scholarly journals The advantage of channeling nucleotides for very processive functions

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 724 ◽  
Author(s):  
Diana Zala ◽  
Uwe Schlattner ◽  
Thomas Desvignes ◽  
Julien Bobe ◽  
Aurélien Roux ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Molecular Mechanisms ◽  
Nucleoside Triphosphate ◽  
High Turnover ◽  
Physiological Importance ◽  
Adenosine Triphosphatases ◽  
Close Proximity ◽  
Nucleoside Diphosphate Kinases ◽  
Very High

Nucleoside triphosphate (NTP)s, like ATP (adenosine 5’-triphosphate) and GTP (guanosine 5’-triphosphate), have long been considered sufficiently concentrated and diffusible to fuel all cellular ATPases (adenosine triphosphatases) and GTPases (guanosine triphosphatases) in an energetically healthy cell without becoming limiting for function. However, increasing evidence for the importance of local ATP and GTP pools, synthesised in close proximity to ATP- or GTP-consuming reactions, has fundamentally challenged our view of energy metabolism. It has become evident that cellular energy metabolism occurs in many specialised ‘microcompartments’, where energy in the form of NTPs is transferred preferentially from NTP-generating modules directly to NTP-consuming modules. Such energy channeling occurs when diffusion through the cytosol is limited, where these modules are physically close and, in particular, if the NTP-consuming reaction has a very high turnover,i.e. is very processive. Here, we summarise the evidence for these conclusions and describe new insights into the physiological importance and molecular mechanisms of energy channeling gained from recent studies. In particular, we describe the role of glycolytic enzymes for axonal vesicle transport and nucleoside diphosphate kinases for the functions of dynamins and dynamin-related GTPases.

scholarly journals The advantage of channeling nucleotides for very processive functions

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 724 ◽  
Author(s):  
Diana Zala ◽  
Uwe Schlattner ◽  
Thomas Desvignes ◽  
Julien Bobe ◽  
Aurélien Roux ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Molecular Mechanisms ◽  
Nucleoside Triphosphate ◽  
High Turnover ◽  
Physiological Importance ◽  
Adenosine Triphosphatases ◽  
Close Proximity ◽  
Nucleoside Diphosphate Kinases ◽  
Very High

Nucleoside triphosphate (NTP)s, like ATP (adenosine 5’-triphosphate) and GTP (guanosine 5’-triphosphate), have long been considered sufficiently concentrated and diffusible to fuel all cellular ATPases (adenosine triphosphatases) and GTPases (guanosine triphosphatases) in an energetically healthy cell without becoming limiting for function. However, increasing evidence for the importance of local ATP and GTP pools, synthesised in close proximity to ATP- or GTP-consuming reactions, has fundamentally challenged our view of energy metabolism. It has become evident that cellular energy metabolism occurs in many specialised ‘microcompartments’, where energy in the form of NTPs is transferred preferentially from NTP-generating modules directly to NTP-consuming modules. Such energy channeling occurs when diffusion through the cytosol is limited, where these modules are physically close and, in particular, if the NTP-consuming reaction has a very high turnover, i.e. is very processive. Here, we summarise the evidence for these conclusions and describe new insights into the physiological importance and molecular mechanisms of energy channeling gained from recent studies. In particular, we describe the role of glycolytic enzymes for axonal vesicle transport and nucleoside diphosphate kinases for the functions of dynamins and dynamin-related GTPases.

scholarly journals Insulin resistance and cancer: the role of insulin and IGFs

2012 ◽  
Vol 20 (1) ◽  
pp. R1-R17 ◽  
Author(s):  
Sefirin Djiogue ◽  
Armel Hervé Nwabo Kamdje ◽  
Lorella Vecchio ◽  
Maulilio John Kipanyula ◽  
Mohammed Farahna ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Cell Proliferation ◽  
Energy Metabolism ◽  
Cell Fate ◽  
Molecular Mechanisms ◽  
Tumor Development ◽  
Epidemiological Studies ◽  
High Energy

Insulin, IGF1, and IGF2 are the most studied insulin-like peptides (ILPs). These are evolutionary conserved factors well known as key regulators of energy metabolism and growth, with crucial roles in insulin resistance-related metabolic disorders such as obesity, diseases like type 2 diabetes mellitus, as well as associated immune deregulations. A growing body of evidence suggests that insulin and IGF1 receptors mediate their effects on regulating cell proliferation, differentiation, apoptosis, glucose transport, and energy metabolism by signaling downstream through insulin receptor substrate molecules and thus play a pivotal role in cell fate determination. Despite the emerging evidence from epidemiological studies on the possible relationship between insulin resistance and cancer, our understanding on the cellular and molecular mechanisms that might account for this relationship remains incompletely understood. The involvement of IGFs in carcinogenesis is attributed to their role in linking high energy intake, increased cell proliferation, and suppression of apoptosis to cancer risks, which has been proposed as the key mechanism bridging insulin resistance and cancer. The present review summarizes and discusses evidence highlighting recent advances in our understanding on the role of ILPs as the link between insulin resistance and cancer and between immune deregulation and cancer in obesity, as well as those areas where there remains a paucity of data. It is anticipated that issues discussed in this paper will also recover new therapeutic targets that can assist in diagnostic screening and novel approaches to controlling tumor development.

scholarly journals Dentistry in the post covid-19 world- are we prepared?

2020 ◽  
Vol 04 (4) ◽  
pp. 01-08
Author(s):  
Vrushali Abhyankar
Keyword(s):  
Exposure Risk ◽  
High Exposure ◽  
Dental Procedures ◽  
Close Proximity ◽  
Dental Profession ◽  
Auxiliary Personnel ◽  
The Impact ◽  
Very High ◽  
Dental Professionals

Background: Covid -19 pandemic has affected dental profession tremendously and has placed dentists and dental professionals in the very high exposure risk jobs. Practicing dentistry requires the provider to be in close proximity of the patients and their oral cavity. Many dental procedures tend to generate aerosols owing to the use of an air rotor or highspeed handpiece. The impact of Covid –19 on dentistry, like all other professions is ever evolving and newer guidelines are published almost every day. The authors also examine the ethical, psychological and financial implications of this pandemic to the dental professionals as well as patients. The important role of organized dentistry is highlighted in facilitating change to adapt to the new norm and implement the safer practice guidelines. Conclusions: The authors conclude that significant changes need to be undertaken to protect patients, dental professionals, auxiliary personnel.

scholarly journals Preventive role of mouthwashes in COVID-19 disease transmission: An overview

2020 ◽  
Vol 10 ◽  
pp. 9
Author(s):  
Zia Arshad Khan
Keyword(s):  
Disease Transmission ◽  
Dental Treatment ◽  
Healthcare Providers ◽  
Dental Patients ◽  
Care Services ◽  
Close Proximity ◽  
The Face ◽  
Very High ◽  
Preventive Role

The current COVID-19 pandemic has changed the face of the health and medical care services. Due to the nature of dental treatment, which involves a very close proximity to patient’s oropharyngeal region and production of aerosols the dental healthcare providers, and dental patients are at a very high risk of getting or transmitting the virus. Efforts are being made to reduce the viral load in patient’s oral cavity, as well the dental clinic. For this, the role of mouthwashes has also been suggested. The aim of the present paper is to discuss the various mouthwashes, which exhibit virucidal actions, especially in relation to COVID-19.

A Phylogenetic Approach to the Uneven Global Distribution of the COVID-19 Pandemic

2022 ◽  
pp. 105-126
Author(s):  
Ole Bernt Lenning ◽  
Ronny Myhre ◽  
May Sissel Vadla ◽  
Geir Sverre Braut
Keyword(s):  
Eastern Europe ◽  
Western Europe ◽  
Molecular Mechanisms ◽  
Sex Bias ◽  
Very High Frequency ◽  
Receptor Modulation ◽  
Different Populations ◽  
Second Wave ◽  
Very High

A possible role of Y chromosomal haplogroups in COVID-19 mortality is discussed without claiming causality. The mortality of COVID-19 seems unequally distributed in different populations and statistically significant regional covariation is presented between COVID-19 mortality and the haplogroup Y-R1b. Y-R1b is suggested as a possible marker for mortality in the first wave of the pandemic affecting the Western Europe. September 2020 the pandemic involved also Eastern Europe severely in a second wave, while South East Asia, with a very high frequency of Y-0, had strikingly low COVID-19 mortality rate. Eastern Europe is dominated by Y-haplogroups (i.e., Y-R1a), with close ancestry to Y-R1b. Molecular mechanisms mediated by the Y chromosome involved in COVID-19 mortality are discussed, presenting a possible role of KDM5D in androgen receptor modulation and regulation of TMPRSS2 known to enable SARS-CoV-2 binding to ACE2 and facilitating virus entrance into the cell and virus replication. Sex bias and comorbidities point at the role of variations in the Y-chromosomal phylogeny.

scholarly journals Role of 16S rRNA Helix 44 in Ribosomal Resistance to Hygromycin B

2003 ◽  
Vol 47 (5) ◽  
pp. 1496-1502 ◽  
Author(s):  
P. Pfister ◽  
M. Risch ◽  
D. E. Brodersen ◽  
E. C. Böttger
Keyword(s):  
16S Rrna ◽  
Mycobacterium Smegmatis ◽  
Molecular Mechanisms ◽  
Aminoglycoside Antibiotic ◽  
Hygromycin B ◽  
Resistance Mutations ◽  
E Coli ◽  
Close Proximity ◽  
Domains Of Life

ABSTRACT Hygromycin B is an aminoglycoside antibiotic active against prokaryotic and eukaryotic ribosomes. Ribosomal alterations in bacteria conferring resistance to hygromycin B have not been described, prompting us to use a single rRNA allelic derivative of the gram-positive bacterium Mycobacterium smegmatis for investigation of the molecular mechanisms involved in ribosomal resistance to hygromycin B in eubacteria. Resistance mutations were found to localize exclusively in 16S rRNA. The mutations observed, i.e., 16S rRNA U1406C, C1496U, and U1498C (E. coli numbering), are in close proximity to the hygromycin B binding site located in conserved helix 44 of 16S rRNA. The 16S rRNA positions involved in hygromycin B resistance are highly conserved in all three domains of life, explaining the lack of specificity and general toxicity of hygromycin B.

scholarly journals The Chemokine Systems at the Crossroads of Inflammation and Energy Metabolism in the Development of Obesity

2021 ◽  
Vol 22 (24) ◽  
pp. 13528
Author(s):  
Pei-Chi Chan ◽  
Po-Shiuan Hsieh
Keyword(s):  
Energy Metabolism ◽  
Chemokine Receptors ◽  
Metabolic Disorders ◽  
Molecular Mechanisms ◽  
Potential Effect ◽  
Post Translational Modification ◽  
Chronic Complications ◽  
Inflammatory Milieu ◽  
Near Future

Obesity is characterized as a complex and multifactorial excess accretion of adipose tissue accompanied with alterations in the immune and metabolic responses. Although the chemokine systems have been documented to be involved in the control of tissue inflammation and metabolism, the dual role of chemokines and chemokine receptors in the pathogenesis of the inflammatory milieu and dysregulated energy metabolism in obesity remains elusive. The objective of this review is to present an update on the link between chemokines and obesity-related inflammation and metabolism dysregulation under the light of recent knowledge, which may present important therapeutic targets that could control obesity-associated immune and metabolic disorders and chronic complications in the near future. In addition, the cellular and molecular mechanisms of chemokines and chemokine receptors including the potential effect of post-translational modification of chemokines in the regulation of inflammation and energy metabolism will be discussed in this review.

scholarly journals Mitochondrial Dynamics: A Potential Therapeutic Target for Ischemic Stroke

2021 ◽  
Vol 13 ◽  
Author(s):  
Xiangyue Zhou ◽  
Hanmin Chen ◽  
Ling Wang ◽  
Cameron Lenahan ◽  
Lifei Lian ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Energy Metabolism ◽  
Energy Homeostasis ◽  
Molecular Mechanisms ◽  
Mitochondrial Dynamics ◽  
Neural Function ◽  
Pathophysiological Mechanisms ◽  
New Strategies

Stroke is one of the leading causes of death and disability worldwide. Brain injury after ischemic stroke involves multiple pathophysiological mechanisms, such as oxidative stress, mitochondrial dysfunction, excitotoxicity, calcium overload, neuroinflammation, neuronal apoptosis, and blood-brain barrier (BBB) disruption. All of these factors are associated with dysfunctional energy metabolism after stroke. Mitochondria are organelles that provide adenosine triphosphate (ATP) to the cell through oxidative phosphorylation. Mitochondrial dynamics means that the mitochondria are constantly changing and that they maintain the normal physiological functions of the cell through continuous division and fusion. Mitochondrial dynamics are closely associated with various pathophysiological mechanisms of post-stroke brain injury. In this review, we will discuss the role of the molecular mechanisms of mitochondrial dynamics in energy metabolism after ischemic stroke, as well as new strategies to restore energy homeostasis and neural function. Through this, we hope to uncover new therapeutic targets for the treatment of ischemic stroke.

Mitochondrial matrix calcium ions regulate energy production in myocardium: A cytochemical study

1990 ◽  
Vol 48 (2) ◽  
pp. 166-167
Author(s):  
W.A. Jacob ◽  
R. Hertsens ◽  
A. Van Bogaert ◽  
M. De Smet
Keyword(s):  
Energy Metabolism ◽  
Calcium Ions ◽  
Energy Production ◽  
Regulation Of Respiration ◽  
Free Calcium ◽  
Mitochondrial Matrix ◽  
Cytochemical Study ◽  
Nmr Techniques

In the past most studies of the control of energy metabolism focus on the role of the phosphorylation potential ATP/ADP.Pi on the regulation of respiration. Studies using NMR techniques have demonstrated that the concentrations of these compounds for oxidation phosphorylation do not change appreciably throughout the cardiac cycle and during increases in cardiac work. Hence regulation of energy production by calcium ions, present in the mitochondrial matrix, has been the object of a number of recent studies.Three exclusively intramitochondnal dehydrogenases are key enzymes for the regulation of oxidative metabolism. They are activated by calcium ions in the low micromolar range. Since, however, earlier estimates of the intramitochondnal calcium, based on equilibrium thermodynamic considerations, were in the millimolar range, a physiological correlation was not evident. The introduction of calcium-sensitive probes fura-2 and indo-1 made monitoring of free calcium during changing energy metabolism possible. These studies were performed on isolated mitochondria and extrapolation to the in vivo situation is more or less speculative.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

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