Ca2+ Dependency of N-Cadherin Function Probed by Laser Tweezer and Atomic Force Microscopy
Ca2+ Dependency of N-Cadherin Function Probed by Laser Tweezer and Atomic Force Microscopy
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激光镊子和原子力显微镜探测 N-钙粘蛋白功能的 Ca2 依赖性
DOI：
10.1523/jneurosci.23-35-11008.2003
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
D. Drenckhahn
中科院分区：
文献类型：
--
作者：
W. Baumgartner;N. Golenhofen;Niko Grundhöfer;J. Wiegand;D. Drenckhahn
这项研究的目的是为以下假设提供生物物理学基础：通过细胞外钙 ([Ca2+]e) 的瞬时变化对钙粘蛋白介导的粘附进行活性依赖性调节，从而因果性地参与突触可塑性的协调。通过原子力显微镜和激光镊捕获附着在培养神经元细胞表面的 N-钙粘蛋白包被微珠来表征同亲 N-钙粘蛋白结合，结果表明 N-钙粘蛋白的粘附活性在 0.3 至 0.8 mm [Ca2+]e 之间得到有效调节。此外，我们发现，[Ca2+]i 的增加（已知对诱导突触可塑性至关重要）会导致钙粘蛋白介导的珠粘附显着减少，而这种粘附可以通过抑制肌动蛋白解聚来完全抑制。这项研究的结果表明，N-钙粘蛋白具有理想的生物物理特性，可作为突触活动的 Ca2+ 依赖性传感器，同时，其战略位置可控制突触粘附。 [Ca2+]e 的下降和 [Ca2+]i 的伴随增加可能协同作用，调节突触位点处基于 N-钙粘蛋白的粘附接触。
This study was undertaken to provide a biophysical basis for the hypothesis that activity-dependent modulation of cadherin-mediated adhesion by transient changes of extracellular calcium ([Ca2+]e) is causally involved in coordination of synaptic plasticity. Characterization of homophilic N-cadherin binding by atomic force microscopy and laser tweezer trapping of N-cadherin-coated microbeads attached to the cell surface of cultured neuronal cells showed that adhesive activity of N-cadherin is effectively regulated between 0.3 and 0.8 mm [Ca2+]e. Furthermore, we show that an increase of [Ca2+]i, which is known to be essential for induction of synaptic plasticity, causes significant reduction of cadherin-mediated bead adhesion that could be completely suppressed by inhibition of actin depolymerization. The results of this study show that N-cadherin has ideal biophysical properties to serve as a Ca2+-dependent sensor for synaptic activity and, at the same time, is strategically located to control synaptic adhesion. A drop of [Ca2+]e and a concomitant increase of [Ca2+]i may act in concert to modulate N-cadherin-based adhesive contacts at synaptic sites.
DOI：
10.1073/pnas.100139797
发表时间：
2000-06-06
影响因子：
11.1
作者：
Krucker, T;Siggins, GR;Halpain, S
通讯作者：
Halpain, S