黄鳝IRF-4和IRF-10的表达研究

目的:干扰素调节因子是一类能够调控干扰素及其相关免疫基因表达的转录因子,研究黄鳝干扰素调节因子的结构及表达有助于阐明黄鳝抗病毒的机理。方法:利用PCR扩增技术获得了黄鳝干扰素调节因子10(IRF-10)和IRF-4的部分cDNA序列,再利用半定量PCR技术检测了黄鳝不同发育阶段、不同组织IRF-10和IRF-4的表达。结果:IRF-10和IRF-4在黄鳝三个不同的发育阶段表达量基本一致,但两者在黄鳝不同组织表达呈现明显的差异,IRF-10组成型表达于黄鳝各个组织中,而IRF-4仅在肠、中肾和脑中呈现很高的表达,其他组织表达很弱。结论:IRF-10组成型地表达于黄鳝各个组织,且表达量很高;而IRF-4中仅在主要免疫器官表达,且表达量较弱。     

抗病毒天然免疫通路中IRF-3调控新机制

干扰素调节因子-3(interferon regulatory factor-3,IRF-3)是IRF家族中重要 转录因子之一,在调控干扰素(interferon, IFN)基因表达和抗病毒天然免疫反应中具有重要作 用. 最新发现的MITA (mediator of IRF-3 activation, 又称STING/ERIS)蛋白是宿主抗病 毒天然免疫反应中的一种重要调节分子. 病毒侵染时,MITA与IRF-3相互作用,特异性激活 IRF-3,并募集TANK结合激酶1（TANK binding kinase 1, TBK1）与IFN通路中的线粒体抗 病毒信号蛋白MAVS(mitochondrial anti-viral signaling protein)形成复合物,且MITA可 被TBK1磷酸化,诱导Ⅰ型IFN及IFN刺激基因(interferon stimulate genes, ISG)的表达 ,诱发抗病毒天然免疫反应. 同时还发现,泛素连接酶RNF5（ring finger protein 5）可对MITA 发生泛素化修饰从而抑制其对IRF-3活化,实现对宿主抗病毒天然免疫反应负调节作用. 本 室研究发现,严重性急性呼吸系统综合症冠状病毒(severe acute respiratory syndrome co ronavirus, SARS-CoV）和人类新型冠状病毒（human coronavirus NL63, HCoV-NL63）的 木瓜样蛋白酶（papain-like protease, PLP）利用其特有的去泛素化酶（deubiquitinase, DUB）活性,通过宿主细胞泛素-蛋白酶体信号系统对IRF-3的泛素化等翻译后修饰进行调节 ,从而成为该种病毒逃逸机体抗病毒防御系统主要手段之一.     

短尾蝮蛇IRF-2基因的克隆和特征分析

报道了短尾蝮蛇Gloydius brevicaudus干扰素调节因子2基因(IRF-2)的克隆和cDNA全序列测定分析.目前除在爬行类外,IRF-2基因在大部分的脊椎动物如鱼类、两栖类、鸟类和哺乳类都有报道.为了获得爬行类IRF-2基因的全序列,从短尾蝮蛇的肾、脾、肝和肠4种组织中使用Trizol试剂盒提取了总RNA.从已知的IRF-2基因序列比对设计了简并引物来扩增保守片段.最后使用RACE方法得到IRF-2的cDNA全序列.结果 显示短尾蝮蛇的IRF-2基因开放阅读框包含有978个核苷酸,编码326个氨基酸,其3′UTR包含137个核苷酸.与脊椎动物其他四足动物序列比对分析还发现,短尾蝮蛇的IRF-2基因和推导的氨基酸序列都非常保守,与大部分四足动物的IRF-2相似.从其氨基酸序列中可以辨别出DBD、IDA2和transactivating domain等大部分元件和阻遏模体.     

条纹斑竹鲨IRF-1基因的克隆和特征分析

鱼类中IRF-1基因的克隆测序目前仅局限于辐鳍鱼类1,2,而在软骨鱼类中未见报道。IRF-1是干扰素调节因子家族的成员之一3。除作为干扰素的转录调节因子外4,还具有其他功能5-10。作为天然免疫重要的调节因子其基因在哺乳类中得到了广泛的克隆和分析。IRF-1与其他家族成员一样,在氨基末端前115个氨基酸都具较高同源性,具有色氨酸重复特征且包围在DNA绑定域周围。       

PAI-2与IRF-3相互作用的鉴定

2型纤溶酶原激活物抑制剂 (plasminogenactivatorinhibitortype 2 ,PAI 2 )除了参与纤溶活性的调节、肿瘤的浸润和迁移外 ,在抑制细胞凋亡方面也发挥着重要作用。现已明确 ,PAI 2分子中的CD螺旋间区是PAI 2与其他蛋白质相互作用的结构域 ,该区的缺失将直接导致PAI 2丧失对TNF α诱导细胞凋亡的拮抗功能 ,但其作用机制不详。以PAI 2的CD螺旋间区为诱饵 ,利用Gal 4酵母双杂交系统筛选凋亡过程中的HeLa细胞cDNA文库 ,发现干扰素调节因子 3(interferonregulatoryfactor 3,IRF 3)C端的 98个氨基酸残基与PAI 2的CD螺旋间区之间存在相互作用。通过RT PCR获得IRF 3的全长cDNA。免疫共沉淀实验进一步证实PAI 2通过其CD螺旋间区与IRF 3在细胞内也存在特异性的相互作用。IRF 3是一种转录调节因子 ,在抗病毒感染、免疫调节、病毒诱导的细胞凋亡中发挥重要作用。因此证实PAI 2与IRF 3之间存在相互作用 ,为进一步研究PAI 2参与抗病毒感染或抗细胞凋亡等方面打下了基础     

TRIM59 interacts with ECSIT and negatively regulates NF-κB and IRF-3/7-mediated signal pathways

A series of inhibitors of d-amino acid oxidase (DAAO) are specific in blocking chronic pain, including formalin-induced tonic pain, neuropathic pain and bone cancer pain. This study used RNA interference technology to further validate the notion that spinal DAAO mediates formalin-induced pain. To target DAAO, a siRNA/DAAO formulated in polyetherimide (PEI) complexation and a shRNA/DAAO (shDAAO, with the same sequence as siRNA/DAAO after intracellular processing) expressed in recombinant adenoviral vectors were designed. The siRNA/DAAO was effective in blocking DAAO expression in NRK-52E rat kidney tubule epithelial cells, compared to the nonspecific oligonucleotides. Furthermore, multiple-daily intrathecal injections of both siRNA/DAAO and Ad-shDAAO for 7 days significantly inhibited spinal DAAO expression by 50-80% as measured by real-time quantitative PCR and Western blot, and blocked spinal DAAO enzymatic activity by approximately 60%. Meanwhile, both siRNA/DAAO and Ad-shDAAO prevented formalin-induced tonic phase pain by approximately 60%. Multiple-daily intrathecal injections of siRNA/DAAO and Ad-shDAAO also blocked more than 30% spinal expression of GFAP, a biomarker for the activation of astrocytes. These results further suggest that down-regulation of spinal DAAO expression and enzymatic activity leads to analgesia with its mechanism potentially related to activation of astrocytes in the spinal cord.     

Roles of electrostatic interaction and dispersion in CH···CH,CH···π, and π···π ethylene dimers

The structural, mechanical, electronic, and optical properties of orthorhombic Bi₂S₃ and Bi₂Se₃ compounds have been investigated by means of first principles calculations. The calculated lattice parameters and internal coordinates are in very good agreement with the experimental findings. The elastic constants are obtained, then the secondary results such as bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, anisotropy factor, and Debye temperature of polycrystalline aggregates are derived, and the relevant mechanical properties are also discussed. Furthermore, the band structures and optical properties such as real and imaginary parts of dielectric functions, energy-loss function, the effective number of valance electrons, and the effective optical dielectric constant have been computed. We also calculated some nonlinearities for Bi₂S₃ and Bi₂Se₃ (tensors of elasto-optical coefficients) under pressure.

问·题·解·答

问:假根与真根有什么区别?答:假根,一般为低等植物所特有,是具有吸收和固着作用的丝状结构,分枝或不分枝,仅由伸长的单细胞或单列的多细胞所构成,无组织分化。如藻类、真菌就具有这种假根。但是现存的高等植物中,苔藓植物以及蕨类植物的原叶体上也具有假根。真根较之于假根,主要在于有机械、输导等组织的分化。真根植物可以说是由仅有假根的无根类型逐渐进化而来的。一般来说,蕨类的孢子体世代以及种子植物都具有。不过,在某些如水生或腐生的种子植物中,由于其生存环境的特殊性,     

卡波氏肉瘤相关疱疹病毒(KSHV)vIL-6通过IRF-3负性调控IFN-β转录表达

卡波氏肉瘤相关疱疹病毒(Kaposi's sarcoma-associated herpesvirus,KSHV),又称人类疱疹病毒8型(Human herpesvirus 8,HHV-8),是艾滋病感染者中发病率最高的肿瘤-卡波氏肉瘤的致病性病原体。本实验对KSHV裂解期蛋白-病毒白细胞介素6(Viral interleukin-6,vIL-6)抑制宿主固有免疫机制进行初步探讨。利用仙台病毒刺激人胚肾细胞(HEK293T)激活抗病毒固有免疫,观察vIL-6过表达后对IFN-β的作用及机制,利用实时定量PCR检测IFN-β基因表达及双荧光素酶实验分析IFN-β基因启动子的活性。过表达vIL-6后,IFN-β基因mRNA水平表达明显下降,进一步实验证明vIL-6可抑制IFN-β基因启动子活性,且vIL-6可特异性作用于IFN-β基因启动子PRDIII-PRDI区。本研究首次证实了KSHV vIL-6可通过抑制IFN-β启动子活性从而调控IFN-β表达,且这种作用主要通过IRF-3信号途径。     

自学·质疑·精讲·练习

自学·质疑·精讲·练习”课堂教学方法,简易可行,便于推广,适宜不同年级、不同教学内容,便于穿插演示实验、讲解法等其他教学方法,使学生的主体作用、教师的主导作用得以充分发挥,有利于增强学生的集体主义精神,有利于培养学生的自学能力,提高分析问题、解决问题...     

·科研快讯·

《科学-转化医学》:按摩或可加速受损肌肉康复按摩疗法近年来被越来越多的人所接受。一项新研究也显示,按摩疗法可通过与大多数镇痛药相同的生物学机制来减轻肌肉疼痛,可能有助于受损肌肉     

Effect of stepwise microhydration on the methylammonium···phenol and ammonium···phenol interaction

A computational study has been performed for studying the characteristics of the interaction of phenol with ammonium and methylammonium cations. The effect of the presence of water molecules has also been considered by microhydrating the clusters with up to three water molecules. Clusters of phenol with ammonium and methylammonium cations present similar characteristics, though ammonium complexes have been found to be more stable than the methylammonium ones. The first water molecule included in the complexes interacts with a N-H group of ammoniun cations and simultaneously with the hydroxyl oxygen atom of phenol (or the aromatic ring). This first water molecule is more tightly bound in the complex, so the stability gain as more water molecules are included drops significantly by 2-3 kcal?mol^?1 with respect to the first one. As more water molecules are included, the differences between favorable coordination sites (the cation, the hydroxyl group or a previous water molecule) decrease. As a consequence, several of the most stable complexes located including three water molecules already exhibit hydrogen bonds between the hydroxyl group and one water molecule. The results indicate that a cyclic pattern formed by a series of hydrogen bonds: π···H-N-H···O-H···O-?, is characteristic of the most stable minima, being kept as more water molecules are included in the system. Therefore, this pattern can be expected to be crucial in ammonium cations···phenol interaction if exposed to the solvent to any degree.     

爱鸟·观鸟·赏鸟·护鸟

<正>"春眠不觉晓,处处闻啼鸟",唐代诗人孟浩然的诗句是我们儿时便能诵读的。春天代表着希望,鸟类寓意着新生。在这样一个春光明媚的时刻,我们怎能忘怀"自在娇莺恰恰啼"的美丽画卷呢?说到鸟类,我们总有无限的美好遐思——它们自由奔放,翱翔长空。它们婀娜多姿,步态轻盈。它们歌喉动听,嘤嘤啼啭……鸟类是自     

读者·作者·审者·编者

《中国生物化学与分子生物学报》自2006年1月起改为月刊为缩短出版周期,提高期刊学术水平和刊印质量,经《中国生物化学与分子生物学报》编委会讨论决定,上报中国生物化学与分子生物学会同意,获得中国科协和北京市新闻出版局批准,本刊自2006年1月起改为月刊,每月20日出版.每期96