scholarly journals Arabidopsis thaliana EARLY RESPONSIVE TO DEHYDRATION 7 Localizes to Lipid Droplets via Its Senescence Domain

2021 ◽  
Vol 12 ◽  
Author(s):  
Nathan M. Doner ◽  
Damien Seay ◽  
Marina Mehling ◽  
Siqi Sun ◽  
Satinder K. Gidda ◽  
...  
Keyword(s):  
Stress Responses ◽  
Mammalian Cells ◽  
Lipid Droplets ◽  
Plant Stress ◽  
Plant Cells ◽  
Normal Growth ◽  
Cell Types ◽  
Growth Conditions ◽  
Functional Aspects ◽  
Necessary And Sufficient

Lipid droplets (LDs) are neutral-lipid-containing organelles found in all kingdoms of life and are coated with proteins that carry out a vast array of functions. Compared to mammals and yeast, relatively few LD proteins have been identified in plants, particularly those associated with LDs in vegetative (non-seed) cell types. Thus, to better understand the cellular roles of LDs in plants, a more comprehensive inventory and characterization of LD proteins is required. Here, we performed a proteomics analysis of LDs isolated from drought-stressed Arabidopsis leaves and identified EARLY RESPONSIVE TO DEHYDRATION 7 (ERD7) as a putative LD protein. mCherry-tagged ERD7 localized to both LDs and the cytosol when ectopically expressed in plant cells, and the protein’s C-terminal senescence domain (SD) was both necessary and sufficient for LD targeting. Phylogenetic analysis revealed that ERD7 belongs to a six-member family in Arabidopsis that, along with homologs in other plant species, is separated into two distinct subfamilies. Notably, the SDs of proteins from each subfamily conferred targeting to either LDs or mitochondria. Further, the SD from the ERD7 homolog in humans, spartin, localized to LDs in plant cells, similar to its localization in mammals; although, in mammalian cells, spartin also conditionally localizes to other subcellular compartments, including mitochondria. Disruption of ERD7 gene expression in Arabidopsis revealed no obvious changes in LD numbers or morphology under normal growth conditions, although this does not preclude a role for ERD7 in stress-induced LD dynamics. Consistent with this possibility, a yeast two-hybrid screen using ERD7 as bait identified numerous proteins involved in stress responses, including some that have been identified in other LD proteomes. Collectively, these observations provide new insight to ERD7 and the SD-containing family of proteins in plants and suggest that ERD7 may be involved in functional aspects of plant stress response that also include localization to the LD surface.

scholarly journals Versatile Physiological Functions of Plant GSK3-Like Kinases

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 697
Author(s):  
Juan Mao ◽  
Wenxin Li ◽  
Jing Liu ◽  
Jianming Li
Keyword(s):  
Stress Responses ◽  
Glycogen Synthase ◽  
Plant Stress ◽  
Normal Growth ◽  
Growth Conditions ◽  
Genetic Studies ◽  
Physiological Functions ◽  
Environmental Signals ◽  
Plant Stress Responses ◽  
Diverse Plant

The plant glycogen synthase kinase 3 (GSK3)-like kinases are highly conserved protein serine/threonine kinases that are grouped into four subfamilies. Similar to their mammalian homologs, these kinases are constitutively active under normal growth conditions but become inactivated in response to diverse developmental and environmental signals. Since their initial discoveries in the early 1990s, many biochemical and genetic studies were performed to investigate their physiological functions in various plant species. These studies have demonstrated that the plant GSK3-like kinases are multifunctional kinases involved not only in a wide variety of plant growth and developmental processes but also in diverse plant stress responses. Here we summarize our current understanding of the versatile physiological functions of the plant GSK3-like kinases along with their confirmed and potential substrates.

scholarly journals Identification of Key Genes in ‘Luang Pratahn’, Thai Salt-Tolerant Rice, Based on Time-Course Data and Weighted Co-expression Networks

2021 ◽  
Vol 12 ◽  
Author(s):  
Pajaree Sonsungsan ◽  
Pheerawat Chantanakool ◽  
Apichat Suratanee ◽  
Teerapong Buaboocha ◽  
Luca Comai ◽  
...  
Keyword(s):  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Time Course ◽  
Rice Variety ◽  
Enrichment Analysis ◽  
Normal Growth ◽  
Growth Conditions ◽  
Pathway Enrichment Analysis ◽  
Key Genes

Salinity is an important environmental factor causing a negative effect on rice production. To prevent salinity effects on rice yields, genetic diversity concerning salt tolerance must be evaluated. In this study, we investigated the salinity responses of rice (Oryza sativa) to determine the critical genes. The transcriptomes of ‘Luang Pratahn’ rice, a local Thai rice variety with high salt tolerance, were used as a model for analyzing and identifying the key genes responsible for salt-stress tolerance. Based on 3' Tag-Seq data from the time course of salt-stress treatment, weighted gene co-expression network analysis was used to identify key genes in gene modules. We obtained 1,386 significantly differentially expressed genes in eight modules. Among them, six modules indicated a significant correlation within 6, 12, or 48h after salt stress. Functional and pathway enrichment analysis was performed on the co-expressed genes of interesting modules to reveal which genes were mainly enriched within important functions for salt-stress responses. To identify the key genes in salt-stress responses, we considered the two-state co-expression networks, normal growth conditions, and salt stress to investigate which genes were less important in a normal situation but gained more impact under stress. We identified key genes for the response to biotic and abiotic stimuli and tolerance to salt stress. Thus, these novel genes may play important roles in salinity tolerance and serve as potential biomarkers to improve salt tolerance cultivars.

scholarly journals Broad and Complex Roles of NBR1-Mediated Selective Autophagy in Plant Stress Responses

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2562
Author(s):  
Yan Zhang ◽  
Zhixiang Chen
Keyword(s):  
Stress Responses ◽  
Mammalian Cells ◽  
Plant Stress ◽  
Protein Aggregates ◽  
Degradation Pathway ◽  
Plant Responses ◽  
Stress Memory ◽  
Selective Autophagy ◽  
Cargo Proteins ◽  
Plant Stress Responses

Selective autophagy is a highly regulated degradation pathway for the removal of specific damaged or unwanted cellular components and organelles such as protein aggregates. Cargo selectivity in selective autophagy relies on the action of cargo receptors and adaptors. In mammalian cells, two structurally related proteins p62 and NBR1 act as cargo receptors for selective autophagy of ubiquitinated proteins including aggregation-prone proteins in aggrephagy. Plant NBR1 is the structural and functional homolog of mammalian p62 and NBR1. Since its first reports almost ten years ago, plant NBR1 has been well established to function as a cargo receptor for selective autophagy of stress-induced protein aggregates and play an important role in plant responses to a broad spectrum of stress conditions including heat, salt and drought. Over the past several years, important progress has been made in the discovery of specific cargo proteins of plant NBR1 and their roles in the regulation of plant heat stress memory, plant-viral interaction and special protein secretion. There is also new evidence for a possible role of NBR1 in stress-induced pexophagy, sulfur nutrient responses and abscisic acid signaling. In this review, we summarize these progresses and discuss the potential significance of NBR1-mediated selective autophagy in broad plant responses to both biotic and abiotic stresses.

Drought and cold stress responses in orostachys spinosa L.

2018 ◽  
Vol 22 (03) ◽  
pp. 77-81
Author(s):  
Otgonsuvd B ◽  
Ouyngerel Sh ◽  
Altanzaya T
Keyword(s):  
Electron Transfer ◽  
Drought Stress ◽  
Stress Responses ◽  
Photochemical Efficiency ◽  
Normal Growth ◽  
Growth Conditions ◽  
Photochemical Efficiency Of Psii ◽  
Succulent Plant ◽  
Drought Conditions ◽  
Long Time

Orostachys spinosa L. is a succulent plant native to predominantly East Asia. The objective of this study was to identify physiological and morphological responses of O. spinosa L. species to cold, drought stress in laboratory conditions. Exposure of plants to a drought stress for 28 days slightly decreased the photochemical efficiency of PSII and the Fv/Fm values were 10-15% lower (0.75±0.01) compared with the control plants (0.85±0.01). For cold treatments, plants were exposed to 4°C for 60 days and for recovery transferred to normal growth conditions for 14 days. Fv/Fm photochemical efficiency of PSII can be used to monitor PSII photoinhibition. This parameter describes the efficiency of the electron transfer within PSII.The results of this study demonstrated that O. spinosa L. plants were better adapted to cold and drought conditions as they showed less visible symptoms and highest Fv/Fm levels at the long time chilling and drought stress.

scholarly journals Arabidopsis Ubiquitin-Conjugating Enzymes UBC7, UBC13, and UBC14 Are Required in Plant Responses to Multiple Stress Conditions

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 723
Author(s):  
Hui Feng ◽  
Sheng Wang ◽  
Dengfeng Dong ◽  
Ruiyang Zhou ◽  
Hong Wang
Keyword(s):  
Stress Responses ◽  
Plant Stress ◽  
Normal Growth ◽  
Stress Sensitivity ◽  
Stress Conditions ◽  
Plant Responses ◽  
Multiple Stress ◽  
Protein Ubiquitination ◽  
E2 Enzymes ◽  
Erad Pathway

Protein ubiquitination plays important roles in plants, including stress responses. The ubiquitin (Ub) E2 enzymes are required in the transfer of Ub to a substrate and are also important in determining the Ub-chain linkage specificity. However, for many of the 37 E2 genes in Arabidopsis thaliana, there is currently little or no understanding of their functions. In this study, we investigated three members of an E2 subfamily. The single, double, and triple mutants of UBC7, UBC13, and UBC14 did not show any phenotypic changes under normal conditions, but were more sensitive than the wild-type (WT) plants to multiple stress conditions, suggesting that the three genes are not critical for normal growth, but required in plant stress responses. The severity of the phenotypes increased from single to triple mutants, suggesting that the functions of the three genes are not completely redundant. The three E2s are closely related to the yeast Ubc7 and its homologs in animals and human, which are an important component of the endoplasmic reticulum (ER)-associated degradation (ERAD) pathway. The stress sensitivity phenotypes of the mutants and shared evolutionary root with the Ubc7 homologs in yeast and metazoans suggest that UBC7, UBC13, and UBC14 may function in the plant ERAD pathway.

scholarly journals Poly(ADP-Ribose) Polymerases in Host-Pathogen Interactions, Inflammation, and Immunity

2018 ◽  
Vol 83 (1) ◽  
Author(s):  
Pamlea N. Brady ◽  
Anupam Goel ◽  
Margaret A. Johnson
Keyword(s):  
Stress Responses ◽  
Mammalian Cells ◽  
Inflammatory Responses ◽  
Plant Stress ◽  
Parp Inhibitors ◽  
Host Responses ◽  
Antiviral Protein ◽  
Host Pathogen Interactions ◽  
Host Pathogen ◽  
Plant Stress Responses

SUMMARYThe literature review presented here details recent research involving members of the poly(ADP-ribose) polymerase (PARP) family of proteins. Among the 17 recognized members of the family, the human enzyme PARP1 is the most extensively studied, resulting in a number of known biological and metabolic roles. This review is focused on the roles played by PARP enzymes in host-pathogen interactions and in diseases with an associated inflammatory response. In mammalian cells, several PARPs have specific roles in the antiviral response; this is perhaps best illustrated by PARP13, also termed the zinc finger antiviral protein (ZAP). Plant stress responses and immunity are also regulated by poly(ADP-ribosyl)ation. PARPs promote inflammatory responses by stimulating proinflammatory signal transduction pathways that lead to the expression of cytokines and cell adhesion molecules. Hence, PARP inhibitors show promise in the treatment of inflammatory disorders and conditions with an inflammatory component, such as diabetes, arthritis, and stroke. These functions are correlated with the biophysical characteristics of PARP family enzymes. This work is important in providing a comprehensive understanding of the molecular basis of pathogenesis and host responses, as well as in the identification of inhibitors. This is important because the identification of inhibitors has been shown to be effective in arresting the progression of disease.

scholarly journals Loss of the ribosomal RNA methyltransferase NSUN5 impairs global protein synthesis and normal growth

2019 ◽  
Vol 47 (22) ◽  
pp. 11807-11825 ◽  
Author(s):  
Clemens Heissenberger ◽  
Lisa Liendl ◽  
Fabian Nagelreiter ◽  
Yulia Gonskikh ◽  
Guohuan Yang ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Ribosomal Rna ◽  
Stress Responses ◽  
Mammalian Cells ◽  
Translational Regulation ◽  
Regulation Of Gene Expression ◽  
Normal Growth ◽  
Rna Modifications ◽  
Partial Loss ◽  
Global Protein Synthesis

Abstract Modifications of ribosomal RNA expand the nucleotide repertoire and thereby contribute to ribosome heterogeneity and translational regulation of gene expression. One particular m5C modification of 25S ribosomal RNA, which is introduced by Rcm1p, was previously shown to modulate stress responses and lifespan in yeast and other small organisms. Here, we report that NSUN5 is the functional orthologue of Rcm1p, introducing m5C3782 into human and m5C3438 into mouse 28S ribosomal RNA. Haploinsufficiency of the NSUN5 gene in fibroblasts from William Beuren syndrome patients causes partial loss of this modification. The N-terminal domain of NSUN5 is required for targeting to nucleoli, while two evolutionary highly conserved cysteines mediate catalysis. Phenotypic consequences of NSUN5 deficiency in mammalian cells include decreased proliferation and size, which can be attributed to a reduction in total protein synthesis by altered ribosomes. Strikingly, Nsun5 knockout in mice causes decreased body weight and lean mass without alterations in food intake, as well as a trend towards reduced protein synthesis in several tissues. Together, our findings emphasize the importance of single RNA modifications for ribosome function and normal cellular and organismal physiology.

Although calnexin is essential in S. pombe, its highly conserved central domain is dispensable for viability

1999 ◽  
Vol 112 (23) ◽  
pp. 4449-4460 ◽  
Author(s):  
A. Elagoz ◽  
M. Callejo ◽  
J. Armstrong ◽  
L.A. Rokeach
Keyword(s):  
Central Region ◽  
Mammalian Cells ◽  
Normal Growth ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Wild Type ◽  
Lectin Activity ◽  
Central Domain ◽  
Folding Intermediates ◽  
Mutant Cells

In mammalian cells, the calnexin/calreticulin chaperones play a key role in glycoprotein folding and its control within the endoplasmic reticulum (ER), by interacting with folding intermediates via their monoglucosylated glycans. This lectin activity has been mapped in mammalian calnexin/calreticulin chaperones to the central region, which is a highly conserved feature of calnexin/calreticulin molecules across species. The central domain has also been implicated in Ca(2+) binding, and it has been proposed to be involved in the regulation of calcium homeostasis in the ER. Herein, we show that although the Schizosaccharomyces pombe calnexin is essential for viability, cells lacking its 317-amino-acid highly conserved central region are viable under normal growth conditions. However, the central region appears to be necessary for optimal growth under high ER-stress, suggesting that this region is important under extreme folding situations (such as DTT and temperature). The minimal length of calnexin required for viability spans the C-terminal 123 residues. Furthermore, cells with the central domain of the protein deleted were affected in their morphology at 37 degrees C, probably due to a defect in cell wall synthesis, although these mutant cells exhibited the same calcium tolerance as wild-type cells at 30 degrees C.

Overexpression of maize ZmDBP3 enhances tolerance to drought and cold stress in transgenic Arabidopsis plants

Biologia ◽  
2009 ◽  
Vol 64 (6) ◽  
Author(s):  
Chang-Tao Wang ◽  
Yin-Mao Dong
Keyword(s):  
Cold Stress ◽  
Stress Responses ◽  
Nuclear Localization Signal ◽  
Transgenic Arabidopsis ◽  
Normal Growth ◽  
Growth Conditions ◽  
Maize Seedlings ◽  
Transgenic Arabidopsis Plants ◽  
Localization Signal ◽  
Responsive Element

AbstractC-repeat/dehydration-responsive element binding factors (CBF/DREBs), belonging to the AP2/ERF superfamily, play a vital regulatory role in abiotic stress responses in plants. The ZmDBP3 gene, a member of the A-1 subgroup of the CBF/DREB subfamily, was isolated from maize seedlings. The predicted ZmDBP3 protein contained a putative nuclear localization signal and an activation region. As a trans-acting factor, the ZmDBP3 protein accumulated in the nucleus in a subcellular localization assay, and activated CRT/DRE-containing genes under normal growth conditions in transgenic Arabidopsis plants. ZmDBP3 transcription was highly activated by cold and moderately by salt. Overexpression of ZmDBP3 improved drought and cold stress tolerance in transgenic Arabidopsis plants. These results suggested that ZmDBP3 produces a CRT/DRE-binding transcription factor and may have an important role in improving drought and cold tolerance in plants.

scholarly journals Structural and functional studies of the decapping exoribonucleases

2014 ◽  
Vol 70 (a1) ◽  
pp. C1397-C1397
Author(s):  
Jeong Ho Chang ◽  
Liang Tong
Keyword(s):  
Quality Control ◽  
Mammalian Cells ◽  
Catalytic Mechanism ◽  
Control Mechanism ◽  
Normal Growth ◽  
Growth Conditions ◽  
Current Understanding ◽  
Messenger Rnas ◽  
End Capping ◽  
Quality Control Mechanism

Recent studies showed that two homologous yeast proteins, Rai1 and Dxo1, function in a quality control mechanism to clear cells of incompletely 5' end-capped messenger RNAs (mRNAs). Rai1 possesses a novel decapping activity that can remove the entire cap structure dinucleotide from an mRNA. This activity is targeted preferentially towards mRNAs with unmethylated caps in contrast to the canonical decapping enzyme, Dcp2, which targets mRNAs with a methylated cap. Dxo1 also has robust decapping activity on RNAs with unmethylated caps, but it has no detectable pyrophosphohydrolase activity. Unexpectedly, we found that Dxo1 also possesses distributive, 5'-3' exoribonuclease activity, and we named Dxo1 (originally Ydr370C) for this new eukaryotic enzyme with both decapping and exonuclease activities. Studies of yeast in which both Dxo1 and Rai1 are disrupted reveal that mRNAs with incomplete caps are produced even under normal growth conditions, in sharp contrast to current understanding of the capping process. Here, we introduce that their mammalian homolog, Dom3Z (referred to as DXO), possesses pyrophosphohydrolase, decapping, and 5'-3' exoribonuclease activities. Surprisingly, we found that DXO preferentially degrades defectively capped pre-mRNAs in cells. Additional studies show that incompletely capped pre-mRNAs are inefficiently spliced at all introns, a fact that contrasts with current understanding, and are also poorly cleaved for polyadenylation. Crystal structures of DXO in complex with substrate mimic and products at a resolution of up to 1.5 Å provide elegant insights into the catalytic mechanism and molecular basis for their three apparently distinct activities. Our data reveal a pre-mRNA 5' end capping quality control mechanism in mammalian cells, indicating DXO as the central player for this mechanism, and demonstrate an unexpected intimate link between proper 5' end capping and subsequent pre-mRNA processing.

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