title: Characterization of cyclic adenosine diphosphate-ribose-induced Ca2+ release in T lymphocyte cell lines.
abstract: Ca2+ release from intracellular stores is one of the major events transducing extracellular signals into living cells. Recently, a metabolite of nicotinamide adenine dinucleotide+ (NAD+), termed "cyclic adenosine diphosphate-ribose" (cADPr), has been described to release Ca2+ from caffeine-sensitive internal stores of cells. Jurkat T cells possess intracellular Ca2+ stores sensitive to caffeine, so a potential involvement of cADPr in Ca2+ signaling was investigated. cADPr released Ca2+ in a dose-dependent manner from intracellular stores of permeabilized Jurkat T cells. Half maximal release was obtained at 2.25 microM cADPr. Prior addition of D-myo-inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) or thapsigargin did not influence cADPr-induced Ca2+ release, indicating the presence of different Ca2+ pools sensitive to Ins(1,4,5)P3 and cADPr. The specificity of the response was confirmed using the inhibitors ruthenium red, 8-NH2-cADPr, and 8-Br-cADPr. All three compounds blocked cADPr-induced, but not Ins(1,4,5)P3-induced, Ca2+ release in a dose-dependent manner. Cyclic GMP (cGMP)-induced Ca2+ release was also partly antagonized by ruthenium red, indicating involvement of a cGMP-dependent step in the formation of cADPr. The presence of endogenous cADPr was analyzed directly by HPLC. Sequential separation on strong anion exchange HPLC and reverse-phase, ion-pair HPLC resulted in a single symmetric peak co-eluting with standard cADPr. The identity of this endogenous material was further confirmed by its ability to release Ca2+ in saponin-permeabilized Jurkat T cells.
authors.affiliation: Department of Enzyme Chemistry, University of Hamburg, Germany.
authors.forename: A H
authors.initials: AH
authors.lastname: Guse
authors.forename: C P
authors.initials: CP
authors.lastname: da Silva
authors.forename: F
authors.initials: F
authors.lastname: Emmrich
authors.forename: G A
authors.initials: GA
authors.lastname: Ashamu
authors.forename: B V
authors.initials: BV
authors.lastname: Potter
authors.forename: G W
authors.initials: GW
authors.lastname: Mayr
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000031:analogs & derivatives* / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D036563:Cyclic ADP-Ribose; D006801:Humans; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D036563:Cyclic ADP-Ribose; D000246:Adenosine Diphosphate Ribose; D002118:Calcium