title: Role of mitogen-activated protein kinase phosphatase during the cellular response to genotoxic stress. Inhibition of c-Jun N-terminal kinase activity and AP-1-dependent gene activation.
abstract: Irradiation of mammalian cells with short wavelength ultraviolet light (UVC) evokes a cascade of phosphorylation events leading to altered gene expression. Both the classic mitogen-activated protein (MAP) kinases and the distantly related c-Jun N-terminal kinases (JNK) contribute to the response via phosphorylation of transcription factors including AP-1. These kinases are themselves regulated via reversible phosphorylation, and several recently identified specific MAP kinase phosphatases (MKP) have been implicated in down-regulating MAP kinase-dependent gene expression in response to mitogens. Here, we provide evidence that MKP-1 plays a role in regulating transcriptional activation in response to UVC as well as another genotoxic agent, methyl methanesulfonate (MMS). We further demonstrate that JNK is a likely target for MKP-1. JNK is shown to be activated by UVC and MMS treatment, while MAP kinase activation occurs only with UVC. Like JNK activation, MKP-1 mRNA is induced by both treatments, and elevated MKP-1 expression coincides with a decline in JNK activity. Constitutive expression of MKP-1 in vivo inhibits JNK activity and reduces UVC- and MMS-induced activation of AP-1-dependent reporter genes.
authors.affiliation: Section on Gene Expression and Aging, NIA, National Institutes of Health, Baltimore, Maryland 21224, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: M
authors.initials: M
authors.lastname: Gorospe
authors.forename: C
authors.initials: C
authors.lastname: Yang
authors.forename: N J
authors.initials: NJ
authors.lastname: Holbrook
mesh_terms: D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018797:Cell Cycle Proteins; D054638:Dual Specificity Phosphatase 1; D004790:Enzyme Induction; D015971:Gene Expression Regulation, Enzymologic; D006367:HeLa Cells; D006801:Humans; D017874:Immediate-Early Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases; D008741:Methyl Methanesulfonate / Q000633:toxicity; D020928:Mitogen-Activated Protein Kinases; D009153:Mutagens / Q000633:toxicity*; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D015533:Transcriptional Activation; D014466:Ultraviolet Rays
chemical_list: D018797:Cell Cycle Proteins; D017874:Immediate-Early Proteins; D009153:Mutagens; D018808:Transcription Factor AP-1; D008741:Methyl Methanesulfonate; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; C517019:DUSP1 protein, human; D054638:Dual Specificity Phosphatase 1; C517021:Dusp1 protein, rat; D017027:Protein Tyrosine Phosphatases