The Epstein-Barr Virus BILF1 Gene Encodes a G Protein-coupled Receptor That Inhibits Phosphorylation of RNA-dependent Protein Kinase
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Epstein-Barr virus (EBV) infection is associated with many lymphoproliferative diseases, such as infectious mononucleosis and Burkitt's lymphoma. Consequently, EBV is one of the most extensively studied herpesviruses. Surprisingly, a putative G protein-coupled receptor (GPCR) gene of EBV, BILF1, has hitherto escaped attention, yet BILF1-like genes are conserved among all known lymphocryptovirus species, suggesting that they play a pivotal role in viral infection. To determine the function of EBV BILF1, the activity of this gene and its products was studied. BILF1-specific mRNA was detected in various EBV-positive cell types and found to be expressed predominantly during the immediate early and early phases of infection in vitro. Interestingly, in COS-7 cells transfected with BILF1 expression constructs, a decrease in forskolin-induced CRE-mediated transcription was measured, as well as an increase in NF-kappaB-mediated transcription. In contrast, CRE-mediated transcription was increased in EBV-positive Burkitt's lymphoma cells as well as EBV-positive lymphoblastoid B cells transfected with BILF1, whereas NF-kappaB-mediated transcription levels remained unaffected in these cells. All observed activities were sensitive to treatment with pertussis toxin, indicating that the BILF1-encoded protein mediates these activities by coupling to G proteins of the G(i/o) class. Finally, reduced levels of phosphorylated RNA-dependent antiviral protein kinase were observed in COS-7 and Burkitt's lymphoma cells transfected with BILF1. Neither of the observed effects required a ligand to interact with the BILF1 gene product, suggesting that BILF1 encodes a constitutively active GPCR capable of modulating various intracellular signaling pathways.
Epstein-Barr Virus History and Pathogenesis.
Yu H, Robertson E Viruses. 2023; 15(3).
PMID: 36992423 PMC: 10056551. DOI: 10.3390/v15030714.
Gong M, Myster F, van Campe W, Roels S, Mostin L, van den Berg T Viruses. 2023; 15(2).
PMID: 36851740 PMC: 9968110. DOI: 10.3390/v15020526.
Patterns of human and porcine gammaherpesvirus-encoded BILF1 receptor endocytosis.
Mavri M, Glisic S, Sencanski M, Vrecl M, Rosenkilde M, Spiess K Cell Mol Biol Lett. 2023; 28(1):14.
PMID: 36810008 PMC: 9942385. DOI: 10.1186/s11658-023-00427-y.
Functional Implications of Epstein-Barr Virus Lytic Genes in Carcinogenesis.
Yap L, Wong A, Paterson I, Young L Cancers (Basel). 2022; 14(23).
PMID: 36497262 PMC: 9740547. DOI: 10.3390/cancers14235780.
Mavri M, Kubale V, Depledge D, Zuo J, Huang C, Breuer J Front Endocrinol (Lausanne). 2022; 13:862940.
PMID: 35721730 PMC: 9204316. DOI: 10.3389/fendo.2022.862940.