Study for the cellular signal transduction of Neurofibromatosis Type 1 and Type 2 tumor suppressor gene products to establish the medical molecular target for NF1 and NF2

神经纤维瘤病1型（NF 1）和2型（NF 2）是一种常染色体显性遗传疾病，与双侧前庭神经鞘瘤、脑膜瘤和胶质瘤等颅内肿瘤的发生密切相关。为了阐明NF 1和NF 2基因产物的生物学功能，我们利用siRNA技术和蛋白质组学策略分析了NF 1和NF 2基因产物的细胞信号转导。1）NF 1; NF 1 siRNA诱导特征性形态学变化，如过度的肌动蛋白应力纤维形成，coffin磷酸化水平升高，其通过解聚和切断肌动蛋白丝来调节肌动蛋白细胞骨架重组，并且通过Rho-ROCK-LIMK 2途径的激活来促进，这需要Ras激活。用定量差异蛋白质组学策略（iTRAQ）鉴定了53个与神经纤维蛋白相关的蛋白质。这些蛋白质包括钙调素反应介体蛋白-2（CRMP-2）、钙调素（CaM）、14-3-3蛋白、Micr ...更多信息 在PC 12细胞中，CRMP 2和微管蛋白与神经纤维蛋白的结合通过其磷酸化方式调节。NF 1 SiRNA显著抑制PC 12细胞突起的生长，其作用机制与通过GSK-3b、Rho激酶等调节CRMP-2磷酸化有关。神经纤维蛋白在调节细胞骨架重组的机制中具有重要作用，其影响细胞运动、粘附和分化。2）NF 2;鉴定了28种merlin的细胞结合蛋白，主要集中在DNA修复酶，如聚ADP-核糖聚合酶，DNA-PK亚基Ku-抗原85和70。Merlin蛋白的N端（19-339）区域是它们相互作用的关键。merlin和PARP的亚细胞共定位主要在它们的核区域，并具有merlin的核输出信号（内斯）依赖性。这种核积累随着细胞DNA损伤而增加，而MEF（PARP-/-）不能在其核区域积累merlin。这些结果表明，merlin是一个细胞质-核穿梭蛋白指导其NES依赖的运输途径与PARP。NF蛋白通过其细胞相关蛋白进行功能调节是必不可少的，NF基因异常引起的NF蛋白功能异常调节可能参与NF相关的发病机制。少

The neurofibromatosis type 1 (NF1) and type 2 (NF2) are autosomal dominantly inherited disorders, and strongly associated with development of intracranial tumors including bilateral vestibular schwannomas, meningiomas and gliomas. To elucidate the biological function of NF1 and NF2 gene products, and, we analyzed their cellular signal transductions by using siRNA techniques and proteomic strategies. 1)NF1 ; NF1 siRNA induces characteristic morphological changes, such as excessive actin stress fiber formation, with elevated phosphorylation levels of coffin, which regulates actin cytoskeletal reorganization by depolymerizing and severing actin filaments, and that was promoted by the activation of a Rho-ROCK-LIMK2 pathway, which requires Ras activation. Fifty three proteins associating to neurofibromin were identified with the quantitative differential proteomic strategy (iTRAQ). These proteins contain collapsin response mediator protein-2 (CRMP-2), calmodulin (CaM), 14-3-3 proteins, Micr … More otubule-associated proteins, coffilin etc. In PC12 cells, the associations of CRMP2 and tubulin to neurofibromin were regulated by their phosphorylation manners. NF1 SiRNA significantly inhibited the neurite extension of PC12 cells, which was correlated with the regulation of CRMP-2 phosphorylations via GSK-3b, Rho-kinase, and other kinases. Neurofibromin has significant roles in the machinery regulating cellular cytoskeletal reorganization, which affects cell motility, adhesion, and differentiations. 2)NF2 ; 28 cellular binding proteins of merlin were identified, and focused on DNA repair enzymes such as poly ADP-ribose polymerase, DNA-PK subunits Ku-antigen 85 and 70. The N-terminal (19-339) region of merlin is essential for their interaction. Subcellular co-localizations of merlin and PARP were observed mainly in their nuclear region with a nuclear export signal (NES) dependent manner of merlin. This nuclear accumulation increased with cellular DNA damages, whereas MEF (PARP-/-) could not accumulate merlin in their nuclear region. These results suggest that merlin is a cytoplasmic-nuclear shuttling protein directed by its NES-dependent transport pathway being associated with PARP. Functional regulations of NF proteins via their cellular associating proteins are essential, and their abnormal regulations caused by NF gene aberrations may be implicated in NF-related pathogenesis. Less