scholarly journals Negative Control of rpoS Expression by Phosphoenolpyruvate:Carbohydrate Phosphotransferase System inEscherichia coli

2001 ◽  
Vol 183 (2) ◽  
pp. 520-527 ◽  
Author(s):  
Chiharu Ueguchi ◽  
Naoko Misonou ◽  
Takeshi Mizuno
Keyword(s):  
Cyclic Amp ◽  
Carbon Metabolism ◽  
Translational Control ◽  
Transcriptional Control ◽  
Molecular Mechanisms ◽  
Negative Control ◽  
Inescherichia Coli ◽  
Phosphotransferase System ◽  
Number Of Factors ◽  
Complex Manner

ABSTRACT The ςS (or ς38) subunit of RNA polymerase, encoded by the rpoS gene, is a crucial regulator in the transcriptional control of a set of genes under stressful conditions, such as nutrient starvation. The expression ofrpoS is regulated in a complex manner at the levels of transcription, translation, and stability of the product. Although a number of factors involved in the regulation of rpoSexpression have been identified, the underlying molecular mechanisms are not fully understood. In this study, we identified the Crr (or EIIAGlc) protein as a novel factor that plays an important role not only in the transcriptional control but also in the translational control of rpoS expression. Crr is an important component in glucose uptake through the well-characterized phosphoenolpyruvate:carbohydrate phosphotransferase system. The results of a series of genetic analyses revealed that Crr negatively controlsrpoS translation and transcription. The observed transcriptional control by Crr appears to be mediated by cyclic AMP. However, it was found that Crr negatively controls rpoStranslation rather directly. These results suggest a possible linkage between the control of rpoS expression and carbon metabolism.

scholarly journals Regulation of Translation in the Protozoan Parasite Leishmania

2020 ◽  
Vol 21 (8) ◽  
pp. 2981
Author(s):  
Zemfira N. Karamysheva ◽  
Sneider Alexander Gutierrez Guarnizo ◽  
Andrey L. Karamyshev
Keyword(s):  
Drug Resistance ◽  
Translational Control ◽  
Transcriptional Control ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Protozoan Parasite ◽  
Sand Fly ◽  
Mammalian Host ◽  
Translational Machinery

Leishmaniasis represents a serious health problem worldwide and drug resistance is a growing concern. Leishmania parasites use unusual mechanisms to control their gene expression. In contrast to many other species, they do not have transcriptional regulation. The lack of transcriptional control is mainly compensated by post-transcriptional mechanisms, including tight translational control and regulation of mRNA stability/translatability by RNA-binding proteins. Modulation of translation plays a major role in parasite survival and adaptation to dramatically different environments during change of host; however, our knowledge of fine molecular mechanisms of translation in Leishmania remains limited. Here, we review the current progress in our understanding of how changes in the translational machinery promote parasite differentiation during transmission from a sand fly to a mammalian host, and discuss how translational reprogramming can contribute to the development of drug resistance.

scholarly journals Screen Key Genes Associated with Distraction-Induced Osteogenesis of Stem Cells Using Bioinformatics Methods

2021 ◽  
Vol 22 (12) ◽  
pp. 6505
Author(s):  
Jishizhan Chen ◽  
Jia Hua ◽  
Wenhui Song
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Enrichment Analysis ◽  
Negative Control ◽  
Gene Set Enrichment Analysis ◽  
Venn Diagram ◽  
Hub Genes ◽  
Protein Protein Interaction ◽  
Two Samples ◽  
Key Genes

Applying mesenchymal stem cells (MSCs), together with the distraction osteogenesis (DO) process, displayed enhanced bone quality and shorter treatment periods. The DO guides the differentiation of MSCs by providing mechanical clues. However, the underlying key genes and pathways are largely unknown. The aim of this study was to screen and identify hub genes involved in distraction-induced osteogenesis of MSCs and potential molecular mechanisms. Material and Methods: The datasets were downloaded from the ArrayExpress database. Three samples of negative control and two samples subjected to 5% cyclic sinusoidal distraction at 0.25 Hz for 6 h were selected for screening differentially expressed genes (DEGs) and then analysed via bioinformatics methods. The Gene Ontology (GO) terms and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway enrichment were investigated. The protein–protein interaction (PPI) network was visualised through the Cytoscape software. Gene set enrichment analysis (GSEA) was conducted to verify the enrichment of a self-defined osteogenic gene sets collection and identify osteogenic hub genes. Results: Three hub genes (IL6, MMP2, and EP300) that were highly associated with distraction-induced osteogenesis of MSCs were identified via the Venn diagram. These hub genes could provide a new understanding of distraction-induced osteogenic differentiation of MSCs and serve as potential gene targets for optimising DO via targeted therapies.

scholarly journals Functional antagonism of chromatin modulators regulates epithelial-mesenchymal transition

2021 ◽  
Vol 7 (9) ◽  
pp. eabd7974
Author(s):  
Michela Serresi ◽  
Sonia Kertalli ◽  
Lifei Li ◽  
Matthias Jürgen Schmitt ◽  
Yuliia Dramaretska ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Transcriptional Control ◽  
Molecular Mechanisms ◽  
Developmental Process ◽  
Epithelial Mesenchymal Transition ◽  
Chromatin Remodelers ◽  
Mesenchymal Transition ◽  
Signature Genes ◽  
Chromatin Regulators ◽  
The Impact

Epithelial-mesenchymal transition (EMT) is a developmental process hijacked by cancer cells to modulate proliferation, migration, and stress response. Whereas kinase signaling is believed to be an EMT driver, the molecular mechanisms underlying epithelial-mesenchymal interconversion are incompletely understood. Here, we show that the impact of chromatin regulators on EMT interconversion is broader than that of kinases. By combining pharmacological modulation of EMT, synthetic genetic tracing, and CRISPR interference screens, we uncovered a minority of kinases and several chromatin remodelers, writers, and readers governing homeostatic EMT in lung cancer cells. Loss of ARID1A, DOT1L, BRD2, and ZMYND8 had nondeterministic and sometimes opposite consequences on epithelial-mesenchymal interconversion. Together with RNAPII and AP-1, these antagonistic gatekeepers control chromatin of active enhancers, including pan-cancer-EMT signature genes enabling supraclassification of anatomically diverse tumors. Thus, our data uncover general principles underlying transcriptional control of cancer cell plasticity and offer a platform to systematically explore chromatin regulators in tumor-state–specific therapy.

scholarly journals The Role of Translation Initiation Regulation in Haematopoiesis

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Godfrey Grech ◽  
Marieke von Lindern
Keyword(s):  
Gene Expression ◽  
Translation Initiation ◽  
Translational Control ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Regulation Of Gene Expression ◽  
Mrna Translation ◽  
Translation Control ◽  
Haematological Disorders

Organisation of RNAs into functional subgroups that are translated in response to extrinsic and intrinsic factors underlines a relatively unexplored gene expression modulation that drives cell fate in the same manner as regulation of the transcriptome by transcription factors. Recent studies on the molecular mechanisms of inflammatory responses and haematological disorders indicate clearly that the regulation of mRNA translation at the level of translation initiation, mRNA stability, and protein isoform synthesis is implicated in the tight regulation of gene expression. This paper outlines how these posttranscriptional control mechanisms, including control at the level of translation initiation factors and the role of RNA binding proteins, affect hematopoiesis. The clinical relevance of these mechanisms in haematological disorders indicates clearly the potential therapeutic implications and the need of molecular tools that allow measurement at the level of translational control. Although the importance of miRNAs in translation control is well recognised and studied extensively, this paper will exclude detailed account of this level of control.

Negative control of norepinephrine on the thyroid cyclic AMP system

1982 ◽  
Vol 721 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Pascale Cochaux ◽  
Jacqueline Van Sande ◽  
Jacques E. Dumont
Keyword(s):  
Cyclic Amp ◽  
Negative Control ◽  
Amp System

scholarly journals Sinorhizobium meliloti Mutants Lacking Phosphotransferase System Enzyme HPr or EIIA Are Altered in Diverse Processes, Including Carbon Metabolism, Cobalt Requirements, and Succinoglycan Production

2008 ◽  
Vol 190 (8) ◽  
pp. 2947-2956 ◽  
Author(s):  
Catalina Arango Pinedo ◽  
Ryan M. Bringhurst ◽  
Daniel J. Gage
Keyword(s):  
Carbon Metabolism ◽  
Sinorhizobium Meliloti ◽  
Carbon Sources ◽  
Deletion Mutants ◽  
Symbiotic Relationship ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Carbon Utilization ◽  
Carbon Regulation ◽  
Extreme Sensitivity

ABSTRACT Sinorhizobium meliloti is a member of the Alphaproteobacteria that fixes nitrogen when it is in a symbiotic relationship. Genes for an incomplete phosphotransferase system (PTS) have been found in the genome of S. meliloti. The genes present code for Hpr and ManX (an EIIAMan-type enzyme). HPr and EIIA regulate carbon utilization in other bacteria. hpr and manX in-frame deletion mutants exhibited altered carbon metabolism and other phenotypes. Loss of HPr resulted in partial relief of succinate-mediated catabolite repression, extreme sensitivity to cobalt limitation, rapid die-off during stationary phase, and altered succinoglycan production. Loss of ManX decreased expression of melA-agp and lac, the operons needed for utilization of α- and β-galactosides, slowed growth on diverse carbon sources, and enhanced accumulation of high-molecular-weight succinoglycan. A strain with both hpr and manX deletions exhibited phenotypes similar to those of the strain with a single hpr deletion. Despite these strong phenotypes, deletion mutants exhibited wild-type nodulation and nitrogen fixation when they were inoculated onto Medicago sativa. The results show that HPr and ManX (EIIAMan) are involved in more than carbon regulation in S. meliloti and suggest that the phenotypes observed occur due to activity of HPr or one of its phosphorylated forms.

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