scholarly journals Expression Analysis of Multiple dnaK Genes in the Cyanobacterium Synechococcus elongatus PCC 7942

2007 ◽  
Vol 189 (10) ◽  
pp. 3751-3758 ◽  
Author(s):  
Masumi Sato ◽  
Kaori Nimura-Matsune ◽  
Satoru Watanabe ◽  
Taku Chibazakura ◽  
Hirofumi Yoshikawa
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Light Stress ◽  
Synechococcus Elongatus ◽  
Stress Conditions ◽  
Heat Shock Gene ◽  
Upstream Region ◽  
Sequence Motif ◽  
Sequence Element ◽  
Pcc 7942

ABSTRACT We analyzed the stress responses of three dnaK homologues (dnaK1, dnaK2, and dnaK3) in the cyanobacterium Synechococcus elongatus PCC 7942. A reporter assay showed that under stress conditions the expression of only the dnaK2 gene was induced, suggesting a functional assignment of these homologues. RNA blot hybridization indicated a typical stress response of dnaK2 to heat and high-light stress. Primer extension mapping showed that dnaK2 was transcribed from similar sites under various stress conditions. Although no known sequence motif was detected in the upstream region, a 20-bp sequence element was highly conserved in dnaK2; it was essential not only for the stress induction but also for the basal expression of dnaK2. The ubiquitous upstream localization of this element in each heat shock gene suggests its important role in the cyanobacterial stress response.

Glycogen synthesis is a required component of the nitrogen stress response in Synechococcus elongatus PCC 7942

2013 ◽  
Vol 2 (2) ◽  
pp. 98-106 ◽  
Author(s):  
Jason W. Hickman ◽  
Kimberly M. Kotovic ◽  
Cameron Miller ◽  
Paul Warrener ◽  
Brett Kaiser ◽  
...  
Keyword(s):  
Stress Response ◽  
Glycogen Synthesis ◽  
Synechococcus Elongatus ◽  
Nitrogen Stress ◽  
Synechococcus Elongatus Pcc 7942 ◽  
Pcc 7942

scholarly journals Stable Reference Gene Selection for RT-qPCR Analysis inSynechococcus elongatusPCC 7942 under Abiotic Stresses

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xiao Luo ◽  
Jiaxing Li ◽  
Tianliang Chang ◽  
Hongyan He ◽  
Yi Zhao ◽  
...  
Keyword(s):  
Reference Gene ◽  
Reference Genes ◽  
Time Course ◽  
Light Stress ◽  
Nacl Stress ◽  
High Light ◽  
Stress Conditions ◽  
Internal Reference ◽  
High Light Stress ◽  
Pcc 7942

Synechococcus elongatusPCC 7942 (S. elongatusPCC 7942) is a model cyanobacteria species for circadian clock mechanism studies. It has also been widely used as a bioreactor to produce biofuels and other metabolic products. Quantitative real-time PCR (qPCR) technology is the most commonly used method for studying the expression of specific genes, in which the relative expression level of target genes is calibrated by stably expressed internal reference genes. In this work, we examined the expression of nine candidate reference genes in time-course samples ofS. elongatusPCC 7942 under no treatment (control), NaCl-stress conditions, H2O2-stress conditions, and high light-stress conditions. Based on the qPCR amplification parameters, the stability ranking of these candidate reference genes was established by three statistical software programs, geNorm, NormFinder, and BestKeeper. Considering all the stress conditions or high light stress alone, the results showed that the combination ofprsandsecAwas the best choice for the double reference gene calibration method by qPCR. The combination ofsecAandppc,rimMandrnpA,rnpA,andilvDwas most stable under no treatment, NaCl-stress conditions, and H2O2-stress conditions, respectively.rimMwas stable under only special conditions and should be carefully chosen.16SandrnpBwere not suitable as internal reference genes forS. elongatusPCC 7942 qPCR experiments under all experimental conditions. To validate the above results, a cyanobacterial core clock gene,kaiC, was used to evaluate the actual performance of the optimized reference genes by qPCR, as well as the worst reference genes under different stress conditions. The results indicated that the best reference gene yielded more accurate calibration results for qPCR experiments carried out inS. elongatusPCC 7942 time-course samples.

scholarly journals PpSARK Regulates Moss Senescence and Salt Tolerance through ABA Related Pathway

2018 ◽  
Vol 19 (9) ◽  
pp. 2609 ◽  
Author(s):  
Ping Li ◽  
Hong Yang ◽  
Gaojing Liu ◽  
Wenzhang Ma ◽  
Chuanhong Li ◽  
...  
Keyword(s):  
Salt Stress ◽  
Stress Response ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Physcomitrella Patens ◽  
Stress Conditions ◽  
Negative Regulator ◽  
Salt Stress Response ◽  
Functional Roles ◽  
Related Pathway

Senescence-associated receptor-like kinase (SARK) family members in Arabidopsis, soybean, and rice are known to be positive regulators of leaf senescence. In the meantime, SARKs are extensively involved in stress response. However, their function and underlying molecular mechanism in stress responses in moss are not well known. Here, we investigated functional roles of SARK isolated from Physcomitrella patens (PpSARK) in salt stress response and senescence. PpSARK transcripts significantly accumulated under NaCl and abscisic acid (ABA) treatments, with higher expression in the moss gametophyte stage. Insertional gain-of-function mutants of PpSARK (PpSARKg) were more tolerant to salt stress and ABA than wild type (WT), whereas senescence of mutants was delayed during the protonema stage. Expression of stress-responsive genes in the ABA related pathway, such as PpABI3, PpABI5, PpPP2C, and PpLEA were significantly higher in PpSARKg and WT under salt stress conditions, suggesting that PpSARK might positively regulate salt tolerance via an ABA-related pathway. Endogenous ABA contents also increased 3-fold under salt stress conditions. These results indicate that PpSARK functions as a positive regulator in salt stress responses, while possibly functioning as a negative regulator in senescence in moss.

scholarly journals Histone H3 T11 phosphorylation by Sch9 and CK2 regulates lifespan by controlling the nutritional stress response

2018 ◽  
Author(s):  
Seunghee Oh ◽  
Tamaki Suganuma ◽  
Madelaine M. Gogol ◽  
Jerry L. Workman
Keyword(s):  
Stress Response ◽  
Signaling Pathways ◽  
Stress Responses ◽  
Histone H3 ◽  
Nutritional Stress ◽  
Stress Conditions ◽  
Metabolic Status ◽  
Chromatin Regulation ◽  
Nutrient Signaling ◽  
Altered Metabolism

AbstractUpon nutritional stress, the metabolic status of cells is changed by nutrient signaling pathways to ensure survival. Altered metabolism by nutrient signaling pathways has been suggested to influence cellular lifespan. However, it remains unclear how chromatin regulation is involved in this process. Here, we found that histone H3 threonine 11 phosphorylation (H3pT11) functions as a marker for nutritional stress and aging. Sch9 and CK2 kinases cooperatively regulate H3pT11 under stress conditions. Importantly, H3pT11 defective mutants prolonged chronological lifespan by altering nutritional stress responses. Thus, the phosphorylation of H3T11 by Sch9 and CK2 engages a nutritional stress response to chromatin in the regulation of lifespan.

scholarly journals Histone H3 threonine 11 phosphorylation by Sch9 and CK2 regulates chronological lifespan by controlling the nutritional stress response

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Seunghee Oh ◽  
Tamaki Suganuma ◽  
Madelaine M Gogol ◽  
Jerry L Workman
Keyword(s):  
Stress Response ◽  
Signaling Pathways ◽  
Stress Responses ◽  
Histone H3 ◽  
Nutritional Stress ◽  
Stress Conditions ◽  
Metabolic Status ◽  
Chronological Lifespan ◽  
Nutrient Signaling ◽  
Altered Metabolism

Upon nutritional stress, the metabolic status of cells is changed by nutrient signaling pathways to ensure survival. Altered metabolism by nutrient signaling pathways has been suggested to influence cellular lifespan. However, it remains unclear how chromatin regulation is involved in this process. Here, we found that histone H3 threonine 11 phosphorylation (H3pT11) functions as a marker for nutritional stress and aging. Sch9 and CK2 kinases cooperatively regulate H3pT11 under stress conditions. Importantly, H3pT11 defective mutants prolonged chronological lifespan (CLS) by altering nutritional stress responses. Thus, the phosphorylation of H3T11 by Sch9 and CK2 links a nutritional stress response to chromatin in the regulation of CLS.

scholarly journals Listeria monocytogenes σB Has a Small Core Regulon and a Conserved Role in Virulence but Makes Differential Contributions to Stress Tolerance across a Diverse Collection of Strains

2010 ◽  
Vol 76 (13) ◽  
pp. 4216-4232 ◽  
Author(s):  
H. F. Oliver ◽  
R. H. Orsi ◽  
M. Wiedmann ◽  
K. J. Boor
Keyword(s):  
Oxidative Stress ◽  
Listeria Monocytogenes ◽  
Stress Response ◽  
Cell Invasion ◽  
Stress Responses ◽  
Stress Conditions ◽  
Infection Model ◽  
Expression Microarrays ◽  
Phylogenetic Lineages ◽  
And Oxidative Stress

ABSTRACT Listeria monocytogenes strains are classified in at least three distinct phylogenetic lineages. There are correlations between lineage classification and source of bacterial isolation; e.g., human clinical and food isolates usually are classified in either lineage I or II. However, human clinical isolates are overrepresented in lineage I, while food isolates are overrepresented in lineage II. σB, a transcriptional regulator previously demonstrated to contribute to environmental stress responses and virulence in L. monocytogenes lineage II strains, was hypothesized to provide differential abilities for L. monocytogenes survival in various niches (e.g., food and human clinical niches). To determine if the contributions of σB to stress response and virulence differ across diverse L. monocytogenes strains, ΔsigB mutations were created in strains belonging to lineages I, II, IIIA, and IIIB. Paired parent and ΔsigB mutant strains were tested for survival under acid and oxidative stress conditions, Caco-2 cell invasion efficiency, and virulence using the guinea pig listeriosis infection model. Parent and ΔsigB mutant strain transcriptomes were compared using whole-genome expression microarrays. σB contributed to virulence in each strain. However, while σB contributed significantly to survival under acid and oxidative stress conditions and Caco-2 cell invasion in lineage I, II, and IIIB strains, the contributions of σB were not significant for these phenotypes in the lineage IIIA strain. A core set of 63 genes was positively regulated by σB in all four strains; different total numbers of genes were positively regulated by σB in the strains. Our results suggest that σB universally contributes to L. monocytogenes virulence but specific σB-regulated stress response phenotypes vary among strains.

scholarly journals A Conserved Stress-activated Protein Kinase Regulates a Core Stress Response in the Human PathogenCandida albicans

2004 ◽  
Vol 15 (9) ◽  
pp. 4179-4190 ◽  
Author(s):  
Deborah A. Smith ◽  
Susan Nicholls ◽  
Brian A. Morgan ◽  
Alistair J.P. Brown ◽  
Janet Quinn
Keyword(s):  
Stress Response ◽  
Protein Kinase ◽  
Stress Responses ◽  
Stress Conditions ◽  
Human Pathogen ◽  
Environmental Niche ◽  
The Core ◽  
Response To Stress ◽  
Molecular Circuitry

Previous work has implicated the Hog1 stress-activated protein kinase (SAPK) in osmotic and oxidative stress responses in the human pathogen Candida albicans. In this study, we have characterized the role of Hog1 in mediating these and other stress responses in C. albicans. We provide evidence that a SAPK-dependent core stress response exists in this pathogen. The Hog1 SAPK is phosphorylated and it accumulates in the nucleus in response to diverse stress conditions. In addition, we have identified Hog1-regulated genes that are induced in response to stress conditions that activate Hog1. These analyses reveal both activator and repressor functions for the Hog1 SAPK. Our results also demonstrate that stress cross-protection, a classical hallmark of the core stress response, occurs in C. albicans between stresses that activate the Hog1 SAPK. Importantly, we find that the core stress response in C. albicans has adapted to the environmental niche of this human pathogen. This niche specificity is reflected by the specific environmental conditions that drive the Hog1-regulated core stress response in C. albicans and by differences in the molecular circuitry that control this response.

scholarly journals Lub1 Participates in Ubiquitin Homeostasis and Stress Response via Maintenance of Cellular Ubiquitin Contents in Fission Yeast

2004 ◽  
Vol 24 (6) ◽  
pp. 2324-2331 ◽  
Author(s):  
Yasunari Ogiso ◽  
Reiko Sugiura ◽  
Tsuneyoshi Kamo ◽  
Satoshi Yanagiya ◽  
Yabin Lu ◽  
...  
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Mrna Level ◽  
Negative Regulation ◽  
Stress Conditions ◽  
Cellular Processes ◽  
Accelerated Degradation ◽  
Genes Encoding ◽  
Ubiquitin Proteasome ◽  
Posttranscriptional Level

ABSTRACT Ubiquitin-dependent proteolysis plays a pivotal role in stress responses. To investigate the mechanisms of these cellular processes, we have been studying Schizosaccharomyces pombe mutants that have altered sensitivities to various stress conditions. Here, we showed that Lub1, a homologue of Ufd3p/Zzz4p/Doa1p in budding yeast, is involved in the regulation of ubiquitin contents. Disruption of the lub1+ gene resulted in monoubiquitin as well as multiubiquitin depletion without change in mRNA level and in hypersensitivity to various stress conditions. Consistently, overexpression of genes encoding ubiquitin suppressed the defects associated with lub1 mutation, indicating that the phenotypes of the lub1 mutants under stress conditions were due to cellular ubiquitin shortage at the posttranscriptional level. In addition, the lub1-deleted cells showed aberrant functions in ubiquitin/proteasome-dependent proteolysis, with accelerated degradation of ubiquitin. Also Cdc48, a stress-induced chaperon-like essential ATPase, was found to interact with Lub1, and this association might contribute to the stabilization of Lub1. Our results indicated that Lub1 is responsible for ubiquitin homeostasis at the protein level through a negative regulation of ubiquitin degradation.

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