Synonymous mutations

同义突变
  • 文章类型: Journal Article
    二十年来的多次爆发和高死亡率强调了尼帕病毒(NiV)作为优先研究领域。该研究的重点是识别来自不同地理区域的NiV人类分离株的序列中的突变景观。
    来自马来西亚的人类样本的37个NiV基因组,孟加拉国,和印度进行了系统发育和宏基因组分析,以使用MEGA11软件和meta-CATS网络服务器破译基因组变异性。使用单似然祖先计数方法,在NiV基因中发现了同义和非同义突变.Further,非同义变异用于鉴定所有NiV蛋白的突变.
    NiV分离株分为NiV-M,NiV-B,和基于系统发育分析的NiV-I进化枝。宏基因组分析显示,NiV三个进化枝基因组的非编码区和编码区存在1636种变异。非同义突变的进一步分析显示磷蛋白高度突变,而基质蛋白是稳定的。
    使用人类分离株的比较基因组学方法解密突变模式提供了对NiV蛋白稳定性的宝贵见解,可进一步用于了解宿主-病原体相互作用的变化并开发有效的治疗措施。
    UNASSIGNED: Multiple outbreaks over two decades and a high mortality rate have emphasized the Nipah virus (NiV) as a priority research area. The study focuses on identifying the mutational landscape in sequences from NiV human isolates from different geographical regions.
    UNASSIGNED: Thirty-seven NiV genomes of human samples from Malaysia, Bangladesh, and India were subjected to phylogeny and metagenomic analysis to decipher the genome variability using MEGA11 software and the meta-CATS web server. Using the Single-Likelihood Ancestor Counting method, the synonymous and nonsynonymous mutations among NiV genes were identified. Further, the nonsynonymous variations were used to identify mutations in all the NiV proteins.
    UNASSIGNED: The NiV isolates were categorized into NiV-M, NiV-B, and NiV-I clades based on phylogenetic analysis. Metagenomic analysis revealed 1636 variations in the noncoding and coding regions of the genomes of the three clades of NiV. Further analysis of nonsynonymous mutations showed the phosphoprotein to be highly mutating, whereas the matrix protein was stable.
    UNASSIGNED: Deciphering the mutation pattern using a comparative genomics approach for human isolates provided valuable insight into the stability of NiV proteins which can be further used for understanding variations in host-pathogen interaction and developing effective therapeutic measures.
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  • 文章类型: Journal Article
    背景:假设葡萄糖-6-磷酸脱氢酶(G6PD)缺乏对疟疾感染具有保护作用,然而,对于8-氨基喹啉在G6PD缺乏个体中的自由基治疗引起的溶血毒性,人们提出了安全性问题.疟疾流行地区G6PD缺乏症的高流行率也使消除和控制疟疾变得复杂。因此,需要准确鉴定G6PD缺乏症,以确定有资格使用8-氨基喹啉类药物治疗疟疾的人群.
    方法:通过显微镜诊断为疟疾的408名泰国参与者中G6PD缺乏症的患病率(71),和疟疾阴性对照(337),使用基于水溶性四唑盐的表型测试进行评估。高分辨率熔解(HRM)曲线分析是从先前的研究中开发出来的,以便能够检测15种常见的错觉,亚洲人群中的同义和内含子G6PD突变。对鉴定的突变进行生化和结构表征以了解酶缺乏的分子机制。
    结果:基于表型测试,G6PD缺乏症(<30%活性)的患病率为6.13%(25/408),在15.20%(62/408)的参与者中发现中度缺乏症(30-70%活性).通过HRM分析鉴定了几种具有新发现的双错义变体的G6PD基因型,包括G6PD高河+Viangchan,G6PD巴利亚多利德+万昌和G6PD广州+万昌。检测到具有中等至正常酶活性的同义(c.1311C>T)和内含子(c.1365-13T>C和c.486-34delT)突变的显着高频率。双错义突变的催化活性低于其相应的单错义突变,导致严重的酶缺乏。虽然突变对结合亲和力影响较小,结构不稳定是G6PD缺乏个体中观察到的酶缺乏的关键因素。
    结论:不同程度的酶缺乏,G6PD基因分型可用作表型筛选的补充,以鉴定符合8-氨基喹啉的人。从这项研究中获得的信息可能对疟疾的管理和治疗有用,以及预防被研究人群对某些药物和食物的意外反应。
    BACKGROUND: It was hypothesized that glucose-6-phosphate dehydrogenase (G6PD) deficiency confers a protective effect against malaria infection, however, safety concerns have been raised regarding haemolytic toxicity caused by radical cure with 8-aminoquinolines in G6PD-deficient individuals. Malaria elimination and control are also complicated by the high prevalence of G6PD deficiency in malaria-endemic areas. Hence, accurate identification of G6PD deficiency is required to identify those who are eligible for malaria treatment using 8-aminoquinolines.
    METHODS: The prevalence of G6PD deficiency among 408 Thai participants diagnosed with malaria by microscopy (71), and malaria-negative controls (337), was assessed using a phenotypic test based on water-soluble tetrazolium salts. High-resolution melting (HRM) curve analysis was developed from a previous study to enable the detection of 15 common missense, synonymous and intronic G6PD mutations in Asian populations. The identified mutations were subjected to biochemical and structural characterisation to understand the molecular mechanisms underlying enzyme deficiency.
    RESULTS: Based on phenotypic testing, the prevalence of G6PD deficiency (< 30% activity) was 6.13% (25/408) and intermediate deficiency (30-70% activity) was found in 15.20% (62/408) of participants. Several G6PD genotypes with newly discovered double missense variants were identified by HRM assays, including G6PD Gaohe + Viangchan, G6PD Valladolid + Viangchan and G6PD Canton + Viangchan. A significantly high frequency of synonymous (c.1311C>T) and intronic (c.1365-13T>C and c.486-34delT) mutations was detected with intermediate to normal enzyme activity. The double missense mutations were less catalytically active than their corresponding single missense mutations, resulting in severe enzyme deficiency. While the mutations had a minor effect on binding affinity, structural instability was a key contributor to the enzyme deficiency observed in G6PD-deficient individuals.
    CONCLUSIONS: With varying degrees of enzyme deficiency, G6PD genotyping can be used as a complement to phenotypic screening to identify those who are eligible for 8-aminoquinolines. The information gained from this study could be useful for management and treatment of malaria, as well as for the prevention of unanticipated reactions to certain medications and foods in the studied population.
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  • 文章类型: Letter
    背景:ATM激酶构成了DNA损伤的主要调控中心,并通过磷酸化MDM2蛋白激活p53反应途径,对p53mRNA二级结构产生亲和力。这种相互作用的破坏阻止了新生p53的激活。MDM2蛋白-p53mRNA与上游DNA损伤传感器ATM激酶相互作用的联系以及p53mRNA在DNA损伤感知机制中的作用,仍然备受期待。
    方法:邻近连接测定(PLA)已被广泛用于揭示蛋白质-mRNA和蛋白质-蛋白质相互作用的亚细胞定位。ELISA和免疫共沉淀证实了体外和细胞中的相互作用。
    结果:这项研究提供了一种新的机制,使p53mRNA与ATM激酶相互作用,并表明L22L同义突变体,已知改变p53mRNA的二级结构,阻止互动。在DNA损伤感知途径中的相关机制作用,这与下游的DNA损伤反应有关,正在探索。DNA损伤(双链DNA断裂激活ATM)后,激活的MDMX蛋白竞争ATM-p53mRNA相互作用,并阻止p53mRNA与NBS1(MRN复合物)的关联。这些数据还揭示了ATM上的结合结构域和磷酸化事件,其调节复合物到细胞质的相互作用和运输。
    结论:提出的模型显示了ATM与p53mRNA的新型相互作用,并描述了DNA损伤传感与下游p53激活途径之间的联系;支持改变二级mRNA结构的同义突变的功能含义上升。
    The ATM kinase constitutes a master regulatory hub of DNA damage and activates the p53 response pathway by phosphorylating the MDM2 protein, which develops an affinity for the p53 mRNA secondary structure. Disruption of this interaction prevents the activation of the nascent p53. The link of the MDM2 protein-p53 mRNA interaction with the upstream DNA damage sensor ATM kinase and the role of the p53 mRNA in the DNA damage sensing mechanism, are still highly anticipated.
    The proximity ligation assay (PLA) has been extensively used to reveal the sub-cellular localisation of the protein-mRNA and protein-protein interactions. ELISA and co-immunoprecipitation confirmed the interactions in vitro and in cells.
    This study provides a novel mechanism whereby the p53 mRNA interacts with the ATM kinase enzyme and shows that the L22L synonymous mutant, known to alter the secondary structure of the p53 mRNA, prevents the interaction. The relevant mechanistic roles in the DNA Damage Sensing pathway, which is linked to downstream DNA damage response, are explored. Following DNA damage (double-stranded DNA breaks activating ATM), activated MDMX protein competes the ATM-p53 mRNA interaction and prevents the association of the p53 mRNA with NBS1 (MRN complex). These data also reveal the binding domains and the phosphorylation events on ATM that regulate the interaction and the trafficking of the complex to the cytoplasm.
    The presented model shows a novel interaction of ATM with the p53 mRNA and describes the link between DNA Damage Sensing with the downstream p53 activation pathways; supporting the rising functional implications of synonymous mutations altering secondary mRNA structures.
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  • 文章类型: Journal Article
    基于CRISPR-Cas的基因组编辑在细菌中广泛使用,范围从构建单个突变体到大规模平行文库。该程序依赖于指导RNA指导的基因组切割,然后用模板修复,该模板引入所需的突变以及同义的“免疫”突变,以防止编辑后基因组的重新切割。因为免疫突变不会改变蛋白质序列,他们通常被认为是中立的。然而,同义突变可以改变mRNA结构,从而改变编码蛋白质的水平。我们已经通过构建超过50,000个编辑的文库来测试免疫突变是中性的假设,该文库仅由大肠杆菌中的同义突变组成。成千上万的编辑对大肠杆菌在乙酸盐上生长期间的适应性有重大影响,高浓度时有毒的不良碳源。高影响力编辑的百分比在基因之间以及基因内不同位置有很大差异。我们重建了具有高影响力编辑的克隆,发现69%的克隆确实对乙酸盐的生长产生了显着影响。有趣的是,在葡萄糖生长过程中,受影响的编辑较少,优选的碳源,这表明,当生物体遇到具有挑战性的条件时,由同义突变引起的蛋白质表达变化可能是最重要的。最后,我们表明同义编辑可以产生广泛的影响;在ptsI的5'末端的同义编辑改变了数百个基因的表达。我们的结果表明,在基于CRISPR-Cas的基因组编辑过程中引入的同义免疫编辑不应被认为是无害的。
    CRISPR-Cas-based genome editing is widely used in bacteria at scales ranging from construction of individual mutants to massively parallel libraries. This procedure relies on guide RNA-directed cleavage of the genome followed by repair with a template that introduces a desired mutation along with synonymous \"immunizing\" mutations to prevent re-cleavage of the genome after editing. Because the immunizing mutations do not change the protein sequence, they are often assumed to be neutral. However, synonymous mutations can change mRNA structures in ways that alter levels of the encoded proteins. We have tested the assumption that immunizing mutations are neutral by constructing a library of over 50,000 edits that consist of only synonymous mutations in Escherichia coli. Thousands of edits had substantial effects on fitness during growth of E. coli on acetate, a poor carbon source that is toxic at high concentrations. The percentage of high-impact edits varied considerably between genes and at different positions within genes. We reconstructed clones with high-impact edits and found that 69% indeed had significant effects on growth in acetate. Interestingly, fewer edits affected fitness during growth in glucose, a preferred carbon source, suggesting that changes in protein expression caused by synonymous mutations may be most important when an organism encounters challenging conditions. Finally, we showed that synonymous edits can have widespread effects; a synonymous edit at the 5\' end of ptsI altered expression of hundreds of genes. Our results suggest that the synonymous immunizing edits introduced during CRISPR-Cas-based genome editing should not be assumed to be innocuous.
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  • 文章类型: Journal Article
    背景:同义突变,改变DNA序列,但不改变编码的蛋白质序列,会影响蛋白质的结构和功能,mRNA成熟,和mRNA的半衰期。最近的几项研究已经探索了同义突变可能在癌症中富集的可能性。然而,这些研究都没有控制所有三种类型的突变异质性(患者,组织学,和基因),已知会影响非同义癌症相关基因的准确识别。我们的目标是在同义突变的研究中采用当前的非同义突变标准。
    结果:这里,我们创建了一个算法,MutSigCVsyn,改编的MutSigCV,基于非编码背景模型,识别富含同义突变的癌症相关基因,该模型考虑了这些水平上的突变异质性。使用MutSigCVsyn,我们首先分析了来自全基因组泛癌分析(PCAWG)的2572个癌症全基因组样本,以确定非同义癌症驱动因素作为质量控制.表明算法的准确性,我们发现这些候选基因的58.6%也被发现在癌症普查基因(CGC)列表,在PCAWG癌症驱动因素列表中发现了66.2%。然后,我们应用它来鉴定30个推定的癌症相关基因,这些基因在相同的样品中富集了同义突变。有希望的候选基因之一是B细胞淋巴瘤2(BCL-2)基因。BCL-2通过拮抗促凋亡BCL-2家族成员蛋白的作用来调节凋亡。BCL2中的同义突变富集在其抗凋亡结构域中,并且可能在癌细胞增殖中起作用。
    结论:我们的研究介绍了MutSigCVsyn,一种解释患者突变异质性的算法,组织学,和基因水平,使用全基因组测序数据鉴定富含同义突变的癌症相关基因。我们确定了30个推定的候选基因,这些基因将受益于有关同义突变在癌症生物学中的作用的未来实验研究。
    BACKGROUND: Synonymous mutations, which change the DNA sequence but not the encoded protein sequence, can affect protein structure and function, mRNA maturation, and mRNA half-lives. The possibility that synonymous mutations might be enriched in cancer has been explored in several recent studies. However, none of these studies control for all three types of mutational heterogeneity (patient, histology, and gene) that are known to affect the accurate identification of non-synonymous cancer-associated genes. Our goal is to adopt the current standard for non-synonymous mutations in an investigation of synonymous mutations.
    RESULTS: Here, we create an algorithm, MutSigCVsyn, an adaptation of MutSigCV, to identify cancer-associated genes that are enriched for synonymous mutations based on a non-coding background model that takes into account the mutational heterogeneity across these levels. Using MutSigCVsyn, we first analyzed 2572 cancer whole-genome samples from the Pan-cancer Analysis of Whole Genomes (PCAWG) to identify non-synonymous cancer drivers as a quality control. Indicative of the algorithm accuracy we find that 58.6% of these candidate genes were also found in Cancer Census Gene (CGC) list, and 66.2% were found within the PCAWG cancer driver list. We then applied it to identify 30 putative cancer-associated genes that are enriched for synonymous mutations within the same samples. One of the promising gene candidates is the B cell lymphoma 2 (BCL-2) gene. BCL-2 regulates apoptosis by antagonizing the action of proapoptotic BCL-2 family member proteins. The synonymous mutations in BCL2 are enriched in its anti-apoptotic domain and likely play a role in cancer cell proliferation.
    CONCLUSIONS: Our study introduces MutSigCVsyn, an algorithm that accounts for mutational heterogeneity at patient, histology, and gene levels, to identify cancer-associated genes that are enriched for synonymous mutations using whole genome sequencing data. We identified 30 putative candidate genes that will benefit from future experimental studies on the role of synonymous mutations in cancer biology.
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  • 文章类型: Journal Article
    最近的研究表明,与先前收集的MPXV基因组相比,新采样的猴痘病毒(MPXV)基因组表现出与载脂蛋白BmRNA编辑催化多肽样3(APOBEC3)介导的编辑一致的突变。尚不清楚这些单核苷酸多态性(SNP)是由APOBEC3诱导的编辑引起的还是一个或多个MPXV动物储库内的遗传漂移的结果。我们基于通用时间可逆模型的概括开发了一种简单的方法,以表明观察到的SNP很可能是APOBEC3诱导的编辑的结果。统计特征使我们能够提取谱系信息并估计进化事件。
    Recent studies show that newly sampled monkeypox virus (MPXV) genomes exhibit mutations consistent with Apolipoprotein B mRNA Editing Catalytic Polypeptide-like3 (APOBEC3)-mediated editing compared to MPXV genomes collected earlier. It is unclear whether these single-nucleotide polymorphisms (SNPs) result from APOBEC3-induced editing or are a consequence of genetic drift within one or more MPXV animal reservoirs. We develop a simple method based on a generalization of the General-Time-Reversible model to show that the observed SNPs are likely the result of APOBEC3-induced editing. The statistical features allow us to extract lineage information and estimate evolutionary events.
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  • 文章类型: Journal Article
    背景:由于各种生物和社会困惑,家族性酒精使用障碍(AUD)的基础仍然是一个谜。本研究使用了三种最被采用和记录最多的大鼠模型,结合酒精偏好/非酒精偏好(P/NP)系列和高饮酒/低饮酒(HAD/LAD)复制系列,通过全基因组分析的镜头检查的AUD。
    方法:我们使用了P/NP系的完整基因组测序和先前发表的HAD/LAD重复序列,以增强与AUD相关的变异的发现,并消除与遗传背景和随机遗传漂移的混淆。具体来说,我们使用高阶统计方法来搜索遗传变异,其在整个基因本体中的频率变化与选择方向的表型变化相对应,也就是说,乙醇饮用偏好。
    结果:我们的第一个发现是,除了导致翻译变化的变异,与饮酒倾向相关的主要遗传变化是沉默突变和基因3'非翻译区(3'UTR)突变.这些类型的突变都不会改变翻译蛋白的氨基酸序列,但它们会影响基因转录的速率和构象。包括其稳定性和改变基因功效的翻译后事件。这一发现表明人类基因组研究的重点是基因功效的变化。确定的关键本体是与神经元和神经胶质的Na电压门控通道相关的中心基因(包括Scn1a,Scn2a,Scn2b,Scn3a,Scn7a,和Scn9a亚型)和兴奋性谷氨酸能分泌(包括Grm2和Myo6),这两者在神经可塑性中都是必不可少的。此外,我们确定了疼痛的伤害感受或感觉感知,\“在伤害感受中包含变体(Arrb1,Ccl3,Ephb1)和enlist钠(Scn1a,Scn2a,Scn2b,Scn3a,Scn7a),疼痛激活(Scn9a),和钾通道(Kcna1)基因。
    结论:本文使用的多模型分析减少了随机漂移和“创始人”遗传背景的混杂效应。在所有三种动物模型中,最分化的双向选择基因是Scn9a,Scn1a,和Kcna,所有这些都在伤害感受本体中进行了注释。神经可塑性和伤害感受的复杂性增加了神经可塑性和疼痛(生理或心理)是与AUD发展遗传相关的突出表型的假设的强度。
    BACKGROUND: The basis for familial alcohol use disorder (AUD) remains an enigma due to various biological and societal confounds. The present study used three of the most adopted and documented rat models, combining the alcohol-preferring/non-alcohol-preferring (P/NP) lines and high alcohol-drinking/low alcohol-drinking (HAD/LAD) replicated lines, of AUD as examined through the lens of whole genomic analyses.
    METHODS: We used complete genome sequencing of the P/NP lines and previously published sequences of the HAD/LAD replicates to enhance the discovery of variants associated with AUD and to remove confounding with genetic background and random genetic drift. Specifically, we used high-order statistical methods to search for genetic variants whose frequency changes in whole sets of gene ontologies corresponded with phenotypic changes in the direction of selection, that is, ethanol-drinking preference.
    RESULTS: Our first finding was that in addition to variants causing translational changes, the principal genetic changes associated with drinking predisposition were silent mutations and mutations in the 3\' untranslated regions (3\'UTR) of genes. Neither of these types of mutations alters the amino acid sequence of the translated protein but they influence both the rate and conformation of gene transcription, including its stability and posttranslational events that alter gene efficacy. This finding argues for refocusing human genomic studies on changes in gene efficacy. Among the key ontologies identified were the central genes associated with the Na+ voltage-gated channels of neurons and glia (including the Scn1a, Scn2a, Scn2b, Scn3a, Scn7a, and Scn9a subtypes) and excitatory glutamatergic secretion (including Grm2 and Myo6), both of which are essential in neuroplasticity. In addition, we identified \"Nociception or Sensory Perception of Pain,\" which contained variants in nociception (Arrb1, Ccl3, Ephb1) and enlist sodium (Scn1a, Scn2a, Scn2b, Scn3a, Scn7a), pain activation (Scn9a), and potassium channel (Kcna1) genes.
    CONCLUSIONS: The multi-model analyses used herein reduced the confounding effects of random drift and the \"founders\" genetic background. The most differentiated bidirectionally selected genes across all three animal models were Scn9a, Scn1a, and Kcna, all of which are annotated in the nociception ontology. The complexity of neuroplasticity and nociception adds strength to the hypothesis that neuroplasticity and pain (physical or psychological) are prominent phenotypes genetically linked to the development of AUD.
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  • 文章类型: Journal Article
    2019年冠状病毒病的传播(COVID-19),由严重呼吸综合征冠状病毒2(SARS-CoV-2)引起,已经发展成为全球大流行。迄今为止,在从患者身上收集的SARS-CoV-2分离株中已鉴定出数千种遗传变异。序列分析揭示了病毒序列的密码子适应指数(CAI)值随着时间的推移而降低,但有偶尔的波动。通过进化建模,发现这种现象可能是由于病毒在传播过程中的突变偏好造成的。使用双荧光素酶测定法,进一步发现,病毒序列中密码子的去优化可能会削弱病毒进化过程中的蛋白质表达,表明密码子使用可能在病毒适应性中起重要作用。最后,鉴于密码子使用在蛋白质表达中的重要性,特别是对于mRNA疫苗,它设计了几种密码子优化的OmicronBA.2.12.1,BA4/5和XBB.1.5刺突mRNA疫苗候选物,并通过实验验证了它们的高水平表达。这项研究强调了密码子使用在病毒进化中的重要性,并为mRNA和DNA疫苗开发中的密码子优化提供了指导。
    The spread of coronavirus disease 2019 (COVID-19), caused by severe respiratory syndrome coronavirus 2 (SARS-CoV-2), has progressed into a global pandemic. To date, thousands of genetic variants have been identified among SARS-CoV-2 isolates collected from patients. Sequence analysis reveals that the codon adaptation index (CAI) values of viral sequences have decreased over time but with occasional fluctuations. Through evolution modeling, it is found that this phenomenon may result from the virus\'s mutation preference during transmission. Using dual-luciferase assays, it is further discovered that the deoptimization of codons in the viral sequence may weaken protein expression during virus evolution, indicating that codon usage may play an important role in virus fitness. Finally, given the importance of codon usage in protein expression and particularly for mRNA vaccines, it is designed several codon-optimized Omicron BA.2.12.1, BA.4/5, and XBB.1.5 spike mRNA vaccine candidates and experimentally validated their high levels of expression. This study highlights the importance of codon usage in virus evolution and provides guidelines for codon optimization in mRNA and DNA vaccine development.
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  • 文章类型: Journal Article
    视网膜母细胞瘤响应于双等位基因RB1突变或MYCN扩增而形成,并通过次级基因组变化的积累发展为更具侵袭性和治疗抗性的表型。进展相关的变化包括复发性体细胞拷贝数改变和典型的非复发性核苷酸变异,包括同义词和非编码变体,其意义尚不清楚。为了确定核苷酸变异是否会反复影响特定的生物过程,我们在168个外显子组或全基因组测序的视网膜母细胞瘤和12个肿瘤匹配细胞系中鉴定了改变的基因和过度表达的变异基因本体.除了RB1突变,MYCN扩增,并建立了视网膜母细胞瘤SCNA,分析揭示了与多种生物过程相关的变异基因的富集,包括组蛋白单同质化,mRNA加工(P)体组装,有丝分裂姐妹染色单体分离和胞质分裂。重要的是,非编码和同义变体增加了每个过度表示的生物过程术语的富集显著性.为了评估这种突变的影响,我们检查了PCGF3的3'UTR变体(Polycomb阻遏复合物I的BCOR结合成分)的后果,CDC14B的双3UTR变体(姐妹染色单体分离的调节剂),以及DYNC1H1(P体组件的调节器)的同义变体。一个PCGF3和两个CDC14B3'UTR变体之一损害了基因表达,而碱基编辑的DYNC1H1同义变体改变了蛋白酶的敏感性和稳定性。视网膜母细胞瘤细胞系仅保留了在肿瘤中检测到的约50%的变体,并富集了影响p53信号传导的新变体。这些发现揭示了视网膜母细胞瘤细胞系和肿瘤的潜在重要差异,并暗示了同义和非编码变体。与非同义变体一起,视网膜母细胞瘤的肿瘤发生。
    Retinoblastomas form in response to biallelic RB1 mutations or MYCN amplification and progress to more aggressive and therapy-resistant phenotypes through accumulation of secondary genomic changes. Progression-related changes include recurrent somatic copy number alterations and typically non-recurrent nucleotide variants, including synonymous and non-coding variants, whose significance has been unclear. To determine if nucleotide variants recurrently affect specific biological processes, we identified altered genes and over-represented variant gene ontologies in 168 exome or whole-genome-sequenced retinoblastomas and 12 tumor-matched cell lines. In addition to RB1 mutations, MYCN amplification, and established retinoblastoma somatic copy number alterations, the analyses revealed enrichment of variant genes related to diverse biological processes including histone monoubiquitination, mRNA processing (P) body assembly, and mitotic sister chromatid segregation and cytokinesis. Importantly, non-coding and synonymous variants increased the enrichment significance of each over-represented biological process term. To assess the effects of such mutations, we examined the consequences of a 3\' UTR variant of PCGF3 (a BCOR-binding component of Polycomb repressive complex I), dual 3\' UTR variants of CDC14B (a regulator of sister chromatid segregation), and a synonymous variant of DYNC1H1 (a regulator of P-body assembly). One PCGF3 and one of two CDC14B 3\' UTR variants impaired gene expression whereas a base-edited DYNC1H1 synonymous variant altered protease sensitivity and stability. Retinoblastoma cell lines retained only ~50% of variants detected in tumors and enriched for new variants affecting p53 signaling. These findings reveal potentially important differences in retinoblastoma cell lines and tumors and implicate synonymous and non-coding variants, along with non-synonymous variants, in retinoblastoma oncogenesis.
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  • 文章类型: Journal Article
    目的:小型猪被认为是人类异种移植的理想器官供体,但其侏儒症背后的机制仍有待阐明。IGF-1R是哺乳动物体型形成的关键因素,包括骨骼肌的形成和发育。细胞外结构域(ECD)与配体结合,导致下游途径激活的现象。
    方法:在本研究中,将大型长白猪(LP)和小型巴马香(BM)猪的两种IGF-1RECD单倍型的编码序列克隆到pcDNA3.1载体中,以生成pcDNA3.1-LP和pcDNA3.1-BM。然后将两种重组载体转染到骨骼肌细胞中。
    结果:发现IGF-1R转录本在pcDNA3.1-LP组中的表达水平高于pcDNA3.1-BM组。来自LP的IGF-1RECD促进细胞增殖和CyclinD1表达,并促进蛋白激酶B的磷酸化(产生p-AKT)。此外,来自LP的IGF-1RECD增加了细胞分化和成肌决定因子(MyoD)的表达。
    结论:我们的数据表明,不同体型猪品种之间的IGF-1RECD单倍型影响IGF-1R表达,进而通过激活下游信号通路影响骨骼肌细胞的增殖和分化。
    OBJECTIVE: Miniature pigs are considered ideal organ donors for xenotransplantation in humans, but the mechanism underlying their dwarfism remains to be elucidated. IGF-1R is a crucial factor in body size formation in mammals, including skeletal muscle formation and development. The extracellular domain (ECD) binds to the ligand, a phenomenon that results in the activation of downstream pathways.
    METHODS: In this study, the coding sequences of two IGF-1R ECD haplotypes of the large Landrace (LP) pig and the small Bama Xiang (BM) pig were cloned into pcDNA3.1 vectors to generate pcDNA3.1-LP and pcDNA3.1-BM. The two recombinant vectors were then transfected into skeletal muscle cells.
    RESULTS: IGF-1R transcript was found to be expressed at higher levels in the pcDNA3.1-LP group than in the pcDNA3.1-BM group. The IGF-1R ECD from LP promoted cell proliferation and CyclinD1 expression, and promoted the phosphorylation of protein kinase B (to yield p-AKT). Moreover, the IGF-1R ECD from LP increased cell differentiation and the expression of myogenic determination factor (MyoD).
    CONCLUSIONS: Our data indicated that the IGF-1R ECD haplotypes between pig breeds with different body sizes affect IGF-1R expression, in turn affecting the proliferation and differentiation of skeletal muscle cells by activating downstream signalling pathways.
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