Dataset Information

Epstein-Barr Virus Latent Membrane Protein 1 targets cIAP1, cIAP2 and TRAF2 for Proteasomal Degradation to Activate the Non-canonical NF-κB Pathway.

ABSTRACT: The Epstein-Barr virus oncoprotein Latent Membrane Protein 1 (LMP1) is expressed in multiple malignancies and is critical for B-cell immortalization. LMP1 constitutively activates NF-κB signaling pathways, which are essential for EBV-mediated B cell transformation and for transformed B cell survival. Reverse genetic analysis revealed two LMP1 regions critical for primary human B cell immortalization, termed transformation effector site (TES) 1 and 2, which activate multiple host growth and survival pathways, in particular NF-κB. Of these, only TES1 signaling is required for B-cell transformation within the first several weeks of infection. TES1 signaling is also critical for EBV-transformed lymphoblastoid B-cell survival. However, precisely how TES1 initiates NF-κB signaling has remained incompletely understood. Here, we provide multiple lines of evidence that TES1 associates with cellular inhibitor of apoptosis protein 1 and 2 (cIAP1/2) in a tumor necrosis factor associated factor 3 (TRAF3) dependent manner. TES1 signaling drives cIAP1 autoubiquitination and targets TRAF2, cIAP1 and 2 for proteasomal degradation in a TRAF3 dependent manner. Overexpression of either cIAP1 or 2 impaired LMP1 TES1-mediated non-canonical NF-κB activation. Collectively, these studies suggest that LMP1 TES1 initiates non-canonical NF-κB signaling distinctly from CD40 and other host immunoreceptors, thereby highlighting a therapeutic target.

SUBMITTER: Sun Y

PROVIDER: S-EPMC12424949 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Epstein-Barr Virus Latent Membrane Protein 1 targets cIAP1, cIAP2 and TRAF2 for Proteasomal Degradation to Activate the Non-canonical NF-κB Pathway.

Sun Yizhe Y Li Shunji S Mitra Bidisha B Zhong Ling L Zhang Aretina A Gewurz Benjamin E BE

bioRxiv : the preprint server for biology 20250906

The Epstein-Barr virus oncoprotein Latent Membrane Protein 1 (LMP1) is expressed in multiple malignancies and is critical for B-cell immortalization. LMP1 constitutively activates NF-κB signaling pathways, which are essential for EBV-mediated B cell transformation and for transformed B cell survival. Reverse genetic analysis revealed two LMP1 regions critical for primary human B cell immortalization, termed transformation effector site (TES) 1 and 2, which activate multiple host growth and survi ...[more]

PMID: 40950096

Similar Datasets

Project description:Epstein-Barr Virus (EBV) Latent Membrane Protein 1 (LMP1) transforms rodent fibroblasts and is expressed in most EBV-associated malignancies. LMP1 Transformation Effector Site 2 (TES2)/C-Terminal Activation Region 2 (CTAR2) activates NF-kappaB, p38, JNK, ERK and IRF7 pathways. We have investigated LMP1 TES2 genome-wide RNA effects at 4 time points after LMP1 TES2 expression in HEK 293 cells. Using a False Discovery Rate (FDR) of < 0.001 after correction for multiple hypotheses, LMP1 TES2 caused > 2-fold changes in 1916 mRNAs; 1479 RNAs were up-regulated and 437 down-regulated. In contrast to TNFalpha stimulation, which transiently up-regulates many target genes, LMP1 TES2 maintained most RNA effects through the time course, despite robust and sustained induction of negative feedback regulators, such as IkappaBalpha and A20. LMP1 TES2 regulated RNAs encode many NF-kappaB signaling proteins and secondary interacting proteins. Consequently, many LMP1 TES2-regulated RNAs encode proteins that form an extensive interactome. Gene Set Enrichment Analyses found LMP1 TES2 up-regulated genes to be significantly enriched for Pathways in Cancer, B-and T-cell receptor signaling, and Toll-like receptor signaling. Surprisingly, LMP1 TES2 and IkappaBalpha super-repressor co-expression decreased LMP1 TES2 RNA effects to only 5 RNAs with FDR<0.001 and >2 fold change. Thus, canonical NF-kappaB activation is critical for almost all LMP1 TES2 RNA effects in HEK-293 cells and a more significant therapeutic target than previously appreciated. An LMP1 double point mutant (P204A, Q206A) was used to construct a HEK-293 TET-On LMP1 TES2 cell line. Stable cell clones were selected that carry an inducible system for LMP1 TES2 expression. The Tet-system is composed of three parts: 1) the LMP1 TES2 cDNA cloned into the tetracycline-regulated pJEF vector; 2) a tetracycline suppressor (tTS) that binds Tet-operator sites in the absence of tetracyclines and silences expression; 3) a reverse-tetracycline transactivator fused to the 4-hydroxy tamoxifen (4HT) ligand binding domain (rTTA M2). LMP1 expression was induced by addition of doxycycline (1 ug/ml) and 4HT (100 nM). For simultaneous inducible expression of LMP1 TES2 and an IkBa super-repressor, a stable cell line was derived. A pJEF vector encoding IkBa residues 37-317 was introduced into the inducible LMP1 TES2 cell line. Cell lines were cultured with DMEM (GIBCO) supplemented with 10% tetracycline-free serum (Clontech). LMP1 expression was induced by addition of tetracycline (1 ug/ml). RNA samples were collected from triplicate samples using RNABee (Qiagen) according to the manufacturer’s instructions from 293 cells induced for LMP1 TES2 (and IkBa super-repressor, where indicated) expression at 0, 6, 9, 12 and 24 hours of induction. Cells were in the log-phase of growth. Gene expression profiles were assayed using the Affymetrix HU-133 plus2 GeneChip according to the manufacturer's instructions. Real-time RT-PCR was performed with the Power SYBR Green RNA-to-CT™ 1-Step Kit (Applied Biosystems, Foster City, CA). Fold changes were determined using delta delta Ct method and normalized by GAPDH expression levels. RNA expression data were normalized using RMA and array quality assessed by NUSE and RLE scores. The data was collected according to methods that fall under the MIAME standards.

Dataset Information

Epstein-Barr Virus Latent Membrane Protein 1 targets cIAP1, cIAP2 and TRAF2 for Proteasomal Degradation to Activate the Non-canonical NF-κB Pathway.

Publications

Epstein-Barr Virus Latent Membrane Protein 1 targets cIAP1, cIAP2 and TRAF2 for Proteasomal Degradation to Activate the Non-canonical NF-κB Pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets