CRACM3 regulates the stability of non-excitable exocytotic vesicle fusion pores in a Ca(2+)-independent manner via molecular interaction with syntaxin4.
CRACM3 regulates the stability of non-excitable exocytotic vesicle fusion pores in a Ca(2+)-independent manner via molecular interaction with syntaxin4.
复制标题
CRACM3通过与语法的分子相互作用来调节Ca（2+）独立方式中不可驱动的胞囊囊泡融合孔的稳定性。
DOI：
10.1038/srep28133
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发表时间：
2016-06-15
影响因子：
4.6
通讯作者：
Maeyama K
中科院分区：
文献类型：
--
作者：
Liu S;Sahid MN;Takemasa E;Kiyoi T;Kuno M;Oshima Y;Maeyama K
Ca2+ 释放激活钙通道 3 (CRACM3) 是 Ca2+ 选择性通道 CRAC 家族的独特成员。在非兴奋性胞吐作用模型中，我们发现CRACM3的胞外L3结构域和胞质C端以活性依赖性方式与可溶性N-乙基马来酰亚胺敏感因子附着受体蛋白syntaxin4的N肽相互作用。我们的生化、电生理和单囊泡研究表明，CRACM3 的敲低通过减少囊泡融合孔的开放时间来抑制功能性胞吐作用，而不影响 Ca2+ 流入、活性依赖性膜电容 (Cm) 变化和融合事件总数。相反，过度表达CRACM3会显着损害独立于Ca2+的细胞胞吐作用，导致Cm变化受损，减少融合事件的数量，并延长融合孔的停留时间。 CRACM3 以与改变的分子表达一致的方式改变囊泡融合孔的稳定性。我们的研究结果表明，CRACM3 在胞吐作用中发挥着更大的作用，而不仅仅是充当 Ca2+ 通道的补偿亚基。
Ca2+ release-activated calcium channel 3 (CRACM3) is a unique member of the CRAC family of Ca2+-selective channels. In a non-excitable exocytosis model, we found that the extracellular L3 domain and the cytoplasmic C-terminus of CRACM3 interacted in an activity-dependent manner with the N-peptide of syntaxin4, a soluble N-ethylmaleimide-sensitive factor attachment receptor protein. Our biochemical, electrophysiological and single-vesicle studies showed that knockdown of CRACM3 suppressed functional exocytosis by decreasing the open time of the vesicle fusion pore without affecting Ca2+ influx, the activity-dependent membrane capacitance (Cm) change, and the total number of fusion events. Conversely, overexpressing CRACM3 significantly impaired cell exocytosis independent of Ca2+, led to an impaired Cm change, decreased the number of fusion events, and prolonged the dwell time of the fusion pore. CRACM3 changes the stability of the vesicle fusion pore in a manner consistent with the altered molecular expression. Our findings imply that CRACM3 plays a greater role in exocytosis than simply acting as a compensatory subunit of a Ca2+ channel.