scholarly journals Mitochondrial Nucleoid: Shield and Switch of the Mitochondrial Genome

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Sung Ryul Lee ◽  
Jin Han
Keyword(s):  
Gene Expression ◽  
Protein Complexes ◽  
Mitochondrial Diseases ◽  
Research Field ◽  
Fundamental Question ◽  
Mitochondrial Nucleoid ◽  
Significant Interest ◽  
Associated Proteins ◽  
Multicellular Organisms ◽  
Nucleoid Structure

Mitochondria preserve very complex and distinctively unique machinery to maintain and express the content of mitochondrial DNA (mtDNA). Similar to chromosomes, mtDNA is packaged into discrete mtDNA-protein complexes referred to as a nucleoid. In addition to its role as a mtDNA shield, over 50 nucleoid-associated proteins play roles in mtDNA maintenance and gene expression through either temporary or permanent association with mtDNA or other nucleoid-associated proteins. The number of mtDNA(s) contained within a single nucleoid is a fundamental question but remains a somewhat controversial issue. Disturbance in nucleoid components and mutations in mtDNA were identified as significant in various diseases, including carcinogenesis. Significant interest in the nucleoid structure and its regulation has been stimulated in relation to mitochondrial diseases, which encompass diseases in multicellular organisms and are associated with accumulation of numerous mutations in mtDNA. In this review, mitochondrial nucleoid structure, nucleoid-associated proteins, and their regulatory roles in mitochondrial metabolism are briefly addressed to provide an overview of the emerging research field involving mitochondrial biology.

Nanoparticle-plasma Membrane Interactions: Thermodynamics, Toxicity and Cellular Response

2020 ◽  
Vol 27 (20) ◽  
pp. 3330-3345
Author(s):  
Ana G. Rodríguez-Hernández ◽  
Rafael Vazquez-Duhalt ◽  
Alejandro Huerta-Saquero
Keyword(s):  
Gene Expression ◽  
Immune Responses ◽  
Cellular Response ◽  
Cellular Level ◽  
Membrane Interactions ◽  
Daily Lives ◽  
Cellular Physiology ◽  
Associated Proteins ◽  
First Contact ◽  
Insight Into

Nanomaterials have become part of our daily lives, particularly nanoparticles contained in food, water, cosmetics, additives and textiles. Nanoparticles interact with organisms at the cellular level. The cell membrane is the first protective barrier against the potential toxic effect of nanoparticles. This first contact, including the interaction between the cell membranes -and associated proteins- and the nanoparticles is critically reviewed here. Nanoparticles, depending on their toxicity, can cause cellular physiology alterations, such as a disruption in cell signaling or changes in gene expression and they can trigger immune responses and even apoptosis. Additionally, the fundamental thermodynamics behind the nanoparticle-membrane and nanoparticle-proteins-membrane interactions are discussed. The analysis is intended to increase our insight into the mechanisms involved in these interactions. Finally, consequences are reviewed and discussed.

scholarly journals The secreted endoribonuclease ENDU-2 from the soma protects germline immortality in C. elegans

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wenjing Qi ◽  
Erika D. V. Gromoff ◽  
Fan Xu ◽  
Qian Zhao ◽  
Wei Yang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cell ◽  
Small Rnas ◽  
C Elegans ◽  
Cleavage Activity ◽  
Response To Temperature ◽  
Multicellular Organisms ◽  
Cell Immortality ◽  
Mature Mrnas ◽  
Endoribonuclease Activity

AbstractMulticellular organisms coordinate tissue specific responses to environmental information via both cell-autonomous and non-autonomous mechanisms. In addition to secreted ligands, recent reports implicated release of small RNAs in regulating gene expression across tissue boundaries. Here, we show that the conserved poly-U specific endoribonuclease ENDU-2 in C. elegans is secreted from the soma and taken-up by the germline to ensure germline immortality at elevated temperature. ENDU-2 binds to mature mRNAs and negatively regulates mRNA abundance both in the soma and the germline. While ENDU-2 promotes RNA decay in the soma directly via its endoribonuclease activity, ENDU-2 prevents misexpression of soma-specific genes in the germline and preserves germline immortality independent of its RNA-cleavage activity. In summary, our results suggest that the secreted RNase ENDU-2 regulates gene expression across tissue boundaries in response to temperature alterations and contributes to maintenance of stem cell immortality, probably via retaining a stem cell specific program of gene expression.

scholarly journals Computational design and experimental characterization of a photo-controlled mRNA-cap guanine-N7 methyltransferase

2021 ◽  
Author(s):  
Dennis Reichert ◽  
Helena Schepers ◽  
Julian Simke ◽  
Horst Lechner ◽  
Wolfgang Dörner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Computational Design ◽  
Eukaryotic Cells ◽  
Transcriptional Level ◽  
Experimental Characterization ◽  
Temporal Control ◽  
Control Of Gene Expression ◽  
Multicellular Organisms

The spatial and temporal control of gene expression at the post-transcriptional level is essential in eukaryotic cells and developing multicellular organisms. In recent years optochemical and optogenetic tools have enabled...

scholarly journals Environmental RNAi pathways in the two-spotted spider mite

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Mosharrof Mondal ◽  
Jacob Peter ◽  
Obrie Scarbrough ◽  
Alex Flynt
Keyword(s):  
Gene Expression ◽  
Small Rna ◽  
Spider Mite ◽  
Genetic Manipulation ◽  
Model Organisms ◽  
Rnai Pathway ◽  
Plant Host ◽  
Rnai Technology ◽  
Two Spotted Spider Mite ◽  
Multicellular Organisms

Abstract Background RNA interference (RNAi) regulates gene expression in most multicellular organisms through binding of small RNA effectors to target transcripts. Exploiting this process is a popular strategy for genetic manipulation and has applications that includes arthropod pest control. RNAi technologies are dependent on delivery method with the most convenient likely being feeding, which is effective in some animals while others are insensitive. The two-spotted spider mite, Tetranychus urticae, is prime candidate for developing RNAi approaches due to frequent occurrence of conventional pesticide resistance. Using a sequencing-based approach, the fate of ingested RNAs was explored to identify features and conditions that affect small RNA biogenesis from external sources to better inform RNAi design. Results Biochemical and sequencing approaches in conjunction with extensive computational assessment were used to evaluate metabolism of ingested RNAs in T. urticae. This chelicerae arthropod shows only modest response to oral RNAi and has biogenesis pathways distinct from model organisms. Processing of synthetic and plant host RNAs ingested during feeding were evaluated to identify active substrates for spider mite RNAi pathways. Through cataloging characteristics of biochemically purified RNA from these sources, trans-acting small RNAs could be distinguished from degradation fragments and their origins documented. Conclusions Using a strategy that delineates small RNA processing, we found many transcripts have the potential to enter spider mite RNAi pathways, however, trans-acting RNAs appear very unstable and rare. This suggests potential RNAi pathway substrates from ingested materials are mostly degraded and infrequently converted into regulators of gene expression. Spider mites infest a variety of plants, and it would be maladaptive to generate diverse gene regulators from dietary RNAs. This study provides a framework for assessing RNAi technology in organisms where genetic and biochemical tools are absent and benefit rationale design of RNAi triggers for T.urticae.

scholarly journals Binding of an X-Specific Condensin Correlates with a Reduction in Active Histone Modifications at Gene Regulatory Elements

Genetics ◽  
2019 ◽  
Vol 212 (3) ◽  
pp. 729-742 ◽  
Author(s):  
Lena Annika Street ◽  
Ana Karina Morao ◽  
Lara Heermans Winterkorn ◽  
Chen-Yu Jiao ◽  
Sarah Elizabeth Albritton ◽  
...  
Keyword(s):  
Gene Expression ◽  
Histone Modifications ◽  
Chromatin Immunoprecipitation ◽  
Protein Complexes ◽  
Regulatory Elements ◽  
Evolutionarily Conserved ◽  
Chromatin Immunoprecipitation Sequencing ◽  
Gene Regulatory Elements ◽  
Gene Regulatory ◽  
Regulatory Sites

Condensins are evolutionarily conserved protein complexes that are required for chromosome segregation during cell division and genome organization during interphase. In Caenorhabditis elegans, a specialized condensin, which forms the core of the dosage compensation complex (DCC), binds to and represses X chromosome transcription. Here, we analyzed DCC localization and the effect of DCC depletion on histone modifications, transcription factor binding, and gene expression using chromatin immunoprecipitation sequencing and mRNA sequencing. Across the X, the DCC accumulates at accessible gene regulatory sites in active chromatin and not heterochromatin. The DCC is required for reducing the levels of activating histone modifications, including H3K4me3 and H3K27ac, but not repressive modification H3K9me3. In X-to-autosome fusion chromosomes, DCC spreading into the autosomal sequences locally reduces gene expression, thus establishing a direct link between DCC binding and repression. Together, our results indicate that DCC-mediated transcription repression is associated with a reduction in the activity of X chromosomal gene regulatory elements.

Molecular Mechanisms Underlying the Anti-Breast Cancer Stem Cell Activity of Pterocladia capillacea and Corallina officinalis Polysaccharides

2021 ◽  
Vol 21 ◽  
Author(s):  
Hebatallah G. Hafez ◽  
Rafat M. Mohareb ◽  
Sohair M. Salem ◽  
Azza A. Matloub ◽  
Emad F. Eskander ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Protein Complexes ◽  
Cell Activity ◽  
Sulfated Polysaccharide ◽  
Corallina Officinalis ◽  
Stem Cell Activity ◽  
Mcf 7

Objective: This study aimed to appraise the activity of Pterocladia capillacea and Corallina officinalis polysaccharides against breast cancer stem cells (BCSCs). P. capillacea and C. officinalis polysaccharides were characterized to be sulfated polysaccharide-protein complexes. Methods: Cytotoxicity of the polysaccharides against MDA-MB-231 and MCF-7 cell lines along with their impact on CD44+/CD24− and aldehyde dehydrogenase 1(ALDH1) positive BCSC population were determined. Their effect on gene expression of CSC markers, Wnt/β-catenin and Notch signaling pathways was evaluated. Results: P. capillacea and C. officinalis polysaccharides inhibited the growth of breast cancer cells and reduced BCSC subpopulation. P. capillacea polysaccharides significantly down-regulated OCT4, SOX2, ALDH1A3 and vimentin in MDA-MB-231 as well as in MCF-7 cells except for vimentin that was up-regulated in MCF-7 cells. C. officinalis polysaccharides exhibited similar effects except for OCT4 that was up-regulated in MDA-MB-231 cells. Significant suppression of Cyclin D1 gene expression was noted in MDA-MB-231 and MCF-7 cells treated with P. capillacea or C. officinalis polysaccharides. β-catenin and c-Myc genes were significantly down-regulated in MDA-MB-231 cells treated with C. officinalis and P. capillacea polysaccharides, respectively, while being up-regulated in MCF-7 cells treated with either of them. Additionally, P. capillacea and C. officinalis polysaccharides significantly down-regulated Hes1 gene in MCF-7 cells despite increasing Notch1 gene expression level. However, significant down-regulation of Notch1 gene was observed in MDA-MB-231 cells treated with P. capillacea polysaccharides. Conclusion: Collectively, this study provides evidence for the effectiveness of P. capillacea and C. officinalis polysaccharides in targeting BCSCs through interfering with substantial signaling pathways contributing to their functionality.

Sign in / Sign up

Export Citation Format

Share Document