共查询到20条相似文献，搜索用时 203 毫秒
1.
Tapscott SJ 《Science (New York, N.Y.)》2000,289(5485):1701-1702
Triplet repeat diseases are disorders in which there is expansion of a repeat sequence of three nucleotides in the affected gene. Although the pathology usually results from production of a defective protein, myotonic dystrophy (DM) has proved to be a puzzle because the expanded repeats appear in a non-coding region of the affected DMPK gene. In a Perspective, Tapscott explains how findings from a new mouse model of DM (Mankodi et al.) could solve this paradox. 相似文献
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Liquori CL Ricker K Moseley ML Jacobsen JF Kress W Naylor SL Day JW Ranum LP 《Science (New York, N.Y.)》2001,293(5531):864-867
Myotonic dystrophy (DM), the most common form of muscular dystrophy in adults, can be caused by a mutation on either chromosome 19q13 (DM1) or 3q21 (DM2/PROMM). DM1 is caused by a CTG expansion in the 3' untranslated region of the dystrophia myotonica-protein kinase gene (DMPK). Several mechanisms have been invoked to explain how this mutation, which does not alter the protein-coding portion of a gene, causes the specific constellation of clinical features characteristic of DM. We now report that DM2 is caused by a CCTG expansion (mean approximately 5000 repeats) located in intron 1 of the zinc finger protein 9 (ZNF9) gene. Parallels between these mutations indicate that microsatellite expansions in RNA can be pathogenic and cause the multisystemic features of DM1 and DM2. 相似文献
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J S Chamberlain J A Pearlman D M Muzny R A Gibbs J E Ranier C T Caskey A A Reeves 《Science (New York, N.Y.)》1988,239(4846):1416-1418
Complementary DNA clones were isolated that represent the 5' terminal 2.5 kilobases of the murine Duchenne muscular dystrophy (Dmd) messenger RNA (mRNA). Mouse Dmd mRNA was detectable in skeletal and cardiac muscle and at a level approximately 90 percent lower in brain. Dmd mRNA is also present, but at much lower than normal levels, in both the muscle and brain of three different strains of dystrophic mdx mice. The identification of Dmd mRNA in brain raises the possibility of a relation between human Duchenne muscular dystrophy (DMD) gene expression and the mental retardation found in some DMD males. These results also provide evidence that the mdx mutations are allelic variants of mouse Dmd gene mutations. 相似文献
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Antisense RNA directed against the 3' noncoding region prevents dormant mRNA activation in mouse oocytes 总被引：22，自引：0，他引：22
S Strickland J Huarte D Belin A Vassalli R J Rickles J D Vassalli 《Science (New York, N.Y.)》1988,241(4866):680-684
Primary mouse oocytes contain untranslated stable messenger RNA for tissue plasminogen activator (t-PA). During meiotic maturation, this maternal mRNA undergoes a 3'-polyadenylation, is translated, and is degraded. Injections of maturing oocytes with different antisense RNA's complementary to both coding and noncoding portions of t-PA mRNA all selectively blocked t-PA synthesis. RNA blot analysis of t-PA mRNA in injected, matured oocytes suggested a cleavage of the RNA.RNA hybrid region, yielding a stable 5' portion, and an unstable 3' portion. In primary oocytes, the 3' noncoding region was susceptible to cleavage, while the other portions of the mRNA were blocked from hybrid formation until maturation occurred. Injection of antisense RNA complementary to 103 nucleotides of its extreme 3' untranslated region was sufficient to prevent the polyadenylation, translational activation, and destabilization of t-PA mRNA. These results demonstrate a critical role for the 3' noncoding region of a dormant mRNA in its translational recruitment during meiotic maturation of mouse oocytes. 相似文献
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Oxidation-reduction and the molecular mechanism of a regulatory RNA-protein interaction 总被引：72，自引：0，他引：72
Iron-responsive elements (IREs) are RNA motifs that have been identified within the 5' untranslated region of ferritin messenger RNA and the 3' untranslated region of transferrin receptor mRNA. A single IRE mediates iron-dependent control of ferritin translation, whereas multiple IREs are found in the region of the transferrin receptor mRNA responsible for iron-dependent control of mRNA stability. A cytosolic protein binds in vitro to the IREs of both mRNAs. The IRE-binding protein (IRE-BP) is shown to require free sulfhydryl groups for its specific interaction with the IRE. Treatment of lysates with reducing agents increases the binding activity, whereas agents that block sulfhydryls inhibit binding. Iron starvation, leading to decreased ferritin translation, results in increased binding activity, which is explained by an increase in the fraction of the IRE-BP that is in a fully reduced state. 相似文献
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Spahn CM Kieft JS Grassucci RA Penczek PA Zhou K Doudna JA Frank J 《Science (New York, N.Y.)》2001,291(5510):1959-1962
Initiation of protein synthesis in eukaryotes requires recruitment of the 40S ribosomal subunit to the messenger RNA (mRNA). In most cases, this depends on recognition of a modified nucleotide cap on the 5' end of the mRNA. However, an alternate pathway uses a structured RNA element in the 5' untranslated region of the messenger or viral RNA called an internal ribosomal entry site (IRES). Here, we present a cryo-electron microscopy map of the hepatitis C virus (HCV) IRES bound to the 40S ribosomal subunit at about 20 A resolution. IRES binding induces a pronounced conformational change in the 40S subunit and closes the mRNA binding cleft, suggesting a mechanism for IRES-mediated positioning of mRNA in the ribosomal decoding center. 相似文献
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A subline of U937 cells (U937D) was obtained in which creatine kinase B (CK-B) messenger RNA was present and bound to ribosomes, but CK activity was undetectable. Transformation of U937D cells with retrovirus vectors that contain the 3' untranslated region (3' UTR) of CK-B messenger RNA exhibited CK activity with no change in abundance of CK-B mRNA. The 3' UTR formed a complex in vitro with a component of S100 extracts from wild-type cells. This binding activity was not detectable in S100 extracts from cells that expressed CK activity after transformation with the 3' UTR-containing vector. These results suggest that translation of CK-B is repressed by binding of a soluble factor or factors to the 3' UTR. 相似文献
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油松胚珠转录组微卫星特征分析 总被引：1，自引：0，他引：1
为利用微卫星分子标记技术进一步研究油松胚珠发育分子调控机制以及微卫星对油松胚珠发育的影响,本文以前期高通量测序结果为基础,用MISA软件对所获得的转录组数据进行SSR位点的发掘和分析,为后续研究提供重要信息资源和数据保障。得到的1412个SSR位点存在于1274条序列中,平均每2.15kb出现一个SSR。油松胚珠转录组微卫星中存在87种重复基元,其中(A/T)n比例最高,约占45.89%;出现频率较高的重复类型是单核苷酸(46.88%)和三核苷酸(34.99%)重复。所得微卫星多为长度<20bp的短重复序列,≥20bp仅占总数的5.67%,重复序列出现频率与长度呈负相关。所得的SSR位点大部分位于非编码区,位于编码区的仅232个,有18个跨越了编码区和非编码区;编码区中占比例最高的是三核苷酸重复序列(105个,45.26%)。 相似文献
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Leucine-tRNA initiates at CUG start codons for protein synthesis and presentation by MHC class I 总被引：1，自引：0，他引：1
Starck SR Jiang V Pavon-Eternod M Prasad S McCarthy B Pan T Shastri N 《Science (New York, N.Y.)》2012,336(6089):1719-1723
Effective immune surveillance by cytotoxic T cells requires newly synthesized polypeptides for presentation by major histocompatibility complex (MHC) class I molecules. These polypeptides are produced not only from conventional AUG-initiated, but also from cryptic non-AUG-initiated, reading frames by distinct translational mechanisms. Biochemical analysis of ribosomal initiation complexes at CUG versus AUG initiation codons revealed that cells use an elongator leucine-bound transfer RNA (Leu-tRNA) to initiate translation at cryptic CUG start codons. CUG/Leu-tRNA initiation was independent of the canonical initiator tRNA (AUG/Met-tRNA(i)(Met)) pathway but required expression of eukaryotic initiation factor 2A. Thus, a tRNA-based translation initiation mechanism allows non-AUG-initiated protein synthesis and supplies peptides for presentation by MHC class I molecules. 相似文献
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A persistent untranslated sequence within bacteriophage T4 DNA topoisomerase gene 60 总被引：30，自引：0，他引：30
W M Huang S Z Ao S Casjens R Orlandi R Zeikus R Weiss D Winge M Fang 《Science (New York, N.Y.)》1988,239(4843):1005-1012
A 50-nucleotide untranslated region is shown to be present within the coding sequence of Escherichia coli bacteriophage T4 gene 60, which encodes one of the subunits for its type II DNA topoisomerase. This interruption is part of the transcribed messenger RNA and appears not to be removed before translation. Thus, the usual colinearity between messenger RNA and the encoded protein sequence apparently does not exist in this case. The interruption is bracketed by a direct repeat of five base pairs. A mechanism is proposed in which folding of the untranslated region brings together codons separated by the interruption so that the elongating ribosome may skip the 50 nucleotides during translation. The alternative possibility, that the protein is efficiently translated from a very minor and undetectable form of processed messenger RNA, seems unlikely, but has not been completely ruled out. 相似文献
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Goyenvalle A Vulin A Fougerousse F Leturcq F Kaplan JC Garcia L Danos O 《Science (New York, N.Y.)》2004,306(5702):1796-1799
Most mutations in the dystrophin gene create a frameshift or a stop in the mRNA and are associated with severe Duchenne muscular dystrophy. Exon skipping that naturally occurs at low frequency sometimes eliminates the mutation and leads to the production of a rescued protein. We have achieved persistent exon skipping that removes the mutated exon on the dystrophin messenger mRNA of the mdx mouse, by a single administration of an AAV vector expressing antisense sequences linked to a modified U7 small nuclear RNA. We report the sustained production of functional dystrophin at physiological levels in entire groups of muscles and the correction of the muscular dystrophy. 相似文献
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Translational blockade imposed by cytokine-derived UA-rich sequences 总被引：49，自引：0，他引：49
The messenger RNAs specifying certain proteins involved in the inflammatory response and certain oncoproteins contain a conserved UA-rich sequence in the 3' untranslated region. This sequence, which is composed of several interspersed repeats of the octanucleotide UUAUUUAU, has been shown to destabilize mRNA in some eukaryotes. However, this effect is not seen when mRNAs are transferred to Xenopus oocytes, which made it possible to separate stability from translational regulation. For interferon, granulocyte-macrophage colony-stimulating factor, and c-fos RNAs, the UA-rich sequence was observed to preclude mRNA translation. 相似文献
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CP基因3'端短片段介导的对马铃薯Y病毒的抗性 总被引：3，自引：0，他引：3
【目的】探明马铃薯Y病毒脉坏死株系（PVYN）CP基因3′端序列短片段的不同结构转基因诱导转基因植物产生RNA介导抗性的有效性。【方法】以PVYN的CP基因cDNA 3′端202 bp片段构建非翻译的正向重复和反向重复结构的植物表达载体转化烟草。【结果】攻毒试验表明前者没有一例转基因植株表现为抗病，而转化反向重复结构的转基因植株82.8%表现近似免疫的高度抗病型，Southern印迹杂交证明目的基因已整合到烟草基因组，Northern印迹杂交结果显示反向重复结构转基因植物的抗病性与RNA的表达量呈现负相关。【结论】抗病性是RNA介导的病毒抗性。3′端短片段诱导产生的转基因抗病株比例比5′端短片段诱导产生的高。 相似文献
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A new probe for the diagnosis of myotonic muscular dystrophy 总被引：11，自引：0，他引：11
R J Bartlett M A Pericak-Vance L Yamaoka J Gilbert M Herbstreith W Y Hung J E Lee T Mohandas G Bruns C Laberge 《Science (New York, N.Y.)》1987,235(4796):1648-1650
Myotonic muscular dystrophy (DM) is the most common muscular dystrophy, affecting adults as well as children. It is inherited as an autosomal dominant trait and is characterized by variable expressivity and late age-of-onset. Linkage studies have established the locus on chromosome 19. In order to identify tightly linked probes for diagnosis as well as to define in detail the DM gene region, chromosome 19 libraries were constructed and screened for restriction fragment length polymorphisms tightly linked to DM. A genomic clone, LDR152 (D19S19), was isolated that is tightly linked to DM; recombination fraction = 0.0 (95% confidence limits 0.0-0.03); lod score, 15.4. 相似文献
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Major histocompatibility complex (MHC) class I molecules display tens of thousands of peptides on the cell surface, derived from virtually all endogenous proteins, for inspection by cytotoxic T cells (CTLs). We show that, in normal mouse cells, MHC I molecules present a peptide encoded in the 3' "untranslated" region. Despite its rarity, the peptide elicits CTL responses and induces self-tolerance, establishing that immune surveillance extends well beyond conventional polypeptides. Furthermore, translation of this cryptic peptide occurs by a previously unknown mechanism that decodes the CUG initiation codon as leucine rather than the canonical methionine. 相似文献