A Single Amino Acid in EBNA-2 Determines Superior B Lymphoblastoid Cell Line Growth Maintenance by Epstein-Barr Virus Type 1 EBNA-2
| Autor: | Michelle J. West, Claudio Elgueta Karstegl, Paulo B. Correia, Laila Cancian, Michael J. McClellan, Julian Cano-Flanagan, Stelios Tzellos, Paul J. Farrell |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Transcriptional Activation
Chromatin Immunoprecipitation Genes Viral viruses Immunology Cell Biology Microbiology Cell Line Viral Matrix Proteins Viral Proteins Transactivation hemic and lymphatic diseases Virology Serine medicine Humans Amino Acids Promoter Regions Genetic Transcription factor Gene B cell Receptors CXCR Aspartic Acid B-Lymphocytes Binding Sites Cell growth Molecular biology Genome Replication and Regulation of Viral Gene Expression DNA-Binding Proteins HEK293 Cells medicine.anatomical_structure Epstein-Barr Virus Nuclear Antigens Insect Science Sequence motif Chromatin immunoprecipitation |
| Zdroj: | Journal of Virology. 88:8743-8753 |
| ISSN: | 1098-5514 0022-538X |
| DOI: | 10.1128/jvi.01000-14 |
| Popis: | Sequence differences in the EBNA-2 protein mediate the superior ability of type 1 Epstein-Barr virus (EBV) to transform human B cells into lymphoblastoid cell lines compared to that of type 2 EBV. Here we show that changing a single amino acid (S442D) from serine in type 2 EBNA-2 to the aspartate found in type 1 EBNA-2 confers a type 1 growth phenotype in a lymphoblastoid cell line growth maintenance assay. This amino acid lies in the transactivation domain of EBNA-2, and the S442D change increases activity in a transactivation domain assay. The superior growth properties of type 1 EBNA-2 correlate with the greater induction of EBV LMP-1 and about 10 cell genes, including CXCR7. In chromatin immunoprecipitation assays, type 1 EBNA-2 is shown to associate more strongly with EBNA-2 binding sites near the LMP-1 and CXCR7 genes. Unbiased motif searching of the EBNA-2 binding regions of the differentially regulated cell genes identified an ETS-interferon regulatory factor composite element motif that closely corresponds to the sequences known to mediate EBNA-2 regulation of the LMP-1 promoter. It appears that the superior induction by type 1 EBNA-2 of the cell genes contributing to cell growth is due to their being regulated in a manner different from that for most EBNA-2-responsive genes and in a way similar to that for the LMP-1 gene. IMPORTANCE The EBNA-2 transcription factor plays a key role in B cell transformation by EBV and defines the two EBV types. Here we identify a single amino acid (Ser in type 1 EBV, Asp in type 2 EBV) of EBNA-2 that determines the superior ability of type 1 EBNA-2 to induce a key group of cell genes and the EBV LMP-1 gene, which mediate the growth advantage of B cells infected with type 1 EBV. The EBNA-2 binding sites in these cell genes have a sequence motif similar to the sequence known to mediate regulation of the EBV LMP-1 promoter. Further detailed analysis of transactivation and promoter binding provides new insight into the physiological regulation of cell genes by EBNA-2. |
| Databáze: | OpenAIRE |
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