Roles of cADPR and NAADP in pancreatic cells

摘要

Cyclic ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP) are Ca2+-mobilizing nucleotides that were discovered in the late 1980s.Two decades of investigations have built up a considerable understanding about these two molecules that are related because both are derived from pyridine nucleotides and known to be generated by CD38/ADP-ribosyl cyclases,cADPR has been shown to target the ryanodine receptors in the endoplasmic reticulum whereas NAADP stimulates the two-pore channels in the endo-lysosomes.Accumulating results indicate that cADPR and NAADP are second messenger molecules mediating Ca2+ signaling activated by a wide range of agonists.This article reviews what is known about these two molecules,especially regarding their signaling roles in the pancreatic cells.