Adenovirus E1B 19,000-molecular-weight protein activates c-Jun N-terminal kinase and c-Jun-mediated transcription.
Adenovirus E1B proteins (19,000-molecular-weight [19K] and 55K proteins) inhibit apoptosis and cooperate with adenovirus E1A to induce full oncogenic transformation of primary cells. The E1B 19K protein has previously been shown to be capable of activating transcription; however, the underlying mechanisms are unclear. Here, we show that adenovirus infection activates the c-Jun N-terminal kinase (JNK) and that the E1B gene products are necessary for adenovirus to activate JNK. In transfection assays, we show that the E1B 19K protein is sufficient to activate JNK and can strongly induce c-Jun-dependent transcription. Mapping studies show that the C-terminal portion of E1B 19K is necessary for induction of c-Jun-mediated transcription. Using dominant-negative mutants of several kinases upstream of JNK, we show that MEKK1 and MKK4, but not Ras, are involved in the induction of JNK activity by adenovirus infection. The same dominant-negative kinase mutants also block the ability of E1B 19K to induce c-Jun-mediated transcription. Taken together, these results suggest that E1B 19K may utilize the MEKK1-MKK4-JNK signaling pathway to activate c-Jun-dependent transcription and demonstrate a novel, kinase-activating activity of E1B 19K that may underlie its ability to regulate transcription.
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Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA.
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D017500:Adenovirus E1A Proteins / Q000235:genetics / Q000378:metabolism; D017501:Adenovirus E1B Proteins / Q000235:genetics / Q000378:metabolism*; D000260:Adenoviruses, Human / Q000502:physiology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins; D004789:Enzyme Activation; D006367:HeLa Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D048371:MAP Kinase Kinase 3; D048670:MAP Kinase Kinase 4; D048728:MAP Kinase Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D017500:Adenovirus E1A Proteins; D017501:Adenovirus E1B Proteins; D004268:DNA-Binding Proteins; C052130:GAL4 protein, S cerevisiae; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048728:MAP Kinase Kinase Kinase 1; C482576:MAP3K1 protein, human; D048371:MAP Kinase Kinase 3; D048670:MAP Kinase Kinase 4; C482530:MAP2K3 protein, human; C482559:MAP2K4 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases