Abstract
The LMP2 gene, which encodes a protein required for efficient presentation of viral antigens, requires both unphosphorylated Stat1 and IRF1 for basal expression. LMP2 expression is down-regulated by the adenovirus protein E1A, which binds to Stat1 and CBP/p300, and by the mutant E1A protein RG2, which binds to Stat1 but not to CBP/p300, but not by the mutant protein Delta2-36, which does not bind to either Stat1 or CBP/p300. Stat1 and IRF1 associate in untreated cells and bind as a complex to the overlapping ICS-2/GAS element of the LMP2 promoter. E1A interferes with the formation of this complex by occupying domains of Stat1 that bind to IRF1. These results reveal how adenovirus infection attenuates LMP2 expression, thereby interfering with the presentation of viral antigens.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenoviridae / pathogenicity
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Adenovirus E1A Proteins / pharmacology*
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Cell Line
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DNA-Binding Proteins / metabolism*
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Down-Regulation
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Gene Expression Regulation, Viral / genetics*
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Humans
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Interferon Regulatory Factor-1
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Mutation
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Phosphoproteins / metabolism*
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Promoter Regions, Genetic
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Protein Binding
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STAT1 Transcription Factor
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Trans-Activators / metabolism*
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Viral Matrix Proteins / genetics*
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Viral Matrix Proteins / metabolism
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Viral Proteins / genetics
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Viral Proteins / metabolism
Substances
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Adenovirus E1A Proteins
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DNA-Binding Proteins
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EBV-associated membrane antigen, Epstein-Barr virus
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IRF1 protein, human
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Interferon Regulatory Factor-1
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Phosphoproteins
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STAT1 Transcription Factor
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STAT1 protein, human
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Trans-Activators
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Viral Matrix Proteins
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Viral Proteins