scholarly journals Regulation of mRNA cap methylation

2009 ◽  
Vol 425 (2) ◽  
pp. 295-302 ◽  
Author(s):  
Victoria H. Cowling
Keyword(s):  
Gene Expression ◽  
Cell Viability ◽  
Nuclear Export ◽  
Present Review ◽  
Biological Processes ◽  
Experimental Systems ◽  
Efficient Gene ◽  
Cellular Mrnas ◽  
Eukaryotic Organisms ◽  
The Impact

The 7-methylguanosine cap added to the 5′ end of mRNA is essential for efficient gene expression and cell viability. Methylation of the guanosine cap is necessary for the translation of most cellular mRNAs in all eukaryotic organisms in which it has been investigated. In some experimental systems, cap methylation has also been demonstrated to promote transcription, splicing, polyadenylation and nuclear export of mRNA. The present review discusses how the 7-methylguanosine cap is synthesized by cellular enzymes, the impact that the 7-methylguanosine cap has on biological processes, and how the mRNA cap methylation reaction is regulated.

scholarly journals The crucial roles of N6-methyladenosine (m6A) modification in the carcinogenesis and progression of colorectal cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhihao Fang ◽  
Yiqiu Hu ◽  
Jinhui Hu ◽  
Yanqin Huang ◽  
Shu Zheng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
Nuclear Export ◽  
Messenger Rna ◽  
Regulatory Proteins ◽  
Biological Processes ◽  
The Past ◽  
Common Cancer ◽  
Potential Applications ◽  
Regulated Gene Expression

AbstractAs the predominant modification in RNA, N6-methyladenosine (m6A) has attracted increasing attention in the past few years since it plays vital roles in many biological processes. This chemical modification is dynamic, reversible and regulated by several methyltransferases, demethylases and proteins that recognize m6A modification. M6A modification exists in messenger RNA and affects their splicing, nuclear export, stability, decay, and translation, thereby modulating gene expression. Besides, the existence of m6A in noncoding RNAs (ncRNAs) could also directly or indirectly regulated gene expression. Colorectal cancer (CRC) is a common cancer around the world and of high mortality. Increasing evidence have shown that the changes of m6A level and the dysregulation of m6A regulatory proteins have been implicated in CRC carcinogenesis and progression. However, the underlying regulation laws of m6A modification to CRC remain elusive and better understanding of these mechanisms will benefit the diagnosis and therapy. In the present review, the latest studies about the dysregulation of m6A and its regulators in CRC have been summarized. We will focus on the crucial roles of m6A modification in the carcinogenesis and development of CRC. Moreover, we will also discuss the potential applications of m6A modification in CRC diagnosis and therapeutics.

scholarly journals Direct and widespread role for the nuclear receptor EcR in mediating the response to ecdysone in Drosophila

2019 ◽  
Vol 116 (20) ◽  
pp. 9893-9902 ◽  
Author(s):  
Christopher M. Uyehara ◽  
Daniel J. McKay
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Nuclear Receptor ◽  
Binding Sites ◽  
Transcriptional Responses ◽  
Enhancer Activity ◽  
Developmental Transitions ◽  
Experimental Systems ◽  
The Impact

The ecdysone pathway was among the first experimental systems employed to study the impact of steroid hormones on the genome. In Drosophila and other insects, ecdysone coordinates developmental transitions, including wholesale transformation of the larva into the adult during metamorphosis. Like other hormones, ecdysone controls gene expression through a nuclear receptor, which functions as a ligand-dependent transcription factor. Although it is clear that ecdysone elicits distinct transcriptional responses within its different target tissues, the role of its receptor, EcR, in regulating target gene expression is incompletely understood. In particular, EcR initiates a cascade of transcription factor expression in response to ecdysone, making it unclear which ecdysone-responsive genes are direct EcR targets. Here, we use the larval-to-prepupal transition of developing wings to examine the role of EcR in gene regulation. Genome-wide DNA binding profiles reveal that EcR exhibits widespread binding across the genome, including at many canonical ecdysone response genes. However, the majority of its binding sites reside at genes with wing-specific functions. We also find that EcR binding is temporally dynamic, with thousands of binding sites changing over time. RNA-seq reveals that EcR acts as both a temporal gate to block precocious entry to the next developmental stage as well as a temporal trigger to promote the subsequent program. Finally, transgenic reporter analysis indicates that EcR regulates not only temporal changes in target enhancer activity but also spatial patterns. Together, these studies define EcR as a multipurpose, direct regulator of gene expression, greatly expanding its role in coordinating developmental transitions.

scholarly journals Mutational Signatures as Sensors of Environmental Exposures: Role of Smoking in COVID-19 Vulnerabilities

2021 ◽  
Author(s):  
Yoo-Ah Kim ◽  
Ermin Hodzic ◽  
Ariella Saslafsky ◽  
Damian Wojtowicz ◽  
Bayarbaatar Amgalan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Environmental Factors ◽  
Disease Progression ◽  
Environmental Exposures ◽  
Biological Processes ◽  
Mutational Signatures ◽  
Mutational Signature ◽  
The Impact ◽  
Pathway Level

Background: Environmental exposures such as smoking are widely recognized risk factors in the emergence of lung diseases such as lung cancer and acute respiratory distress syndrome (ARDS). However, the strength of environmental exposures is difficult to measure, making it challenging to understand their impacts. On the other hand, some COVID-19 patients develop ARDS in an unfavorable disease progression and smoking has been suggested as a potential risk factor among others. Yet initial studies on COVID-19 cases reported contradictory results on the effects of smoking on the disease. Some suggest that smoking might have a protective effect against it while other studies report an increased risk. A better understanding of how the exposure to smoking and other environmental factors affect biological processes relevant to SARS-CoV-2 infection and unfavorable disease progression is needed. Approach: In this study, we utilize mutational signatures associated with environmental factors as sensors of their exposure level. Many environmental factors including smoking are mutagenic and leave characteristic patterns of mutations, called mutational signatures, in affected genomes. We postulated that analyzing mutational signatures, combined with gene expression, can shed light on the impact of the mutagenic environmental factors to the biological processes. In particular, we utilized mutational signatures from lung adenocarcinoma (LUAD) data set collected in TCGA to investigate the role of environmental factors in COVID-19 vulnerabilities. Integrating mutational signatures with gene expression in normal tissues and using a pathway level analysis, we examined how the exposure to smoking and other mutagenic environmental factors affects the infectivity of the virus and disease progression. Results: By delineating changes associated with smoking in pathway-level gene expression and cell type proportions, our study demonstrates that mutational signatures can be utilized to study the impact of exogenous mutagenic factors on them. Consistent with previous findings, our analysis showed that smoking mutational signature (SBS4) is associated with activation of cytokines mediated singling pathways, leading to inflammatory responses. Smoking related changes in cell composition were also observed, including the correlation of SBS4 with the expansion of goblet cells. On the other hand, increased basal cells and decreased ciliated cells in proportion were associated with the strength of a different mutational signature (SBS5), which is present abundantly but not exclusively in smokers. In addition, we found that smoking increases the expression levels of genes that are upregulated in severe COVID-19 cases. Jointly, these results suggest an unfavorable impact of smoking on the disease progression and also provide novel findings on how smoking impacts biological processes in lung.

scholarly journals A Review on the Role of miR-1290 in Cell Proliferation, Apoptosis and Invasion

2021 ◽  
Vol 8 ◽  
Author(s):  
Soudeh Ghafouri-Fard ◽  
Tayyebeh Khoshbakht ◽  
Bashdar Mahmud Hussen ◽  
Mohammad Taheri ◽  
Mohammad Samadian
Keyword(s):  
Cell Proliferation ◽  
Present Review ◽  
Molecular Pathways ◽  
Biological Processes ◽  
Affect Expression ◽  
Non Coding Rnas ◽  
The Impact

MicroRNAs (miRNAs) have been shown to affect expression of several genes contributing in important biological processes. miR-1290 a member of this family with crucial roles in the carcinogenesis. This miRNA is transcribed from MIR1290 gene on chromosome 1p36.13. This miRNA has interactions with a number of mRNA coding genes as well as non-coding RNAs SOCS4, GSK3, BCL2, CCNG2, KIF13B, INPP4B, hMSH2, KIF13B, NKD1, FOXA1, IGFBP3, CCAT1, FOXA1, NAT1, SMEK1, SCAI, ZNF667-AS1, ABLIM1, Circ_0000629 and CDC73. miR-1290 can also regulate activity of JAK/STAT3, PI3K/AKT, Wnt/β-catenin and NF-κB molecular pathways. Most evidence indicates the oncogenic roles of miR-1290, yet controversial evidence also exists. In the present review, we describe the results of in vitro, animal and human investigations about the impact of miR-1290 in the development of malignancies.

scholarly journals Roles of the oviduct in mammalian fertilization

Reproduction ◽  
2012 ◽  
Vol 144 (6) ◽  
pp. 649-660 ◽  
Author(s):  
P Coy ◽  
F A García-Vázquez ◽  
P E Visconti ◽  
M Avilés
Keyword(s):  
Gene Expression ◽  
Fallopian Tube ◽  
Mammalian Species ◽  
Present Review ◽  
Specific Site ◽  
Biological Processes ◽  
Anatomical Region ◽  
Oviductal Epithelium ◽  
Mammalian Fertilization

The oviduct or Fallopian tube is the anatomical region where every new life begins in mammalian species. After a long journey, the spermatozoa meet the oocyte in the specific site of the oviduct named ampulla and fertilization takes place. The successful fertilization depends on several biological processes that occur in the oviduct some hours before this rendezvous and affect both gametes. Estrogen and progesterone, released from the ovary, orchestrate a series of changes by genomic and nongenomic pathways in the oviductal epithelium affecting gene expression, proteome, and secretion of its cells into the fluid bathing the oviductal lumen. In addition, new regulatory molecules are being discovered playing important roles in oviductal physiology and fertilization. The present review tries to describe these processes, building a comprehensive map of the physiology of the oviduct, to better understand the importance of this organ in reproduction. With this purpose, gamete transport, sperm and oocyte changes in the oviductal environment, and other interactions between gametes and oviduct are discussed in light of recent publications in the field.

scholarly journals An effective model of endogenous clocks and external stimuli determining circadian rhythms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tim Breitenbach ◽  
Charlotte Helfrich-Förster ◽  
Thomas Dandekar
Keyword(s):  
Biological Effects ◽  
Research Field ◽  
Effective Model ◽  
High Dose ◽  
Mathematical Framework ◽  
Biological Processes ◽  
Response Curves ◽  
Eukaryotic Organisms ◽  
External Stimuli ◽  
The Impact

AbstractCircadian endogenous clocks of eukaryotic organisms are an established and rapidly developing research field. To investigate and simulate in an effective model the effect of external stimuli on such clocks and their components we developed a software framework for download and simulation. The application is useful to understand the different involved effects in a mathematical simple and effective model. This concerns the effects of Zeitgebers, feedback loops and further modifying components. We start from a known mathematical oscillator model, which is based on experimental molecular findings. This is extended with an effective framework that includes the impact of external stimuli on the circadian oscillations including high dose pharmacological treatment. In particular, the external stimuli framework defines a systematic procedure by input-output-interfaces to couple different oscillators. The framework is validated by providing phase response curves and ranges of entrainment. Furthermore, Aschoffs rule is computationally investigated. It is shown how the external stimuli framework can be used to study biological effects like points of singularity or oscillators integrating different signals at once. The mathematical framework and formalism is generic and allows to study in general the effect of external stimuli on oscillators and other biological processes. For an easy replication of each numerical experiment presented in this work and an easy implementation of the framework the corresponding Mathematica files are fully made available. They can be downloaded at the following link: https://www.biozentrum.uni-wuerzburg.de/bioinfo/computing/circadian/.

scholarly journals Maternal Vitamin and Mineral Supplementation and Rate of Maternal Weight Gain Affects Placental Expression of Energy Metabolism and Transport-Related Genes

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 385
Author(s):  
Wellison J. S. Diniz ◽  
Lawrence P. Reynolds ◽  
Pawel P. Borowicz ◽  
Alison K. Ward ◽  
Kevin K. Sedivec ◽  
...  
Keyword(s):  
Gene Expression ◽  
Weight Gain ◽  
Ion Homeostasis ◽  
Biological Processes ◽  
Maternal Weight Gain ◽  
Maternal Weight ◽  
Maternal Vitamin ◽  
Mineral Supplementation ◽  
Vitamin And Mineral Supplementation ◽  
The Impact

Maternal nutrients are essential for proper fetal and placental development and function. However, the effects of vitamin and mineral supplementation under two rates of maternal weight gain on placental genome-wide gene expression have not been investigated so far. Furthermore, biological processes and pathways in the placenta that act in response to early maternal nutrition are yet to be elucidated. Herein, we examined the impact of maternal vitamin and mineral supplementation (from pre-breeding to day 83 post-breeding) and two rates of gain during the first 83 days of pregnancy on the gene expression of placental caruncles (CAR; maternal placenta) and cotyledons (COT; fetal placenta) of crossbred Angus beef heifers. We identified 267 unique differentially expressed genes (DEG). Among the DEGs from CAR, we identified ACAT2, SREBF2, and HMGCCS1 that underlie the cholesterol biosynthesis pathway. Furthermore, the transcription factors PAX2 and PAX8 were over-represented in biological processes related to kidney organogenesis. The DEGs from COT included SLC2A1, SLC2A3, SLC27A4, and INSIG1. Our over-representation analysis retrieved biological processes related to nutrient transport and ion homeostasis, whereas the pathways included insulin secretion, PPAR signaling, and biosynthesis of amino acids. Vitamin and mineral supplementation and rate of gain were associated with changes in gene expression, biological processes, and KEGG pathways in beef cattle placental tissues.

Gene expression profiling and clinical relevance unravel the role hypoxia and immune signaling genes and pathways in breast cancer

2020 ◽  
Vol 1 ◽  
Author(s):  
Mohammad Azhar Kamal ◽  
Mohiuddin Khan Warsi ◽  
Afnan Alnajeebi ◽  
Haytham A Ali ◽  
Nawal Helmi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Gene Expression Profiling ◽  
Signaling Pathways ◽  
Expression Profiling ◽  
Gene List ◽  
Molecular Signatures ◽  
Biological Processes ◽  
Immune Signaling ◽  
The Impact

Hypoxia most often occurs in cancer and the occurrence of hypoxia helps the cells in adapting different responses than the normal such as the activation of of those signaling pathways which regulate proliferation, angiogenesis, and cell death. There are large number of genes which are known to be associated with diverse biological processes and their control and coordination and in different cancers, the hypoxia-response differs. In this study our goal is to understand the impact of alteration in expression of hypoxia and immune systems related genes and its survival in breast cancer and analyzed the hallmarks of molecular signatures. For this purpose we have collected the hypoxia-associated genes based on the literature related with diverse biological processes and functions. For all these genes, we have studied the survival analysis, breast cancer gene expression profiling, and relevant hypoxic genes alterations. Based on our study, we conclude that there are 17 critical pathways and 40 genes from hypoxic gene list appear to play the major roles in case of breast cancer and overall we observe that immune signaling pathways and its components are highly altered in case of breast cancer. Among the top raked hallmarks of molecular signatures are apoptosis, hypoxia, DNA repair, E2F targets, MYC targets, androgen and estrogen response, and TNFa signaling.

Biogenesis and the regulation of the maturation of miRNAs

2013 ◽  
Vol 54 ◽  
pp. 17-28 ◽  
Author(s):  
Nham Tran ◽  
Gyorgy Hutvagner
Keyword(s):  
Gene Expression ◽  
Regulation Of Gene Expression ◽  
Biological Processes ◽  
Cell Functions ◽  
Control Gene Expression ◽  
Protein Expressions ◽  
Fundamental Process ◽  
Non Coding Rnas ◽  
The Stability ◽  
Eukaryotic Organisms

Regulation of gene expression is a fundamental process in both prokaryotic and eukaryotic organisms. Multiple regulatory mechanisms are in place to control gene expression at the level of transcription, post-transcription and post-translation to maintain optimal RNA and protein expressions in cells. miRNAs (microRNAs) are abundant short 21–23 nt non-coding RNAs that are key regulators of virtually all eukaryotic biological processes. The levels of miRNAs in an organism are crucial for proper development and sustaining optimal cell functions. Therefore the processing and regulation of the processing of these miRNAs are critical. In the present chapter we highlight the most important steps of miRNA processing, describe the functions of key proteins involved in the maturation of miRNAs, and discuss how the generation and the stability of miRNAs are regulated.

scholarly journals Nsp1 protein of SARS-CoV-2 disrupts the mRNA export machinery to inhibit host gene expression

2021 ◽  
Vol 7 (6) ◽  
pp. eabe7386 ◽  
Author(s):  
Ke Zhang ◽  
Lisa Miorin ◽  
Tadashi Makio ◽  
Ishmael Dehghan ◽  
Shengyan Gao ◽  
...  
Keyword(s):  
Gene Expression ◽  
Nuclear Export ◽  
Messenger Rna ◽  
Mrna Export ◽  
Host Gene ◽  
Nuclear Pore ◽  
Host Gene Expression ◽  
Host Interactions ◽  
Inhibitory Function ◽  
Cellular Mrnas

The ongoing unprecedented severe acute respiratory syndrome caused by the SARS-CoV-2 outbreak worldwide has highlighted the need for understanding viral-host interactions involved in mechanisms of virulence. Here, we show that the virulence factor Nsp1 protein of SARS-CoV-2 interacts with the host messenger RNA (mRNA) export receptor heterodimer NXF1-NXT1, which is responsible for nuclear export of cellular mRNAs. Nsp1 prevents proper binding of NXF1 to mRNA export adaptors and NXF1 docking at the nuclear pore complex. As a result, a significant number of cellular mRNAs are retained in the nucleus during infection. Increased levels of NXF1 rescues the Nsp1-mediated mRNA export block and inhibits SARS-CoV-2 infection. Thus, antagonizing the Nsp1 inhibitory function on mRNA export may represent a strategy to restoring proper antiviral host gene expression in infected cells.

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