Functional ryanodine receptor expression is required for NAADP-mediated local Ca2+ signaling in T-lymphocytes
Functional ryanodine receptor expression is required for NAADP-mediated local Ca2+ signaling in T-lymphocytes
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DOI：
10.1074/jbc.m413085200
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发表时间：
2005-06-03
影响因子：
4.8
通讯作者：
Guse, AH
中科院分区：
文献类型：
--
作者：
Dammermann, W;Guse, AH
烟酸腺嘌呤二核苷酸磷酸(NAADP)是一种有效的钙激活核苷酸，参与T细胞钙信号转导(Berg，I.，Potter，B.V.L.，Mayr，G.W.和Guse，A.H.(2000)J.Cell Biol)。150、581-588)。本研究的目的是分析NAADP刺激T淋巴细胞后获得的第一个亚细胞内钙信号是否依赖于兰尼定受体的功能表达。结合显微注射和高分辨率共聚焦钙成像，我们证明了亚细胞钙信号先于全局钙信号，其特征是幅度类似于30到100 nm，直径类似于0.5微米。Ryanodine受体拮抗剂Ru红和Ryanodine与NAADP共同注射可阻断NAADP的作用，而D-肌醇1，4，5-三磷酸拮抗剂肝素和钙离子内流阻断剂SKF&96365则不起作用。这一药理学方法得到了分子击倒方法的证实。Ryanodine受体表达显著降低的Jurkat T细胞克隆对微量注射NAADP无反应。综上所述，我们的数据提示T淋巴细胞对NAADP敏感的钙释放通道是兰尼定受体。
Nicotinic acid adenine dinucleotide phosphate (NAADP) is a potent Ca2+-mobilizing nucleotide involved in T cell Ca2+ signaling ( Berg, I., Potter, B. V. L., Mayr, G. W., and Guse, A. H. (2000) J. Cell Biol. 150, 581-588). The objective of this study was to analyze whether the first subcellular Ca2+ signals obtained upon NAADP stimulation of T-lymphocytes depend on the functional expression of ryanodine receptors. Using combined microinjection and high resolution confocal calcium imaging, we demonstrate here that subcellular Ca2+ signals, characterized by amplitudes between similar to 30 and 100 nM and diameters of similar to 0.5 mu m, preceded global Ca2+ signals. Co-injection of the ryanodine receptor antagonists ruthenium red and ryanodine together with NAADP abolished the effects of NAADP, whereas the D-myo-inositol 1,4,5- trisphosphate antagonist heparin and the Ca2+ entry blocker SKF& 96365 were without effect. This pharmacological approach was confirmed by a molecular knock-down approach. Jurkat T cell clones with largely reduced expression of ryanodine receptors did not respond to microinjections of NAADP. Taken together, our data suggest that the Ca2+ release channel sensitive to NAADP in T- lymphocytes is the ryanodine receptor.