11月21日，國(guó)際著名期刊Neuron發(fā)表了中科院生物物理所徐濤研究組在囊泡轉(zhuǎn)運(yùn)與分泌領(lǐng)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,。
線蟲是很好的研究遺傳和發(fā)育的系統(tǒng),，但其在細(xì)胞生物學(xué)特別是囊泡轉(zhuǎn)運(yùn)與分泌領(lǐng)域的貢獻(xiàn)卻十分有限，其主要原因在于缺少高時(shí)空分辨的研究手段,。徐濤研究組克服了這個(gè)技術(shù)局限,，發(fā)展了模式生物線蟲的單細(xì)胞分離和培養(yǎng)方法，首次在線蟲單神經(jīng)元上用膜電容檢測(cè)技術(shù)記錄到胞吐和胞吞過(guò)程,，結(jié)合改進(jìn)的碳纖微電極技術(shù)和囊泡轉(zhuǎn)運(yùn)的顯微成像技術(shù)等先進(jìn)的生物物理方法,，將高時(shí)空分辨的分泌檢測(cè)技術(shù)應(yīng)用在線蟲上，建立了在線蟲細(xì)胞水平研究調(diào)控型分泌的技術(shù)平臺(tái),。利用該技術(shù)平臺(tái),，證明了核心致密囊泡的胞吐過(guò)程需要一種稱為UNC-31(CAPS在線蟲中的同源蛋白)的蛋白,，闡明了該蛋白參與囊泡錨定的作用機(jī)制，并發(fā)現(xiàn)了UNC-13(Munc13-1在線蟲中的同源蛋白)與UNC-31 蛋白之間存在相互作用,。該工作開辟了利用線蟲模式生物研究囊泡分泌的新方向,。
兩年來(lái)，徐濤研究組通過(guò)一系列創(chuàng)新技術(shù)和研究方法,，揭示了囊泡錨定,、啟動(dòng)、融合等生理過(guò)程中的重要調(diào)控通路,，在Cell,、Nature子刊系列發(fā)表了3篇重要論文，對(duì)該領(lǐng)域的發(fā)展產(chǎn)生了積極的推動(dòng)作用,。（生物物理研究所）
原始出處:
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
[email protected]
Corresponding author
Zheng-Xing Wu
[email protected]
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.
