Ca(2+) release induced by cADP-ribose is mediated by FKBP12.6 proteins in mouse bladder smooth muscle.

We examined the role and molecular mechanism of cADPR action on Ca(2+) spark properties in mouse bladder smooth muscle. Dialysis of cADPR with patch pipettes increased frequency and amplitude of spontaneous transient out currents (STOCs) to 6.1+/-0.87 currents/min from 1.2+/-0.36 currents/min (control) and to 179.8+/-48.7pA from 36.4+/-22.6pA (control), respectively, in wildtype (WT) cells, and the effects of cADPR on STOCs were significantly blocked by JVT-591, a RYR2 stabilizer. In contrast, no significant changes were observed in FKBP12.6 null cells. Further studies indicated that Ca(2+) spark properties were altered by cADPR in WT but not FKBP12.6 null cells, namely, Ca(2+) spark frequency was increased by about 3.4-fold, peak Ca(2+) (F/F0) increased to 1.72+/-0.57 from 1.56+/-0.13, size increased to 2.86+/-0.26 microM from 1.92+/-0.14 microM, rise time and half-time decay were prolonged 1.6-fold and 2.3-fold, respectively, in WT cells. Furthermore, in the presence of thapsigargin cADPR still altered Ca(2+) spark properties, and cADPR increased F/F0 without affecting Ca(2+) spark decay time in voltage clamping cells. Dissociation studies demonstrated that application of cADPR resulted in significant removal of FKBP12.6 proteins from sarcoplasmic reticulum (SR) microsomes, and that treatment of the RyR2 immunoprecipitation complexes with cADPR or FK506 disrupted the interaction between RyR2 and FKBP12.6. Finally, cADPR altered SR Ca(2+) load in WT myocytes but not in FKBP12.6-null myocytes. Taken together, these results suggest that Ca(2+) release induced by cADPR is mediated by FKBP12.6 proteins in mouse bladder smooth muscle.

Zheng J ，Wenzhi B ，Miao L ，Hao Y ，Zhang X ，Yin W ，Pan J ，Yuan Z ，Song B ，Ji G ... -  《-》

Dissociation of FKBP12.6 from ryanodine receptor type 2 is regulated by cyclic ADP-ribose but not beta-adrenergic stimulation in mouse cardiomyocytes.

Zhang X ，Tallini YN ，Chen Z ，Gan L ，Wei B ，Doran R ，Miao L ，Xin HB ，Kotlikoff MI ，Ji G ... -  《-》

Role of cyclic ADP-ribose in Ca2+-induced Ca2+ release and vasoconstriction in small renal arteries.

Teggatz EG ，Zhang G ，Zhang AY ，Yi F ，Li N ，Zou AP ，Li PL ... -  《MICROVASCULAR RESEARCH》

RYR2 proteins contribute to the formation of Ca(2+) sparks in smooth muscle.

Ji G ，Feldman ME ，Greene KS ，Sorrentino V ，Xin HB ，Kotlikoff MI ... -  《-》

Cyclic ADP-ribose increases Ca2+ removal in smooth muscle.

Bradley KN ，Currie S ，MacMillan D ，Muir TC ，McCarron JG ... -  《JOURNAL OF CELL SCIENCE》