title: Redox response of the endogenous calcineurin inhibitor Adapt 78.
abstract: Adapt 78 (DSCR 1/calcipressin/MCIP 1) is a potent natural inhibitor of calcineurin, an important intracellular phosphatase that mediates many cellular responses to calcium. We previously reported two major cytosolic isoforms (1 and 4) of Adapt 78, and that isoform 4 is an oxidative and calcium stress-response protein. Using a higher cell culture density and new antibody, we again observed that both major isoforms localized to the cytosol, but a significant level of isoform 4 (but not isoform 1) was also detected in the nucleus where it was present in the non-soluble region and not associated with RNA. Exposure of cells to hydrogen peroxide led to the significant loss of isoform 4 from the nucleus with a moderate increase in cytosolic localization. The change in isoform 4 phosphorylation state in response to oxidative stress, characterized by a loss of the lesser (hypo) phosphorylated Adapt 78, was not due to accelerated degradation, although general Adapt 78 degradation was proteosome mediated. Finally, stimulation of Jurkat and primary T-lymphocyte signaling led to isoform 4 induction. This induction was BAPTA, diphenylene iodonium, and N-acetylcysteine inhibitable, and accompanied by induction of the classic immune response mediator and calcineurin-pathway-stimulated interleukin-2. These studies reveal new redox-related activities for Adapt 78 isoform 4, which may contribute to its known calcineurin-regulating and cytoprotective activities, and further suggest that Adapt 78 plays a role in basic T-cell response.
authors.affiliation: Center for Immunology and Microbial Disease, The Albany Medical College, Albany, NY 12208, USA.
authors.forename: Ananth V
authors.initials: AV
authors.lastname: Narayan
authors.forename: Rebecca
authors.initials: R
authors.lastname: Stadel
authors.forename: Amy B
authors.initials: AB
authors.lastname: Hahn
authors.forename: Dipti L
authors.initials: DL
authors.lastname: Bhoiwala
authors.forename: Geysha
authors.initials: G
authors.lastname: Cornielle
authors.forename: Erwin
authors.initials: E
authors.lastname: Sarazin
authors.forename: Issam
authors.initials: I
authors.lastname: Koleilat
authors.forename: Dana R
authors.initials: DR
authors.lastname: Crawford
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D065095:Calcineurin Inhibitors; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D005609:Free Radicals; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007376:Interleukin-2 / Q000378:metabolism; D019169:Jurkat Cells; D008856:Microscopy, Fluorescence; D009861:Onium Compounds / Q000494:pharmacology; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010766:Phosphorylation; D020033:Protein Isoforms; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000494:pharmacology*; D013347:Subcellular Fractions / Q000378:metabolism; D013601:T-Lymphocytes / Q000378:metabolism; D013997:Time Factors
chemical_list: D065095:Calcineurin Inhibitors; D005609:Free Radicals; D007376:Interleukin-2; D009861:Onium Compounds; D020033:Protein Isoforms; D012333:RNA, Messenger; D004533:Egtazic Acid; D012313:RNA; C007517:diphenyleneiodonium; D006861:Hydrogen Peroxide; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D000111:Acetylcysteine