PMID:15150262

Citation	Thomas, D, Blakqori, G, Wagner, V, Banholzer, M, Kessler, N, Elliott, RM, Haller, O and Weber, F (2004) Inhibition of RNA polymerase II phosphorylation by a viral interferon antagonist. J. Biol. Chem. 279:31471-7
Abstract	Many viruses subvert the cellular interferon (IFN) system with so-called IFN antagonists. Bunyamwera virus (BUNV) belongs to the family Bunyaviridae and is transmitted by arthropods. We have recently identified the nonstructural protein NSs of BUNV as a virulence factor that inhibits IFN-beta gene expression in the mammalian host. Here, we demonstrate that NSs targets the RNA polymerase II (RNAP II) complex. The C-terminal domain (CTD) of RNAP II consists of 52 repeats of the consensus sequence YSPTSPS. Phosphorylation at serine 5 is required for efficient initiation of transcription, and subsequent phosphorylation at serine 2 is required for mRNA elongation and 3'-end processing. In BUNV-infected mammalian cells, serine 5 phosphorylation occurred normally. Furthermore, RNAP II was able to bind to the IFN-beta gene promoter as revealed by chromatin immunoprecipitation analysis, indicating that the initiation of transcription was not disturbed by NSs. However, NSs prevented CTD phosphorylation at serine 2, suggesting a block in transition from initiation to elongation. Surprisingly, no interference with CTD phosphorylation was observed in insect cells. Our results indicate that BUNV uses an unconventional mechanism to block IFN synthesis in the mammalian host by directly dysregulating RNAP II. Moreover, by inducing a general transcriptional block, NSs may contribute to the lytic infection observed in mammalian cells as opposed to persistent infection in the insect host.
Links	PubMed Online version:10.1074/jbc.M400938200
Keywords	Animals; Bunyamwera virus/pathogenicity; Cell Line; Cercopithecus aethiops; Gene Expression/drug effects; Genes, Reporter/drug effects; Humans; Interferon-beta/antagonists & inhibitors; Phosphorylation; Promoter Regions, Genetic; Protein Structure, Tertiary; RNA Polymerase II/antagonists & inhibitors; RNA Polymerase II/chemistry; RNA Polymerase II/metabolism; Vero Cells; Viral Nonstructural Proteins/pharmacology
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Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
BUNYW:NSS		GO:0039523: suppression by virus of host RNA polymerase II activity	ECO:0000315:		P		Fig. 2: wildtype reduced phosphorylation of serine 2 in RNA polymerase II, mutant didn't Fig. 3: phosphorylated serine 2 and phosphorylated serine 5 were not very noticeable in cells expressing NSs CTD phosphorylation affects RNA polymerase II regulation	complete CACAO 9888
BUNYW:NSS		GO:0039501: suppression by virus of host type I interferon production	ECO:0000314:		P		Fig. 1A: cells were transfected with IFN-beta promoter-luciferase plasmids and NSs expression plasmids, cells expressing NSs had lower levels of IFN-beta promoter activation than cells expressing control protein	complete CACAO 9893
BUNYW:NSS		GO:0039584: suppression by virus of host protein kinase activity	ECO:0000314:		P		Fig. 1A: cells were transfected with thymidine kinase promoter-luciferase reporter plasmids and NSs expression plasmids, cells expressing Ns had lower levels of thymidine kinase promoter activity than cells expressing control protein	complete CACAO 9894
BUNYW:NSS	involved_in	GO:0039523: suppression by virus of host RNA polymerase II activity	ECO:0000315: mutant phenotype evidence used in manual assertion		P		Seeded From UniProt	complete
BUNYW:NSS	involved_in	GO:0039501: suppression by virus of host type I interferon production	ECO:0000314: direct assay evidence used in manual assertion		P		Seeded From UniProt	complete

References

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