title: Modulation of store-operated Ca2+ entry by cyclic-ADP-ribose.
abstract: Store-operated Ca2+ entry plays an important role in Ca2+ homeostasis in cells but the mechanisms of control of these channels are not completely understood. We describe an investigation of the role of the CD38-cyclic-ADP-ribose (cADPR)-ryanodine-channel (RyR) signaling pathway in store-operated Ca2+ entry in human smooth muscle. We observed that human myometrial cells have a functional store-operated Ca2+ entry mechanism. Furthermore, we observed the presence of transient receptor potential 1, 3, 4, 5, and 6 ion channels in human myometrial cells. Store-operated Ca2+ transient was inhibited by at least 50-70% by several inhibitors of the RyR, including ryanodine (10 microM), dantrolene (10 microM), and ruthenium red (10 microM). Furthermore, the cell permeable inhibitor of the cADPR-system, 8-Br-cADPR (100 microM), is a potent inhibitor of the store-operated entry, decreasing the store operated entry by 80%. Pre-incubation of cells with 100 microM cADPR and the hydrolysis-resistant cADPR analog 3-deaza-cADPR (50 microM), but not with ADP-ribose (ADPR) leads to a 1.6-fold increase in the store-operated Ca2+ transient. In addition, we observed that nicotinamide (1-10 mM), an inhibitor of cADPR synthesis, also leads to inhibition of the store-operated Ca2+ transient by 50-80%. Finally, we observed that the transient receptor potential channels, RyR, and CD38 can be co-immunoprecipitated, indicating that they interact in vivo. Our observations clearly implicate the CD38-cADPR-ryanodine signaling pathway in the regulation of store-operated Ca2+ entry in human smooth muscle cells.
authors.affiliation: Signal Transduction Laboratory, Department of Anesthesiology, Mayo Clinic and Foundation, Rochester, MN 55905, USA.
authors.forename: M
authors.initials: M
authors.lastname: Thompson
authors.forename: T
authors.initials: T
authors.lastname: White
authors.forename: E N
authors.initials: EN
authors.lastname: Chini
mesh_terms: D051997:ADP-ribosyl Cyclase 1; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D036563:Cyclic ADP-Ribose / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D009215:Myometrium / Q000166:cytology* / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D015398:Signal Transduction; D050051:Transient Receptor Potential Channels / Q000378:metabolism
chemical_list: D019837:Ryanodine Receptor Calcium Release Channel; D050051:Transient Receptor Potential Channels; D036563:Cyclic ADP-Ribose; D051997:ADP-ribosyl Cyclase 1; D002118:Calcium