scholarly journals Functional Analysis of PSRP1, the Chloroplast Homolog of a Cyanobacterial Ribosome Hibernation Factor

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 209
Author(s):  
Kevin Swift ◽  
Prakitchai Chotewutmontri ◽  
Susan Belcher ◽  
Rosalind Williams-Carrier ◽  
Alice Barkan
Keyword(s):  
Driving Force ◽  
Growth Conditions ◽  
Psba Gene ◽  
Standard Laboratory ◽  
Chloroplast Evolution ◽  
Bacterial Ribosome ◽  
Chloroplast Translation ◽  
Stress Survival ◽  
Response To Stress ◽  
Post Stress

Bacterial ribosome hibernation factors sequester ribosomes in an inactive state during the stationary phase and in response to stress. The cyanobacterial ribosome hibernation factor LrtA has been suggested to inactivate ribosomes in the dark and to be important for post-stress survival. In this study, we addressed the hypothesis that Plastid Specific Ribosomal Protein 1 (PSRP1), the chloroplast-localized LrtA homolog in plants, contributes to the global repression of chloroplast translation that occurs when plants are shifted from light to dark. We found that the abundance of PSRP1 and its association with ribosomes were similar in the light and the dark. Maize mutants lacking PSRP1 were phenotypically normal under standard laboratory growth conditions. Furthermore, the absence of PSRP1 did not alter the distribution of chloroplast ribosomes among monosomes and polysomes in the light or in the dark, and did not affect the light-regulated synthesis of the chloroplast psbA gene product. These results suggest that PSRP1 does not play a significant role in the regulation of chloroplast translation by light. As such, the physiological driving force for the retention of PSRP1 during chloroplast evolution remains unclear.

scholarly journals A Comprehensive Subcellular Proteomic Survey of Salmonella Grown under Phagosome-Mimicking versus Standard Laboratory Conditions

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Roslyn N. Brown ◽  
James A. Sanford ◽  
Jea H. Park ◽  
Brooke L. Deatherage ◽  
Boyd L. Champion ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Protein Localization ◽  
Subcellular Location ◽  
Growth Conditions ◽  
Standard Laboratory ◽  
Response Regulators ◽  
Regulatory Systems ◽  
Protein Properties ◽  
Good Agreement

Towards developing a systems-level pathobiological understanding of Salmonella enterica, we performed a subcellular proteomic analysis of this pathogen grown under standard laboratory and phagosome-mimicking conditions in vitro. Analysis of proteins from cytoplasmic, inner membrane, periplasmic, and outer membrane fractions yielded coverage of 25% of the theoretical proteome. Confident subcellular location could be assigned to over 1000 proteins, with good agreement between experimentally observed location and predicted/known protein properties. Comparison of protein location under the different environmental conditions provided insight into dynamic protein localization and possible moonlighting (multiple function) activities. Notable examples of dynamic localization were the response regulators of two-component regulatory systems (e.g., ArcB and PhoQ). The DNA-binding protein Dps that is generally regarded as cytoplasmic was significantly enriched in the outer membrane for all growth conditions examined, suggestive of moonlighting activities. These observations imply the existence of unknown transport mechanisms and novel functions for a subset of Salmonella proteins. Overall, this work provides a catalog of experimentally verified subcellular protein locations for Salmonella and a framework for further investigations using computational modeling.

scholarly journals Formation of the phenomenon of stigmatization against individuals affected in emergencies from representatives of various social groups

2017 ◽  
Vol 7 (1) ◽  
pp. 193-205 ◽  
Author(s):  
N.M. Zakharova ◽  
A.S. Baeva ◽  
I.V. Gurin ◽  
V.V. Shkurko
Keyword(s):  
Mental Disorders ◽  
Traumatic Experience ◽  
Emergency Situations ◽  
Social Stereotypes ◽  
Personality Vulnerability ◽  
Response To Stress ◽  
Socio Demographic Factors ◽  
The City ◽  
The Town ◽  
Post Stress

In this article the authors consider the phenomenon of stigmatization as one of the unfavorable socio-psychological results of emergency situations raising the level of personality vulnerability though not studied enough so far. A study was made to reveal stigmatization with relation to persons who had suffered from emergency situations, among the inhabitants of the two regions exposed to terroristic attacks: that of North Ossetiya (the town of Beslan and the city of Vladikavkaz) and the Central Region (the city of Moscow). Analysis of the obtained data permitted one to make a conclusion of the presence of signs of stigmatization in both groups of respondents, of insufficient awareness in society of the specificities of individual forms of response to stress, of manifestations of post-stress mental disorders, as well as a transfer of social stereotypes related to persons with mental disorders to the victims. Socio-demographic factors causing outward stigmatization have been defined. A degree of expression of stigmatization tendencies depends on a respondent’s social status as well as on the past traumatic experience.

scholarly journals Filamentation in Candida albicans is modulated by adaptive translation of farnesol signalling genes

2021 ◽  
Author(s):  
Carla Oliveira ◽  
Ana Rita Guimarães ◽  
Inês Correia ◽  
Inês Sousa ◽  
Ana Poim ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Molecular Mechanisms ◽  
Phenotypic Diversity ◽  
Critical Role ◽  
Normal Growth ◽  
Morphological Diversity ◽  
Growth Conditions ◽  
Response To Stress ◽  
Variable Morphology

AbstractThe complex biology of the human pathogen Candida albicans is reflected in its remarkable ability to proliferate in numerous body sites, adapt to drastic changes in the environment, form various types of colonies and grow in yeast, pseudo-hyphal and hyphal forms. Much has been learnt in recent years about the relevance of this phenotypic plasticity, but the mechanisms that support it are still not fully understood. We have demonstrated that atypical translation of the CUG codon is a source of unexpected morphological diversity. The CUG codon is translated as both leucine (Leu) (~3%) and serine (Ser) (~97%) in normal growth conditions, but Ser/Leu levels change in response to stress. Remarkably, recombinant C. albicans strains incorporating between 20% and 99% of Leu at CUG sites display a diverse array of phenotypes and produce colonies of variable morphology containing a mixture of yeast, pseudohyphal and hyphal cells. In this work we investigate the role of the CUG codon in the yeast-hypha transition. Our data show that increasing incorporation levels of Leu at CUG sites trigger hyphal initiation under non-inducing conditions by reducing farnesol production, and increasing the degradation of the Nrg1 hyphal repressor. We propose that dual CUG Ser/Leu translation triggers filamentation via the Nrg1 pathway.ImportanceThe unique translation of the CUG codon as both Ser (~97%) and Leu (~3%) plays a key role in the production of high genomic and phenotypic diversity in C. albicans. The molecular mechanisms that support such diversity are poorly understood. Here, we show that increased Leu incorporation at CUG sites induce hyphae formation in media where C. albicans normally grows in the yeast form. The data show that increasing Leu at CUG sites triggers the degradation of the hyphal repressor Nrg1, allowing for full expression of hyphal genes. Since filamentation is important for invasion of host tissues, this work shows how the atypical translation of a single codon may play a critical role in the virulence of all fungi of the CTG clade.

scholarly journals Differential expression of duplicated ribosomal protein genes modifies ribosome composition in response to stress

2019 ◽  
Vol 48 (4) ◽  
pp. 1954-1968 ◽  
Author(s):  
Mustafa Malik Ghulam ◽  
Mathieu Catala ◽  
Sherif Abou Elela
Keyword(s):  
Ribosomal Protein ◽  
Rna Polymerase Ii ◽  
Ribosomal Proteins ◽  
Normal Growth ◽  
Growth Conditions ◽  
Duplicated Genes ◽  
Ribosomal Protein Genes ◽  
Expression Ratio ◽  
Gene Copies ◽  
Response To Stress

Abstract In Saccharomyces cerevisiae, most ribosomal proteins are synthesized from duplicated genes, increasing the potential for ribosome heterogeneity. However, the contribution of these duplicated genes to ribosome production and the mechanism determining their relative expression remain unclear. Here we demonstrate that in most cases, one of the two gene copies generate the bulk of the active ribosomes under normal growth conditions, while the other copy is favored only under stress. To understand the origin of these differences in paralog expression and their contribution to ribosome heterogeneity we used RNA polymerase II ChIP-Seq, RNA-seq, polyribosome association and peptide-based mass-spectrometry to compare their transcription potential, splicing, mRNA abundance, translation potential, protein abundance and incorporation into ribosomes. In normal conditions a post-transcriptional expression hierarchy of the duplicated ribosomal protein genes is the product of the efficient splicing, high stability and efficient translation of the major paralog mRNA. Exposure of the cell to stress modifies the expression ratio of the paralogs by repressing the expression of the major paralog and thus increasing the number of ribosomes carrying the minor paralog. Together the data indicate that duplicated ribosomal protein genes underlie a modular network permitting the modification of ribosome composition in response to changing growth conditions.

The stress response and the plasma disappearance of corticosteroid and glucose in a marine teleost, the sea raven

1994 ◽  
Vol 72 (3) ◽  
pp. 379-386 ◽  
Author(s):  
M. M. Vijayan ◽  
T. W. Moon
Keyword(s):  
Life Style ◽  
Acute Stress ◽  
High Threshold ◽  
Delayed Response ◽  
Tissue Uptake ◽  
Air Exposure ◽  
Sea Raven ◽  
Confinement Stress ◽  
Response To Stress ◽  
Post Stress

The objective of the study was to examine the physiological response to stress in a marine species with a sluggish life-style. The sea raven (Hemitripterus americanus), a marine benthic predator, did not produce elevated catecholamine levels when handled for blood removal, which facilitated repeated blood sampling from the same fish without cannulation. However, this species did release catecholamines in response to an acute stress (1 min of air exposure followed by 1 min of chasing), suggesting a high threshold (degree of external stimulation) for catecholamine release in this species. Plasma cortisol concentration increased significantly only after 1 h and remained elevated 4 h post-stress, showing a delayed response compared with salmonids. Plasma glucose concentration increased significantly at 0.5 h post-stress and remained elevated even at 24 h, while lactate levels dropped between 4 and 24 h post-stress. The delayed cortisol increase may not be due to altered plasma clearance, as no change in the plasma disappearance or tissue uptake of cortisol-derived radioactivity occurred with confinement stress in this species. Also, confinement stress did not alter the plasma disappearance or tissue uptake of radioactivity derived from glucose, indicating a higher production of glucose during stress. Food deprivation significantly increased the plasma disappearance and tissue uptake of both cortisol- and glucose-derived radioactivity in the sea raven. These results indicate that the hormonal response to stress in the sea raven is different from that of salmonids. This altered response may be an adaptation to prevent excess energy mobilization in a species with an inactive life-style and low metabolic activity.

scholarly journals Stxbp4 Regulates ΔNp63 Stability by Suppression of RACK1-Dependent Degradation

2009 ◽  
Vol 29 (14) ◽  
pp. 3953-3963 ◽  
Author(s):  
Yingchun Li ◽  
Melissa J. Peart ◽  
Carol Prives
Keyword(s):  
Squamous Cell Carcinoma ◽  
Normal Growth ◽  
Genotoxic Stress ◽  
Growth Conditions ◽  
Carcinoma Cells ◽  
Scaffold Proteins ◽  
Proliferating Cells ◽  
Protein Levels ◽  
Response To Stress

ABSTRACT p63, a member of the p53 tumor suppressor family, is essential for the development of epidermis as well as other stratified epithelia. Collective evidence indicates that ΔNp63 proteins, the N-terminally deleted versions of p63, are essential for the proliferation and survival of stratified epithelial cells and squamous cell carcinoma cells. But in response to DNA damage, ΔNp63 proteins are quickly downregulated in part through protein degradation. To elucidate the mechanisms by which ΔNp63 proteins are maintained at relatively high levels in proliferating cells but destabilized in response to stress, we sought to identify p63 interactive proteins that regulate p63 stability. We found that Stxbp4 and RACK1, two scaffold proteins, play central roles in balancing ΔNp63 protein levels. While Stxbp4 functions to stabilize ΔNp63 proteins, RACK1 targets ΔNp63 for degradation. Under normal growth conditions, Stxbp4 is indispensable for maintaining high basal levels of ΔNp63 and preventing RACK1-mediated p63 degradation. Upon genotoxic stress, however, Stxbp4 itself is downregulated, correlating with ΔNp63 destabilization mediated in part by RACK1. Taken together, we have delineated key mechanisms that regulate ΔNp63 protein stability in vivo.

scholarly journals HDAC6 regulates sensitivity to cell death in response to stress and post-stress recovery

2017 ◽  
Vol 22 (2) ◽  
pp. 253-261 ◽  
Author(s):  
Hyun-Wook Ryu ◽  
Hye-Rim Won ◽  
Dong Hoon Lee ◽  
So Hee Kwon
Keyword(s):  
Cell Death ◽  
Stress Recovery ◽  
Response To Stress ◽  
Post Stress

scholarly journals A genetic analysis reveals novel histone residues required for transcriptional reprogramming upon stress

2020 ◽  
Vol 48 (7) ◽  
pp. 3455-3475
Author(s):  
Cristina Viéitez ◽  
Gerard Martínez-Cebrián ◽  
Carme Solé ◽  
René Böttcher ◽  
Clement M Potel ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Growth Conditions ◽  
Proof Of Concept ◽  
Transcriptional Program ◽  
Post Translational Modifications ◽  
Transcriptional Reprogramming ◽  
Histone Ptms ◽  
Response To Stress ◽  
State Growth

Abstract Cells have the ability to sense, respond and adapt to environmental fluctuations. Stress causes a massive reorganization of the transcriptional program. Many examples of histone post-translational modifications (PTMs) have been associated with transcriptional activation or repression under steady-state growth conditions. Comparatively less is known about the role of histone PTMs in the cellular adaptive response to stress. Here, we performed high-throughput genetic screenings that provide a novel global map of the histone residues required for transcriptional reprogramming in response to heat and osmotic stress. Of note, we observed that the histone residues needed depend on the type of gene and/or stress, thereby suggesting a ‘personalized’, rather than general, subset of histone requirements for each chromatin context. In addition, we identified a number of new residues that unexpectedly serve to regulate transcription. As a proof of concept, we characterized the function of the histone residues H4-S47 and H4-T30 in response to osmotic and heat stress, respectively. Our results uncover novel roles for the kinases Cla4 and Ste20, yeast homologs of the mammalian PAK2 family, and the Ste11 MAPK as regulators of H4-S47 and H4-T30, respectively. This study provides new insights into the role of histone residues in transcriptional regulation under stress conditions.

scholarly journals TIP49b, a Regulator of Activating Transcription Factor 2 Response to Stress and DNA Damage

2001 ◽  
Vol 21 (24) ◽  
pp. 8398-8413 ◽  
Author(s):  
Ssang-Goo Cho ◽  
Anindita Bhoumik ◽  
Limor Broday ◽  
Vladimir Ivanov ◽  
Barry Rosenstein ◽  
...  
Keyword(s):  
Dna Damage ◽  
Transcription Factor ◽  
Transcriptional Control ◽  
Constitutive Expression ◽  
Normal Growth ◽  
Growth Conditions ◽  
Interacting Protein ◽  
Response To Stress ◽  
Activating Transcription Factor

ABSTRACT Activating transcription factor 2 (ATF2/CRE-BP1) is implicated in transcriptional control of stress-responsive genes. A yeast two-hybrid screen identified TBP-interacting protein 49b (TIP49b), a component of the INO80 chromatin-remodeling complex, as a novel ATF2-interacting protein. TIP49b's association with ATF2 is phosphorylation dependent and requires amino acids 150 to 248 of ATF2 (ATF2150–248), which are implicated in intramolecular inhibition of ATF2 transcriptional activities. Forced expression of TIP49b efficiently attenuated ATF2 transcriptional activities under normal growth conditions as well as after UV treatment, ionizing irradiation, or activation of p38 kinase, all of which induced ATF2 phosphorylation and increased TIP49b-ATF2 association. Constitutive expression of ATF2150–248 peptide outcompeted TIP49b interaction with ATF2 and alleviated the suppression of ATF2 transcriptional activities. Expression of ATF2150–248 in fibroblasts or melanoma but not in ATF2-null cells caused a profound G2M arrest and increased degree of apoptosis following irradiation. The interaction between ATF2 and TIP49b constitutes a novel mechanism that serves to limit ATF2 transcriptional activities and highlights the central role of ATF2 in the control of the cell cycle and apoptosis in response to stress and DNA damage.

scholarly journals mRNA decapping is an evolutionarily conserved modulator of neuroendocrine signaling that controls development and ageing

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Fivos Borbolis ◽  
John Rallis ◽  
George Kanatouris ◽  
Nikolitsa Kokla ◽  
Antonis Karamalegkos ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nuclear Localization ◽  
Normal Development ◽  
Model Organisms ◽  
Mrna Decapping ◽  
Evolutionarily Conserved ◽  
Stress Survival ◽  
Response To Stress ◽  
Decapping Enzyme ◽  
Wing Morphogenesis

Eukaryotic 5’−3’ mRNA decay plays important roles during development and in response to stress, regulating gene expression post-transcriptionally. In Caenorhabditis elegans, deficiency of DCAP-1/DCP1, the essential co-factor of the major cytoplasmic mRNA decapping enzyme, impacts normal development, stress survival and ageing. Here, we show that overexpression of dcap-1 in neurons of worms is sufficient to increase lifespan through the function of the insulin/IGF-like signaling and its effector DAF-16/FOXO transcription factor. Neuronal DCAP-1 affects basal levels of INS-7, an ageing-related insulin-like peptide, which acts in the intestine to determine lifespan. Short-lived dcap-1 mutants exhibit a neurosecretion-dependent upregulation of intestinal ins-7 transcription, and diminished nuclear localization of DAF-16/FOXO. Moreover, neuronal overexpression of DCP1 in Drosophila melanogaster confers longevity in adults, while neuronal DCP1 deficiency shortens lifespan and affects wing morphogenesis, cell non-autonomously. Our genetic analysis in two model-organisms suggests a critical and conserved function of DCAP-1/DCP1 in developmental events and lifespan modulation.

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