title: The EHV-1 UL4 protein that tempers viral gene expression interacts with cellular transcription factors.
abstract: The UL4 gene is conserved within the genome of defective interfering particles of equine herpesvirus type 1 (EHV-1) that mediate persistent infection. Here, we show that the UL4 protein inhibits EHV-1 reporter gene expression by decreasing the level of transcribed mRNA. The UL4 protein did not bind any gene class of EHV-1 promoters in electromobility or chromatin immunoprecipitation assays, but directly interacted with the TATA box-binding protein (TBP) and the carboxy-terminal domain of RNA polymerase II both in vitro (GST-pulldown assays) and in infected cells (coimmunoprecipitation analyses). Microarray analyses of the expression of the 78 EHV-1 genes revealed that viral late genes important for virion assembly displayed enhanced expression in cells infected with UL4-null virus as compared to wild-type or UL4-restored EHV-1. Quantitative PCR analyses showed that viral DNA replication was not retarded in cells infected with the UL4-null virus as compared to wild-type EHV-1.
authors.affiliation: Center for Molecular and Tumor Virology, Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Center for Molecular and Tumor Virology, Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Charvat
authors.affiliation: Center for Molecular and Tumor Virology, Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA.
authors.forename: Seong K
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Center for Molecular and Tumor Virology, Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, USA. Electronic address: docall@lsuhsc.edu.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: O'Callaghan
mesh_terms: D000818:Animals; D002460:Cell Line; D015967:Gene Expression Regulation, Viral; D006566:Herpesviridae Infections / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D004861:Herpesvirus 1, Equid / Q000235:genetics* / Q000378:metabolism*; D054884:Host-Pathogen Interactions; D006801:Humans; D051379:Mice; D011485:Protein Binding; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D035181:TATA-Box Binding Protein / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D035181:TATA-Box Binding Protein; D014764:Viral Proteins; C076117:UL4 protein, Equine herpesvirus 1; D012319:RNA Polymerase II
keywords: DNA microarray; Defective interfering particles; Equine herpesvirus 1; Herpesvirus gene regulation; Inhibition; RNA polymerase II; Transcription; Transcription factors