Spliceosomal complex components are critical for the adjusting the C:N balance during high-light acclimation
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ABSTRACT:
PROVIDER: PRJNA992550 | ENA |
REPOSITORIES: ENA
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Project description:Plant acclimation to an ever-changing environment is decisive for growth, reproduction and survival. Light availability, as one crucial factor for plant growth, limits biomass production on both ends of the intensity spectrum, and a sophisticated light acclimation response evolved to counteract drawbacks from low and high light (HL) intensities in nature. Among others, adjustment of plant metabolism is central to HL acclimation and accumulation of photoprotective and antioxidative anthocyanins is commonly observed. Despite a good understanding of the biosynthesis, mechanisms and factors regulating anthocyanin accumulation and the associated HL acclimation response are less clear. Two Arabidopsis mutants of spliceosomal complex components exhibiting a pronounced anthocyanin overaccumulation in HL were isolated from a forward genetic screen aiming to isolate new factors crucial for plant acclimation. Time-resolved physiological, transcriptome and metabolome analysis within the first hours of HL exposure revealed a vital function of the spliceosomal complex components for rapidly adjusting gene expression and metabolism. More precisely, deficiency of INCREASED LEVEL OF POLPLOIDY1 (ILP1), its interaction partner NTC-RELATED PROTEIN 1 (NTR1), and PLEIOTROPIC REGULATORY LOCUS 1 (PRL1) resulted in a marked overaccumulation of carbohydrates and regulatory sugar phosphates and strongly diminished amino acid biosynthesis, one major sink for carbon blocks and nitrogen in HL. However, ilp1, ntr1 and prl1 mutants, which showed symptoms of nitrogen deficiency, were not affected in N assimilation but showed a limitation in the consumption of glutamate as the primary amino group donor for stimulated amino acid biosynthesis in HL. The comprehensive analysis revealed a critical function of the spliceosome in the conditional regulation of the C:N balance and the accumulation of protective compounds during HL acclimation. The importance of gene expression, metabolic regulation, and re-direction of carbon towards anthocyanin biosynthesis for HL acclimation is discussed.
2024-12-31 | GSE236872 | GEO
Project description:Appropriate expression of most eukaryotic genes requires the removal of introns from their pre-messenger RNAs (pre-mRNAs), a process catalyzed by the spliceosome. In higher eukaryotes a large family of auxiliary factors known as SR proteins can improve the splicing efficiency of transcripts containing suboptimal splice sites by interacting with distinct sequences present in those pre-mRNAs. The yeast Saccharomyces cerevisiae lacks functional equivalents of most of these factors; thus, it has been unclear whether the spliceosome could effectively distinguish among transcripts. To address this question, we have used a microarray-based approach to examine the effects of mutations in 18 highly conserved core components of the spliceosomal machinery. The kinetic profiles reveal clear differences in the splicing defects of particular pre-mRNA substrates. Most notably, the behaviors of ribosomal protein gene transcripts are generally distinct from other intron-containing transcripts in response to several spliceosomal mutations. However, dramatically different behaviors can be seen for some pairs of transcripts encoding ribosomal protein gene paralogs, suggesting that the spliceosome can readily distinguish between otherwise highly similar pre-mRNAs. The ability of the spliceosome to distinguish among its different substrates may therefore offer an important opportunity for yeast to regulate gene expression in a transcript-dependent fashion. Given the high level of conservation of core spliceosomal components across eukaryotes, we expect that these results will significantly impact our understanding of how regulated splicing is controlled in higher eukaryotes as well. Keywords: time course, splicing mutant, splicing-specific microarray
2007-04-04 | GSE7419 | GEO
Project description:Therapy-induced Secretion of Spliceosomal Components Mediates Pro-Survival Crosstalk Between Ovarian Cancer Cells
| PRJNA1010733 | ENA
Project description:Photosystem II (PSII) is the most thermally sensitive component of photosynthesis. Thermal acclimation of this complex activity is likely to be critically important to the ability of photosynthetic organisms to tolerate temperature changes in the environment. We have analysed gene expression using whole-genome microarrays and monitored alterations in physiology during acclimation of PSII to elevated growth temperature in Synechocystis sp. PCC 6803. PSII acclimation is complete within 480 minutes of exposure to elevated temperature and is associated with a highly dynamic transcriptional response. 176 genes were identified and classified into seven distinct response profile groups. Response profiles suggest the existence of an early transient phase and a sustained phase to the acclimation response. The early phase was characterised by induction of general stress response genes, including heat shock proteins, which are likely to influence PSII thermal stability. The sustained phase consisted of acclimation-specific alterations that are involved in other cellular processes. Sustained responses included genes involved in phycobillisome structure and modification, photosynthesis, respiration, lipid metabolism and motility. Approximately 60% of genes with sustained altered expression levels have no known function. The potential role of differentially expressed genes in thermotolerance and acclimation is discussed. We have characterised the acclimation physiology of selected gene ‘knockouts’ to elucidate possible gene function in the response. All mutants show lower PSII rates under normal growth conditions. Basal PSII thermotolerance was affected by mutations in clpB1, cpcC2, hspA, htpG and slr1674. Final PSII thermotolerance was affected by mutations in cpcC2, hik34, hspA and hypA1, suggesting that these gene products play roles in long-term thermal acclimation of PSII.
2010-04-09 | GSE21133 | GEO
Project description:The acclimation of plants to environmental factors (light/temperature/nutrient availability) plays a crucial role in determining their tolerance to stress their ability to compete with other plants and the efficiency with which external inputs are used for growth and productivity. Some of the clearest responses involve the major modifications in the composition of the photosynthetic apparatus in response to light intensity. Photosynthetic acclimation. The acclimation response involves changes in the abundance of a large number of proteins in different cell compartments occurring at different intensity thresholds. The signal transduction chain is complex and involves crosstalk between redox control and other pathways that control photosynthetic gene expression but is poorly understood. Over the past 7 years we have laid the foundations for a molecular genetic approach by characterising the responses of Arabidopsis thaliana to growth in and transfer between high and low light conditions(1-6). Arabidopsis exhibits all the key features of photosynthetic acclimation: changes in maximum photosynthetic rate in leaf structure and in the levels of light-harvesting complexes photosystems and enzymes of carbon metabolism. Method: Samples A-1, A-2 and A-3 were grown at a light intensity of 400 umol.m-2.s-1 until rosette growth was complete. Plants for samples A-2 and A-3 were then transferred to 100 umol.m-2.s-1. Samples A-4, A-5 and A-6 were grown at 100umol.m-2.s-1 until rosette growth was complete, when plants for samples A-5 and A-6 were transferred to 400 umol.m-2.s-1. Samples were taken 24 hours after transfer to the different light intensity and samples A-3 and A-6 were taken 72 hours after transfer. Keywords: Photosynthesis
2007-01-22 | GSE6163 | GEO
Project description:Earlier findings indicated that light plays a critical role in the development of frost tolerance in winter cereals. However, the exact mechanism is still poorly understood. In the present work the effects of light during the cold acclimation period were studied in chilling-sensitive maize plants. The results show that although exposure to relatively high light intensities during cold acclimation at 15 °C causes various stress symptoms, it enhances the effectiveness of acclimation to chilling conditions (5 °C in the light). Interestingly, certain stress responses were light-dependent not only in the leaves, but also in the roots. A microarray study was also conducted to achieve a better understanding of the interaction of low temperature and light intensity during the cold hardening period. Numerous genes significantly differentially expressed were observed in almost all assimilation and metabolic pathways. Acclimation at moderately low temperature and low light intensity reduced the level of soluble sugars, while chilling increased it. Greater accumulation during hardening was detected at relatively high light intensity. It seems that the photoinhibition induced by low temperature is a necessary evil for cold acclimation processes in plants.
2020-12-31 | GSE107913 | GEO
Project description:[SHAPE-MaP_4_mM] U1 snRNP regulates recruitment of early spliceosomal components by disrupting SRSF1-pre-mRNA interactions
| PRJNA779796 | ENA
Project description:[RNP-MaP] U1 snRNP regulates recruitment of early spliceosomal components by disrupting SRSF1-pre-mRNA interactions
| PRJNA779795 | ENA
Project description:[SHAPE-MaP_10_mM] U1 snRNP regulates recruitment of early spliceosomal components by disrupting SRSF1-pre-mRNA interactions
| PRJNA837264 | ENA
Project description:Ascorbate (vitamin C) is an important antioxidant in leaves with multiple functions in photosynthesis and its levels are tightly regulated by light quality. The majority of work to date has focussed on regulation of ascorbate levels via biosynthesis. However, the pathway of ascorbate degradation, which is localised in the apoplast may additionally play a significant role. The degradative pathway begins with ascorbate oxidation by the enzyme ascorbate oxidase (AO) and hence we have examined the impact of manipulation of ascorbate oxidase activity on the content of ascorbate and the acclimation of photosynthesis to changing light levels. Leaf ascorbate content was highly light dependent in Nicotiana tobaccum being double in high compared with low light conditions. In contrast ascorbate oxidase activity was not altered by changing light levels. Transgenic tobacco lines with reduced or enhanced AO activity exhibited no morphological phenotype and photosynthesis under high light was similarly impaired irrespective of the measured AO activity. However further investigation between AO activity and leaf acclimation to changing light intensity revealed a suite of metabolic and transcriptome changes indicating a role for the apoplastic ascorbate pool in chloroplast to nucleus communication. In all genotypes, transcripts associated with ascorbate synthesis and recycling were less abundant following transition from high to low light. However transcripts associated with glutathione recycling, light harvesting, reaction centre function and the Calvin cycle were all increased in abundance. Following the transition from high to low light increases in leaf threonate, an ascorbate degradation product, were proportional to AO activity. A number of chloroplast synthesised amino acids were significantly increased both during high light and following transfer back to LL for 12 h. Similarly, several primary carbohydrates and TCA intermediates were significantly enhanced following high light treatment. In addition to light effects, AO activity had a significant impact on ï¢-alanine, aspartate and threonine. Intriguingly, a large number of fatty acids were reduced in antisense AO and wild-type plants immediately after high light stress however the content of these compounds were significantly increased in overexpressing sense lines. We conclude that AO mediated turnover plays an important role in adjusting cellular ascorbate content to photosynthetic need in a fluctuating light environment and that light mediated signals rapidly adjust that the apoplastic ascorbate pool.
2017-03-01 | E-MTAB-4816 | biostudies-arrayexpress