NAADP as an intracellular messenger regulating lysosomal calcium-release channels.
Recent studies into the mechanisms of action of the Ca(2+)-mobilizing messenger NAADP (nicotinic acid-adenine dinucleotide phosphate) have demonstrated that a novel family of intracellular Ca(2+)-release channels termed TPCs (two-pore channels) are components of the NAADP receptor. TPCs appear to be exclusively localized to the endolysosomal system. These findings confirm previous pharmacological and biochemical studies suggesting that NAADP targets acidic Ca(2+) stores rather than the endoplasmic reticulum, the major site of action of the other two principal Ca(2+)-mobilizing messengers, InsP(3) and cADPR (cADP-ribose). Studies of the messenger roles of NAADP and the function of TPCs highlight the novel role of lysosomes and other organelles of the endocytic pathway as messenger-regulated Ca(2+) stores which also affects the regulation of the endolysosomal system.
Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK. antony.galione@pharm.ox.ac.uk
Antony
A
Galione
Anthony J
AJ
Morgan
Abdelilah
A
Arredouani
Lianne C
LC
Davis
Katja
K
Rietdorf
Margarida
M
Ruas
John
J
Parrington
D000818:Animals; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D011992:Endosomes / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism*; D009249:NADP / Q000031:analogs & derivatives* / Q000378:metabolism
D015220:Calcium Channels; D009249:NADP; C024376:NAADP; D002118:Calcium