Samsonov Andrey, Yu Jiang-Zhou, Rasenick Mark, Popov Sergey V
Department of Physiology and Biophysics M/C 901, University of Illinois at Chicago, 835 S. Wolcott Avenue, Chicago, IL 60612, USA.
J Cell Sci. 2004 Dec 1;117(Pt 25):6129-41. doi: 10.1242/jcs.01531.
Tau is a major microtubule-associated protein which induces bundling and stabilization of axonal microtubules (MTs). To investigate the interaction of tau with MTs in living cells, we expressed GFP-tau fusion protein in cultured Xenopus embryo neurons and performed time-lapse imaging of tau-labeled MTs. Tau uniformly labeled individual MTs regardless of their assembly/disassembly status and location along the axon. Photobleaching experiments indicated that interaction of tau with MTs is very dynamic, with a half-time of fluorescence recovery of the order of 3 seconds. Treatment of cells with taxol, a drug that suppresses MT dynamics, rapidly induced detachment of tau from MTs. Although binding of tau to straight MTs was uniform, there was a heightened concentration of tau at the sites of high MT curvature. Our results suggest that dynamic interaction of tau with MTs may modify local mechanical properties of individual MTs and play a crucial role in the remodeling of the MT cytoskeleton during neuronal plasticity.
Tau是一种主要的微管相关蛋白，可诱导轴突微管（MTs）的成束和稳定。为了研究tau与活细胞中MTs的相互作用，我们在培养的非洲爪蟾胚胎神经元中表达了GFP-tau融合蛋白，并对tau标记的MTs进行了延时成像。无论MTs的组装/拆卸状态以及其在轴突上的位置如何，Tau均能均匀地标记单个MTs。光漂白实验表明，tau与MTs的相互作用非常动态，荧光恢复半衰期约为3秒。用紫杉醇（一种抑制MT动力学的药物）处理细胞，可迅速诱导tau从MTs上脱离。尽管tau与直MTs的结合是均匀的，但在MT曲率高的部位tau浓度升高。我们的结果表明，tau与MTs的动态相互作用可能会改变单个MTs的局部力学性质，并在神经元可塑性过程中MT细胞骨架的重塑中起关键作用。
