scholarly journals Persulphide-responsive transcriptional regulation and metabolism in bacteria

Author(s):  
Takayuki Shimizu ◽  
Shinji Masuda

Abstract Hydrogen sulphide (H2S) impacts on bacterial growth both positively and negatively; it is utilized as an electron donor for photosynthesis and respiration, and it inactivates terminal oxidases and iron-sulphur clusters. Therefore, bacteria have evolved H2S-responsive detoxification mechanisms for survival. Sulphur assimilation in bacteria has been well studied, and sulphide:quinone oxidoreductase, persulphide dioxygenase, rhodanese and sulphite oxidase were reported as major sulphide-oxidizing enzymes of sulphide assimilation and detoxification pathways. However, how bacteria sense sulphide availability to control H2S and sulphide metabolism remains largely unknown. Recent studies have identified several bacterial (per)sulphide-sensitive transcription factors that change DNA-binding affinity through persulphidation of specific cysteine residues in response to highly reactive sulphur-containing chemicals and reactive sulphur species (RSS). This review focuses on current understanding of the persulphide-responsive transcription factors and RSS metabolism regulated by RSS sensory proteins.

2021 ◽  
pp. ASN.2020081177
Author(s):  
Jingping Yang ◽  
Difei Zhang ◽  
Masaru Motojima ◽  
Tsutomu Kume ◽  
Qing Hou ◽  
...  

BackgroundTranscriptional programs control cell fate, and identifying their components is critical for understanding diseases caused by cell lesion, such as podocytopathy. Although many transcription factors (TFs) are necessary for cell-state maintenance in glomeruli, their roles in transcriptional regulation are not well understood.MethodsThe distribution of H3K27ac histones in human glomerulus cells was analyzed to identify superenhancer-associated TFs, and ChIP-seq and transcriptomics were performed to elucidate the regulatory roles of the TFs. Transgenic animal models of disease were further investigated to confirm the roles of specific TFs in podocyte maintenance.ResultsSuperenhancer distribution revealed a group of potential TFs in core regulatory circuits in human glomerulus cells, including FOXC1/2, WT1, and LMX1B. Integration of transcriptome and cistrome data of FOXC1/2 in mice resolved transcriptional regulation in podocyte maintenance. FOXC1/2 regulated differentiation-associated transcription in mature podocytes. In both humans and animal models, mature podocyte injury was accompanied by deregulation of FOXC1/2 expression, and FOXC1/2 overexpression could protect podocytes in zebrafish.ConclusionsFOXC1/2 maintain podocyte differentiation through transcriptional stabilization. The genome-wide chromatin resources support further investigation of TFs’ regulatory roles in glomeruli transcription programs.


2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Jieyun Hong ◽  
Shijun Li ◽  
Xiaoyu Wang ◽  
Chugang Mei ◽  
Linsen Zan

Sirtuins, NAD+-dependent deacylases and ADP-ribosyltransferases, are critical regulators of metabolism involved in many biological processes, and are involved in mediating adaptive responses to the cellular environment. SIRT4 is a mitochondrial sirtuin and has been shown to play a critical role in maintaining insulin secretion and glucose homeostasis. As a regulator of lipid homeostasis, SIRT4 can repress fatty acid oxidation and promote lipid anabolism in nutrient-replete conditions. Using real-time quantitative PCR (qPCR) to explore the molecular mechanisms of transcriptional regulation of bovine SIRT4 during adipocyte differentiation, we found that bovine SIRT4 is expressed at high levels in bovine subcutaneous adipose tissue. SIRT4 knockdown led to decreased expression of adipogenic differentiation marker genes during adipocyte differentiation. The core promoter of bovine SIRT4 was identified in the −402/−60 bp region of the cloned 2-kb fragment containing the 5′-regulatory region. Binding sites were identified in this region for E2F transcription factor-1 (E2F1), CCAAT/enhancer-binding protein β (CEBPβ), homeobox A5 (HOXA5), interferon regulatory factor 4 (IRF4), paired box 4 (PAX4), and cAMP responsive element-binding protein 1 (CREB1) by using Electrophoretic mobility shift assay (EMSA) and luciferase reporter gene assay. We also found that E2F1, CEBPβ, and HOXA5 transcriptionally activate SIRT4 expression, whereas, IRF4, PAX4, and CREB1 transcriptionally repress SIRT4 expression. We further verified that SIRT4 knockdown could affect the ability of these transcription factors (TFs) to regulate the differentiation of bovine adipocytes. In conclusion, our results shed light on the mechanisms underlying the transcriptional regulation of SIRT4 expression in bovine adipocytes.


Endocrinology ◽  
2005 ◽  
Vol 146 (3) ◽  
pp. 1012-1017 ◽  
Author(s):  
Tatsuya Kobayashi ◽  
Henry Kronenberg

Regulation of gene expression by transcription factors is one of the major mechanisms for controlling cellular functions. Recent advances in genetic manipulation of model animals has allowed the study of the roles of various genes and their products in physiological settings and has demonstrated the importance of specific transcription factors in bone development. Three lineages of bone cells, chondrocytes, osteoblasts, and osteoclasts, develop and differentiate according to their distinct developmental programs. These cells go through multiple differentiation stages, which are often regulated by specific transcription factors. In this minireview, we will discuss selected transcription factors that have been demonstrated to critically affect bone cell development. Further study of these molecules will lead to deeper understanding in mechanisms that govern development of bone.


2018 ◽  
Author(s):  
E. Shannon Torres ◽  
Roger B. Deal

ABSTRACTPlants adapt to changes in their environment by regulating transcription and chromatin organization. The histone H2A variant H2A.Z and the SWI2/SNF2 ATPase BRAHMA have overlapping roles in positively and negatively regulating environmentally responsive genes in Arabidopsis, but the extent of this overlap was uncharacterized. Both have been associated with various changes in nucleosome positioning and stability in different contexts, but their specific roles in transcriptional regulation and chromatin organization need further characterization. We show that H2A.Z and BRM act both cooperatively and antagonistically to contribute directly to transcriptional repression and activation of genes involved in development and response to environmental stimuli. We identified 8 classes of genes that show distinct relationships between H2A.Z and BRM and their roles in transcription. We found that H2A.Z contributes to a range of different nucleosome properties, while BRM stabilizes nucleosomes where it binds and destabilizes and/or repositions flanking nucleosomes. H2A.Z and BRM contribute to +1 nucleosome destabilization, especially where they coordinately regulate transcription. We also found that at genes regulated by both BRM and H2A.Z, both factors overlap with the binding sites of light-regulated transcription factors PIF4, PIF5, and FRS9, and that some of the FRS9 binding sites are dependent on H2A.Z and BRM for accessibility. Collectively, we comprehensively characterized the antagonistic and cooperative contributions of H2A.Z and BRM to transcriptional regulation, and illuminated their interrelated roles in chromatin organization. The variability observed in their individual functions implies that both BRM and H2A.Z have more context-specific roles within diverse chromatin environments than previously assumed.


2019 ◽  
Vol 284 ◽  
pp. 113263
Author(s):  
Ellyse B. Noy ◽  
Yugo Watanabe ◽  
Sylvia V.H. Grommen ◽  
Bert De Groef

1999 ◽  
Vol 19 (1) ◽  
pp. 194-204 ◽  
Author(s):  
Axel Imhof ◽  
Marion Schuierer ◽  
Oliver Werner ◽  
Markus Moser ◽  
Christina Roth ◽  
...  

ABSTRACT AP-2 transcription factors have been suggested to exert key regulatory functions in vertebrate embryonic development, in tumorigenicity of various cancer cell types, and in controlling cell cycle and apoptotic effector genes. In this study, we investigated transcriptional regulation of the AP-2α gene promoter mediated by an autoregulatory element (referred to as A32) with a core consensus AP-2 binding site at position −336 relative to the mRNA initiation site. AP-2 and multiple different nuclear proteins in HeLa and Neuro2A cell extracts form specific bandshifts with the A32 element. By screening a mouse brain cDNA expression library, we isolated two different cDNAs encoding the transcription factor BTEB-1 and a novel zinc finger protein, AP-2rep. AP-2rep reveals a modular structure with homology to transcription factors of the wt-1/egr-1-family. AP-2rep, BTEB-1, and AP-2 interact in a mutually exclusive manner with overlapping binding sites in the A32 element. Transfection studies revealed that BTEB-1 is a strong activator of AP-2α promoter activity, whereas cotransfected AP-2α resulted in moderate autoactivation of promoter activity. In contrast, AP-2rep confers strong transcriptional repression to the AP-2α gene, and we observed an excellent correlation between induction of AP-2rep mRNA expression and downregulation of AP-2α mRNA during development of the kidney. In summary, we have identified multiple transcription factors and cloned from an expression library a novel zinc finger silencing factor, AP-2rep, mediating positive and negative regulation of AP-2α expression through a set of overlappingcis-regulatory promoter elements.


2019 ◽  
Vol 20 (7) ◽  
pp. 1600 ◽  
Author(s):  
Purnima Singh ◽  
Iny Mathew ◽  
Ankit Verma ◽  
Akhilesh Tyagi ◽  
Pinky Agarwal

Transcriptional regulation includes both activation and repression of downstream genes. In plants, a well-established class of repressors are proteins with an ERF-associated amphiphilic repression/EAR domain. They contain either DLNxxP or LxLxL as the identifying hexapeptide motif. In rice (Oryza sativa), we have identified a total of 266 DLN repressor proteins, with the former motif and its modifications thereof comprising 227 transcription factors and 39 transcriptional regulators. Apart from DLNxxP motif conservation, DLNxP and DLNxxxP motifs with variable numbers/positions of proline and those without any proline conservation have been identified. Most of the DLN repressome proteins have a single DLN motif, with higher relative percentage in the C-terminal region. We have designed a simple yeast-based experiment wherein a DLN motif can successfully cause strong repression of downstream reporter genes, when fused to a transcriptional activator of rice or yeast. The DLN hexapeptide motif is essential for repression, and at least two “DLN” residues cause maximal repression. Comparatively, rice has more DLN repressor encoding genes than Arabidopsis, and DLNSPP motif from rice is 40% stronger than the known Arabidopsis SRDX motif. The study reports a straightforward assay to analyze repressor activity, along with the identification of a strong DLN repressor from rice.


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