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|Section2= |Section3= }} Cyclic ADP Ribose, frequently abbreviated as cADPR, is a cyclic adenine nucleotide (like cAMP) with two phosphate groups present on 5' OH of the adenosine (like ADP), further connected to another ribose at the 5' position, which, in turn, closes the cycle by glycosidic bonding to the nitrogen 1 (N1) of the same adenine base (whose position N9 has the glycosidic bond to the other ribose). The N1-glycosidic bond to adenine is what distinguishes cADPR from ADP-ribose (ADPR), the non-cyclic analog. cADPR is produced from nicotinamide adenine dinucleotide (NAD+) by ADP-ribosyl cyclases (EC 3.2.2.5) as part of a second messenger system. ==Function== cADPR is a cellular messenger for calcium signaling. It stimulates calcium-induced calcium release at lower cytosolic concentrations of Ca2+. Primary target of cADPR is the ER Ca2+ uptake mechanism. Potentiation of Ca2+ release by cADPR is mediated by increased accumulation of Ca2+ in the SR and subsequent luminal Ca2+-dependent activation of ryanodine receptors (RyRs).〔Lukyanenko V, Györke I, Wiesner TF, Györke S. 2001. Potentiation of Ca(2+) release by cADP-ribose in the heart is mediated by enhanced ER Ca2+ uptake into the sarcoplasmic reticulum. Circ Res. 89(7):614-22. (PMID 11577027 ); (10.1161/hh1901.098066 )〕 Some reports suggest that cADPR binding makes FKBP12.6, which normally binds RyR2, to fall off the RYR2. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cyclic ADP-ribose」の詳細全文を読む スポンサード リンク
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