| 1. |
- Bentsink, Leónie, et al.
(författare)
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Natural variation for seed dormancy in Arabidopsis is regulated by additive genetic and molecular pathways
- 2010
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : PNAS. - 0027-8424 .- 1091-6490. ; 107:9, s. 4264-4269
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Tidskriftsartikel (refereegranskat)abstract
- Timing of germination is presumably under strong natural selection as it determines the environmental conditions in which a plant germinates and initiates its postembryonic life cycle. To investigate how seed dormancy is controlled, quantitative trait loci (QTL) analyses has been performed in six Arabidopsis thaliana recombinant inbred line populations by analyzing them simultaneously using a mixed model QTL approach. The recombinant inbred line populations were derived from crosses between the reference accession Landsberg erecta (Ler) and accessions from different world regions. In total, 11 delay of germination (DOG) QTL have been identified, and nine of them have been confirmed by near isogenic lines (NILs). The absence of strong epistatic interactions between the different DOG loci suggests that they affect dormancy mainly by distinct genetic pathways. This was confirmed by analyzing the transcriptome of freshly harvested dry seeds of five different DOG NILs. All five DOG NILs showed discernible and different expression patterns compared with the expression of their genetic background Ler. The genes identified in the different DOG NILs represent largely different gene ontology profiles. It is proposed that natural variation for seed dormancy in Arabidopsis is mainly controlled by different additive genetic and molecular pathways rather than epistatic interactions, indicating the involvement of several independent pathways.
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| 2. |
- Gamm, Magdalena, et al.
(författare)
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Increased sucrose levels mediate selective mRNA translation in Arabidopsis
- 2014
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Ingår i: BMC Plant Biology. - : Springer Science and Business Media LLC. - 1471-2229. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Protein synthesis is a highly energy demanding process and is regulated according to cellular energy levels. Light and sugar availability affect mRNA translation in plant cells but the specific roles of these factors remain unclear. In this study, sucrose was applied to Arabidopsis seedlings kept in the light or in the dark, in order to distinguish sucrose and light effects on transcription and translation. These were studied using microarray analysis of steady-state mRNA and mRNA bound to translating ribosomes. Results: Steady-state mRNA levels were affected differently by sucrose in the light and in the dark but general translation increased to a similar extent in both conditions. For a majority of the transcripts changes of the transcript levels were followed by changes in polysomal mRNA levels. However, for 243 mRNAs, a change in polysomal occupancy (defined as polysomal levels related to steady-state levels of the mRNA) was observed after sucrose treatment in the light, but not in the dark condition. Many of these mRNAs are annotated as encoding ribosomal proteins, supporting specific translational regulation of this group of transcripts. Unexpectedly, the numbers of ribosomes bound to each mRNA decreased for mRNAs with increased polysomal occupancy. Conclusions: Our results suggest that sucrose regulate translation of these 243 mRNAs specifically in the light, through a novel regulatory mechanism. Our data shows that increased polysomal occupancy is not necessarily leading to more ribosomes per transcript, suggesting a mechanism of translational induction not solely dependent on increased translation initiation rates.
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| 3. |
- Hanson, Johannes, 1969-, et al.
(författare)
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Sugar perception and signaling : an update
- 2009
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Ingår i: Current opinion in plant biology. - : Elsevier. - 1369-5266 .- 1879-0356. ; 12:5, s. 562-567
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Tidskriftsartikel (refereegranskat)abstract
- Sugars act as potent signaling molecules in plants. Several sugar sensors, including the highly studied glucose sensor HEXOKINASE1 (HXK1), have been identified or proposed. Many additional sensors likely exist, as plants respond to other sugars and sugar metabolites, such as sucrose and trehalose 6-phosphate. Sugar sensing and signaling is a highly complex process resulting in many changes in physiology and development and is integrated with other signaling pathways in plants such as those for inorganic nutrients, hormones, and different stress factors. Importantly, KIN10 and KIN11 protein kinases are central in coordinating several of the responses to sugars and stress. bZIP transcription factors were found to mediate effects of sugar signaling on gene expression and metabolite content.
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| 4. |
- Hanson, Johannes, 1969-, et al.
(författare)
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The sucrose regulated transcription factor bZIP11 affects amino acid metabolism by regulating the expression of ASPARAGINE SYNTHETASE1 and PROLINE DEHYDROGENASE2
- 2008
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Ingår i: The Plant Journal. - : John Wiley & Sons. - 0960-7412 .- 1365-313X. ; 53:6, s. 935-949
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Tidskriftsartikel (refereegranskat)abstract
- Translation of the transcription factor bZIP11 is repressed by sucrose in a process that involves a highly conserved peptide encoded by the 5' leaders of bZIP11 and other plant basic region leucine zipper (bZip) genes. It is likely that a specific signaling pathway operating at physiological sucrose concentrations controls metabolism via a feedback mechanism. In this paper bZIP11 target processes are identified using transiently increased nuclear bZIP11 levels and genome-wide expression analysis. bZIP11 affects the expression of hundreds of genes with proposed functions in biochemical pathways and signal transduction. The expression levels of approximately 80% of the genes tested are not affected by bZIP11 promoter-mediated overexpression of bZIP11. This suggests that <20% of the identified genes appear to be physiologically relevant targets of bZIP11. ASPARAGINE SYNTHETASE1 and PROLINE DEHYDROGENASE2 are among the rapidly activated bZIP11 targets, whose induction is independent of protein translation. Transient expression experiments in Arabidopsis protoplasts show that the bZIP11-dependent activation of the ASPARAGINE SYNTHETASE1 gene is dependent on a G-box element present in the promoter. Increased bZIP11 expression leads to decreased proline and increased phenylalanine levels. A model is proposed in which sugar signals control amino acid levels via the bZIP11 transcription factor.
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| 5. |
- Hummel, Maureen, et al.
(författare)
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Dynamic protein composition of Arabidopsis thaliana cytosolic ribosomes in response to sucrose feeding as revealed by label free MSE proteomics
- 2012
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Ingår i: Proteomics. - : Wiley. - 1615-9853 .- 1615-9861. ; 12:7, s. 1024-1038
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Tidskriftsartikel (refereegranskat)abstract
- Cytosolic ribosomes are among the largest multisubunit cellular complexes. Arabidopsis thaliana ribosomes consist of 79 different ribosomal proteins (r-proteins) that each are encoded by two to six (paralogous) genes. It is unknown whether the paralogs are incorporated into the ribosome and whether the relative incorporation of r-protein paralogs varies in response to environmental cues. Immunopurified ribosomes were isolated from A. thaliana rosette leaves fed with sucrose. Trypsin digested samples were analyzed by qTOF-LC-MS using both MSE and classical MS/MS. Peptide features obtained by using these two methods were identified using MASCOT and Proteinlynx Global Server searching the theoretical sequences of A. thaliana proteins. The A. thaliana genome encodes 237 r-proteins and 69% of these were identified with proteotypic peptides for most of the identified proteins. These r-proteins were identified with average protein sequence coverage of 32% observed by MSE. Interestingly, the analysis shows that the abundance of r-protein paralogs in the ribosome changes in response to sucrose feeding. This is particularly evident for paralogous RPS3aA, RPS5A, RPL8B, and RACK1 proteins. These results show that protein synthesis in the A. thaliana cytosol involves a heterogeneous ribosomal population. The implications of these findings in the regulation of translation are discussed.
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| 6. |
- Hummel, Maureen, et al.
(författare)
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Proteomic LC-MS analysis of Arabidopsis cytosolic ribosomes : Identification of ribosomal protein paralogs and re-annotation of the ribosomal protein genes
- 2015
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Ingår i: Journal of Proteomics. - : Elsevier BV. - 1874-3919 .- 1876-7737. ; 128, s. 436-449
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Tidskriftsartikel (refereegranskat)abstract
- Arabidopsis thaliana cytosolic ribosomes are large complexes containing eighty-one distinct ribosomal proteins (r-proteins), four ribosomal RNAs (rRNA) and a plethora of associated (non-ribosomal) proteins. In plants, r-proteins of cytosolic ribosomes are each encoded by two to seven different expressed and similar genes, forming an r-protein family. Distinctions in the r-protein coding sequences of gene family members are a source of variation between ribosomes. We performed proteomic investigation of actively translating cytosolic ribosomes purified using both immunopurification and a classic sucrose cushion centrifugation-based protocol from plants of different developmental stages. Both 1D and 2D LC MSE with data-independent acquisition as well as conventional data-dependent MS/MS procedures were applied. This approach provided detailed identification of 165 r-protein paralogs with high coverage based on proteotypic peptides. The detected r-proteins were the products of the majority (68%) of the 242 cytosolic r-protein genes encoded by the genome. A total of 70 distinct r-proteins were identified. Based on these results and information from DNA microarray and ribosome footprint profiling studies a re-annotation of Arabidopsis r-proteins and genes is proposed. This compendium of the cytosolic r-protein proteome will serve as a template for future investigations on the dynamic structure and function of plant ribosomes. Biological significance: Translation is one of the most energy demanding processes in a living cell and is therefore carefully regulated. Translational activity is tightly linked to growth control and growth regulating mechanism. Recently established translational profiling technologies, including the profiling of mRNAs associated with polysomes and the mapping of ribosome footprints on mRNAs, have revealed that the expression of gene expression is often fine-tuned by differential translation of gene transcripts. The eukaryotic ribosome, the hub of these important processes, consists of close to eighty different proteins (depending on species) and four large RNAs assembled into two highly conserved subunits. In plants and to lesser extent in yeast the r-proteins are encoded by more than one actively transcribed gene. As r-protein gene paralogs frequently do not encode identical proteins and are regulated by growth conditions and development, in vivo ribosomes are heterogeneous in their protein content The regulatory and physiological importance of this heterogeneity is unknown. Here, an improved annotation of the more than two hundred r-protein genes of Arabidopsis is presented that combines proteomic and advanced mRNA expression data. This proteomic investigation and re-annotation of Arabidopsis ribosomes establish a base for future investigations of translational control in plants.
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| 7. |
- Hummel, Maureen, et al.
(författare)
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Sucrose-mediated translational control
- 2009
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Ingår i: Annals of Botany. - : Oxford University Press. - 0305-7364 .- 1095-8290. ; 104:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Environmental factors greatly impact plant gene expression and concentrations of cellular metabolites such as sugars and amino acids. The changed metabolite concentrations affect the expression of many genes both transcriptionally and post-transcriptionally.RECENT PROGRESS: Sucrose acts as a signalling molecule in the control of translation of the S1 class basic leucine zipper transcription factor (bZIP) genes. In these genes the main bZIP open reading frames (ORFs) are preceded by upstream open reading frames (uORFs). The presence of uORFs generally inhibits translation of the following ORF but can also be instrumental in specific translational control. bZIP11, a member of the S1 class bZIP genes, harbours four uORFs of which uORF2 is required for translational control in response to sucrose concentrations. This uORF encodes the Sucrose Control peptide (SC-peptide), which is evolutionarily conserved among all S1 class bZIP genes in different plant species. Arabidopsis thaliana bZIP11 and related bZIP genes seem to be important regulators of metabolism. These proteins are targets of the Snf1-related protein kinase 1 (SnRK1) KIN10 and KIN11, which are responsive to energy deprivation as well as to various stresses. In response to energy deprivation, ribosomal biogenesis is repressed to preserve cellular function and maintenance. Other key regulators of ribosomal biogenesis such as the protein kinase Target of Rapamycin (TOR) are tightly regulated in response to stress.CONCLUSIONS: Plants use translational control of gene expression to optimize growth and development in response to stress as well as to energy deprivation. This Botanical Briefing discusses the role of sucrose signalling in the translational control of bZIP11 and the regulation of ribosomal biogenesis in response to metabolic changes and stress conditions.
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| 8. |
- Lastdrager, Jeroen, et al.
(författare)
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Sugar signals and the control of plant growth and development
- 2014
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Ingår i: Journal of Experimental Botany. - : Oxford University Press. - 0022-0957 .- 1460-2431. ; 65:3, s. 799-807
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Forskningsöversikt (refereegranskat)abstract
- Sugars are key regulators that control plant growth and development, including biomass accumulation. Major sugar-responsive signalling systems are reviewed, with emphasis on trehalose 6-phosphate, TOR kinase, SnRK1, and the C/S1-bZIP network.Sugars have a central regulatory function in steering plant growth. This review focuses on information presented in the past 2 years on key players in sugar-mediated plant growth regulation, with emphasis on trehalose 6-phosphate, target of rapamycin kinase, and Snf1-related kinase 1 regulatory systems. The regulation of protein synthesis by sugars is fundamental to plant growth control, and recent advances in our understanding of the regulation of translation by sugars will be discussed.
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| 9. |
- Li, Ping, et al.
(författare)
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Fructose sensitivity is suppressed in Arabidopsis by the transcription factor ANAC089 lacking the membrane-bound domain
- 2011
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 108:8, s. 3436-3441
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Tidskriftsartikel (refereegranskat)abstract
- In living organisms sugars not only provide energy and carbon skeletons but also act as evolutionarily conserved signaling molecules. The three major soluble sugars in plants are sucrose, glucose, and fructose. Information on plant glucose and sucrose signaling is available, but to date no fructose-specific signaling pathway has been reported. In this study, sugar repression of seedling development was used to study fructose sensitivity in the Landsberg erecta (Ler)/Cape Verde Islands (Cvi) recombinant inbred line population, and eight fructose-sensing quantitative trait loci (QTLs) (FSQ1-8) were mapped. Among them, FSQ6 was confirmed to be a fructose-specific QTL by analyzing near-isogenic lines in which Cvi genomic fragments were introgressed in the Ler background. These results indicate the existence of a fructose-specific signaling pathway in Arabidopsis. Further analysis demonstrated that the FSQ6-associated fructose-signaling pathway functions independently of the hexokinase1 (HXK1) glucose sensor. Remarkably, fructose-specific FSQ6 downstream signaling interacts with abscisic acid (ABA)- and ethylene-signaling pathways, similar to HXK1-dependent glucose signaling. The Cvi allele of FSQ6 acts as a suppressor of fructose signaling. The FSQ6 gene was identified using map-based cloning approach, and FSQ6 was shown to encode the transcription factor gene Arabidopsis NAC (petunia No apical meristem and Arabidopsis transcription activation factor 1, 2 and Cup-shaped cotyledon 2) domain containing protein 89 (ANAC089). The Cvi allele of FSQ6/ANAC089 is a gain-of-function allele caused by a premature stop in the third exon of the gene. The truncated Cvi FSQ6/ANAC089 protein lacks a membrane association domain that is present in ANAC089 proteins from other Arabidopsis accessions. As a result, Cvi FSQ6/ANAC089 is constitutively active as a transcription factor in the nucleus.
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| 10. |
- Ma, Jingkun, et al.
(författare)
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The sucrose-regulated Arabidopsis transcription factor bZIP11 reprograms metabolism and regulates trehalose metabolism
- 2011
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 191:3, s. 733-745
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Tidskriftsartikel (refereegranskat)abstract
- • The Arabidopsis basic region-leucine zipper transcription factor 11 (bZIP11) is known to be repressed by sucrose through a translational inhibition mechanism that requires the conserved sucrose control peptide encoded by the mRNA leader. The function of bZIP11 has been investigated in over-expression studies, and bZIP11 has been found to inhibit plant growth. The addition of sugar does not rescue the growth inhibition phenotype. Here, the function of the bZIP11 transcription factor was investigated. • The mechanism by which bZIP11 regulates growth was studied using large-scale and dedicated metabolic analysis, biochemical assays and molecular studies. • bZIP11 induction results in a reprogramming of metabolism and activation of genes involved in the metabolism of trehalose and other minor carbohydrates such as myo-inositol and raffinose. bZIP11 induction leads to reduced contents of the prominent growth regulatory molecule trehalose 6-phosphate (T6P). • The metabolic changes detected mimic in part those observed in carbon-starved plants. It is proposed that bZIP11 is a powerful regulator of carbohydrate metabolism that functions in a growth regulatory network that includes T6P and the sucrose non-fermenting-1 related protein kinase 1 (SnRK1).
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| 11. |
- Prior, Matthew J., et al.
(författare)
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Arabidopsis bZIP11 Is a Susceptibility Factor during Pseudomonas syringae Infection
- 2021
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Ingår i: Molecular Plant-Microbe Interactions. - : American Phytopathological Society. - 0894-0282 .- 1943-7706. ; 34:4, s. 439-447
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Tidskriftsartikel (refereegranskat)abstract
- The induction of plant nutrient secretion systems is critical for successful pathogen infection. Some bacterial pathogens (e.g., Xanthomonas spp.) use transcription activator-like (TAL) effectors to induce transcription of SWEET sucrose efflux transporters. Pseudomonas syringae pv. tomato strain DC3000 lacks TAL effectors yet is able to induce multiple SWEETs in Arabidopsis thaliana by unknown mechanisms. Because bacteria require other nutrients in addition to sugars for efficient reproduction, we hypothesized that Pseudomonas spp. may depend on host transcription factors involved in secretory programs to increase access to essential nutrients. Bioinformatic analyses identified the Arabidopsis basic-leucine zipper transcription factor bZIP11 as a potential regulator of nutrient transporters, including SWEETs and UmamiT amino acid transporters. Inducible downregulation of bZIP11 expression in Arabidopsis resulted in reduced growth of P. syringae pv. tomato strain DC3000, whereas inducible overexpression of bZIP11 resulted in increased bacterial growth, supporting the hypothesis that bZIP11-regulated transcription programs are essential for maximal pathogen titer in leaves. Our data are consistent with a model in which a pathogen alters host transcription factor expression upstream of secretory transcription networks to promote nutrient efflux from host cells.
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| 12. |
- Rahmani, Fatemeh, et al.
(författare)
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Sucrose control of translation mediated by an upstream open reading frame-encoded peptide
- 2009
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Ingår i: Plant Physiology. - : ASPB PUBLICATIONS. - 0032-0889 .- 1532-2548. ; 150:3, s. 1356-1367
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Tidskriftsartikel (refereegranskat)abstract
- Regulation of gene expression through translational control is common in many organisms. The Arabidopsis (Arabidopsis thaliana) transcription factor bZIP11 is translational repressed in response to sucrose (Suc), resulting in Suc-regulated changes in amino acid metabolism. The 5' leader of the bZIP11 mRNA harbors several upstream open reading frames (uORFs), of which the second uORF is well conserved among bZIP11 homologous genes. The uORF2 element encodes a Suc control peptide (SC-peptide) of 28 residues that is sufficient for imposing Suc-induced repression of translation (SIRT) on a heterologous mRNA. Detailed analysis of the SC-peptide suggests that it functions as an attenuator peptide. Results suggest that the SC-peptide inhibits bZIP11 translation in response to high Suc levels by stalling the ribosome on the mRNA. The conserved noncanonical AUG contexts of bZIP11 uORFs allow inefficient translational initiation of the uORF, resulting in translation initiation of the scanning ribosome at the AUG codon of the bZIP11 main ORF. The results presented show that Suc-dependent signaling mediates differential translation of mRNAs containing SC-peptides encoding uORFs.
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| 13. |
- Smeekens, Sjef, et al.
(författare)
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Sugar signals and molecular networks controlling plant growth
- 2010
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Ingår i: Current opinion in plant biology. - : Elsevier. - 1369-5266 .- 1879-0356. ; 13:3, s. 274-279
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, several regulatory systems that link carbon nutrient status to plant growth and development have emerged. In this paper, we discuss the growth promoting functions of the hexokinase (HXK) glucose sensor, the trehalose 6-phosphate (T6P) signal and the Target of Rapamycin (TOR) kinase pathway, and the growth inhibitory function of the SNF1-related Protein Kinase1 (SnRK1) and the C/S1 bZIP transcription factor network. It is crucial that these systems interact closely in regulating growth and in several cases crosstalk has been demonstrated. Importantly, these nutrient controlled systems must interact with other growth regulatory pathways.
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| 14. |
- van der Horst, Sjors, et al.
(författare)
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Metabolite Control of Translation by Conserved Peptide uORFs : The Ribosome as a Metabolite Multisensor
- 2020
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Ingår i: Plant Physiology. - Rockville : American Society for Plant Biologists. - 0032-0889 .- 1532-2548. ; 182:1, s. 110-122
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Tidskriftsartikel (refereegranskat)abstract
- The regulation of gene expression is intensely investigated in diverse biological systems. Gene expression involves RNA transcription, RNA splicing, RNA stability, translation, posttranslational modification, and protein stability. Particular attention has been given to mRNA levels due to advances in microarray analysis and RNA-sequencing techniques. However, transcript levels do not necessarily correlate with protein levels or functionality (Conrads et al., 2005; Gibon et al., 2006; Bianchini et al., 2008), and complex layers of posttranscriptional regulation have been uncovered, foremost mRNA translation. Translation can be regulated both globally and in a transcript-specific manner. Examples of global mRNA translational regulation include availability of ribosomes and translation initiation, elongation, and termination factors. In transcript-specific translational regulation, individual mRNA species or mRNA groups are selectively translated. For example, mRNAs can be sequestered in stress granules, removing them from the translatable mRNA pool (Chantarachot and BaileySerres, 2018). mRNA sequence or structural features can affect translatability directly or indirectly, the latter via small RNAs or mRNA-binding proteins (for review, see Merchante et al., 2017). Upstream open reading frames (uORFs) have been shown to participate in both global and transcript-specific regulation (von Arnim et al., 2014). Here, recent advances in translation regulation by uORFs are discussed, focusing on uORFs encoding sequence-conserved peptides (CPuORFs).
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| 15. |
- van der Horst, Sjors, et al.
(författare)
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Novel pipeline identifies new upstream ORFs and non-AUG initiating main ORFs with conserved amino acid sequences in the 5 ' leader of mRNAs in Arabidopsis thaliana
- 2019
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Ingår i: RNA. - : Cold Spring Harbor Laboratory Press (CSHL). - 1355-8382 .- 1469-9001. ; 25:3, s. 292-304
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Tidskriftsartikel (refereegranskat)abstract
- Eukaryotic mRNAs contain a 5' leader sequence preceding the main open reading frame (mORF) and, depending on the species, 20%-50% of eukaryotic mRNAs harbor an upstream ORF (uORF) in the 5' leader. An unknown fraction of these uORFs encode sequence conserved peptides (conserved peptide uORFs, CPuORFs). Experimentally validated CPuORFs demonstrated to regulate the translation of downstream mORFs often do so in a metabolite concentration-dependent manner. Previous research has shown that most CPuORFs possess a start codon context suboptimal for translation initiation, which turns out to be favorable for translational regulation. The suboptimal initiation context may even include non-AUG start codons, which makes CPuORFs hard to predict. For this reason, we developed a novel pipeline to identify CPuORFs unbiased of start codon using well-annotated sequence data from 31 eudicot plant species and rice. Our new pipeline was able to identify 29 novel Arabidopsis thaliana (Arabidopsis) CPuORFs, conserved across a wide variety of eudicot species of which 15 do not initiate with an AUG start codon. In addition to CPuORFs, the pipeline was able to find 14 conserved coding regions directly upstream and in frame with the mORF, which likely initiate translation on a non-AUG start codon. Altogether, our pipeline identified highly conserved coding regions in the 5' leaders of Arabidopsis transcripts, including in genes with proven functional importance such as LHY, a key regulator of the circadian clock, and the RAPTOR1 subunit of the target of rapamycin (TOR) kinase.
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| 16. |
- Weltmeier, Fridtjof, et al.
(författare)
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Expression patterns within the Arabidopsis C/S1 bZIP transcription factor network : availability of heterodimerization partners controls gene expression during stress response and development.
- 2009
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Ingår i: Plant Molecular Biology. - : Springer. - 0167-4412 .- 1573-5028. ; 69:1-2, s. 107-119
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Tidskriftsartikel (refereegranskat)abstract
- Members of the Arabidopsis group C/S1 basic leucine zipper (bZIP) transcription factor (TF) network are proposed to implement transcriptional reprogramming of plant growth in response to energy deprivation and environmental stresses. The four group C and five group S1 members form specific heterodimers and are, therefore, considered to cooperate functionally. For example, the interplay of C/S1 bZIP TFs in regulating seed maturation genes was analyzed by expression studies and target gene regulation in both protoplasts and transgenic plants. The abundance of the heterodimerization partners significantly affects target gene transcription. Therefore, a detailed analysis of the developmental and stress related expression patterns was performed by comparing promoter: GUS and transcription data. The idea that the C/S1 network plays a role in the allocation of nutrients is supported by the defined and partially overlapping expression patterns in sink leaves, seeds and anthers. Accordingly, metabolic signals strongly affect bZIP expression on the transcriptional and/or post-transcriptional level. Sucrose induced repression of translation (SIRT) was demonstrated for all group S1 bZIPs. In particular, transcription of group S1 genes strongly responds to various abiotic stresses, such as salt (AtbZIP1) or cold (AtbZIP44). In summary, heterodimerization and expression data provide a basic framework to further determine the functional impact of the C/S1 network in regulating the plant energy balance and nutrient allocation.
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| 17. |
- Wind, Julia J., et al.
(författare)
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ABI4 : versatile activator and repressor
- 2013
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Ingår i: Trends in Plant Science. - : Elsevier BV. - 1360-1385 .- 1878-4372. ; 18:3, s. 125-132
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Tidskriftsartikel (refereegranskat)abstract
- The ABSCISIC ACID INSENSITIVE4 (ABI4) gene was discovered to be an abscisic acid (ABA) signaling responsive transcription factor active during seed germination. The evolutionary history of the ABI4 gene supports its role as an ABA signaling intermediate in land plants. Investigating the ABI4 protein-cis element interaction supports the proposal that ABI4 binding to its known CE1 cis-element competes with transcription factor binding to the overlapping G-Box element. Recent publications report on ABI4 as a regulatory factor in diverse processes. In developing seedlings, ABI4 mediates sugar signaling, lipid breakdown, and plastid-to-nucleus signaling. Moreover, ABI4 is a regulator of rosette growth, redox signaling, cell wall metabolism and the effect of nitrate on lateral root development.
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| 18. |
- Wind, Julia, et al.
(författare)
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Sucrose : metabolite and signaling molecule
- 2010
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Ingår i: Phytochemistry. - : Elsevier. - 0031-9422 .- 1873-3700. ; 71:14-15, s. 1610-1614
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Tidskriftsartikel (refereegranskat)abstract
- Sucrose is a molecule that is synthesized only by oxygenic photosynthetic organisms. In plants, sucrose is synthesized in source tissues and then can be transported to sink tissues, where it is utilized or stored. Interestingly, sucrose is both a metabolite and a signaling molecule. Manipulating the rate of the synthesis, transport or degradation of sucrose affects plant growth, development and physiology. Altered sucrose levels changes the quantity of sucrose derived metabolites and sucrose-specific signaling. In this paper, these changes are summarized. Better understanding of sucrose metabolism and sucrose sensing systems in plants will lead to opportunities to adapt plant metabolism and growth.
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