核孔蛋白p62促进非受体型酪氨酸激酶c-Ab1进入细胞核

发布时间：2018-05-04 06:00

本文选题：c-Abl + 核孔蛋白p62　；参考：《中国人民解放军军事医学科学院》2005年博士论文

【摘要】：非受体酪氨酸激酶c-Abl广泛表达于各组织细胞中,其序列高度保守。它的亚细胞定位与其功能密切相关。细胞核内的c-Abl在细胞凋亡调控以及DNA损伤修复过程中起重要作用,而胞质中的c-Abl则与细胞黏附、细胞分化和氧化应激有关。c-Abl借助其C端的3个核定位信号(NLS)和一个核输出信号(NES)完成细胞核-细胞质间的穿梭过程。与此形成鲜明对照的是,具有恶性转化能力的c-Abl突变体都只定位于细胞质中。例如BCR-Abl,虽然它具有与c-Abl相同的C端序列和NLS、NES,但它只存在于胞质中,而且胞质中BCR-Abl的组成型活化是导致人类慢性粒细胞白血病(CML)的重要原因。目前,关于c-Abl核-质穿梭的详细机制还不清楚。通过酵母双杂交系统,以人类Ib型c-Abl作为诱饵蛋白,进行Hela细胞cDNA文库的筛选。获得了一个可能在c-AM核-质穿梭过程中具有调控作用的蛋白:核孔蛋白p62。核孔复合物(NPC)是大分子物质进行核.质运输的唯一通道,p62是NPC的一个重要组成部分,它位于中央通道内侧,在许多物质的核-质穿梭过程中具有调节作用。通过免疫共沉淀和体外结合实验证实:c-Ab1和p62之间具有相互作用,而且这种相互作用是通过c-Ab1的SH3结构域与p62的P299位点之间的结合实现的;p62可被c-Ab1部分磷酸化;在电离辐射和阿糖胞苷所致的DNA损伤的研究中发现,c-Ab1与p62及其二聚体的结合在DNA损伤早期呈增多的趋势,在DNA损伤后期,二者之间的结合减少;此外,通过亚细胞组分的分离和激光共聚焦显微镜观察,发现p62具有促进c—Ab1进入细胞核的作用。
[Abstract]:Non-receptor tyrosine kinase c-Abl is widely expressed in various tissue cells and its sequence is highly conserved. Its subcellular localization is closely related to its function. The c-Abl in the nucleus plays an important role in the regulation of apoptosis and the repair of DNA damage, while the c-Abl in the cytoplasm adheres to the cell. Cell differentiation is related to oxidative stress. C-Abl completes the nucleus-cytoplasmic shuttle process by means of three nuclear localization signals (NLSs) and a nuclear output signal (NES) at its C-terminal. In contrast, c-Abl mutants with malignant transformation were located only in cytoplasm. BCR-AblA, for example, has the same C-terminal sequence as c-Abl and NLS- NES, but it only exists in the cytoplasm, and the constitutive activation of BCR-Abl in the cytoplasm is an important cause of human chronic myeloid leukemia (CML). At present, the detailed mechanism of c-Abl nuclear-cytoplasmic shuttle is not clear. The cDNA library of Hela cells was screened by yeast two-hybrid system with human Ib type c-Abl as bait protein. We obtained a protein that may play a regulatory role in the c-AM nuclear-cytoplasmic shuttle process: nuclear porin p62. Nuclear pore complex (NPC) is a macromolecular substance that carries out nucleation. P62, the only channel for mass transport, is an important part of NPC. It is located inside the central channel and plays a regulatory role in the nuclear-cytoplasmic shuttle process of many substances. By immunoprecipitation and in vitro binding experiments, it was proved that there was interaction between w / c Ab1 and p62, which could be partially phosphorylated by c-Ab1 through the binding of SH3 domain of c-Ab1 and P299 site of p62. In the study of DNA damage induced by ionizing radiation and cytarabine, it was found that the binding of c-Ab1 to p62 and its dimer increased at the early stage of DNA injury, and decreased at the late stage of DNA injury. Through the separation of subcellular components and the observation of laser confocal microscopy, it was found that p62 could promote the entry of c-Ab1 into the nucleus.
【学位授予单位】：中国人民解放军军事医学科学院
【学位级别】：博士
【学位授予年份】：2005
【分类号】：Q55

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