MDC1 is coupled to activated CHK2 in mammalian DNA damage response pathways

Forkhead-homology-associated (FHA) domains function as protein-protein modules that recognize phosphorylated serine/threonine motifs. Interactions between FHA domains and phosphorylated proteins are thought to have essential roles in the transduction of DNA damage signals; however, it is unclear how FHA-domain-containing proteins participate in mammalian DNA damage responses. Here we report that a FHA-domain-containing protein-mediator of DNA damage checkpoint protein 1 (MDC1; previously known as KIAA0170)--is involved in DNA damage responses. MDC1 localizes to sites of DNA breaks and associates with CHK2 after DNA damage. This association is mediated by the MDC1 FHA domain and the phosphorylated Thr 68 of CHK2. Furthermore, MDC1 is phosphorylated in an ATM/CHK2-dependent manner after DNA damage, suggesting that MDC1 may function in the ATM-CHK2 pathway. Consistent with this hypothesis, suppression of MDC1 expression results in defective S-phase checkpoint and reduced apoptosis in response to DNA damage, which can be restored by the expression of wild-type MDC1 but not MDC1 with a deleted FHA domain. Suppression of MDC1 expression results in decreased p53 stabilization in response to DNA damage. These results suggest that MDC1 is recruited through its FHA domain to the activated CHK2, and has a critical role in CHK2-mediated DNA damage responses.     

A CORBA-Based Multidatabase System——Panorama Project

0　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｎｅｅｄｆｏｒｉｎｔｅｇｒａｔｉｏｎｏｆｄｉｆｆｅｒｅｎｔｄａｔａｂａｓｅｍａｎａｇｅｍｅｎｔｓｙｓｔｅｍｓ (ＤＢＭＳｓ) ,ｍａｋｉｎｇｄｉｆｆｅｒｅｎｃｅｓｂｅｔｗｅｅｎｔｈｅｓｅｓｙｓｔｅｍｓｉｎｖｉｓｉｂｌｅａｎｄｐｒｏｖｉｄｉｎｇｕｓｅｒｓｗｉｔｈａｕｎｉｆｏｒｍａｃｃｅｓｓｔｏａｌｌｔｈｅｄａｔａｂａｓｅｓｈａｓｇｒｏｗｎｒａｐｉｄｌｙｄｕｒｉｎｇｔｈｅｌａｓｔｄｅｃａｄｅ .Ｈｏｗｅｖｅｒ,ｄａｔａｂａｓｅａｕｔｏｎｏｍｙａｎｄｈｅｔｅｒｏｇｅｎｅｉｔｙ…     

Involvement of nitric oxide in the signal transduction of salicylic acid regulating stomatal movement

The effects and the relationship between sali-cylic acid(SA)and nitric oxide(NO) on Vicia faba L.stomatal movement were studied.The results here showed that exogenous SA and NO induced stomatal closure,100μmol/L SA induced a rapid and striking NO increase in the cytosol of guard cells.This phenomenon was largely prevented by 2000μmol/L 2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide(PTIO),a specific NO scavenger,and 25μmol/L N^G-nitro-L-Arg-methyl eater (L-NAME),an inhibitor of NO synthase(NOS) in mammalian cells that also inhibits plant NOS.In addition,SA-induced stomatal closure was largely prevented by PTIO and L-NAME.These results provide evidence that guard cells generate NO in response to SA via NOS-like activity,and that such NO production is required for full stomatal closure in response to SA.H-(1,2,4)-oxadiazole-[4,3-α]quinoxalin-l-one(ODQ),an inhibitor of guanylate cyclase,and nicotinamide,an antagonist of cADPR production,inhibited the effects of SA-and NO-induced stomatal closure.It suggests that both cGMP and cADPR might mediate the signal transduction of SA and NO-induced stomatal closure.     

浅谈公路旧桥的加固

作者根据近年对超限运输桥梁及大中型桥梁的加固实践经验,介绍了公路旧桥各组成部分的加固方法和施工措施。     

生态观对区域发展规划的方法论研究

概括分析了生态足迹和区域发展规划的概念、理论及发展背景,并对其理论的国内外演变历程加以详细论述,尤其是对生态足迹模型理论做了深入的探析.在此基础上,通过分析生态观对经济发展产生的作用、生态观为区域规划带来的影响以及区域规划为生态经济的发展带来的条件,来完成生态观对区域发展规划的方法论研究,以期为制定区域经济及区域可持续发展政策提供理论支持.     

探讨戴芬在妇科镇痛领域的应用

目的 探讨妇科门诊手术无吕腔操作的方法。方法 204例患者随机分为3组，分别经戴芬（双氯芬酸钠）口服、利多卡因宫颈注射及精神无痛法镇痛，观察术中疼痛程度和不良反应。结果 无痛结果，戴芬＞利多卡因＞精神无痛法；不良反应，戴芬＜利多卡因＜精神无痛法。结论 戴芬用于妇科门诊手术痛领域效果好。     

南村地质灾害分析

通过实际资料，详细论述了南村的地质灾害现状，初步分析了南村地质灾害的形成机理，并讨论了校区地质灾害应采取的防治对策。     

河南的红菇科真菌资源研究（Ⅲ）

红菇属（Ｒｕｓｓｕｌａ）的大多数种类分布在温带地区。河南省位于暖温带和亚热带的过渡地带，因此红菇属的种类分布较为丰富。本文继续描述河南境内分布的红菇属的种类及其经济价值。     

铁路无缝线路下采煤问题的研究

根据随机介质理论，阐述了因煤层采后地表变形对无缝线路稳定性的影响，得出了不宜在无缝线路下采煤的结论。     

干簧继电器簧片Au—Rh配套电镀工艺研究

研究了电镀液组分和工艺控制参量对Fe－50％Ni合金簧片An－Rh配套镀层显微组织、性能的影响。工艺优化结果表明：采用2#镀铑液，控制镀轮时的电流密度0．6A／dn2、时间8min、温度50℃，可获得显微组织呈颗粒状均匀致密分布、无明显龟壳状裂纹的优良Au－Rh配套镀层。