title: Glycogen synthase kinase-3 inhibits the DNA binding activity of NFATc.
abstract: The NFAT family of transcription factors is required for the expression of numerous immunologically important genes and plays a pivotal role in both the initiation and coordination of the immune response. NFAT family members appear to be regulated primarily at the level of their subcellular localization. Here we show that NFATc is additionally regulated at the level of its DNA binding activity. Using gel mobility shift assays, we demonstrate that the intrinsic DNA binding activity of NFATc is negatively regulated by phosphorylation. We found that activation of calcineurin activity in cells and dephosphorylation of NFATc in vitro enhanced NFATc DNA binding activity, whereas phosphorylation of NFATc in vitro inhibited its ability to bind DNA. Through the analysis of NFATc mutants, we identified the conserved Ser-Pro repeat motifs as critical quantitative determinants of NFATc DNA binding activity. In addition, we provide several lines of evidence to suggest that the phosphorylation of the Ser-Pro repeats by glycogen synthase kinase-3 inhibits the ability of NFATc to bind DNA. Taken together, these studies afford new insights into the regulation of NFATc and underscore the potential role of glycogen synthase kinase-3 in the regulation of NFAT-dependent gene expression.
authors.affiliation: Department of Microbiology-Immunology, Northwestern University Medical School, Chicago, Illinois 60611, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Neal
authors.forename: N A
authors.initials: NA
authors.lastname: Clipstone
mesh_terms: D020816:Amino Acid Motifs / Q000502:physiology; D000818:Animals; D019556:COS Cells; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3; D038341:Glycogen Synthase Kinases; D006801:Humans; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D010766:Phosphorylation; D011392:Proline / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D012694:Serine; D004247:DNA; D011392:Proline; D038341:Glycogen Synthase Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D038362:Glycogen Synthase Kinase 3