共查询到20条相似文献,搜索用时 0 毫秒
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Kerényi Z Mérai Z Hiripi L Benkovics A Gyula P Lacomme C Barta E Nagy F Silhavy D 《The EMBO journal》2008,27(11):1585-1595
Nonsense-mediated mRNA decay (NMD) is a quality control system that degrades mRNAs containing premature termination codons. Although NMD is well characterized in yeast and mammals, plant NMD is poorly understood. We have undertaken the functional dissection of NMD pathways in plants. Using an approach that allows rapid identification of plant NMD trans factors, we demonstrated that two plant NMD pathways coexist, one eliminates mRNAs with long 3'UTRs, whereas a distinct pathway degrades mRNAs harbouring 3'UTR-located introns. We showed that UPF1, UPF2 and SMG-7 are involved in both plant NMD pathways, whereas Mago and Y14 are required only for intron-based NMD. The molecular mechanism of long 3'UTR-based plant NMD resembled yeast NMD, whereas the intron-based NMD was similar to mammalian NMD, suggesting that both pathways are evolutionarily conserved. Interestingly, the SMG-7 NMD component is targeted by NMD, suggesting that plant NMD is autoregulated. We propose that a complex, autoregulated NMD mechanism operated in stem eukaryotes, and that despite aspect of the mechanism being simplified in different lineages, feedback regulation was retained in all kingdoms. 相似文献
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MicroRNA or NMD: Why Have Two RNA Silencing Systems? 总被引:1,自引:0,他引:1
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Ajamian L Abrahamyan L Milev M Ivanov PV Kulozik AE Gehring NH Mouland AJ 《RNA (New York, N.Y.)》2008,14(5):914-927
The HIV-1 ribonucleoprotein (RNP) contains the major structural protein, pr55(Gag), viral genomic RNA, as well as the host protein, Staufen1. In this report, we show that the nonsense-mediated decay (NMD) factor UPF1 is also a component of the HIV-1 RNP. We investigated the role of UPF1 in HIV-1-expressing cells. Depletion of UPF1 by siRNA resulted in a dramatic reduction in steady-state HIV-1 RNA and pr55(Gag). Pr55(Gag) synthesis, but not the cognate genomic RNA, was efficiently rescued by expression of an siRNA-insensitive UPF1, demonstrating that UPF1 positively influences HIV-1 RNA translatability. Conversely, overexpression of UPF1 led to a dramatic up-regulation of HIV-1 expression at the RNA and protein synthesis levels. The effects of UPF1 on HIV-1 RNA stability were observed in the nucleus and cytoplasm and required ongoing translation. We also demonstrate that the effects exerted by UPF1 on HIV-1 expression were dependent on its ATPase activity, but were separable from its role in NMD and did not require interaction with UPF2. 相似文献
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茉莉酸(jasmonic acid, JA)是一种植物内源合成的脂类激素,在植物响应胁迫的调控中发挥着重要作用。本文概括了JA的生物合成与代谢途径及其调控机制;总结了JA信号的传导通路;系统归纳了JA在植物响应生物和非生物胁迫应答中的作用机制和调控网络,重点关注了最新的研究进展。此外,本文梳理了JA与其他植物激素在植物抗逆性调节过程中的信号交流。最后讨论了JA信号通路介导的植物抗逆性研究中亟待解决的问题,并展望了新的分子生物学技术在调控JA信号通路增强作物抗性中的应用前景,以期为植物的抗逆性研究和改良提供参考。 相似文献
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Marcello Clerici André Mourão Irina Gutsche Niels H Gehring Matthias W Hentze Andreas Kulozik Jan Kadlec Michael Sattler Stephen Cusack 《The EMBO journal》2009,28(15):2293-2306
Nonsense‐mediated decay (NMD) is a eukaryotic quality control mechanism that degrades mRNAs carrying premature stop codons. In mammalian cells, NMD is triggered when UPF2 bound to UPF3 on a downstream exon junction complex interacts with UPF1 bound to a stalled ribosome. We report structural studies on the interaction between the C‐terminal region of UPF2 and intact UPF1. Crystal structures, confirmed by EM and SAXS, show that the UPF1 CH‐domain is docked onto its helicase domain in a fixed configuration. The C‐terminal region of UPF2 is natively unfolded but binds through separated α‐helical and β‐hairpin elements to the UPF1 CH‐domain. The α‐helical region binds sixfold more weakly than the β‐hairpin, whereas the combined elements bind 80‐fold more tightly. Cellular assays show that NMD is severely affected by mutations disrupting the beta‐hairpin binding, but not by those only affecting alpha‐helix binding. We propose that the bipartite mode of UPF2 binding to UPF1 brings the ribosome and the EJC in close proximity by forming a tight complex after an initial weak encounter with either element. 相似文献
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《植物学报(英文版)》2025,67(3)
Small peptides (SPs) are pivotal signaling molecules that play essential roles in the precise regulation of plant growth, development, and stress responses. Recent advancements in sequencing technologies, bioinformatics approaches, and biochemical and molecular techniques have significantly enhanced the accuracy of SP identification, unveiling their diverse biological functions in plants. This review provides a comprehensive overview of the characteristics and methodologies for identifying SPs in plants. It highlights recent discoveries regarding the biological roles and signaling pathways of SPs in regulating plant growth, development, and plant–microbial interactions, as well as their contributions to plant resilience under various environmental stresses, including abiotic stress, nutrient deficiencies, and biotic challenges. Additionally, we discuss current insights into the potential applications of SPs and outline future research directions aimed at leveraging these molecules to enhance plant adaptation to environmental challenges. By integrating recent findings, this review lays a foundation for advancing the understanding and utilization of SPs to improve plant resilience and productivity. 相似文献
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Ei Ei Min Bijoyita Roy Nadia Amrani Feng He Allan Jacobson 《RNA (New York, N.Y.)》2013,19(8):1105-1115
The central nonsense-mediated mRNA decay (NMD) regulator, Upf1, selectively targets nonsense-containing mRNAs for rapid degradation. In yeast, Upf1 preferentially associates with mRNAs that are NMD substrates, but the mechanism of its selective retention on these mRNAs has yet to be elucidated. Previously, we demonstrated that Upf1 associates with 40S ribosomal subunits. Here, we define more precisely the nature of this association using conventional and affinity-based purification of ribosomal subunits, and a two-hybrid screen to identify Upf1-interacting ribosomal proteins. Upf1 coimmunoprecipitates specifically with epitope-tagged 40S ribosomal subunits, and Upf1 association with high-salt washed or puromycin-released 40S subunits was found to occur without simultaneous eRF1, eRF3, Upf2, or Upf3 association. Two-hybrid analyses and in vitro binding assays identified a specific interaction between Upf1 and Rps26. Using mutations in domains of UPF1 known to be crucial for its function, we found that Upf1:40S association is modulated by ATP, and Upf1:Rps26 interaction is dependent on the N-terminal Upf1 CH domain. The specific association of Upf1 with the 40S subunit is consistent with the notion that this RNA helicase not only triggers rapid decay of nonsense-containing mRNAs, but may also have an important role in dissociation of the premature termination complex. 相似文献
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Nonsense-mediated mRNA decay (NMD) represents a key mechanism to control the expression of wild-type and aberrant mRNAs. Phosphorylation of the protein UPF1 in the context of translation termination contributes to committing mRNAs to NMD. We report that translation termination is inhibited by UPF1 and stimulated by cytoplasmic poly(A)-binding protein (PABPC1). UPF1 binds to eRF1 and to the GTPase domain of eRF3 both in its GTP- and GDP-bound states. Importantly, mutation studies show that UPF1 can interact with the exon junction complex (EJC) alternatively through either UPF2 or UPF3b to become phosphorylated and to activate NMD. On this basis, we discuss an integrated model where UPF1 halts translation termination and is phosphorylated by SMG1 if the termination-promoting interaction of PABPC1 with eRF3 cannot readily occur. The EJC, with UPF2 or UPF3b as a cofactor, interferes with physiological termination through UPF1. This model integrates previously competing models of NMD and suggests a mechanistic basis for alternative NMD pathways. 相似文献
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Messenger RNAs harboring nonsense codons (or premature translation termination codons [PTCs]) are degraded by a conserved quality-control mechanism known as nonsense-mediated mRNA decay (NMD), which prevents the accumulation of truncated and potentially harmful proteins. In Drosophila melanogaster, degradation of PTC-containing messages is initiated by endonucleolytic cleavage in the vicinity of the nonsense codon. The endonuclease responsible for this cleavage has not been identified. Here, we show that SMG6 is the long sought NMD endonuclease. First, cells expressing an SMG6 protein mutated at catalytic residues fail to degrade PTC-containing messages. Moreover, the SMG6-PIN domain can be replaced with the active PIN domain of an unrelated protein, indicating that its sole function is to provide endonuclease activity for NMD. Unexpectedly, we found that the catalytic activity of SMG6 contributes to the degradation of PTC-containing mRNAs in human cells. Thus, SMG6 is a conserved endonuclease that degrades mRNAs terminating translation prematurely in metazoa. 相似文献
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Jaime A. Verdugo Marie‐Helene Sauge Jean‐Philippe Lacroze Frederic Francis Claudio C. Ramirez 《Physiological Entomology》2015,40(4):265-276
Little is known about the simultaneous effects of drought stress and plant resistance on herbivorous insects. By subjecting the green peach aphid Myzus persicae Sulzer to well‐watered and drought‐stressed plants of both susceptible and resistant peach (Prunus persica), the effects of both stressors on aphid performance and proteomics are tested. Overall, the influence of the water treatment on aphid performance is less pronounced than the effect of host plant genetic resistance. On the susceptible cultivar, aphid survival, host acceptance and ability to colonize the plant do not depend on water treatment. On the resistant cultivar, aphid survival and ability to colonize are higher on drought‐stressed than on well‐watered plants. A study examining the pattern of protein expression aiming to explain the variation in aphid performance finds higher protein expression in aphids on the drought‐stressed susceptible cultivars compared with the well‐watered ones. In the susceptible cultivar, the regulated proteins are related to energy metabolism and exoskeleton functionality, whereas, in the resistant cultivar, the proteins are involved with the cytoskeleton. Comparison of the protein expression ratios for resistant versus susceptible plants reveals that four proteins are down‐regulated in well‐watered plants and 15 proteins are down‐regulated in drought‐stressed plants. Drought stress applied to the susceptible cultivar induces the regulation of proteins in M. persicae that enable physiological adaptation to maintain an almost unaltered aphid performance. By contrast, for aphids on the resistant cultivar subjected to drought stress, the down‐regulation of proteins responds to an induced host susceptibility effect. 相似文献
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Taliansky M Kim SH Mayo MA Kalinina NO Fraser G McGeachy KD Barker H 《The Plant journal : for cell and molecular biology》2004,39(2):194-205
Strong RNA silencing was induced in plants transformed with an amplicon consisting of full-length cDNA of potato leafroll virus (PLRV) expressing green fluorescent protein (GFP), as shown by low levels of PLRV-GFP accumulation, lack of symptoms and accumulation of amplicon-specific short interfering RNAs (siRNAs). Inoculation of these plants with various viruses known to encode silencing suppressor proteins induced a striking synergistic effect leading to the enhanced accumulation of PLRV-GFP, suggesting that it had escaped from silencing. However, PLRV-GFP escape also occurred following inoculation with viruses that do not encode known silencing suppressors and treatment of silenced plants with biotic or abiotic stress agents. We propose that viruses can evade host RNA-silencing defences by a previously unrecognized mechanism that may be associated with a host response to some types of abiotic stress such as heat shock. 相似文献
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The discovery of RNA interference (RNAi) has augmented our knowledge of gene regulation and presents a fascinating technology that has a great potential for application in genetic analysis, disease therapy, plant protection, and many other areas. In this review, we will focus on the biological functions of RNAi and its application in agriculture with a brief introduction to the history of its discovery and molecular mechanism. Supported by National Natural Sciences of China (Grant No. 30630008) and National Key Basic Research and Development Program of China (Grant No. 2007CB108800). 相似文献
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Pratibha Prashar 《Biocontrol Science and Technology》2017,27(10):1123-1144
Members of the endophytic fungal genus Trichoderma have been established as plant-beneficial microbes and are most successful commercial biologicals in the form of bio-fertilisers, biocontrol agents, and growth stimulators. We report the variable interactions among different lentil genotypes and Trichoderma strains in both the presence and absence of biotic stress (root-rot pathogen Aphanomyces euteiches). Two commercial Trichoderma formulations, namely RootShield® (RS) and RootShield® Plus (RSP) based on T. harzianum T22 and T. virens G41, respectively, were evaluated for control of Aphanomyces root rot and plant growth promotion in 23 wild and cultivated lentil genotypes. No significant disease control was recorded with either formulation in any lentil genotype. Significant genotype-specific plant growth promotion was observed in terms of root and shoot development and leaf parameters in a genotype-specific manner. Genotypes of Lens culinaris and Lens tomentosus, both in the primary lentil gene pool, demonstrated the maximum response. The overall effect of Trichoderma treatment was markedly higher under biotically stressed conditions in comparison to unstressed conditions. In many cases, negative responses were recorded, particularly in the absence of root-rot disease. L. tomentosus PI 572390 exhibited positive responses for most of the tested parameters. Our findings clearly indicate that, in the case of lentil, plant genotype plays a major role in interactions among the tested Trichoderma strains and the plant. Moreover, the influence of Trichoderma was greater and more favourable under conditions of biotic stress vs. the absence of stress. 相似文献