Synaptotagmin I and IX function redundantly in controlling fusion pore of large dense core vesicles
Synaptotagmin I and IX function redundantly in controlling fusion pore of large dense core vesicles
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突触结合蛋白 I 和 IX 在控制大致密核心囊泡融合孔中发挥冗余作用
DOI：
10.1016/j.bbrc.2007.07.083
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发表时间：
2007-10-05
影响因子：
3.1
通讯作者：
Xu, Tao
中科院分区：
文献类型：
--
作者：
Zhu, Dan;Zhou, Wei;Xu, Tao
突触结合蛋白（Synaptotagmins，Syts）是一个由至少16个成员组成的大家族，各个Syt亚型具有不同的钙结合特性和亚细胞定位。它仍有待证明是否多种Syt异构体可以独立或合作的某些类型的囊泡功能。在目前的研究中，我们已经开发了NPY-pHluorin，以专门评估大致密核心囊泡（LDCV）的胞吐作用，并研究了Syt I和Syt IX对PC 12细胞中LDCV胞吐作用的需求。我们发现，下调Syt I和Syt IX导致Ca 2+依赖性LDCV胞吐的显著损失。此外，我们的研究结果表明，Syt I和Syt IX在控制融合模式的选择中起着冗余的作用。Syt I和Syt IX的下调在吻和跑模式中呈现更多的融合。我们得出的结论是，Syt I和Syt IX在PC 12细胞LDCV的Ca 2+感应和融合孔扩张中具有冗余功能。(C)2007年爱思唯尔公司All rights reserved.
Synaptotagmins (Syts) constitute a large family of at least 16 members and individual Syt isoforms exhibit distinct Ca2+ -binding properties and subcellular localization. It remains to be demonstrated whether multiple Syt isoforms can function independently or cooperatively on certain type of vesicle. In the current study, we have developed NPY-pHluorin to specifically assess exocytosis of large dense core vesicles (LDCVs) and studied the requirement of Syt I and Syt IX for LDCV exocytosis in PC12 cells. We found that down-regulation of both Syt I and Syt IX resulted in a significant loss of Ca2+ -dependent LDCV exocytosis. Moreover, our results suggest Syt I and Syt IX play redundant role in controlling the choice of fusion modes. Down-regulation of both Syt I and Syt IX renders more fusion in the kiss-and-run mode. We conclude that Syt I and Syt IX function redundantly in Ca2+-sensing and fusion pore dilation on LDCVs in PC12 cells. (C) 2007 Elsevier Inc. All rights reserved.