Functionally significant mutations in the Epstein-Barr virus LMP1 gene and their role in activation of cell signaling pathways

Abstract

Latent membrane protein 1 (LMP1) of the Epstein-Barr virus is a constitutively activated analog of the tumor necrosis factor receptor TNF-R1. LMP1 serves as a viral oncogene able to transform human B-lymphocytes and rodent fibroblasts via activation of numerous cellular signal cascades. Two specific motifs within LMP1 are responsible for interaction of this viral protein with the receptor protein beta-TrCP/HOS SCF of the ubiquitin ligase E3 complex, playing an important role in degradation of numerous cellular proteins including NF-kappaB inhibitor IkappaBalpha. In this study, we demonstrate for the first time the importance of point mutations affecting HOS-recognizing motifs of LMP1 for activation of NF-kappaB, AP1, and PI3K/Akt signaling pathways. It has also been shown that rat fibroblast cell lines (Rat-1) expressing different HOS mutants of LMP1 produce different amounts of reactive nitrogen species. Our data confirm the hypothesis that point mutations in the C-terminal region of the LMP1 cytoplasmic domain can influence the transforming potential of the Epstein-Barr virus.

Combinatorial antibody library from multiple sclerosis patients reveals antibodies that cross‐react with myelin basic protein and EBV antigen

“…The cells were maintained in advanced DMEM (Gibco; Life Technologies, Gaithersburg, MD, USA) medium supplemented with 15% (v/v) FBS (Gibco) and l ‐glutamine (2 mM) at 37°C, 5% CO 2 and 95% humidity. The HEK293 cells were transfected by pSG5/LMP1‐B95‐8 plasmid using Unifect U56 (kindly provided by Natalia Egorova, Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia) as described previously (18).…”

Fluorescence Visualization Screening for EBV‐LMP1‐Targeted DNAzymes

“…EBV-LMP1 regulates multiple signal transduction pathways via its C-terminal. 27,28 In this study, we chose the LMP1 C-terminal as the targeting DNAzyme region, and designed and constructed 4 DNAzymes (DZ509, DZ893, DZ827, and DZ1037).…”

“…In this study, we have provided a visible platform for EGFP vectors to successfully screen DNAzymes with high performance and notable EBV-LMP1 inhibition expression and EBV-LMP1 regulates multiple signal transduction pathways via its C-terminal. 27,28 In this study, we chose the LMP1 C-terminal as the targeting DNAzyme region, and designed and constructed 4 DNAzymes (DZ509, DZ893, DZ827, and DZ1037).…”

Epstein–Barr Virus Strain Variation

“…The sequence variants of LMP1 relative to B95-8 were named Alaskan, China 1, China 2, Med+, Med−, and NC. This more general insight into LMP1 variation taking into account the whole LMP1 sequence (Miller et al 1994;Walling et al 2004;Mainou and Raab-Traub 2006) has also been used by many other groups (Sung et al 1998;Kanai et al 2007;Nagamine et al 2007;Lin et al 2005;Zhao et al 2005;Shibata et al 2006;Saechan et al 2006Saechan et al , 2010Dardari et al 2006;Li et al 2009;Nguyen-Van et al 2008;Diduk et al 2008;Pavlish et al 2008;Wang et al 2007), but there was generally little evidence for a specific disease association of variants. Investigation of variant LMP1 sequences in HIV patients in Switzerland also identified polymorphisms (I124 V/I152L and F144I/D150A/L151I), which were markers of increased NF-κB activation in vitro but were not associated with EBV-associated Hodgkin's lymphoma (Zuercher et al 2012).…”