11月21日，国际著名期刊Neuron发表了中科院生物物理所徐涛研究组在囊泡转运与分泌领域的最新成果PKA activation bypasses the requirement for UNC-31 in the docking of dense core vesicles from C.elegans neurons。
线虫是很好的研究遗传和发育的系统，但其在细胞生物学特别是囊泡转运与分泌领域的贡献却十分有限，其主要原因在于缺少高时空分辨的研究手段。徐涛研究组克服了这个技术局限，发展了模式生物线虫的单细胞分离和培养方法，首次在线虫单神经元上用膜电容检测技术记录到胞吐和胞吞过程，结合改进的碳纤微电极技术和囊泡转运的显微成像技术等先进的生物物理方法，将高时空分辨的分泌检测技术应用在线虫上，建立了在线虫细胞水平研究调控型分泌的技术平台。利用该技术平台，证明了核心致密囊泡的胞吐过程需要一种称为UNC-31(CAPS在线虫中的同源蛋白)的蛋白，阐明了该蛋白参与囊泡锚定的作用机制，并发现了UNC-13(Munc13-1在线虫中的同源蛋白)与UNC-31 蛋白之间存在相互作用。该工作开辟了利用线虫模式生物研究囊泡分泌的新方向。
两年来，徐涛研究组通过一系列创新技术和研究方法，揭示了囊泡锚定、启动、融合等生理过程中的重要调控通路，在Cell、Nature子刊系列发表了3篇重要论文，对该领域的发展产生了积极的推动作用。（生物物理研究所）
原始出处:
Neuron, Vol 56, 657-669, 21 November 2007
Article
PKA Activation Bypasses the Requirement for UNC-31 in the Docking of Dense Core Vesicles from C. elegans Neurons
Ke-Ming Zhou,1,3 Yong-Ming Dong,1,3 Qian Ge,1,3 Dan Zhu,1 Wei Zhou,1 Xian-Guang Lin,1 Tao Liang,1 Zheng-Xing Wu,1, and Tao Xu1,2,
1 Key Laboratory of Molecular Biophysics, Ministry of Education, and Joint Laboratory of Institute of Biophysics, Huazhong University of Science and Technology, Wuhan 430074, China
2 National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
Corresponding author
Tao Xu
xutao@ibp.ac.cn
Corresponding author
Zheng-Xing Wu
ibbwuzx@mail.hust.edu.cn
The nematode C. elegans provides a powerful model system for exploring the molecular basis of synaptogenesis and neurotransmission. However, the lack of direct functional assays of release processes has largely prevented an in depth understanding of the mechanism of vesicular exocytosis and endocytosis in C. elegans. We address this technical limitation by developing direct electrophysiological assays, including membrane capacitance and amperometry measurements, in primary cultured C. elegans neurons. In addition, we have succeeded in monitoring the docking and fusion of single dense core vesicles (DCVs) employing total internal reflection fluorescence microscopy. With these approaches and mutant perturbation analysis, we provide direct evidence that UNC-31 is required for the docking of DCVs at the plasma membrane. Interestingly, the defect in DCV docking caused by UNC-31 mutation can be fully rescued by PKA activation. We also demonstrate that UNC-31 is required for UNC-13-mediated augmentation of DCV exocytosis.
