排序方式: 共有22条查询结果,搜索用时 15 毫秒
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肿瘤的发生和发展主要是由基因突变的累积导致细胞信号通路调控紊乱而引起的.将通路中基因集的两个特性——高覆盖性和高排他性,与基因协变量相结合,提出了一种基于蚁群优化算法的驱动通路搜索方法.旨在基因突变数据及基因协变量数据的基础上,搜索满足高覆盖性和高排他性的通路基因集,从而识别致癌的驱动通路.首先,通过对基因表达水平、复制时间和染色体状态3个基因协变量相互的关联性,以及它们与基因突变频率的相关性进行分析,选择复制时间作为影响基因突变频率的权重协变量.然后,将权重协变量与现有方法结合,构造了一个新的最大权重子矩阵函数作为组合优化问题的目标函数.为克服该优化问题的NP难题,采用蚁群优化算法求解.应用该方法在肺腺癌的突变数据上进行了分析与验证.结果证明,该方法不仅比现有方法找到了更多在已证实通路中的癌基因,而且其中包含多个互斥性显著的基因对,证明了方法的有效性. 相似文献
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海洋浮游植物生长代谢与海洋环境刺激之间的信号传递都涉及细胞内各种信号转导过程,并最终通过调节细胞周期的运行控制浮游植物的增殖、种群生长动力及初级生产力.以cyclin-CDK为中心的细胞周期调控机制以及以Ca2+/CaM为中心的信号系统的研究越来越受到人们的关注. 其中涉及海洋浮游植物细胞周期蛋白种类的发现、细胞信号传递系统的确定、细胞周期蛋白作为生长标志用于精确估计海洋浮游植物的原位生长率、产毒赤潮浮游植物毒素分泌与细胞周期的关系、外源因素对浮游植物细胞周期的影响等.文中综述了近年来国外在海洋浮游植物细胞周期及细胞信号转导方面的最新研究进展. 相似文献
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XINGYu ZHANGShuqiu WANGYouqun JIAWensuo 《科学通报(英文版)》2003,48(5):460-465
Water deficit-induced ABA accumulation is an ideal model or “stimulus-response”system to investigate cellular stress signaling in plant cels,using such a model the cellular stress signaling triggered by water deficit was investigated in Maize L.coleoptile.Water deficit-induced ABA accumulation was sensitively blocked by NaVO3,a potent inhibitor both to plasma membrane H^ -ATPase(PM-H^ -ATPase)and protein tyrosine phosphatase(PTPase).However,while PM-H^ -ATPase activity was unaffected under water deficit and PM-H^ -ATPase activator did not induce an ABA accumulation instead of water deficit,water deficit induced an increase in the protein phosphatase activity,and furthermore,ABA accumulation was inhibited by PAO,a specific inhibitor of PTPase.These results indicate that protein phosphtases may be involved in the cellular signaling in response to water deficit.Further studies identifiled at least four species of protein phosphtase as assayed by using pNPP as substrate,among which one component was especially sensitive to NaVO3.The NaVO3-sensitive enzyme was purified and finally showed a protein band about 66kD on SDS/PAGE.The purified enzyme showed a great activity to some specific PTPase substrates at pH 6.0.In addition to NaVO3,the enzyme was also sensitive to some other PTPase inhibitors such as Zn^2 and MO3^3 ,but not to Ca^2 and Mg^2 ,indicating that it might be a protein tyrosine phosphatase.Interestingly,the purified enzyme could be deactivated by some reducing agent DTT.which was previously proved to be an inhibitor of water deficit-induced ABA accumulation.This result further proved that PTPase might be involved in the cellular signaling of ABA accumulation in response to water deficit. 相似文献
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王利 《西南民族学院学报(自然科学版)》2009,35(2):268-272
G蛋白信号转导调节因子(Regulator of Gprotein signaling,RGS)是G蛋白的信号转导系统的负性调节因子,大部分RGS蛋白通过GTP酶激活蛋白方式发挥作用.本文概述了G蛋白信号转导调节因子的结构、功能、意义及国际最新的研究趋势.对RGS的深入研究有利于对信号转导调节的了解. 相似文献
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二十多年来,布莱恩.科比尔卡(Brian Kobilka)埋头苦干,想要对一个关键的细胞受体进行描述。有时候,进展却是缓慢的,而踏踏实实的方法可能更胜一筹。 相似文献