title: The UL13 and US3 Protein Kinases of Herpes Simplex Virus 1 Cooperate to Promote the Assembly and Release of Mature, Infectious Virions.
abstract: Herpes simplex virus type 1 (HSV-1) encodes two bona fide serine/threonine protein kinases, the US3 and UL13 gene products. HSV-1 ΔUS3 mutants replicate with wild-type efficiency in cultured cells, and HSV-1 ΔUL13 mutants exhibit <10-fold reduction in infectious viral titers. Given these modest phenotypes, it remains unclear how the US3 and UL13 protein kinases contribute to HSV-1 replication. In the current study, we designed a panel of HSV-1 mutants, in which portions of UL13 and US3 genes were replaced by expression cassettes encoding mCherry protein or green fluorescent protein (GFP), respectively, and analyzed DNA replication, protein expression, and spread of these mutants in several cell types. Loss of US3 function alone had largely negligible effect on viral DNA accumulation, gene expression, virion release, and spread. Loss of UL13 function alone also had no appreciable effects on viral DNA levels. However, loss of UL13 function did result in a measurable decrease in the steady-state levels of two viral glycoproteins (gC and gD), release of total and infectious virions, and viral spread. Disruption of both genes did not affect the accumulation of viral DNA, but resulted in further reduction in gC and gD steady-state levels, and attenuation of viral spread and infectious virion release. These data show that the UL13 kinase plays an important role in the late phase of HSV-1 infection, likely by affecting virion assembly and/or release. Moreover, the data suggest that the combined activities of the US3 and UL13 protein kinases are critical to the efficient assembly and release of infectious virions from HSV-1-infected cells.
authors.affiliation: Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL 62794-9626, United States of America.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Gershburg
authors.affiliation: Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL 62794-9626, United States of America.
authors.forename: Joshua
authors.initials: J
authors.lastname: Geltz
authors.affiliation: Rocky Mountain Laboratories, National Institute of Allergy and Infectious Disease, Hamilton, MT 59840, United States of America.
authors.forename: Karin E
authors.initials: KE
authors.lastname: Peterson
authors.affiliation: Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL 62794-9626, United States of America.
authors.forename: William P
authors.initials: WP
authors.lastname: Halford
authors.affiliation: Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL 62794-9626, United States of America.
authors.forename: Edward
authors.initials: E
authors.lastname: Gershburg
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D006561:Herpes Simplex / Q000235:genetics / Q000473:pathology / Q000821:virology*; D006801:Humans; D050505:Mutant Proteins / Q000235:genetics / Q000502:physiology; D011494:Protein Kinases / Q000235:genetics / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology*; D014709:Vero Cells; D014764:Viral Proteins / Q000235:genetics / Q000502:physiology*; D019065:Virus Assembly / Q000235:genetics*; D017201:Virus Shedding / Q000235:genetics*
chemical_list: D050505:Mutant Proteins; D014764:Viral Proteins; D011494:Protein Kinases; C082380:UL13 protein, Simplexvirus; D017346:Protein Serine-Threonine Kinases; C095207:US3 protein, Human herpesvirus 1