Unicellular Ca2+ signaling 'toolkit' at the origin of Metazoa
Unicellular Ca2+ signaling 'toolkit' at the origin of Metazoa
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DOI：
10.1093/molbev/msn077
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发表时间：
2008-07-01
影响因子：
10.7
通讯作者：
Cai, Xinjiang
中科院分区：
文献类型：
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作者：
Cai, Xinjiang
Ca（2+）信号通路控制着几乎所有类型动物细胞的许多生理过程，如受精、肌肉收缩、激素释放以及学习和记忆。每种动物细胞类型表达来自Ca（2+）信号“工具包”的一组独特的分子，以控制Ca（2+）信号的时空模式。一般认为，复杂的Ca（2+）信号“工具包”已经从祖先的多细胞生物体中产生，以适应特定细胞类型的独特生理作用。在这里，我们证明了第一次的存在下，一个广泛的Ca（2+）信号的“工具包”的单细胞choanoflagellate Monosiga brevicollis。领鞭毛虫具有多种类型的动物质膜Ca（2+）通道的同源物，包括钙库操纵通道、配体操纵通道、电压操纵通道、第二信使操纵通道和6个动物瞬时受体电位通道家族中的5个。领鞭毛虫还含有肌醇1，4，5-三磷酸受体的同系物。此外，领鞭毛虫还掌握一套完整的Ca（2+）清除系统，包括质膜和肌/内质网Ca（2+）ATP酶以及3个动物阳离子/Ca（2+）交换蛋白家族的同源物。因此，一个复杂的Ca（2+）信号“工具包”可能在多细胞动物出现之前就已经进化出来了。
Ca(2+) signaling pathways control many physiological processes in almost all types of animal cells such as fertilization, muscle contraction, hormone release, and learning and memory. Each animal cell type expresses a unique group of molecules from the Ca(2+) signaling 'toolkit' to control spatiotemporal patterns of Ca(2+) signaling. It is generally believed that the complex Ca(2+) signaling 'toolkit' has arisen from the ancestral multicellular organisms to fit unique physiological roles of specialized cell types. Here, we demonstrate for the first time the presence of an extensive Ca(2+) signaling 'toolkit' in the unicellular choanoflagellate Monosiga brevicollis. Choanoflagellates possess homologues of various types of animal plasma membrane Ca(2+) channels including the store-operated channel, ligand-operated channels, voltage-operated channels, second messenger-operated channels, and 5 out of 6 animal transient receptor potential channel families. Choanoflagellates also contain homologues of inositol 1,4,5-trisphosphate receptors. Furthermore, choanoflagellates master a complete set of Ca(2+) removal systems including plasma membrane and sarco/endoplasmic reticulum Ca(2+) ATPases and homologues of 3 animal cation/Ca(2+) exchanger families. Therefore, a complex Ca(2+) signaling 'toolkit' might have evolved before the emergence of multicellular animals.