BDNF INDUCES WIDESPREAD CHANGES IN SYNAPTIC PROTEIN CONTENT

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 脑源性神经营养因子(BDNF)在神经元发育、突触连接的形成和可塑性中起重要作用。BDNF的这些作用至少部分归因于神经营养素在全球和局部增加蛋白质合成的能力。然而，只有少数蛋白质在突触被BDNF上调。利用多维蛋白质鉴定技术(MudPIT)和光谱计数进行相对定量，我们发现在培养的皮质神经元经BDNF处理后的突触神经体制剂中有数百种蛋白质表达上调。这些蛋白质分为不同的功能类别，包括与突触小泡的形成和运动、突触结构的维持或重塑、mRNA的加工、转录和翻译有关的蛋白质。一些翻译因子、核糖体蛋白和tRNA合成酶被BDNF迅速上调。这种翻译成分的上调对蛋白质合成抑制剂很敏感，并依赖于哺乳动物靶标雷帕霉素(MTOR)的激活，mTOR是帽依赖的mRNA翻译的调节因子。免疫细胞化学和原位杂交证实了神经元突起中存在这些蛋白及其mRNAs的一部分，Western blotting证实了它们的上调。这些数据表明，BDNF增加了多种突触蛋白的合成，并提示BDNF增强了突触的翻译能力。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The brain-derived neurotrophic factor (BDNF) plays an important role in neuronal development, and in the formation and plasticity of synaptic connections. These effects of BDNF are at least partially due to the ability of the neurotrophin to increase protein synthesis both globally and locally. However, only a few proteins have been shown to be up-regulated at the synapse by BDNF. Using multi-dimensional protein identification technology (MudPIT) and relative quantification by spectra counting, we found that several hundred proteins are up-regulated in a synaptoneurosome preparation derived from cultured cortical neurons after treatment with BDNF. These proteins fall into diverse functional categories, including those involved in synaptic vesicle formation and movement, maintenance or remodeling of synaptic structure, mRNA processing, transcription and translation. A number of translation factors, ribosomal proteins, and tRNA synthetases were rapidly up-regulated by BDNF. This up-regulation of translation components was sensitive to protein synthesis inhibitors, and dependent on the activation of the mammalian target of rapamycin (mTOR), a regulator of cap-dependent mRNA translation. The presence of a subset of these proteins and their mRNAs in neuronal processes was corroborated by immunocytochemistry and in situ hybridization, and their up-regulation was confirmed by Western blotting. The data demonstrate that BDNF increases the synthesis of a wide variety of synaptic proteins and suggest that BDNF enhances the translational capacity of synapses.