CM
authors.lastname: Ho
authors.affiliation: Institute of Infection & Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, United Kingdom.
authors.forename: I'ah Z
authors.initials: IZ
authors.lastname: Donovan-Banfield
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, United States of America.|Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Longwood Ave, Boston, MA 02115, United States of America.
authors.forename: Li
authors.initials: L
authors.lastname: Tan
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, United States of America.|Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Longwood Ave, Boston, MA 02115, United States of America.
authors.forename: Tinghu
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, United States of America.|Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Longwood Ave, Boston, MA 02115, United States of America.
authors.forename: Nathanael S
authors.initials: NS
authors.lastname: Gray
authors.affiliation: Institute of Infection & Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, United Kingdom.
authors.forename: Blair L
authors.initials: BL
authors.lastname: Strang
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000956:Antigens, Viral / Q000378:metabolism; D002478:Cells, Cultured; D003587:Cytomegalovirus / Q000187:drug effects / Q000378:metabolism; D003586:Cytomegalovirus Infections / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D017874:Immediate-Early Proteins / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D009536:Niacinamide / Q000031:analogs & derivatives* / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology*; D011743:Pyrimidines / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
chemical_list: C477642:2-(7-(3,4-dimethoxyphenyl)imidazo(1,2-c)pyrimidin-5-ylamino)nicotinamide; D000956:Antigens, Viral; D006657:Histones; D017874:Immediate-Early Proteins; D016328:NF-kappa B; D011743:Pyrimidines; D014764:Viral Proteins; C044582:immediate-early proteins, cytomegalovirus; D009536:Niacinamide; D051550:I-kappa B Kinase