Activation of stress-activated MAP protein kinases up-regulates expression of transgenes driven by the cytomegalovirus immediate/early promoter.
The immediate/early promoter/enhancer of cytomegalovirus (CMV promoter) is one of the most commonly used promoters for expression of transgenes in eukaryotic cells. In practice, the CMV promoter is often thought of as a constitutively active unregulated promoter. However, we have observed that transcription from the CMV promoter can be up-regulated by a variety of environmental stresses. Many forms of cellular stress stimulate MAP kinase signalling pathways, resulting in activation of stress-activated protein kinases [SAPKs, also called Jun N-terminal kinases (JNKs)] and p38 kinases. We have found that the same conditions that lead to activation of SAPK/JNKs and p38 kinases can also dramatically increase expression from the CMV promoter. Inhibitors of p38 kinases abolished basal transcription from the CMV promoter and completely blocked stress-induced up-regulation of the CMV promoter. Overexpression of a dominant negative JNK kinase had no effect on basal transcription, but significantly reduced up-regulation caused by stress. These results have grave implications for use of the CMV promoter. If the CMV promoter can be up-regulated by cellular stresses, inadvertent activation of the stress kinase pathways may complicate, if not invalidate, the interpretation of a wide range of experiments.
Bruening
W
W
Department of Neurotoxicology, Montreal Neurological Institute, 3801 University Street, Montreal, Quebec H3A 2B4, Canada.
Giasson
B
B
Mushynski
W
W
Durham
H D
HD
D016475:3T3 Cells; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002460:Cell Line; D003587:Cytomegalovirus / Q000235:genetics*; D004789:Enzyme Activation; D015967:Gene Expression Regulation, Viral; D017781:Genes, Immediate-Early; D048031:JNK Mitogen-Activated Protein Kinases; D048728:MAP Kinase Kinase Kinase 1; D051379:Mice; D020928:Mitogen-Activated Protein Kinases; D011401:Promoter Regions, Genetic; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D014158:Transcription, Genetic; D014162:Transfection; D001616:beta-Galactosidase / Q000235:genetics
D012333:RNA, Messenger; 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; C482578:Map3k1 protein, mouse; D001616:beta-Galactosidase