Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs.
Enhanced ER Ca2+ store filling by overexpression of SERCA2b promotes IP3-evoked puffs.
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DOI：
10.1016/j.ceca.2011.04.008
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发表时间：
2011-07
期刊：
影响因子：
4
通讯作者：
Parker I
中科院分区：
文献类型：
--
作者：
Yamasaki-Mann M;Parker I
通过肌醇三磷酸受体 (IP3R) 从内质网 (ER) 释放 Ca2+ 受到 ER Ca2+ 含量的调节，SERCA2b 的过度表达可加速 Ca2+ 封存在 ER 中，已被证明可以增强爪蟾卵母细胞中 IP3 诱发的 Ca2+ 波的频率和幅度。在这里，我们检查了 SERCA 过表达对基本 IP3 诱发的泡的影响，以阐明 ER [Ca2+] 是否可以通过腔调节位点调节 IP3R 功能，此外还简单地确定可用存储的大小和 Ca2+ 释放的电化学驱动力。 SERCA2b 和 Ca2+ 可渗透的烟碱质膜通道在卵母细胞中表达，并传递超极化脉冲以诱导 Ca2+ 流入，从而加载 ER 储备。在 SERCA 过表达细胞中瞬时 Ca2+ 流入后，光释放的 IP3 引起的喷发在响应位点的数量、频率和幅度方面显着增强，而单独 SERCA 过表达或在未过表达 SERCA 的对照细胞中 Ca2+ 流入后，几乎没有明显的变化。有趣的是，我们观察到在长时间潜伏后出现的新群体的出现，并且持续时间较长，支持 IP3R 门控动力学的管腔调节概念。
Liberation of Ca2+ from the endoplasmic reticulum (ER) through inositol trisphosphate receptors (IP3R) is modulated by the ER Ca2+ content, and overexpression of SERCA2b to accelerate Ca2+ sequestration into the ER has been shown to potentiate the frequency and amplitude of IP3-evoked Ca2+ waves in Xenopus oocytes. Here, we examined the effects of SERCA overexpression on the elementary IP3-evoked puffs to elucidate whether ER [Ca2+] may modulate IP3R function via luminal regulatory sites in addition to simply determining the size of the available store and electrochemical driving force for Ca2+ release. SERCA2b and Ca2+ permeable nicotinic plasmalemmal channels were expressed in oocytes, and hyperpolarizing pulses were delivered to induce Ca2+ influx and thereby load ER stores. Puffs evoked by photoreleased IP3 were significantly potentiated in terms of numbers of responding sites, frequency and amplitude following transient Ca2+ influx in SERCA-overexpressing cells, whereas little change was evident with SERCA overexpression alone or following Ca2+ influx in control cells not overexpressing SERCA. Intriguingly, we observed the appearance of a new population of puffs that arose after long latencies and had prolonged durations supporting the notion of luminal regulation of IP3R gating kinetics.
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影响因子：
3.4
作者：
Rose, Heather J.;Dargan, Sheila;Parker, Ian
通讯作者：
Parker, Ian
影响因子：
64.5
作者：
Cárdenas C;Miller RA;Smith I;Bui T;Molgó J;Müller M;Vais H;Cheung KH;Yang J;Parker I;Thompson CB;Birnbaum MJ;Hallows KR;Foskett JK
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Foskett JK
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作者：
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通讯作者：
Berridge, Michael J.
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3.4
作者：
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通讯作者：
Györke, S
影响因子：
3.4
作者：
Shuai, Jianwei;Pearson, John E.;Parker, Ian
通讯作者：
Parker, Ian