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真核生物mRNA应激状态下的帽-非依赖性翻译
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作者 刘子昂 金焰 吴楠 《中国生物化学与分子生物学报》 CAS CSCD 北大核心 2024年第1期1-9,共9页
在真核生物中,mRNA翻译过程包括起始、延伸和终止。其中,翻译的起始阶段最为重要且复杂,它决定了mRNA能否被有效翻译成蛋白质。根据翻译起始机制的不同,真核生物mRNA翻译可以分为传统的帽-依赖性翻译和替代机制帽-非依赖性翻译。当外部... 在真核生物中,mRNA翻译过程包括起始、延伸和终止。其中,翻译的起始阶段最为重要且复杂,它决定了mRNA能否被有效翻译成蛋白质。根据翻译起始机制的不同,真核生物mRNA翻译可以分为传统的帽-依赖性翻译和替代机制帽-非依赖性翻译。当外部环境的刺激或细胞自身的改变使细胞处于应激状态时,传统的帽-依赖性翻译被抑制或下调,替代机制帽-非依赖性翻译得以启动,以保证翻译的顺利进行。真核生物在应激状态下为了维持蛋白质合成的需求,采用多种翻译起始机制来实现帽-非依赖性翻译。其中较常见的是IRES(internal ribosome entry site)、m6A修饰和CITE(cap-independent translation enhancer)所启动的翻译。这些机制允许核糖体在mRNA的特殊区域内部进行启动,而不依赖于传统的m7G帽结构。通过这些机制,真核生物可以在应激状态下仍然进行蛋白质合成,以满足细胞的需要。本文在总结传统帽-依赖性翻译研究进展基础上,着重介绍IRES、m6A和CITE所启动的帽-非依赖性翻译,为更好地探索细胞应激状态下的翻译机制提供参考,为未来的翻译研究和应用提供更多的思路。 展开更多
关键词 真核生物mrna 帽-非依赖性翻译 内部核糖体进入位点 N6-甲基腺苷 帽-非依赖性翻译增强子
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真核生物mRNA翻译起始机制研究进展 被引量:13
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作者 郑超星 马小凤 +2 位作者 张永华 李洪杰 张根发 《遗传》 CAS CSCD 北大核心 2018年第8期607-619,共13页
在真核生物中,m RNA翻译是一个复杂的多步骤过程,包括起始、延伸和终止3个阶段。其中,起始阶段的调控是影响m RNA翻译的关键。目前已经发现,m RNA翻译起始方式有多种,以最早发现的m7G帽依赖性扫描机制最为经典,但当细胞处于逆境,经典起... 在真核生物中,m RNA翻译是一个复杂的多步骤过程,包括起始、延伸和终止3个阶段。其中,起始阶段的调控是影响m RNA翻译的关键。目前已经发现,m RNA翻译起始方式有多种,以最早发现的m7G帽依赖性扫描机制最为经典,但当细胞处于逆境,经典起始机制受到抑制时,其他类型的起始机制会将其替代以保证翻译的顺利进行。本文对目前已发现的真核生物m RNA不同翻译起始机制特别是经典起始机制的替代机制进行了综述,旨在为深入认识真核生物基因在翻译水平上的表达调控提供参考。 展开更多
关键词 翻译起始 真核生物mrna 帽依赖性扫描 IRES CITE
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新型m RNA帽类似物m7GvpppA2-OMeG的合成与生物活性研究
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作者 李忠阳 《广东化工》 CAS 2024年第6期29-33,共5页
帽类似物(Cap Analogs)是一类用于模拟真核细胞mRNA 5’端帽子结构的化合物,它们在m RNA的合成、稳定性、翻译效率以及免疫原性等方面起着重要作用。本研究合成了一种新型mRNA帽类似物m7GvpppA2-OMeG,并通过对其生物活性的研究来探索其... 帽类似物(Cap Analogs)是一类用于模拟真核细胞mRNA 5’端帽子结构的化合物,它们在m RNA的合成、稳定性、翻译效率以及免疫原性等方面起着重要作用。本研究合成了一种新型mRNA帽类似物m7GvpppA2-OMeG,并通过对其生物活性的研究来探索其潜在的应用价值。通过开展一系列细胞和活体实验发现该帽类似物加帽的mRNA相比市售帽类似物加帽的mRNA具有更高的加帽率、更好的稳定性、更高的翻译效率。进一步利用该新型帽类似物构建的单纯疱疹病毒mRNA疫苗在小鼠体内产生的IgG抗体水平和IFN-γ表达水平分别提高了2.70倍和2.67倍,显示出该新型帽类似物在m RNA疫苗应用中的潜力。 展开更多
关键词 帽类似物 体外转录 稳定性 免疫激活 mrna疫苗
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真核翻译起始因子4G1与恶性肿瘤的研究进展
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作者 彭秀娟 张丹凤 《中国医药科学》 2024年第9期31-35,共5页
真核翻译起始因子4G1(eIF4G1)是一种大型支架蛋白,在真核生物mRNA翻译起始过程中,可作为蛋白质的对接位点,介导帽依赖性与非帽依赖性翻译启动。eIF4G1是翻译调控中的重要靶标,被认为参与多种肿瘤细胞的生长、迁移、增殖、侵袭和凋亡。... 真核翻译起始因子4G1(eIF4G1)是一种大型支架蛋白,在真核生物mRNA翻译起始过程中,可作为蛋白质的对接位点,介导帽依赖性与非帽依赖性翻译启动。eIF4G1是翻译调控中的重要靶标,被认为参与多种肿瘤细胞的生长、迁移、增殖、侵袭和凋亡。近年来,随着对eIF4G1研究的深入,临床对其作用和功能也有了更深的理解,本文总结相关文献,对eIF4G1的功能、研究现状及与肿瘤的关系做一简要综述。 展开更多
关键词 真核翻译起始因子4G1 帽依赖性翻译 真核翻译起始因子 肿瘤 mrna
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mRNA的体外转录和加帽工艺研究 被引量:2
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作者 杜志丽 徐宇虹 《广东化工》 CAS 2022年第14期24-27,共4页
利用体外转录信使RNA(IVT mRNA)进行疫苗接种、基因治疗已经成为医学领域的热点。在全球SARS-CoV-2大流行期间,信使RNA(mRNA)药物研发备受关注。成熟的mRNA需要5’帽来保证mRNA的稳定和基因表达。在这项研究中,我们研究了mRNA的体外转录... 利用体外转录信使RNA(IVT mRNA)进行疫苗接种、基因治疗已经成为医学领域的热点。在全球SARS-CoV-2大流行期间,信使RNA(mRNA)药物研发备受关注。成熟的mRNA需要5’帽来保证mRNA的稳定和基因表达。在这项研究中,我们研究了mRNA的体外转录,探讨了不同mRNA加帽方法,包括酶法加帽、抗反向帽类似物(ARCA)加帽以及三核苷酸帽类似物Clean Cap加帽,并尝试了使用多个新型ARCA结构对m RNA进行加帽修饰,为mRNA药物制剂的研发打下了一定的基础。 展开更多
关键词 体外转录m RNA 抗反向帽类似物(ARCA) 三核苷酸帽类似物 m RNA药物 mrna纯度
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mRNA疫苗5’帽结构技术专利现状研究
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作者 曹丽荣 范梦婷 孟湘明 《中国发明与专利》 2021年第8期18-22,50,共6页
随着2020年新型冠状病毒疫情的全球暴发,mRNA疫苗的研发备受关注。mRNA 5’帽结构是提高mRNA的稳定性,延长在体内的时间,并通过结合真核翻译起始因子提高蛋白翻译效率的关键技术。本文围绕着与mRNA稳定性和翻译效率有关的5’帽结构进行... 随着2020年新型冠状病毒疫情的全球暴发,mRNA疫苗的研发备受关注。mRNA 5’帽结构是提高mRNA的稳定性,延长在体内的时间,并通过结合真核翻译起始因子提高蛋白翻译效率的关键技术。本文围绕着与mRNA稳定性和翻译效率有关的5’帽结构进行全球专利申请检索和分析,挖掘该领域的技术创新动态,竞争信息和发展趋势,为我国相关技术发展提供参考与启示。 展开更多
关键词 mrna疫苗 5’帽结构 专利
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Expression of p27Kip1, A Cell Cycle Repressor Protein with Dual Roles for Both Cancer Prevention and Promotion, Is Regulated Primarily at the Level of Unusual p27Kip1 mRNA—A Short Concept Proposal 被引量:2
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作者 Isao Eto 《American Journal of Molecular Biology》 2018年第3期186-193,共8页
The p27Kip1 is a cell cycle repressor protein that regulates primarily the cell cycle transition from G1 to S phase and hence the DNA replication is in the S phase and cell division in the M phase. Expression of p27Ki... The p27Kip1 is a cell cycle repressor protein that regulates primarily the cell cycle transition from G1 to S phase and hence the DNA replication is in the S phase and cell division in the M phase. Expression of p27Kip1 protein has dual roles for both cancer prevention and promotion. For example, numerous nutritional and chemopreventive anti-cancer agents specifically increase the expression of p27Kip1 protein without directly affecting the expression of any other cell cycle regulatory proteins. On the other hand, pro-cancer agents (like glucose, insulin and other growth factors frequently seen in obesity and/or diabetes) specifically decrease the expression of p27Kip1 protein without directly affecting the expression of any other cell cycle regulatory proteins. Unlike expression of any other cell cycle regulatory proteins, expression of p27Kip1 protein is very unusual. The mRNA of p27Kip1 has a very long and unusual 5’-untranslated region (from -575 to -1 in human). It appears that the 5’-untranslated region of p27Kip1 mRNA forms two alternative secondary structures. One increases the expression of p27Kip1 protein when anti-cancer agents are added and another decrease the expression of p27K1p1 when pro-cancer agents are added. For this short concept proposal, Dr. Albert Einstein’s “visualized thought experiments (German: Gedanken experiment)” were used as a fundamental tool for understanding how either anti- or pro-cancer agents bring the primary structure of the 5’-untranslated region of p27Kip1 mRNA into two alternative secondary structures, thereby either increasing or decreasing, respectively, the translation initiation of p27Kip1 protein. 展开更多
关键词 P27KIP1 Cell Cycle Repressor Protein CANCER Prevention Anti-Cancer AGENTS CANCER PROMOTION Pro-Cancer AGENTS P27KIP1 mrna 5-Prime-Untranslated Region Translation Initiation 5-Prime cap Upstream Open Reading Frame Internal Ribosome Entry Site
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目的基因全长cDNA合成及克隆技术进展 被引量:6
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作者 张光祥 马正强 《生物技术通报》 CAS CSCD 2003年第5期1-5,共5页
在基因克隆、基因功能和表达调控研究中 ,获得目的基因尤其是表达丰度低的基因全长cDNA仍然是一个技术难题。本文对近年来有关反转录过程中影响全长cDNA合成的因素与对策的研究进行了总结 ,特别对消除mRNA二级结构阻碍的方法及其效果、... 在基因克隆、基因功能和表达调控研究中 ,获得目的基因尤其是表达丰度低的基因全长cDNA仍然是一个技术难题。本文对近年来有关反转录过程中影响全长cDNA合成的因素与对策的研究进行了总结 ,特别对消除mRNA二级结构阻碍的方法及其效果、较高反应温度和金属离子对模板mRNA完整性的影响、RNA分子伴侣在反应温度不变的情况下改善cDNA第一链质量的效果等作了较为详细的介绍。此外 ,还介绍了确保具有完整5′端的cDNA进入后续研究的几种新方法。 展开更多
关键词 反转录 RNA分子伴侣 目的基因 全长CDNA 克隆
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获取全长cDNA若干方法的比较 被引量:2
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作者 陶爱林 林兴华 张端品 《武汉植物学研究》 CSCD 2003年第2期179-186,共8页
Full length complementary DNAs (cDNA) are crucial for the functional annotation of genes. Several novel experimental approaches for selective enrichment of full length cDNAs are outlined in parallels. Some kinds of re... Full length complementary DNAs (cDNA) are crucial for the functional annotation of genes. Several novel experimental approaches for selective enrichment of full length cDNAs are outlined in parallels. Some kinds of reverse transcriptases and high fidelity PCR enzymes are introduced for promising high efficiency of accurate full length cDNA synthesis. The temperature profiles of the reverse transcription and PCR are also discussed. 展开更多
关键词 全长CDNA 信使RNA 5′帽子结构 高保真PCR 比较
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AKT反馈激活拮抗4EGI-1对黑素瘤A375细胞的抑制作用
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作者 陈兰 邓仁远 +3 位作者 涂云华 叶振源 薛月萃 曹煜 《中国肿瘤生物治疗杂志》 CAS CSCD 北大核心 2015年第4期438-442,共5页
目的:探索4EGI-1对黑素瘤A375细胞中AKT通路的激活作用及后者对4EGI-1抑制A375细胞增殖的影响。方法:用20、40、60μmol/L的4EGI-1处理黑素瘤A375细胞12、24 h,Western boltting检测4EGI-1对A375细胞中AKT磷酸化的影响;A375细胞分别受4E... 目的:探索4EGI-1对黑素瘤A375细胞中AKT通路的激活作用及后者对4EGI-1抑制A375细胞增殖的影响。方法:用20、40、60μmol/L的4EGI-1处理黑素瘤A375细胞12、24 h,Western boltting检测4EGI-1对A375细胞中AKT磷酸化的影响;A375细胞分别受4EGI-1(40μmol/L)、BEZ235(5μmol/L)、4EGI-1(40μmol/L)+BEZ235(5μmol/L)联合处理,CCK-8实验和流式细胞术分别检测4EGI-1、BEZ235单独或联合处理对A375细胞增殖和细胞周期的影响,Western boltting检测对细胞周期相关蛋白Cyclin D1表达的影响。结果:4EGI-1促进A375细胞中AKT的磷酸化,且具有剂量依赖性;而BEZ235能够拮抗4EGI-1对AKT的促磷酸化作用。与4EGI-1组和BEZ235组相比,联合组的A375细胞增殖抑制率显著升高[24 h时,4EGI-1组和BEZ235组抑制率分别为(7.6±1.2)%和(2.4±3.1)%,而联合组抑制率为(19.8±4.3)%;P<0.05],S期细胞比例显著降低(4EGI-1组和BEZ235组S期细胞比例分别为25.65%和25.82%,联合处理组细胞S期为13.08%;P<0.05),Cyclin D1表达显著降低(4EGI-1组和BEZ235组Cyclin D1相对表达值为0.81±0.04和0.76±0.04,联合处理组细胞Cyclin D1相对表达值为0.25±0.03;P<0.05)。结论:AKT反馈激活拮抗4EGI-1对黑素瘤A375细胞的抑制作用,联合使用AKT抑制药物能够增强4EGI-1对A375细胞的生长抑制作用。 展开更多
关键词 黑素瘤 A375细胞 AKT 帽子依赖翻译 4EGI-1
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NOVEL PHOSPHORYLATION SITES OF EUKARYOTIC INITIATION FACTOR-4E AND EVIDENCE THAT PHOSPHORYLATION STABILIZES INTERACTIONS OF THE P~25 AND P~220 SUBUNITS
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作者 卜昕 《Journal of Pharmaceutical Analysis》 CAS 1995年第2期181-181,共1页
The efficient translation of most eukaryotic mRNAs requires an interaction between the 5' m7GTP cap structure of mRNA and eIF-4F which is composed of 25-(eIF 4E),46-(eIF-4A), and 220-kDa (p220) subunits. eIF-4E bi... The efficient translation of most eukaryotic mRNAs requires an interaction between the 5' m7GTP cap structure of mRNA and eIF-4F which is composed of 25-(eIF 4E),46-(eIF-4A), and 220-kDa (p220) subunits. eIF-4E binds specifically to the mRNA cap. Evidence indicates that stimulation of eIF-4E phosphorylation increases the efficiency of the translational initiation by an as yet undefined mechanism. Phosphorylation of both eIF-4E and p220 in intact cells is stimulated by growth factors, and eIF-4E phosphorylation appears to be a critical event during cell growth regulation. To date only serine phosphorylation of eIF-4E has been described in vivo. In these studies we found that treatment of HepG2 cells with okadaic acid resulted in eIF-4E phosphorylation on both serine and threonine residues and that tryptic phosphopeptide maps showed several previously unrecognized phosphopeptides. Analysis of p,,' from control and okadaic acid--treated cells dmonstrated serine and threonine phosphorylation under both conditions. The most notable finding was that hyperphosphorylation of eIF-4E and p220 increased binding of p220 but not eIF-4E to the m7GTP.cap structure. we suggest that phosphorylation of eIF-4E is more complicated than previously recognizes and that hyperphosphorylation of eIF-4E and p220recruits more p220 into the protein complex that associate with mRNA caps. 展开更多
关键词 PHOSPHORYLATION eIF-4EI HepG2 cell mrna cap
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蛭龙活血通瘀胶囊对模型大鼠脑出血后脑组织水肿及ZO-1、Occludin的影响 被引量:8
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作者 王蔚 钟霞 +5 位作者 杜渊 王洪连 谭睿陟 沈宏萍 王丽 杨思进 《中国中医急症》 2020年第12期2084-2086,2096,共4页
目的观察蛭龙活血通瘀胶囊对脑出血大鼠脑含水量、脑系数以及ZO-1、Occludin mRNA水平的影响。方法将96只SD大鼠随机分为假手术组、模型组、蛭龙活血通瘀组(中药组),盐酸法舒地尔组(西药组),各组又分为12 h、48 h、3 d、7 d 4个亚组,各... 目的观察蛭龙活血通瘀胶囊对脑出血大鼠脑含水量、脑系数以及ZO-1、Occludin mRNA水平的影响。方法将96只SD大鼠随机分为假手术组、模型组、蛭龙活血通瘀组(中药组),盐酸法舒地尔组(西药组),各组又分为12 h、48 h、3 d、7 d 4个亚组,各亚组6只大鼠,取大鼠自体尾部血注入基底节区以制备脑出血模型,分别干预后在规定时点检测各组脑含水量及脑系数,采用实时荧光定量PCR法(PCR)检测大鼠脑组织ZO-1、Occludin mRNA水平。结果与模型组比较,中药组、西药组大鼠的脑含水量和脑系数在各时点均明显降低(P<0.01);qRT-PCR结果显示,与模型组比较,中药组、西药组各时点脑组织ZO-1、Occludin mRNA水平均显著上升(P<0.05)。结论蛭龙活血通瘀胶囊能明显改善大鼠脑出血后脑水肿,其机制可能与上调脑组织ZO-1、Occludin mRNA的表达有关。 展开更多
关键词 脑出血 脑组织水肿 ZO-1 mrna Occludin mrna 蛭龙活血通瘀胶囊 大鼠
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Higher Concentrations of Glucose or Insulin Increase the Risk of Various Types of Cancer in Obesity or Type 2 Diabetes by Decreasing the Expression of p27Kip1, a Cell Cycle Repressor Protein 被引量:1
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作者 Isao Eto 《American Journal of Molecular Biology》 2020年第1期1-11,共11页
Research Aims: Obesity and type 2 diabetes are known to be associated with increased risk of various types of cancer. However, the molecular biological mechanism of how the risk of cancer is increased in obesity or ty... Research Aims: Obesity and type 2 diabetes are known to be associated with increased risk of various types of cancer. However, the molecular biological mechanism of how the risk of cancer is increased in obesity or type 2 diabetes is not known. The aim this research is to investigate if the decreased expression of p27Kip1, a cell cycle repressor protein, plays a central role in this mechanism. Research Methods, Previous Studies and Theoretical Backgrounds: It is well known that the expression of p27Kip1 is increased by numerous nutritional or chemopreventive anti-cancer agents. But it has never been known that the expression of p27Kip1 could be decreased, rather than increased, and the risk of cancer could be increased, rather than decreased. This problem was solved recently and this new analytical method was used in this study. Results: 1) The expression of p27Kip1 was indeed significantly decreased in human obese type 2 diabetic individuals relative to the lean normal controls. 2) The expression of p27Kip1 was also significantly decreased in genetically obese rodents relative to the lean normal controls. Additionally, in obese rodents, the concentrations of glucose or insulin were significantly increased relative to the lean normal controls. 3) Using human cells cultured in vitro it was found that the increased concentrations of glucose or insulin decrease the expression of p27Kip1. Conclusions: These results suggest that higher concentrations of glucose or insulin increase the risk of various types of cancer in obesity or type 2 diabetes by decreasing the expression of p27Kip1. 展开更多
关键词 OBESITY Type 2 Diabetes CANCER P27KIP1 mrna Translation Initiation 5’-Untranslated Region (5’UTR) 5’-End cap of P27KIP1 mrna Upstream Open Reading Frame (uORF) Internal RIBOSOME Entry Site (IRES)
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mRNA quality control at the 5' end
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作者 Li-ting ZHAI Song XIANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2014年第5期438-443,共6页
All eukaryotic mRNAs are capped at their 5' end. Capping of mRNAs takes place co-transcriptionally and involves three steps. The intermediates of the capping process, as well as the uncapped 5' tri-phosphate RNA, ar... All eukaryotic mRNAs are capped at their 5' end. Capping of mRNAs takes place co-transcriptionally and involves three steps. The intermediates of the capping process, as well as the uncapped 5' tri-phosphate RNA, are resistant to decapping and degradation by known factors, leading to the assumption that the capping process always proceeds to completion. This view was recently drastically changed. A novel family of enzymes, including the yeast proteins Rail, Dxo1/Ydr370C, and the mammalian protein DXO/Dom3Z, has been identified. These enzymes catalyze the conversion of the improperly capped mRNAs to 5' mono-phosphate RNA, allowing them to be degraded by 5'-3' exoribonucleases. Several of these enzymes also possess 5'-3' exoribonuclease activities themselves, and can single-handedly clear the improperly capped mRNAs. Studying of these enzymes has led to the realization that mRNA capping does not always proceed to completion, and the identification of an mRNA capping quality control mechanism in eukaryotes. In this paper, we briefly review recent advances in this area. 展开更多
关键词 mrna capping Quality control RAIL Dxol DXO
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