Negative regulation of Epstein-Barr virus latent membrane protein 1-mediated functions by the bone morphogenetic protein receptor IA-binding protein, BRAM1.
The latent membrane protein 1 (LMP1) of Epstein-Barr virus causes cellular transformation and activates several intracellular signals, including NF-kappaB and c-Jun N-terminal kinase. Using yeast two-hybrid screening with the LMP1 C-terminal sequence as bait, we demonstrate that BRAM1 (bone morphogenetic protein receptor-associated molecule 1) is an LMP1-interacting protein. BRAM1 associates with LMP1, both in vitro and in vivo, as revealed by confocal microscopy, glutathione S-transferase pull-down, and co-immunoprecipitation assays. This association mainly involves the C-terminal half of BRAM1 comprising the MYND domain and the CTAR2 region of LMP1, which is critical in LMP1-mediated signaling pathways. We show that BRAM1 interferes with LMP1-mediated NF-kappaB activation but not the JNK signaling pathway. Because the CTAR2 region interacts with the tumor necrosis factor (TNF-alpha receptor-associated death domain protein, it is interesting to find that BRAM1 also interferes with NF-kappaB activation mediated by TNF-alpha. BRAM1 interferes LMP1-mediated and TNF-alpha-induced NF-kappaB activation by targeting IkappaBalpha molecules. Moreover, BRAM1 inhibits the resistance of LMP1-expressing cells to TNF-alpha-induced cytotoxicity. We therefore propose that the BRAM1 molecule associates with LMP1 and functions as a negative regulator of LMP1-mediated biological functions.
Graduate Institute of Life Sciences, National Defense Medical Center, Taipei 114, Taiwan, Republic of China.
Pei-Jung
PJ
Chung
Yu-Sun
YS
Chang
Chih-Lung
CL
Liang
Ching-Liang
CL
Meng
D016475:3T3 Cells; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002460:Cell Line; D056970:Co-Repressor Proteins; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D014763:Viral Matrix Proteins / Q000737:chemistry* / Q000378:metabolism
D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; C000606205:Nfkbia protein, mouse; D014409:Tumor Necrosis Factor-alpha; D014763:Viral Matrix Proteins; C094763:ZMYND11 protein, human; C490622:Zmynd11 protein, mouse; D000072000:NF-KappaB Inhibitor alpha; D008156:Luciferases; D005982:Glutathione Transferase; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases