scholarly journals Peroxide processing in photosynthesis: antioxidant coupling and redox signalling

2000 ◽  
Vol 355 (1402) ◽  
pp. 1465-1475 ◽  
Author(s):  
Graham Noctor ◽  
Sonja Veljovic-Jovanovic ◽  
Christine H. Foyer
Keyword(s):  
Gene Expression ◽  
Complex System ◽  
Hydrogen Peroxide ◽  
Antioxidant System ◽  
Redox State ◽  
Redox Homeostasis ◽  
High Capacity ◽  
Control Of Gene Expression ◽  
Redox Signalling ◽  
Production Of Hydrogen

Photosynthesis has a high capacity for production of hydrogen peroxide (H 2 O 2 ), but the intracellular levels of this relatively weak oxidant are controlled by the antioxidant system, comprising a network of enzymatic and non-enzymatic components that notably includes reactions linked to the intracellular ascorbate and glutathione pools. Mutants and transformed plants with specific decreases in key components offer the opportunity to dissect the complex system that maintains redox homeostasis. Since H 2 O 2 is a signal-transducing molecule relaying information on intracellular redox state, the pool size must be rigorously controlled within each compartment of the cell. This review focuses on compartment-specific differences in the stringency of redox coupling between ascorbate and glutathione, and the significance this may have for the flexibility of the control of gene expression that is linked to photosynthetic H 2 O 2 production.

scholarly journals Spot 42 Small RNA Regulates Arabinose-Inducible araBAD Promoter Activity by Repressing Synthesis of the High-Affinity Low-Capacity Arabinose Transporter

2016 ◽  
Vol 199 (3) ◽  
Author(s):  
Jiandong Chen ◽  
Susan Gottesman
Keyword(s):  
Gene Expression ◽  
Promoter Activity ◽  
Transcriptional Control ◽  
Bacterial Species ◽  
High Capacity ◽  
Constitutive Expression ◽  
Receptor Protein ◽  
Control Of Gene Expression ◽  
Content Type ◽  
High Affinity

ABSTRACT The l-arabinose-inducible araBAD promoter (PBAD) enables tightly controlled and tunable expression of genes of interest in a broad range of bacterial species. It has been used successfully to study bacterial sRNA regulation, where PBAD drives expression of target mRNA translational fusions. Here we report that in Escherichia coli, Spot 42 sRNA regulates PBAD promoter activity by affecting arabinose uptake. We demonstrate that Spot 42 sRNA represses araF, a gene encoding the AraF subunit of the high-affinity low-capacity arabinose transporter AraFGH, through direct base-pairing interactions. We further show that endogenous Spot 42 sRNA is sufficient to repress araF expression under various growth conditions. Finally, we demonstrate this posttranscriptional repression has a biological consequence, decreasing the induction of PBAD at low levels of arabinose. This problem can be circumvented using strategies reported previously for avoiding all-or-none induction behavior, such as through constitutive expression of the low-affinity high-capacity arabinose transporter AraE or induction with a higher concentration of inducers. This work adds araF to the set of Spot 42-regulated genes, in agreement with previous studies suggesting that Spot 42, itself negatively regulated by the cyclic AMP (cAMP) receptor protein-cAMP complex, reinforces the catabolite repression network. IMPORTANCE The bacterial arabinose-inducible system is widely used for titratable control of gene expression. We demonstrate here that a posttranscriptional mechanism mediated by Spot 42 sRNA contributes to the functionality of the PBAD system at subsaturating inducer concentrations by affecting inducer uptake. Our finding extends the inputs into the known transcriptional control for the PBAD system and has implications for improving its usage for tunable gene expression.

scholarly journals Electronic control of gene expression and cell behaviour in Escherichia coli through redox signalling

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Tanya Tschirhart ◽  
Eunkyoung Kim ◽  
Ryan McKay ◽  
Hana Ueda ◽  
Hsuan-Chen Wu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Electronic Control ◽  
Cell Behaviour ◽  
Control Of Gene Expression ◽  
Redox Signalling

Effects of pH stress on antioxidant system enzyme activities and gene expression of Fenneropenaeus chinensis

2013 ◽  
Vol 18 (3) ◽  
pp. 556-564 ◽  
Author(s):  
Yun WANG ◽  
Jian LI ◽  
Jitao LI ◽  
Yuying HE ◽  
Zhiqiang CHANG ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antioxidant System ◽  
Enzyme Activities ◽  
Fenneropenaeus Chinensis ◽  
Ph Stress ◽  
Effects Of Ph

A Review on Important Histone Acetyltransferase (HAT) Enzymes as Targets for Cancer Therapy

2019 ◽  
Vol 15 (2) ◽  
pp. 120-130
Author(s):  
Mohammad Ghanbari ◽  
Reza Safaralizadeh ◽  
Kiyanoush Mohammadi
Keyword(s):  
Gene Expression ◽  
Histone Acetyltransferase ◽  
Critical Role ◽  
Cancer Treatments ◽  
Control Of Gene Expression ◽  
Post Translational Modifications ◽  
Therapeutic Drugs ◽  
The Status ◽  
Acetyl Group ◽  
Increase Gene Expression

At the present time, cancer is one of the most lethal diseases worldwide. There are various factors involved in the development of cancer, including genetic factors, lifestyle, nutrition, and so on. Recent studies have shown that epigenetic factors have a critical role in the initiation and development of tumors. The histone post-translational modifications (PTMs) such as acetylation, methylation, phosphorylation, and other PTMs are important mechanisms that regulate the status of chromatin structure and this regulation leads to the control of gene expression. The histone acetylation is conducted by histone acetyltransferase enzymes (HATs), which are involved in transferring an acetyl group to conserved lysine amino acids of histones and consequently increase gene expression. On the basis of similarity in catalytic domains of HATs, these enzymes are divided into different groups such as families of GNAT, MYST, P300/CBP, SRC/P160, and so on. These enzymes have effective roles in apoptosis, signaling pathways, metastasis, cell cycle, DNA repair and other related mechanisms deregulated in cancer. Abnormal activation of HATs leads to uncontrolled amplification of cells and incidence of malignancy signs. This indicates that HAT might be an important target for effective cancer treatments, and hence there would be a need for further studies and designing of therapeutic drugs on this basis. In this study, we have reviewed the important roles of HATs in different human malignancies.

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