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在植物线粒体和叶绿体转录本上,数百个胞嘧啶(C)位点经脱氨基反应变为尿嘧啶(U),这是一种在转录本水平上对遗传信息进行修饰或调控的机制.在植物细胞器中,RNA编辑过程需要不同家族的RNA编辑因子相互作用组装成复杂的编辑复合体,特异地识别编辑位点进行编辑.最初的研究发现,植物RNA编辑受到高特异性五环肽重复(pentatricopeptide repeat, PPR)蛋白的调控,目前在植物中发现400多种PPR家族蛋白,编辑作用复杂.之后对RNA编辑因子互作蛋白/多细胞器RNA编辑因子(RNA editing factor interacting proteins /multiple organellar RNA editing factors,RIP/MORF),细胞器RNA识别基序(organelle RNA recognition motif,ORRM),细胞器锌指蛋白(organelle zinc-finger,OZ)等的研究表明,这些非PPR蛋白组分可以与PPR蛋白形成编辑复合体,共同参与编辑,且RNA编辑复合体具有多样性.RNA编辑因子的缺失会引起植物的生长发育受阻,果实成熟延迟等,对RNA编辑因子的研究显得尤为重要.对植物中RNA编辑因子的功能及其作用机制研究进展进行综述,旨在为后续RNA编辑的研究提供一定的参考. 相似文献
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《中国生物工程杂志》2020,(3)
在植物线粒体和叶绿体转录本上,数百个胞嘧啶(C)位点经脱氨基反应变为尿嘧啶(U),这是一种在转录本水平上对遗传信息进行修饰或调控的机制。在植物细胞器中,RNA编辑过程需要不同家族的RNA编辑因子相互作用组装成复杂的编辑复合体,特异地识别编辑位点进行编辑。最初的研究发现,植物RNA编辑受到高特异性五环肽重复(pentatricopeptide repeat,PPR)蛋白的调控,目前在植物中发现400多种PPR家族蛋白,编辑作用复杂。之后对RNA编辑因子互作蛋白/多细胞器RNA编辑因子(RNA editing factor interacting proteins/multiple organellar RNA editing factors,RIP/MORF)、细胞器RNA识别基序(organelle RNA recognition motif,ORRM)、细胞器锌指蛋白(organelle zinc-finger,OZ)等的研究表明,这些非PPR蛋白组分可以与PPR蛋白形成编辑复合体,共同参与编辑,且RNA编辑复合体具有多样性。RNA编辑因子的缺失会引起植物的生长发育受阻、果实成熟延迟等,对RNA编辑因子的研究显得尤为重要。对植物中RNA编辑因子的功能及其作用机制研究进展进行综述,旨在为后续RNA编辑的研究提供一定的参考。 相似文献
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35肽重复(pentatricopeptide repeat, PPR)蛋白是2000年发现的一类由多个重复单位串联而成的核编码蛋白质。PPR蛋白广泛存在于真核生物中,在陆生植物中尤为普遍。PPR蛋白大多定位于线粒体或叶绿体。多项研究表明,PPR蛋 白为序列特异性RNA结合蛋白质,在细胞器RNA编辑、剪接、稳定、切割及翻译等转录后加工过程发挥重要作用。PPR蛋白功能缺陷导致植物生长发育异常,甚至胚胎致死。本文主要就PPR蛋白功能及作用机制进行综述,并对尚待解决的问题及研究前景加以探讨,以期为PPR蛋白的深入研究提供思路。 相似文献
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PPR蛋白在陆生植物中属于最大的蛋白家族之一,其成员种类和数量均十分庞大。PPR蛋白主要的功能是通过在多种细胞器中进行定位从而参与细胞核和细胞器中特异单链RNA的转录后修饰和编辑,在植物生长发育的多个阶段均发挥着重要的作用。多数PPR蛋白编码基因的突变体呈现异常的发育表型,如胚胎致死、发育迟缓及绿化延迟等。对近年来植物PPR蛋白的分类、定位、RNA修饰的机制及其对植物生长发育影响进行了综述,并展望了植物PPR发挥功能区域和参与的调控网络研究。 相似文献
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植物生长发育是一个极其复杂的生理生化过程,受内外因素共同作用。PPR蛋白是核基因编码的具有重复PPR基序的蛋白,分布广泛,在高等植物中数量巨大。PPR蛋白的靶标一般是线粒体和叶绿体中转录的RNA前体,多数可与MORF互作,参与线粒体和叶绿体基因的RNA编辑。PPR蛋白缺失的突变体植株多数呈现异常表型,影响植物的正常生长发育。本文就近年来发现的PPR蛋白结构、分布,与RNA编辑的关系,及其对植物生长发育的影响进行了综述。 相似文献
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水稻是我国最主要的粮食作物之一。水稻的安全生产越来越依赖分子生物学功能基础研究。PPR(Pentatricopeptide repeat)蛋白是水稻中较大的蛋白家族之一,研究证明PPR蛋白由核基因编码并参与细胞器前体RNA加工,如RNA起始翻译、RNA稳定、RNA剪接、RNA编辑,调控水稻叶绿体和线粒体等的发育,进而影响水稻的花粉、胚、胚乳、叶片及其他组织的生长发育。该类蛋白表达受抑制将严重影响水稻正常生长发育。对近年报道的水稻PPR蛋白结构、分类、定位、RNA作用靶位点、作用方式及其对水稻生长发育的影响进行综述。对已报道水稻PPR蛋白功能作出总结并对今后PPR蛋白对水稻种质资源的创新应用等可能的研究方向进行了展望。 相似文献
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RNA编辑指遗传信息转录后对RNA核苷酸序列的改变,包括碱基替换、核苷酸的插入和删除等过程。RNA编辑系统可分为基于CRISPR-Cas13和非CRISPR-Cas13 RNA编辑系统两种,该文分别阐述了两种系统的分子机制和编辑过程,并总结了新型RNA编辑系统的优势、缺陷以及应用价值。 相似文献
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水稻线粒体coxII基因转录本的编辑位点研究 总被引:1,自引:0,他引:1
RNA编辑是指由RNA水平的核苷酸改变所引起的密码子发生变化的一种预定修饰,它的发现是近年来对分子生物学中心法则的重要补充.本文以红莲型(HL)水稻细胞质雄性不育系粤泰A,保持系粤泰B和杂种F1(不育系A与恢复系71068的杂交一代)为材料,首次研究了线粒体基因coxII转录本的编辑位点.coxII基因的转录本有15个编辑位点,其中有14个发生在密码子的第一和第二位点.这14个位点的编辑可改变氨基酸的种类,并导致所编码蛋白的疏水性以及所编码蛋白在氨基酸序列上的保守性增加. 相似文献
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Higher plants encode hundreds of pentatricopeptide repeat proteins (PPRs) that are involved in several types of RNA processing reactions. Most PPR genes are predicted to be targeted to chloroplasts or mitochondria, and many are known to affect organellar gene expression. In some cases, RNA binding has been directly demonstrated, and the sequences of the cis-elements are known. In this work, we demonstrate that RNA cis-elements recognized by PPRs are constrained in chloroplast genome evolution. Cis-elements for two PPR genes and several RNA editing sites were analyzed for sequence changes by pairwise nucleotide substitution frequency, pairwise indel frequency, and maximum likelihood (ML) phylogenetic distances. All three of these analyses demonstrated that sequences within the cis-element are highly conserved compared with surrounding sequences. In addition, we have compared sequences around chloroplast editing sites and homologous sequences in species that lack an editing site due to the presence of a genomic T. Cis-elements for RNA editing sites are highly conserved in angiosperms; by contrast, comparable sequences around a genomically encoded T exhibit higher rates of nucleotide substitution, higher frequencies of indels, and greater ML distances. The loss in requirement for editing to create the ndhD start codon has resulted in the conversion of the PPR gene responsible for editing that site to a pseudogene. We show that organellar dependence on nuclear-encoded PPR proteins for gene expression has constrained the evolution of cis-elements that are required at the level of RNA processing. Thus, the expansion of the PPR gene family in plants has had a dramatic effect on the evolution of plant organelle genomes. 相似文献
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Yusuke Yagi Takahiro Nakamura Ian Small 《The Plant journal : for cell and molecular biology》2014,78(5):772-782
The pentatricopeptide repeat (PPR) protein family, which is particularly prevalent in plants, includes many sequence‐specific RNA‐binding proteins involved in all aspects of organelle RNA metabolism, including RNA stability, processing, editing and translation. PPR proteins consist of a tandem array of 2‐30 PPR motifs, each of which aligns to one nucleotide in the RNA target. The amino acid side chains at two or three specific positions in each motif confer nucleotide specificity in a predictable and programmable manner. Thus, PPR proteins appear to provide an extremely promising opportunity to create custom RNA‐binding proteins with tailored specificity. We summarize recent progress in understanding RNA recognition by PPR proteins, with a particular focus on potential applications of PPR‐based tools for manipulating RNA, and on the challenges that remain to be overcome before these tools may be routinely used by the scientific community. 相似文献
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Pentatricopeptide repeat (PPR) proteins with an E domain have been identified as specific factors for C to U RNA editing in plant organelles. These PPR proteins bind to a unique sequence motif 5′ of their target editing sites. Recently, involvement of a combinatorial amino acid code in the P (normal length) and S type (short) PPR domains in sequence specific RNA binding was reported. PPR proteins involved in RNA editing, however, contain not only P and S motifs but also their long variants L (long) and L2 (long2) and the S2 (short2) motifs. We now find that inclusion of these motifs improves the prediction of RNA editing target sites. Previously overlooked RNA editing target sites are suggested from the PPR motif structures of known E-class PPR proteins and are experimentally verified. RNA editing target sites are assigned for the novel PPR protein MEF32 (mitochondrial editing factor 32) and are confirmed in the cDNA. 相似文献
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The E domains of pentatricopeptide repeat proteins from different organelles are not functionally equivalent for RNA editing 总被引:1,自引:0,他引:1
Anne‐Laure Chateigner‐Boutin Catherine Colas des Francs‐Small Sota Fujii Kenji Okuda Sandra K. Tanz Ian Small 《The Plant journal : for cell and molecular biology》2013,74(6):935-945
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RNA editing factors of the pentatricopeptide repeat (PPR) family show a very high degree of sequence specificity in the recognition of their target sites. A molecular basis for target recognition by editing factors has been proposed based on statistical correlations but has not been tested experimentally. To achieve this, we systematically mutated the pentatricopeptide motifs in the Arabidopsis thaliana RNA editing factor CLB19 to investigate their individual contribution to RNA recognition. We find that the motifs contributing significantly to the specificity of binding follow the previously proposed recognition rules, distinguishing primarily between purines and pyrimidines. Our results are consistent with proposals that each motif recognizes one nucleotide in the RNA target with the protein aligned parallel to the RNA and contiguous motifs aligned with contiguous nucleotides such that the final PPR motif aligns four nucleotides upstream of the edited cytidine. By altering S motifs in CLB19 and another editing factor, OTP82, and using the modified proteins to attempt to complement the respective mutants, we demonstrate that we can predictably alter the specificity of these factors in vivo. 相似文献