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Wu HYL, Jen J, Hsu PY. What, where, and how: Regulation of translation and the translational landscape in plants. THE PLANT CELL 2024; 36:1540-1564. [PMID: 37437121 PMCID: PMC11062462 DOI: 10.1093/plcell/koad197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 07/14/2023]
Abstract
Translation is a crucial step in gene expression and plays a vital role in regulating various aspects of plant development and environmental responses. It is a dynamic and complex program that involves interactions between mRNAs, transfer RNAs, and the ribosome machinery through both cis- and trans-regulation while integrating internal and external signals. Translational control can act in a global (transcriptome-wide) or mRNA-specific manner. Recent advances in genome-wide techniques, particularly ribosome profiling and proteomics, have led to numerous exciting discoveries in both global and mRNA-specific translation. In this review, we aim to provide a "primer" that introduces readers to this fascinating yet complex cellular process and provide a big picture of how essential components connect within the network. We begin with an overview of mRNA translation, followed by a discussion of the experimental approaches and recent findings in the field, focusing on unannotated translation events and translational control through cis-regulatory elements on mRNAs and trans-acting factors, as well as signaling networks through 3 conserved translational regulators TOR, SnRK1, and GCN2. Finally, we briefly touch on the spatial regulation of mRNAs in translational control. Here, we focus on cytosolic mRNAs; translation in organelles and viruses is not covered in this review.
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Affiliation(s)
- Hsin-Yen Larry Wu
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Joey Jen
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Polly Yingshan Hsu
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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2
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Chang HH, Huang LC, Browning KS, Huq E, Cheng MC. The phosphorylation of carboxyl-terminal eIF2α by SPA kinases contributes to enhanced translation efficiency during photomorphogenesis. Nat Commun 2024; 15:3467. [PMID: 38658612 PMCID: PMC11043401 DOI: 10.1038/s41467-024-47848-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 04/11/2024] [Indexed: 04/26/2024] Open
Abstract
Light triggers an enhancement of global translation during photomorphogenesis in Arabidopsis, but little is known about the underlying mechanisms. The phosphorylation of the α-subunit of eukaryotic initiation factor 2 (eIF2α) at a conserved serine residue in the N-terminus has been shown as an important mechanism for the regulation of protein synthesis in mammalian and yeast cells. However, whether the phosphorylation of this residue in plant eIF2α plays a role in regulation of translation remains elusive. Here, we show that the quadruple mutant of SUPPRESSOR OF PHYA-105 family members (SPA1-SPA4) display repressed translation efficiency after light illumination. Moreover, SPA1 directly phosphorylates the eIF2α C-terminus under light conditions. The C-term-phosphorylated eIF2α promotes translation efficiency and photomorphogenesis, whereas the C-term-unphosphorylated eIF2α results in a decreased translation efficiency. We also demonstrate that the phosphorylated eIF2α enhances ternary complex assembly by promoting its affinity to eIF2β and eIF2γ. This study reveals a unique mechanism by which light promotes translation via SPA1-mediated phosphorylation of the C-terminus of eIF2α in plants.
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Affiliation(s)
- Hui-Hsien Chang
- Department of Biochemical Science and Technology, National Taiwan University, Taipei, 10617, Taiwan
| | - Lin-Chen Huang
- Department of Biochemical Science and Technology, National Taiwan University, Taipei, 10617, Taiwan
| | - Karen S Browning
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Enamul Huq
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Mei-Chun Cheng
- Department of Biochemical Science and Technology, National Taiwan University, Taipei, 10617, Taiwan.
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3
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Yuan S, Zhou G, Xu G. Translation machinery: the basis of translational control. J Genet Genomics 2024; 51:367-378. [PMID: 37536497 DOI: 10.1016/j.jgg.2023.07.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/23/2023] [Accepted: 07/23/2023] [Indexed: 08/05/2023]
Abstract
Messenger RNA (mRNA) translation consists of initiation, elongation, termination, and ribosome recycling, carried out by the translation machinery, primarily including tRNAs, ribosomes, and translation factors (TrFs). Translational regulators transduce signals of growth and development, as well as biotic and abiotic stresses, to the translation machinery, where global or selective translational control occurs to modulate mRNA translation efficiency (TrE). As the basis of translational control, the translation machinery directly determines the quality and quantity of newly synthesized peptides and, ultimately, the cellular adaption. Thus, regulating the availability of diverse machinery components is reviewed as the central strategy of translational control. We provide classical signaling pathways (e.g., integrated stress responses) and cellular behaviors (e.g., liquid-liquid phase separation) to exemplify this strategy within different physiological contexts, particularly during host-microbe interactions. With new technologies developed, further understanding this strategy will speed up translational medicine and translational agriculture.
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Affiliation(s)
- Shu Yuan
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China
| | - Guilong Zhou
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China
| | - Guoyong Xu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, Hubei 430072, China; Hubei Hongshan Laboratory, Wuhan, Hubei 430070, China.
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4
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Williams TD, Rousseau A. Translation regulation in response to stress. FEBS J 2024. [PMID: 38308808 DOI: 10.1111/febs.17076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/07/2023] [Accepted: 01/22/2024] [Indexed: 02/05/2024]
Abstract
Cell stresses occur in a wide variety of settings: in disease, during industrial processes, and as part of normal day-to-day rhythms. Adaptation to these stresses requires cells to alter their proteome. Cells modify the proteins they synthesize to aid proteome adaptation. Changes in both mRNA transcription and translation contribute to altered protein synthesis. Here, we discuss the changes in translational mechanisms that occur following the onset of stress, and the impact these have on stress adaptation.
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Affiliation(s)
- Thomas D Williams
- MRC-PPU, School of Life Sciences, University of Dundee, UK
- Sir William Dunn School of Pathology, University of Oxford, UK
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5
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Zhigailov AV, Nizkorodova AS, Sharipov KO, Polimbetova NS, Iskakov BK. Glyphosate treatment mediates the accumulation of small discrete 5'- and 3'-terminal fragments of 18S rRNA in plant cells. Vavilovskii Zhurnal Genet Selektsii 2023; 27:93-98. [PMID: 37063515 PMCID: PMC10090119 DOI: 10.18699/vjgb-23-13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 04/18/2023] Open
Abstract
Under many kinds of stress, eukaryotic cells rapidly decrease the overall translation level of the majority of mRNAs. However, some molecular mechanisms of protein synthesis inhibition like phosphorylation of eukaryotic elongation factor 2 (eEF2), which are known to be functional in animals and yeast, are not implemented in plants. We suggest that there is an alternative mechanism for the inhibition of protein synthesis in plant cells and possibly, in other eukaryotes, which is based on the discrete fragmentation of 18S rRNA molecules within small ribosomal subunits. We identified four stress-induced small RNAs, which are 5'- and 3'-terminal fragments of 18S rRNA. In the present work, we studied the induction of 18S rRNA discrete fragmentation and phosphorylation of the α-subunit of eukaryotic initiation factor 2 (eIF2α) in germinated wheat embryos in the presence of glyphosate, which imitates the condition of amino acid starvation. Using northern and western blotting, we have shown that stress-induced 18S rRNA fragments started to accumulate in wheat embryos at glyphosate concentrations that did not evoke eIF2α phosphorylation. It was also found that cleavage of 18S rRNA near the 5'-terminus began much earlier than eIF2α phosphorylation, which became noticeable only at higher concentration (500 μM) of glyphosate. This result suggests that discrete fragmentation of 18S rRNA may constitute a regulatory mechanism of mRNA translation in response to stress and may occur in plant cells in parallel with and independently of eIF2α phosphorylation. The identified small 5'- and 3'-terminal fragments of 18S rRNA that accumulate during various stresses may serve as stress resistance markers in the breeding of economically important plant crops.
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Affiliation(s)
- A V Zhigailov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry of the Ministry of Science and Higher Education of the Republic of Kazakhstan, Almaty, Kazakhstan
| | - A S Nizkorodova
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry of the Ministry of Science and Higher Education of the Republic of Kazakhstan, Almaty, Kazakhstan
| | - K O Sharipov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry of the Ministry of Science and Higher Education of the Republic of Kazakhstan, Almaty, Kazakhstan
| | - N S Polimbetova
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry of the Ministry of Science and Higher Education of the Republic of Kazakhstan, Almaty, Kazakhstan
| | - B K Iskakov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry of the Ministry of Science and Higher Education of the Republic of Kazakhstan, Almaty, Kazakhstan
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6
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Zhou Y, Niu R, Tang Z, Mou R, Wang Z, Zhu S, Yang H, Ding P, Xu G. Plant HEM1 specifies a condensation domain to control immune gene translation. NATURE PLANTS 2023; 9:289-301. [PMID: 36797349 DOI: 10.1038/s41477-023-01355-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
Translational reprogramming is a fundamental layer of immune regulation, but how such a global regulatory mechanism operates remains largely unknown. Here we perform a genetic screen and identify Arabidopsis HEM1 as a global translational regulator of plant immunity. The loss of HEM1 causes exaggerated cell death to restrict bacterial growth during effector-triggered immunity (ETI). By improving ribosome footprinting, we reveal that the hem1 mutant increases the translation efficiency of pro-death immune genes. We show that HEM1 contains a plant-specific low-complexity domain (LCD) absent from animal homologues. This LCD endows HEM1 with the capability of phase separation in vitro and in vivo. During ETI, HEM1 interacts and condensates with the translation machinery; this activity is promoted by the LCD. CRISPR removal of this LCD causes more ETI cell death. Our results suggest that HEM1 condensation constitutes a brake mechanism of immune activation by controlling the tissue health and disease resistance trade-off during ETI.
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Affiliation(s)
- Yulu Zhou
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, China
| | - Ruixia Niu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, China
| | - Zhijuan Tang
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, China
| | - Rui Mou
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, China
| | - Zhao Wang
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, China
| | - Sitao Zhu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, China
| | - Hongchun Yang
- School of Life Sciences, Wuhan University, Wuhan, China
- Hubei Hongshan Laboratory, Wuhan, China
| | - Pingtao Ding
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands
| | - Guoyong Xu
- State Key Laboratory of Hybrid Rice, Institute for Advanced Studies (IAS), Wuhan University, Wuhan, China.
- Hubei Hongshan Laboratory, Wuhan, China.
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Lokdarshi A, von Arnim AG. Review: Emerging roles of the signaling network of the protein kinase GCN2 in the plant stress response. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 320:111280. [PMID: 35643606 PMCID: PMC9197246 DOI: 10.1016/j.plantsci.2022.111280] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/07/2022] [Accepted: 03/30/2022] [Indexed: 06/15/2023]
Abstract
The pan-eukaryotic protein kinase GCN2 (General Control Nonderepressible2) regulates the translation of mRNAs in response to external and metabolic conditions. Although GCN2 and its substrate, translation initiation factor 2 (eIF2) α, and several partner proteins are substantially conserved in plants, this kinase has assumed novel functions in plants, including in innate immunity and retrograde signaling between the chloroplast and cytosol. How exactly some of the biochemical paradigms of the GCN2 system have diverged in the green plant lineage is only partially resolved. Specifically, conflicting data underscore and cast doubt on whether GCN2 regulates amino acid biosynthesis; also whether phosphorylation of eIF2α can in fact repress global translation or activate mRNA specific translation via upstream open reading frames; and whether GCN2 is controlled in vivo by the level of uncharged tRNA. This review examines the status of research on the eIF2α kinase, GCN2, its function in the response to xenobiotics, pathogens, and abiotic stress conditions, and its rather tenuous role in the translational control of mRNAs.
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Affiliation(s)
- Ansul Lokdarshi
- Department of Biology, Valdosta State University, Valdosta, GA 31698, USA.
| | - Albrecht G von Arnim
- Department of Biochemistry & Cellular and Molecular Biology, The University of Tennessee, Knoxville, TN 37996-1939, USA; UT-ORNL Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN 37996-1939, USA.
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Gong M, Huang T, Li Y, Li J, Tang L, Su E, Zou G, Bao D. Multi-Omics Analysis of Low-Temperature Fruiting Highlights the Promising Cultivation Application of the Nutrients Accumulation in Hypsizygus marmoreus. J Fungi (Basel) 2022; 8:jof8070695. [PMID: 35887452 PMCID: PMC9315786 DOI: 10.3390/jof8070695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 12/10/2022] Open
Abstract
Hypsizygus marmoreus is a representative edible mushroom with low-temperature fruiting after a long postripening (LFLP). Clarifying the mechanism of LFLP and applying a rigorous low-temperature-limited process will optimize the mushroom cultivation process. This study performed an integrative multi-omics analysis of the molecular mechanism of LFLP in combination with genetic, physiological, and cultivation confirmation. The results showed that the amino acid content was increased during LFLP, mainly arginine. pH analysis showed acidification in the postripening stage and alkalization in the substrates of the reproductive growth stage. An enzyme activity test confirmed the increased enzyme activity of arginase and citrate synthase in the postripening stage. Weighted gene coexpression network analysis of the transcriptome and metabolomics indicated that pH variation is correlated mainly with changes in citrate and arginine. Multi-omics reveals a straightforward way of providing enriched materials for amino acid biosynthesis, namely, synergistically elevating citric acid and arginine through enhanced activity of the arginine synthesis branch pathway in the citrate cycle. Our study confirmed that GCN2 mediated metabolic adaptation by enhancing protein translation, highlighting its regulatory role during LFLP. Exogenously added citric acid and arginine shortened the postripening period by 10 days and increased the fruiting body yield by 10.2~15.5%. This research sheds light on the molecular mechanism of LFLP in H. marmoreus and highlights the promising application of nutrient accumulation in high-efficiency cultivation.
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Affiliation(s)
- Ming Gong
- National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (M.G.); (Y.L.); (L.T.)
- Department of Food Science and Technology, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China;
| | - Tianyu Huang
- College of Food Science and Engineering, Jiangsu Ocean University, Lianyungang 222005, China;
| | - Yan Li
- National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (M.G.); (Y.L.); (L.T.)
| | - Jinxin Li
- Research and Development Center, Shanghai Finc Bio-Tech Inc., Shanghai 201401, China;
| | - Lihua Tang
- National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (M.G.); (Y.L.); (L.T.)
| | - Erzheng Su
- Department of Food Science and Technology, College of Light Industry and Food Engineering, Nanjing Forestry University, Nanjing 210037, China;
| | - Gen Zou
- National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (M.G.); (Y.L.); (L.T.)
- Correspondence: (G.Z.); (D.B.)
| | - Dapeng Bao
- National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China; (M.G.); (Y.L.); (L.T.)
- Correspondence: (G.Z.); (D.B.)
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9
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Zhigailov AV, Stanbekova GE, Nizkorodova AS, Galiakparov NN, Gritsenko DA, Polimbetova NS, Halford NG, Iskakov BK. Phosphorylation of the alpha-subunit of plant eukaryotic initiation factor 2 prevents its association with polysomes but does not considerably suppress protein synthesis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2022; 317:111190. [PMID: 35193739 DOI: 10.1016/j.plantsci.2022.111190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/12/2022] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
Phosphorylation of the α-subunit of eukaryotic initiation factor 2 (eIF2α) and subsequent inhibition of protein synthesis is a major survival response to different stresses in animal and yeast cells. However, the role of this regulatory mechanism in plants is not unambiguously established to date. Here we describe a slight reduction of polysome abundance in Nicotiana benthamiana after the transient expression of a cDNA, AteIF2α(S56D), encoding a phosphomimetic form of Arabidopsis thaliana eIF2α. In contrast, the expression of a cDNA, AteIF2α(S56A), that encodes a non-phosphorylatable form of AteIF2α caused slightly elevated polysome formation compared to the control. Recombinant AteIF2α(S56A) was detected in association with 40S ribosomal subunit-containing complexes and also in the polysomal fraction, while recombinant AteIF2α(S56D) was detected mainly in complex with 40S subunits. Intentional phosphorylation of TaeIF2α induced by L-histidinol in a wheat germ (Triticum aestivum) cell-free extract did not reduce the abundance of polysomes. Interestingly, the phosphorylated TaeIF2(αP) was not detected in the polysomal fraction, similar to AteIF2α(S56D) in the in vivo experiment. Using mRNAs with a 'Strepto-tag' in the 3' untranslated region, the 48S pre-initiation complexes isolated from histidinol-treated wheat germ extracts were shown to contain phosphorylated TaeIF2(αP). Thus, the phosphorylation of plant eIF2 does not greatly affect its ability to participate in the initiation of mRNA translation, in contrast to animals and yeast, in which eIF2α phosphorylation results in profound suppression of protein synthesis.
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Affiliation(s)
- Andrey V Zhigailov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Science Committee, Ministry of Education and Science, Almaty, 050012, Kazakhstan.
| | - Gulshan E Stanbekova
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Science Committee, Ministry of Education and Science, Almaty, 050012, Kazakhstan.
| | - Anna S Nizkorodova
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Science Committee, Ministry of Education and Science, Almaty, 050012, Kazakhstan.
| | - Nurbol N Galiakparov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Science Committee, Ministry of Education and Science, Almaty, 050012, Kazakhstan.
| | - Dilyara A Gritsenko
- Institute of Plant Biology and Biotechnology, Science Committee, Ministry of Education and Science, Almaty, 050040, Kazakhstan.
| | - Nailya S Polimbetova
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Science Committee, Ministry of Education and Science, Almaty, 050012, Kazakhstan.
| | - Nigel G Halford
- Plant Sciences Department, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom.
| | - Bulat K Iskakov
- M.A. Aitkhozhin Institute of Molecular Biology and Biochemistry, Science Committee, Ministry of Education and Science, Almaty, 050012, Kazakhstan.
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10
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Castellano MM, Merchante C. Peculiarities of the regulation of translation initiation in plants. CURRENT OPINION IN PLANT BIOLOGY 2021; 63:102073. [PMID: 34186463 DOI: 10.1016/j.pbi.2021.102073] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/21/2021] [Accepted: 05/27/2021] [Indexed: 06/13/2023]
Abstract
Protein synthesis is a fundamental process for life and, as such, plays a crucial role in the adaptation to energy, developmentaland environmental conditions. For these reasons, and despite the general conservation of the eukaryotic translational machinery, it is not surprising that organisms with different lifestyles have evolved distinct mechanisms of regulation to adapt translation initiation to their intrinsic growth and development. Plants have clear peculiarities compared with other eukaryotes that have also extended to translation control. This review describes the plant-specific mechanisms for regulation of translation initiation, with a focus on those that modulate the eIF4F complexes, central translational regulatory hubs in all eukaryotes, and highlights the latest discoveries on the signaling pathways that regulate their constituents and activity.
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Affiliation(s)
- M Mar Castellano
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA, CSIC), Campus Montegancedo UPM, Pozuelo de Alarcón, Madrid, 28223, Spain.
| | - Catharina Merchante
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Campus de Teatinos, Universidad de Málaga, Málaga, 29071, Spain.
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11
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Howell SH. Evolution of the unfolded protein response in plants. PLANT, CELL & ENVIRONMENT 2021; 44:2625-2635. [PMID: 33840122 DOI: 10.1111/pce.14063] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/26/2021] [Accepted: 03/08/2021] [Indexed: 05/23/2023]
Abstract
The unfolded protein response (UPR) in plants is elicited by endoplasmic reticulum stress, which can be brought about by adverse environmental conditions. The response is mediated by a conserved signalling network composed of two branches - one branch involving inositol requiring enzyme1- basic leucine zipper60 (IRE1-bZIP60) signalling pathway and another branch involving the membrane transcription factors, bZIP17 and -28. The UPR has been reported in Chlamydomonas reinhardtii, a unicellular green alga, which lacks some canonical UPR signalling components found in vascular plants, raising the question whether C. reinhardtii uses other means such as oxidative signalling or Regulated IRE1-Dependent Decay to activate the UPR. In vascular plants, IRE1 splices bZIP60 mRNA in response to endoplasmic reticulum stress by cutting at a site in the RNA that is highly conserved in structure and sequence. Monocots have a single IRE1 gene required for viability in rice, while dicots have two IRE1 genes, IRE1a and -b. Brassicas have a third IRE1 gene, IRE1c, which lacks a lumenal domain, but is required in combination with IRE1b for gametogenesis. Vascular and non-vascular plants upregulate a similar set of genes in response to endoplasmic reticulum stress despite differences in the complexity of their UPR signalling networks.
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Affiliation(s)
- Stephen H Howell
- Genetics, Development and Cell Biology Department, Plant Sciences Institute, Iowa State University, 1111 WOI Road, Ames, Iowa, USA
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