NAADP+ is an agonist of the human P2Y11 purinergic receptor.
Nicotinic acid adenine dinucleotide phosphate (NAADP+) is an intracellular second messenger releasing Ca2+ from intracellular stores in different cell types. In addition, it is also active in triggering [Ca2+](i) increase when applied extracellularly and various underlying mechanisms have been proposed. Here, we used hP2Y(11)-transfected 1321N1 astrocytoma cells to unequivocally establish whether extracellular NAADP+ is an agonist of the P2Y(11) receptor, as previously reported for beta-NAD+ [I. Moreschi, S. Bruzzone, R.A. Nicholas, et al., Extracellular NAD+ is an agonist of the human P2Y11 purinergic receptor in human granulocytes, J. Biol. Chem. 281 (2006) 31419-31429]. Extracellular NAADP+ triggered a concentration-dependent two-step elevation of [Ca2+](i) in 1321N1-hP2Y(11) cells, but not in wild-type 1321N1 cells, secondary to the intracellular production of IP(3), cAMP and cyclic ADP-ribose (cADPR). Specifically, the transient [Ca2+](i) rise proved to be related to IP(3) overproduction and to consequent Ca2+ mobilization, while the sustained [Ca2+](i) elevation was caused by the cAMP/ADP-ribosyl cyclase (ADPRC)/cADPR signalling cascade and by influx of extracellular Ca2+. In human granulocytes, endogenous P2Y(11) proved to be responsible for the NAADP+-induced cell activation (as demonstrated by the use of NF157, a selective and potent inhibitor of P2Y(11)), unveiling a role of NAADP+ as a pro-inflammatory cytokine. In conclusion, we provide unequivocal evidence for the activation of a member of the P2Y receptor subfamily by NAADP+.
Moreschi
Iliana
I
Department of Experimental Medicine, Section of Biochemistry, and Center of Excellence for Biomedical Research (CEBR), University of Genoa, Viale Benedetto XV/1, Genoa, Italy.
Bruzzone
Santina
S
Bodrato
Nicoletta
N
Usai
Cesare
C
Guida
Lucrezia
L
Nicholas
Robert A
RA
Kassack
Matthias U
MU
Zocchi
Elena
E
De Flora
Antonio
A
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002633:Chemotaxis / Q000502:physiology; D036563:Cyclic ADP-Ribose / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D006098:Granulocytes / Q000166:cytology / Q000378:metabolism; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D009249:NADP / Q000031:analogs & derivatives* / Q000378:metabolism; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*
C109734:P2RY11 protein, human; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D036563:Cyclic ADP-Ribose; D009249:NADP; C024376:NAADP; D015544:Inositol 1,4,5-Trisphosphate; D000242:Cyclic AMP; D002118:Calcium