Tau confers drug stability but not cold stability to microtubules in living cells.
Tau confers drug stability but not cold stability to microtubules in living cells.
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发表时间：
1994
影响因子：
4
通讯作者：
P. Baas;T. Pienkowski;K. Cimbalnik;K. Toyama;S. Bakalis;F. J. Ahmad;K. Kosik
中科院分区：
文献类型：
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作者：
P. Baas;T. Pienkowski;K. Cimbalnik;K. Toyama;S. Bakalis;F. J. Ahmad;K. Kosik
我们先前在培养的交感神经元的轴突中定义了两类微管聚合物，它们对诺考达唑的敏感性相差约35倍（Baas和Black（1990）J. Cell Biol.111，495-509）。在这里，我们证明了几乎所有的微管聚合物在这些轴突，包括药物不稳定的聚合物，是稳定的冷。什么因素能解释轴突微管独特的稳定性？在本研究中，我们集中在tau的作用，微管相关蛋白，是高度富集的轴突，在确定微管的稳定性诺考达唑和/或冷在活细胞中。我们使用杆状病毒载体在昆虫卵巢Sf 9细胞中表达非常高水平的tau。细胞通过延伸包含密集微管束的突起来响应（Knops等（1991）J. Cell Biol.114，725-734）。用冷的或2微克/ml诺考达唑处理诱导表达tau的细胞5分钟至6小时。每种处理的结果彼此非常不同。几乎所有的聚合物在冷的前30分钟内解聚，而即使在诺考达唑中6小时后也很少或没有检测到微管解聚。基于这些结果，我们得出结论，tau蛋白几乎肯定是一个因素，在赋予药物稳定性轴突微管，但其他因素或除了tau蛋白是必需的，赋予冷稳定性。
We previously defined two classes of microtubule polymer in the axons of cultured sympathetic neurons that differ in their sensitivity to nocodazole by roughly 35-fold (Baas and Black (1990) J. Cell Biol. 111, 495-509). Here we demonstrate that virtually all of the microtubule polymer in these axons, including the drug-labile polymer, is stable to cold. What factors account for the unique stability properties of axonal microtubules? In the present study, we have focused on the role of tau, a microtubule-associated protein that is highly enriched in the axon, in determining the stability of microtubules to nocodazole and/or cold in living cells. We used a baculovirus vector to express very high levels of tau in insect ovarian Sf9 cells. The cells respond by extending processes that contain dense bundles of microtubules (Knops et al. (1991) J. Cell Biol. 114, 725-734). Cells induced to express tau were treated with either cold or 2 micrograms/ml nocodazole for times ranging from 5 minutes to 6 hours. The results with each treatment were very different from one another. Virtually all of the polymer was depolymerized within the first 30 minutes in cold, while little or no microtubule depolymerization was detected even after 6 hours in nocodazole. Based on these results, we conclude that tau is almost certainly a factor in conferring drug stability to axonal microtubules, but that factors other than or in addition to tau are required to confer cold stability.