Analysis of cellular signal transduction via Neurofibromatosis tumor suppressor gene products and development of their clinical targets

神经纤维瘤病抑癌基因产物神经纤维素：NF1和Merlin：NF2被认为是细胞生长、分化和凋亡的重要调节因子，与神经纤维瘤患者的神经功能异常有关。然而，核因子蛋白的确切细胞功能尚不清楚。在这项研究中，我们利用蛋白质组学策略、专有基因本体(芒果)的功能注释和标准的生化方法来鉴定PC12细胞中与神经元分化相关的蛋白质，这是研究神经营养因子相关神经生物学过程的代表性模型系统。在定量鉴定的1600个非冗余蛋白质中，有72个是新的神经生长因子反应PC12蛋白质，主要与细胞形态发生、凋亡/存活和细胞分化的生物学过程有关。利用这些蛋白质组学策略和数据库，我们鉴定了一组与核因子相关的细胞蛋白，包括轴突调节因子CRMP-2。这些联系对神经元轴突的形成至关重要，并受一系列由神经纤维蛋白控制的CDK5、GSK-3b和Rho激酶激活的调节。我们的研究表明，NF蛋白及其相关蛋白的功能结合对神经细胞的分化是必不可少的，而NF蛋白表达不足或调节异常可导致神经细胞功能受损，这可能是NF相关发病机制中的一个因素。

Neurofibromatosis (NF) tumor suppressor gene products, neurofibromin : NF1 and merlin : NF2, are though to be important regulators of cellular growth, differentiation, and apoptosis, and implicated in the neural abnormality of NF patients. However, the precise cellular function of NF proteins has yet to be clarified. In this study, we utilized proteomic strategies, functional annotation with a proprietary gene ontology (MANGO), and standard biochemical methods to identify proteins related to neuronal differentiation in PC12 cells, which serve as a representative model system for studying NF related neuronal biological processes. Of 1,600 non-redundant proteins quantitatively identified, 72 were novel nerve growth factor-responsive PC12 proteins mostly related to the biological processes of cell morphogenesis, apoptosis/survival, and cell differentiation. Using these proteomic strategies and database, we identified a set of NF-associating cellular proteins, including axon regulator CRMP-2. These associations were crucial for the axon formation in neuron and were regulated by a series of kinase activations by CDK5, GSK-3b, and Rho kinase being controlled by neurofibromin. Our study demonstrates that the functional association of NF proteins and their associating proteins are essential for neuronal cell differentiation and that lack of expression or abnormal regulation of NF proteins can result in impaired function of neural cells, which is likely a factor in NF-related pathogenesis.