scholarly journals The isoenzyme pattern of LDH does not play a physiological role; except perhaps during fast transitions in energy metabolism

Aging ◽  
2011 ◽  
Vol 3 (5) ◽  
pp. 457-460 ◽  
Author(s):  
Bjørn Quistorff ◽  
Niels Grunnet
Keyword(s):  
Energy Metabolism ◽  
Physiological Role ◽  
Isoenzyme Pattern

scholarly journals Selenocysteine β-Lyase: Biochemistry, Regulation and Physiological Role of the Selenocysteine Decomposition Enzyme

Antioxidants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 357 ◽  
Author(s):  
Lucia A. Seale
Keyword(s):  
Amino Acid ◽  
Energy Metabolism ◽  
Subcellular Localization ◽  
Hepatic Steatosis ◽  
Glucose Intolerance ◽  
Physiological Role ◽  
Dependent Manner ◽  
Technical Approach ◽  
Expression And Activity

The enzyme selenocysteine β-lyase (SCLY) was first isolated in 1982 from pig livers, followed by its identification in bacteria. SCLY works as a homodimer, utilizing pyridoxal 5’-phosphate as a cofactor, and catalyzing the specific decomposition of the amino acid selenocysteine into alanine and selenide. The enzyme is thought to deliver its selenide as a substrate for selenophosphate synthetases, which will ultimately be reutilized in selenoprotein synthesis. SCLY subcellular localization is unresolved, as it has been observed both in the cytosol and in the nucleus depending on the technical approach used. The highest SCLY expression and activity in mammals is found in the liver and kidneys. Disruption of the Scly gene in mice led to obesity, hyperinsulinemia, glucose intolerance, and hepatic steatosis, with SCLY being suggested as a participant in the regulation of energy metabolism in a sex-dependent manner. With the physiological role of SCLY still not fully understood, this review attempts to discuss the available literature regarding SCLY in animals and provides avenues for possible future investigation.

Alternative Oxidase and Uncoupling Protein: Thermogenesis Versus Cell Energy Balance

2001 ◽  
Vol 21 (2) ◽  
pp. 213-222 ◽  
Author(s):  
Wieslawa Jarmuszkiewicz ◽  
Claudine M. Sluse-Goffart ◽  
Anibal E. Vercesi ◽  
Francis E. Sluse
Keyword(s):  
Energy Metabolism ◽  
Energy Balance ◽  
Lower Limit ◽  
Alternative Oxidase ◽  
Uncoupling Protein ◽  
Physiological Role ◽  
Mitochondrial Respiratory Chain ◽  
Cell Energy ◽  
Stimulation Of

The physiological role of an alternative oxidase and an uncoupling protein in plant and protists is discussed in terms of thermogenesis and energy metabolism balance in the cell. It is concluded that thermogenesis is restricted not only by a lower-limit size but also by a kinetically-limited stimulation of the mitochondrial respiratory chain.

scholarly journals Disrupted axo-glial junctions result in accumulation of abnormal mitochondria at nodes of Ranvier

2006 ◽  
Vol 2 (3) ◽  
pp. 165-174 ◽  
Author(s):  
STEVEN EINHEBER ◽  
MANZOOR A. BHAT ◽  
JAMES L. SALZER
Keyword(s):  
Energy Metabolism ◽  
Peripheral Nerves ◽  
Physiological Role ◽  
Myelinated Axons ◽  
Local Regulation ◽  
Nodal Region ◽  
Paranodal Junctions ◽  
Abnormal Mitochondria ◽  
Sciatic Nerves ◽  
And Function

Mitochondria and other membranous organelles are frequently enriched in the nodes and paranodes of peripheral myelinated axons, particularly of large caliber axons. The physiological role(s) of this organelle enrichment and the rheologic factors that regulate it are not well understood. Previous studies indicate that axonal transport of organelles across the nodal/paranodal region is regulated locally. In this study, we have examined the ultrastructure of myelinated axons in the sciatic nerves of mice deficient in contactin-associated protein (Caspr), an integral junctional component. These mice, which lack the normal septate-like junctions that promote attachment of the glial (paranodal) loops to the axon, contain aberrant mitochondria in their nodal/paranodal regions. Typically, these mitochondria are large, swollen and occupy prominent varicosities of the nodal axolemma. In contrast, mitochondria outside the nodal/paranodal regions of the myelinated axons appear normal. These findings suggest that paranodal junctions regulate mitochondrial transport and function in the axoplasm of the nodal/paranodal region of myelinated axons of peripheral nerves. They further indicate that paranodal junctions might have a role, either direct or indirect, in the local regulation of energy metabolism in the nodal region.

scholarly journals Physiological Role of Leptin: A Bird’s Eye View

2020 ◽  
Author(s):  
Dipika P Baria ◽  
Tejas J Shah ◽  
Shruti V Brahmbhatt
Keyword(s):  
Immune System ◽  
Energy Metabolism ◽  
Therapeutic Intervention ◽  
Physiological Role ◽  
Therapeutic Interventions ◽  
Central Control ◽  
Neuroendocrine Function ◽  
Regulation Of Metabolism

Since its discovery over fifteen years ago, Leptin remains the cornerstone for researchers because of its important role in central control of energy metabolism. Apart from role in energy metabolism, researchers have identified some newer but important roles of leptin in various areas like neuroendocrine function and regulation of metabolism-immune system interplay. Recently, recombinant human leptin emerged as a therapeutic intervention in various disorders. In this review, we highlighted important biology and physiology of leptin, its association with several disorders, and therapeutic interventions involving leptin.

Developmental changes in energy metabolism ofSchistosoma mansoni and physiological role of oxygen in maintaining parasite function

1986 ◽  
Vol 12 (8) ◽  
pp. 1885-1900 ◽  
Author(s):  
David P. Thompson ◽  
James L. Bennett
Keyword(s):  
Energy Metabolism ◽  
Physiological Role ◽  
Developmental Changes

Plant Uncoupling Mitochondrial Protein and Alternative Oxidase: Energy Metabolism and Stress

2005 ◽  
Vol 25 (3-4) ◽  
pp. 271-286 ◽  
Author(s):  
Jiří Borecký ◽  
Aníbal E. Vercesi
Keyword(s):  
Energy Metabolism ◽  
Alternative Oxidase ◽  
Plant Mitochondria ◽  
Mitochondrial Protein ◽  
Physiological Role ◽  
Mitochondrial Energy Metabolism ◽  
Functional Studies ◽  
Plant Uncoupling Mitochondrial Protein ◽  
And Function

Energy-dissipation in plant mitochondria can be mediated by inner membrane proteins via two processes: redox potential-dissipation or proton electrochemical potential-dissipation. Alternative oxidases (AOx) and the plant uncoupling mitochondrial proteins (PUMP) perform a type of intrinsic and extrinsic regulation of the coupling between respiration and phosphorylation, respectively. Expression analyses and functional studies on AOx and PUMP under normal and stress conditions suggest that the physiological role of both systems lies most likely in tuning up the mitochondrial energy metabolism in response of cells to stress situations. Indeed, the expression and function of these proteins in non-thermogenic tissues suggest that their primary functions are not related to heat production.

scholarly journals Localization of L-arginine-glycine amidinotransferase protein in rat tissues by immunofluorescence microscopy.

1986 ◽  
Vol 34 (4) ◽  
pp. 429-435 ◽  
Author(s):  
D M McGuire ◽  
M D Gross ◽  
R P Elde ◽  
J F van Pilsum
Keyword(s):  
Monoclonal Antibodies ◽  
Energy Metabolism ◽  
Pancreatic Islet ◽  
Immunofluorescence Microscopy ◽  
Physiological Role ◽  
Proximal Tubules ◽  
Rat Tissues ◽  
Alpha Cells ◽  
High Concentration ◽  
Insight Into

Creatine is a major component of energy metabolism and enzymes involved in its synthesis have therefore been of considerable interest. L-arginine-glycine amidinotransferase, commonly called transamidinase, catalyzes the first reaction in the biosynthesis of creatine. This first reaction is believed to occur in the kidney because of the high concentration of transamidinase in that tissue. Transamidinase activity is also found in many other tissues of the rat, but its role in these tissues is not known. Immunochemical studies with antisera and monoclonal antibodies were used to confirm and refine our understanding of the presence of transamidinase in rat tissues. Immunofluorescence histochemistry was performed to localize transamidinase immunoreactivity within specific tissues including cells in the proximal tubules of the kidney, hepatocytes of the liver, and alpha cells of the pancreatic islet. Immunochemical studies with monoclonal antibodies confirm localization of transamidinase immunoreactivity in the proximal tubules of the kidney. The localization of such immunoreactivity in specialized cells yields insight into possible physiological role(s) of transamidinase in the rat.

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.

Detection and mapping of interactions between chromatin and the nuclear envelope in drosophila embryos

1995 ◽  
Vol 53 ◽  
pp. 764-765
Author(s):  
W.F. Marshall ◽  
A.F. Dernburg ◽  
B. Harmon ◽  
J.W. Sedat
Keyword(s):  
Nuclear Envelope ◽  
Chromatin Condensation ◽  
Three Dimensional ◽  
Physiological Role ◽  
Nuclear Surface ◽  
Intact Cells ◽  
Molecular Determinants ◽  
Surface Harmonic ◽  
Drosophila Embryos

Interactions between chromatin and nuclear envelope (NE) have been implicated in chromatin condensation, gene regulation, nuclear reassembly, and organization of chromosomes within the nucleus. To further investigate the physiological role played by such interactions, it will be necessary to determine which loci specifically interact with the nuclear envelope. This will not only facilitate identification of the molecular determinants of this interaction, but will also allow manipulation of the pattern of chromatin-NE interactions to probe possible functions. We have developed a microscopic approach to detect and map chromatin-NE interactions inside intact cells.Fluorescence in situ hybridization (FISH) is used to localize specific chromosomal regions within the nucleus of Drosophila embryos and anti-lamin immunofluorescence is used to detect the nuclear envelope. Widefield deconvolution microscopy is then used to obtain a three-dimensional image of the sample (Fig. 1). The nuclear surface is represented by a surface-harmonic expansion (Fig 2). A statistical test for association of the FISH spot with the surface is then performed.

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