Department of Cell and Developmental Biology, University College London, London WC1E 6BT, UK.
Biochem Soc Trans. 2012 Feb;40(1):153-7. doi: 10.1042/BST20110693.
NAADP (nicotinic acid-adenine dinucleotide phosphate) is a potent Ca2+-mobilizing messenger implicated in many Ca2+-dependent cellular processes. It is highly unusual in that it appears to trigger Ca2+ release from acidic organelles such as lysosomes. These signals are often amplified by archetypal Ca2+ channels located in the endoplasmic reticulum. Recent studies have converged on the TPCs (two-pore channels) which localize to the endolysosomal system as the likely primary targets through which NAADP mediates its effects. 'Chatter' between TPCs and endoplasmic reticulum Ca2+ channels is disrupted when TPCs are directed away from the endolysosomal system. This suggests that intracellular Ca2+ release channels may be closely apposed, possibly at specific membrane contact sites between acidic organelles and the endoplasmic reticulum.
NAADP（烟酰胺腺嘌呤二核苷酸磷酸）是一种有效的 Ca2+动员信使，参与许多依赖 Ca2+的细胞过程。它非常特殊，因为它似乎可以触发酸性细胞器（如溶酶体）释放 Ca2+。这些信号通常通过内质网中典型的 Ca2+通道放大。最近的研究集中在 TPCs（双孔通道）上，它们定位于内溶酶体系统，可能是 NAADP 发挥作用的主要靶点。当 TPCs 被引导离开内溶酶体系统时，TPCs 和内质网 Ca2+通道之间的“喋喋不休”就会中断。这表明细胞内 Ca2+释放通道可能紧密相邻，可能位于酸性细胞器和内质网之间的特定膜接触位点。
