scholarly journals Posttranscriptional Modifications in 16S and 23S rRNAs of the Archaeal Hyperthermophile Sulfolobus solfataricus

1998 ◽  
Vol 180 (11) ◽  
pp. 2883-2888 ◽  
Author(s):  
Kathleen R. Noon ◽  
Eveline Bruenger ◽  
James A. McCloskey

ABSTRACT Posttranscriptional modification is common to many types of RNA, but the majority of information concerning structure and function of modification is derived principally from tRNA. By contrast, less is known about modification in rRNA in spite of accumulating evidence for its direct participation in translation. The structural identities and approximate molar levels of modifications have been established for 16S and 23S rRNAs of the archaeal hyperthermophile Sulfolobus solfactaricus by using combined chromatography-mass spectrometry-based methods. Modification levels are exceptionally high for prokaryotic organisms, with approximately 38 modified sites in 16S rRNA and 50 in 23S rRNA for cells cultured at 75°C, compared with 11 and 23 sites, respectively, in Escherichia coli. We structurally characterized 10 different modified nucleosides in 16S rRNA, 64% (24 residues) of which are methylated at O-2′ of ribose, and 8 modified species in 23S rRNA, 86% (43 residues) of which are ribose methylated, a form of modification shown in earlier studies to enhance stability of the polynucleotide chain. From cultures grown at progressively higher temperatures, 60, 75, and 83°C, a slight trend toward increased ribose methylation levels was observed, with greatest net changes over the 23°C range shown for 2′-O-methyladenosine in 16S rRNA (21% increase) and for 2′-O-methylcytidine (24%) and 2′-O-methylguanosine (22%) in 23S rRNA. These findings are discussed in terms of the potential role of modification in stabilization of rRNA in the thermal environment.

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Justyna Szczykutowicz ◽  
Anna Kałuża ◽  
Maria Kaźmierowska-Niemczuk ◽  
Mirosława Ferens-Sieczkowska

For human infertility both male and female factors may be equally important. Searching for molecular biomarkers of male infertility, neglected for decades, and the attempts to explain regulatory mechanisms of fertilization become thus extremely important. Apart from examination of the structure and function of male gametes, also the possible importance of seminal plasma components should be considered. In this article we discuss data that indicate for the substantial significance of active seminal plasma components for conception and achievement of healthy pregnancy. Seminal plasma impact on the storage and cryopreservation of human and animal sperm and regulatory role of glycodelin on human sperm capacitation as well as hypothesized course of female immune response to allogenic sperm and conceptus has been discussed. The possible involvement of carbohydrates in molecular mechanism of fetoembryonic defense has been also mentioned.


Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 59 ◽  
Author(s):  
Zhiqi Song ◽  
Yanfeng Xu ◽  
Linlin Bao ◽  
Ling Zhang ◽  
Pin Yu ◽  
...  

Coronaviruses (CoVs) have formerly been regarded as relatively harmless respiratory pathogens to humans. However, two outbreaks of severe respiratory tract infection, caused by the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV), as a result of zoonotic CoVs crossing the species barrier, caused high pathogenicity and mortality rates in human populations. This brought CoVs global attention and highlighted the importance of controlling infectious pathogens at international borders. In this review, we focus on our current understanding of the epidemiology, pathogenesis, prevention, and treatment of SARS-CoV and MERS-CoV, as well as provides details on the pivotal structure and function of the spike proteins (S proteins) on the surface of each of these viruses. For building up more suitable animal models, we compare the current animal models recapitulating pathogenesis and summarize the potential role of host receptors contributing to diverse host affinity in various species. We outline the research still needed to fully elucidate the pathogenic mechanism of these viruses, to construct reproducible animal models, and ultimately develop countermeasures to conquer not only SARS-CoV and MERS-CoV, but also these emerging coronaviral diseases.


2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.


2020 ◽  
Vol 118 (3) ◽  
pp. 258a
Author(s):  
Laszlo Csernoch ◽  
Mónika Gönczi ◽  
Zsolt Ráduly ◽  
László Szabó ◽  
Nóra Dobrosi ◽  
...  

2021 ◽  
Vol 9 (1) ◽  
pp. 148
Author(s):  
Marius Bredon ◽  
Elisabeth Depuydt ◽  
Lucas Brisson ◽  
Laurent Moulin ◽  
Ciriac Charles ◽  
...  

The crucial role of microbes in the evolution, development, health, and ecological interactions of multicellular organisms is now widely recognized in the holobiont concept. However, the structure and stability of microbiota are highly dependent on abiotic and biotic factors, especially in the gut, which can be colonized by transient bacteria depending on the host’s diet. We studied these impacts by manipulating the digestive microbiota of the detritivore Armadillidium vulgare and analyzing the consequences on its structure and function. Hosts were exposed to initial starvation and then were fed diets that varied the different components of lignocellulose. A total of 72 digestive microbiota were analyzed according to the type of the diet (standard or enriched in cellulose, lignin, or hemicellulose) and the period following dysbiosis. The results showed that microbiota from the hepatopancreas were very stable and resilient, while the most diverse and labile over time were found in the hindgut. Dysbiosis and selective diets may have affected the host fitness by altering the structure of the microbiota and its predicted functions. Overall, these modifications can therefore have effects not only on the holobiont, but also on the “eco-holobiont” conceptualization of macroorganisms.


Author(s):  
Rachel L. Leon ◽  
Imran N. Mir ◽  
Christina L. Herrera ◽  
Kavita Sharma ◽  
Catherine Y. Spong ◽  
...  

Abstract Children with congenital heart disease (CHD) are living longer due to effective medical and surgical management. However, the majority have neurodevelopmental delays or disorders. The role of the placenta in fetal brain development is unclear and is the focus of an emerging field known as neuroplacentology. In this review, we summarize neurodevelopmental outcomes in CHD and their brain imaging correlates both in utero and postnatally. We review differences in the structure and function of the placenta in pregnancies complicated by fetal CHD and introduce the concept of a placental inefficiency phenotype that occurs in severe forms of fetal CHD, characterized by a myriad of pathologies. We propose that in CHD placental dysfunction contributes to decreased fetal cerebral oxygen delivery resulting in poor brain growth, brain abnormalities, and impaired neurodevelopment. We conclude the review with key areas for future research in neuroplacentology in the fetal CHD population, including (1) differences in structure and function of the CHD placenta, (2) modifiable and nonmodifiable factors that impact the hemodynamic balance between placental and cerebral circulations, (3) interventions to improve placental function and protect brain development in utero, and (4) the role of genetic and epigenetic influences on the placenta–heart–brain connection. Impact Neuroplacentology seeks to understand placental connections to fetal brain development. In fetuses with CHD, brain growth abnormalities begin in utero. Placental microstructure as well as perfusion and function are abnormal in fetal CHD.


Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 727
Author(s):  
Natalia Słabiak-Błaż ◽  
Grzegorz Piecha

The role of endogenous mammalian cardiotonic steroids (CTS) in the physiology and pathophysiology of the cardiovascular system and the kidneys has interested researchers for more than 20 years. Cardiotonic steroids extracted from toads or plants, such as digitalis, have been used to treat heart disease since ancient times. CTS, also called endogenous digitalis-like factors, take part in the regulation of blood pressure and sodium homeostasis through their effects on the transport enzyme called sodium–potassium adenosine triphosphatase (Na/K-ATPase) in renal and cardiovascular tissue. In recent years, there has been increasing evidence showing deleterious effects of CTS on the structure and function of the heart, vasculature and kidneys. Understanding the role of CTS may be useful in the development of potential new therapeutic strategies.


2006 ◽  
Vol 34 (5) ◽  
pp. 863-867 ◽  
Author(s):  
S. Mizielinska ◽  
S. Greenwood ◽  
C.N. Connolly

Maintaining the correct balance in neuronal activation is of paramount importance to normal brain function. Imbalances due to changes in excitation or inhibition can lead to a variety of disorders ranging from the clinically extreme (e.g. epilepsy) to the more subtle (e.g. anxiety). In the brain, the most common inhibitory synapses are regulated by GABAA (γ-aminobutyric acid type A) receptors, a role commensurate with their importance as therapeutic targets. Remarkably, we still know relatively little about GABAA receptor biogenesis. Receptors are constructed as pentameric ion channels, with α and β subunits being the minimal requirement, and the incorporation of a γ subunit being necessary for benzodiazepine modulation and synaptic targeting. Insights have been provided by the discovery of several specific assembly signals within different GABAA receptor subunits. Moreover, a number of recent studies on GABAA receptor mutations associated with epilepsy have further enhanced our understanding of GABAA receptor biogenesis, structure and function.


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