scholarly journals Terminal nucleotidyl transferases (TENTs) in mammalian RNA metabolism

2018 ◽  
Vol 373 (1762) ◽  
pp. 20180162 ◽  
Author(s):  
Zbigniew Warkocki ◽  
Vladyslava Liudkovska ◽  
Olga Gewartowska ◽  
Seweryn Mroczek ◽  
Andrzej Dziembowski

In eukaryotes, almost all RNA species are processed at their 3′ ends and most mRNAs are polyadenylated in the nucleus by canonical poly(A) polymerases. In recent years, several terminal nucleotidyl transferases (TENTs) including non-canonical poly(A) polymerases (ncPAPs) and terminal uridyl transferases (TUTases) have been discovered. In contrast to canonical polymerases, TENTs' functions are more diverse; some, especially TUTases, induce RNA decay while others, such as cytoplasmic ncPAPs, activate translationally dormant deadenylated mRNAs. The mammalian genome encodes 11 different TENTs. This review summarizes the current knowledge about the functions and mechanisms of action of these enzymes. This article is part of the theme issue ‘5′ and 3′ modifications controlling RNA degradation’.

2018 ◽  
Vol 373 (1762) ◽  
pp. 20180171 ◽  
Author(s):  
Dagmar Zigáčková ◽  
Štěpánka Vaňáčová

Most eukaryotic RNAs are posttranscriptionally modified. The majority of modifications promote RNA maturation, others may regulate function and stability. The 3′ terminal non-templated oligouridylation is a widespread modification affecting many cellular RNAs at some stage of their life cycle. It has diverse roles in RNA metabolism. The most prevalent is the regulation of stability and quality control. On the cellular and organismal level, it plays a critical role in a number of pathways, such as cell cycle regulation, cell death, development or viral infection. Defects in uridylation have been linked to several diseases. This review summarizes the current knowledge about the role of the 3′ terminal oligo(U)-tailing in biology of various RNAs in eukaryotes and describes key factors involved in these pathways. This article is part of the theme issue ‘5′ and 3′ modifications controlling RNA degradation’.


2021 ◽  
Vol 16 (5) ◽  
pp. 384-390
Author(s):  
A.E. Abaturov ◽  
V.L. Babуch

The scientific review presents the process of regulation of microRNA content — microRNA degradation. To write the article, information was searched using databases Scopus, Web of Science, MedLine, PubMed, Google Scholar, EMBASE, Global Health, The Cochrane Library, CyberLeninka. The article presents the characteristics of the most important process of RNA metabolism — degradation of 3'→5' RNA. Degradation of microRNA is inherent in organisms of all kingdoms of life and is involved in the regulation of RNA representation, elimination of dysfunctional or incorrectly constructed RNA molecules and processing of RNA precursors. Exoribonucleases that affect the stability of mature forms of miRNA are presented. It is emphasized that XRN exoribonucleases degrade various RNA substrates during total RNA degradation and are involved in specific processes such as nonsense-mediated degradation, gene silencing, rRNA maturation, and transcription termination. It is shown that exoribonuclease XRN2 plays a crucial role in the termination of transcription during viral infection, namely it has cytoplasmic antiviral activity against hepatitis C virus. The role of RNA-degrading exosome in microRNA degradation is presented. RNA-degrading exosome is a ubiquitous complex and 3'-5'-endo- and exoribonucleases of eukaryotes, which interacts with several processing cofactors and degrades almost all classes of cytoplasmic RNA. The article reflects the function of evolutionarily conserved phosphorolytic 3'-5'-exoribonuclease — polynucleotide phosphorylase. The role of exoribonuclease 1, which is an evolutio­narily conserved 3'-5'-exoribonuclease of the DEDDh family, is involved in the final processing of 5.8S rRNA, replication-dependent histone mRNA, siRNA, and miRNA. Eri1 exoribonuclease has been shown to regulate global microRNA homeostasis in lymphocytes and to participate in NK cell development and antiviral response. Thus, one of the mechanisms of regulation of miRNA content is the most important process of RNA metabolism, which is inherent in organisms of all kingdoms of life, namely the degradation of miRNAs.


2020 ◽  
Author(s):  
Anna Hojka-Osinska ◽  
Aleksander Chlebowski ◽  
Ewelina P. Owczarek ◽  
Kamila Afek ◽  
Kamila Kłosowska ◽  
...  

ABSTRACTProcessive exoribonucleases, the executors of RNA decay, participate in multiple physical and functional interactions. Unlike physical ones, functional relationships have not been investigated in human cells. Here we have screened cells deficient in DIS3, XRN2, EXOSC10, DIS3L, and DIS3L2 with a custom siRNA library and determined their functional interactions with diverse pathways of RNA metabolism. We uncover a complex network of positive interactions that buffer alterations in RNA degradation. We reveal important reciprocal actions between RNA decay and transcription and explore alleviating interactions between RNA splicing and DIS3 mediated degradation. We also use a large scale library of genes associated with RNA metabolism to determine genetic interactions of nuclear DIS3 and cytoplasmic DIS3L, revealing their unique functions in RNA degradation and uncovering cooperation between the cytoplasmic degradation and nuclear processing of RNA. Finally, genome-wide siRNA screening of DIS3 reveals processes such as microtubule organization and regulation of telomerase activity that are also functionally associated with nuclear exosome-mediated RNA degradation.


2021 ◽  
Vol 22 (5) ◽  
pp. 2472
Author(s):  
Carl Randall Harrell ◽  
Valentin Djonov ◽  
Vladislav Volarevic

Mesenchymal stem cells (MSCs) are self-renewable, rapidly proliferating, multipotent stem cells which reside in almost all post-natal tissues. MSCs possess potent immunoregulatory properties and, in juxtacrine and paracrine manner, modulate phenotype and function of all immune cells that participate in tissue repair and regeneration. Additionally, MSCs produce various pro-angiogenic factors and promote neo-vascularization in healing tissues, contributing to their enhanced repair and regeneration. In this review article, we summarized current knowledge about molecular mechanisms that regulate the crosstalk between MSCs and immune cells in tissue repair and regeneration.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 299
Author(s):  
Vítor Ennes-Vidal ◽  
Marta Helena Branquinha ◽  
André Luis Souza dos Santos ◽  
Claudia Masini d’Avila-Levy

Calpains are calcium-dependent cysteine peptidases that were originally described in mammals and, thereafter, their homologues were identified in almost all known living organisms. The deregulated activity of these peptidases is associated with several pathologies and, consequently, huge efforts have been made to identify selective inhibitors. Trypanosomatids, responsible for life-threatening human diseases, possess a large and diverse family of calpain sequences in their genomes. Considering that the current therapy to treat trypanosomatid diseases is limited to a handful of drugs that suffer from unacceptable toxicity, tough administration routes, like parenteral, and increasing treatment failures, a repurposed approach with calpain inhibitors could be a shortcut to successful chemotherapy. However, there is a general lack of knowledge about calpain functions in these parasites and, currently, the proteolytic activity of these proteins is still an open question. Here, we highlight the current research and perspectives on trypanosomatid calpains, overview calpain description in these organisms, and explore the potential of targeting the calpain system as a therapeutic strategy. This review gathers the current knowledge about this fascinating family of peptidases as well as insights into the puzzle: are we unable to measure calpain activity in trypanosomatids, or are the functions of these proteins devoid of proteolytic activity in these parasites?


Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 687
Author(s):  
Daniela Gabbia ◽  
Luana Cannella ◽  
Sara De De Martin

A peculiar role for oxidative stress in non-alcoholic fatty liver disease (NAFLD) and its transition to the inflammatory complication non-alcoholic steatohepatitis (NASH), as well as in its threatening evolution to hepatocellular carcinoma (HCC), is supported by numerous experimental and clinical studies. NADPH oxidases (NOXs) are enzymes producing reactive oxygen species (ROS), whose abundance in liver cells is closely related to inflammation and immune responses. Here, we reviewed recent findings regarding this topic, focusing on the role of NOXs in the different stages of fatty liver disease and describing the current knowledge about their mechanisms of action. We conclude that, although there is a consensus that NOX-produced ROS are toxic in non-neoplastic conditions due to their role in the inflammatory vicious cycle sustaining the transition of NAFLD to NASH, their effect is controversial in the neoplastic transition towards HCC. In this regard, there are indications of a differential effect of NOX isoforms, since NOX1 and NOX2 play a detrimental role, whereas increased NOX4 expression appears to be correlated with better HCC prognosis in some studies. Further studies are needed to fully unravel the mechanisms of action of NOXs and their relationships with the signaling pathways modulating steatosis and liver cancer development.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4528
Author(s):  
Katarína Šuchová ◽  
Vladimír Puchart ◽  
Nikolaj Spodsberg ◽  
Kristian B. R. Mørkeberg Krogh ◽  
Peter Biely

Catalytic properties of GH30 xylanases belonging to subfamilies 7 and 8 were compared on glucuronoxylan, modified glucuronoxylans, arabinoxylan, rhodymenan, and xylotetraose. Most of the tested bacterial GH30-8 enzymes are specific glucuronoxylanases (EC 3.2.1.136) requiring for action the presence of free carboxyl group of MeGlcA side residues. These enzymes were not active on arabinoxylan, rhodymenan and xylotetraose, and conversion of MeGlcA to its methyl ester or its reduction to MeGlc led to a remarkable drop in their specific activity. However, some GH30-8 members are nonspecific xylanases effectively hydrolyzing all tested substrates. In terms of catalytic activities, the GH30-7 subfamily is much more diverse. In addition to specific glucuronoxylanases, the GH30-7 subfamily contains nonspecific endoxylanases and predominantly exo-acting enzymes. The activity of GH30-7 specific glucuronoxylanases also depend on the presence of the MeGlcA carboxyl, but not so strictly as in bacterial enzymes. The modification of the carboxyl group of glucuronoxylan had only weak effect on the action of predominantly exo-acting enzymes, as well as nonspecific xylanases. Rhodymenan and xylotetraose were the best substrates for exo-acting enzymes, while arabinoxylan represented hardly degradable substrate for almost all tested GH30-7 enzymes. The results expand current knowledge on the catalytic properties of this relatively novel group of xylanases.


Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1266
Author(s):  
Andreja Figurek ◽  
Merita Rroji ◽  
Goce Spasovski

Fibroblast growth factor-23 (FGF23) appears to be one of the most promising biomarkers and predictors of cardiovascular risk in patients with heart disease and normal kidney function, but moreover in those with chronic kidney disease (CKD). This review summarizes the current knowledge of FGF23 mechanisms of action in the myocardium in the physiological and pathophysiological state of CKD, as well as its cross-talk to other important signaling pathways in cardiomyocytes. In this regard, current therapeutic possibilities and future perspectives are also discussed.


2021 ◽  
Vol 22 (13) ◽  
pp. 7220
Author(s):  
Thuy-Hang Nguyen ◽  
Stephanie Conotte ◽  
Alexandra Belayew ◽  
Anne-Emilie Declèves ◽  
Alexandre Legrand ◽  
...  

Muscular dystrophies (MDs) are a group of inherited degenerative muscle disorders characterized by a progressive skeletal muscle wasting. Respiratory impairments and subsequent hypoxemia are encountered in a significant subgroup of patients in almost all MD forms. In response to hypoxic stress, compensatory mechanisms are activated especially through Hypoxia-Inducible Factor 1 α (HIF-1α). In healthy muscle, hypoxia and HIF-1α activation are known to affect oxidative stress balance and metabolism. Recent evidence has also highlighted HIF-1α as a regulator of myogenesis and satellite cell function. However, the impact of HIF-1α pathway modifications in MDs remains to be investigated. Multifactorial pathological mechanisms could lead to HIF-1α activation in patient skeletal muscles. In addition to the genetic defect per se, respiratory failure or blood vessel alterations could modify hypoxia response pathways. Here, we will discuss the current knowledge about the hypoxia response pathway alterations in MDs and address whether such changes could influence MD pathophysiology.


Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 96
Author(s):  
Alexandra Gartshore ◽  
Matt Kidd ◽  
Lovleen Tina Joshi

Microwaves are a highly utilized electromagnetic wave, used across a range of industries including food processing, communications, in the development of novel medical treatments and biosensor diagnostics. Microwaves have known thermal interactions and theorized non-thermal interactions with living matter; however, there is significant debate as to the mechanisms of action behind these interactions and the potential benefits and limitations of their use. This review summarizes the current knowledge surrounding the implementation of microwave technologies within the medical industry.


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