Fukuda Mitsunori
Fukuda Initiative Research Unit, RIKEN (The Institute of Physical and Chemical Research), Wako, Saitama, Japan.
Neuroreport. 2006 Feb 6;17(2):179-82. doi: 10.1097/01.wnr.0000198435.14142.be.
Synaptotagmin IX has been postulated to function as a major Ca2+ sensor for dense-core vesicle exocytosis in neuroendocrine cells. In this study, we investigated the subcellular localization and developmental expression profile of synaptotagmin IX in the mouse brain and found that it is mainly present in the dense-core vesicle fraction, which is devoid of synaptotagmin I and synaptophysin. We also found that the synaptotagmin IX expression level is constant throughout the postnatal development of the mouse brain, whereas the synaptotagmins I, II, III, VI, and XII are upregulated in parallel with synaptogenesis. These findings suggest that synaptotagmin IX regulates the transport of certain vesicles in the brain other than synaptic vesicles.
突触结合蛋白IX被认为是神经内分泌细胞中致密核心囊泡胞吐作用的主要钙离子传感器。在本研究中，我们调查了突触结合蛋白IX在小鼠大脑中的亚细胞定位和发育表达谱，发现它主要存在于致密核心囊泡部分，该部分不含突触结合蛋白I和突触素。我们还发现，在小鼠大脑出生后的发育过程中，突触结合蛋白IX的表达水平保持恒定，而突触结合蛋白I、II、III、VI和XII则与突触发生同步上调。这些发现表明，突触结合蛋白IX调节大脑中除突触囊泡之外的某些囊泡的运输。
