Stochastic signal inputs for chemotactic response in Dictyostelium cells revealed by single molecule imaging techniques
Stochastic signal inputs for chemotactic response in Dictyostelium cells revealed by single molecule imaging techniques
复制标题
DOI：
10.1016/j.biosystems.2006.07.011
复制
发表时间：
2007-04-01
期刊：
影响因子：
1.6
通讯作者：
Ueda, Masahiro
中科院分区：
文献类型：
--
作者：
Miyanaga, Yukihiro;Matsuoka, Satomi;Ueda, Masahiro
趋化细胞对化学梯度表现出极端的敏感性。趋化所需的信号输入的理论估计表明，响应可以在跨膜信号传递过程中由受体产生的随机输入噪声的强烈影响下实现。这就提出了一个关于定向传感机制的基本问题：细胞如何通过随机操作的受体和下游分子获得关于梯度方向的可靠信息？为了解决这个问题，我们开发了单分子成像技术来可视化活盘基骨柱细胞中负责趋化的信号分子，使我们能够直接监测随机信号过程。与受体结合的化学引诱剂的单分子成像表明，信号输入随时间和空间波动。下游信号分子，如PTEN和含有PH结构域的蛋白质，是趋化信号系统的组成部分，也可以在活细胞的单分子水平上进行跟踪，阐明了趋化信号过程的随机性。本文首先对真核细胞的趋化反应进行了简要的介绍，然后对单分子成像技术进行了解释，最后讨论了这些技术在盘形骨细胞趋化信号系统中的应用。2006爱思唯尔爱尔兰有限公司版权所有。
Chemotactic cells can exhibit extreme sensitivity to chemical gradients. Theoretical estimations of the signal inputs required for chemotaxis suggest that the response can be achieved under the strong influence of stochastic input noise generated by the receptors during the transmembrane signaling. This arises a fundamental question regarding the mechanisms for directional sensing: how do cells obtain reliable information regarding gradient direction by using stochastically operating receptors and the downstream molecules? To address this question, we have developed single molecule imaging techniques to visualize signaling molecules responsible for chemotaxis in living Dictyostelium cells, allowing us to monitor the stochastic signaling processes directly. Single molecule imaging of a chemoattractant bound to a receptor demonstrates that signal inputs fluctuate with time and space. Downstream signaling molecules, such as PTEN and a PH domain-containing protein that are constituent parts of chemotactic signaling system, can also be followed at single molecule level in living cells, illuminating the stochastic nature of chemotactic signaling processes. In this report, we start with a brief introduction of chemotactic response of the eukaryotic cells, followed by an explanation for single molecule imaging techniques, and finally discuss these applications to chemotactic signaling system of Dictyostelium cells. (c) 2006 Elsevier Ireland Ltd. All rights reserved.