Interactions between intracellular Ca2+ stores: Ca2+ released from the NAADP pool potentiates cADPR-induced Ca2+ release
AUTOR(ES)
Chini, E.N.
FONTE
Brazilian Journal of Medical and Biological Research
DATA DE PUBLICAÇÃO
2002-05
RESUMO
Cells possess multiple intracellular Ca2+-releasing systems. Sea urchin egg homogenates are a well-established model to study intracellular Ca2+ release. In the present study the mechanism of interaction between three intracellular Ca2+ pools, namely the nicotinic acid adenine dinucleotide phosphate (NAADP), the cyclic ADP-ribose (cADPR) and the inositol 1',4',5'-trisphosphate (IP3)-regulated Ca2+ stores, is explored. The data indicate that the NAADP Ca2+ pool could be used to sensitize the cADPR system. In contrast, the IP3 pool was not affected by the Ca2+ released by NAADP. The mechanism of potentiation of the cADPR-induced Ca2+ release, promoted by Ca2+ released from the NAADP pool, is mediated by the mechanism of Ca2+-induced Ca2+ release. These data raise the possibility that the NAADP Ca2+ store may have a role as a regulator of the cellular sensitivity to cADPR.
Documentos Relacionados
- NAADP induces Ca2+ oscillations via a two-pool mechanism by priming IP3- and cADPR-sensitive Ca2+ stores
- Ca2+ release from internal stores: role in generating depolarizing after-potentials in rat supraoptic neurones.
- Caffeine-induced release and reuptake of Ca2+ by Ca2+ stores in myocytes from guinea-pig urinary bladder.
- Ca2+ and Sr2+ entry induced Ca2+ release from the intracellular Ca2+ store in smooth muscle cells of rat portal vein.
- Inositol trisphosphate-mediated Ca2+ influx into Xenopus oocytes triggers Ca2+ liberation from intracellular stores.