Configurations indicative of functional sites in spinach chloroplast DNA

Yoshida, Yoshio

doi:10.1016/0309-1651(81)90019-9

Cited by 4 publications

(6 citation statements)

References 22 publications

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“…Additionally, the expression of several different mitochondrial electron transport enzyme subunits is decreased in the brain from DS individuals (Kim et al 2001 ). DS fibroblasts are characterized by increased production of reactive oxygen species (ROS), higher intra-mitochondrial Ca 2+ levels, and bioenergetic deficit, with decreased basal ATP content and lower mitochondrial membrane potential (Schapira 1999 ; Piccoli et al 2013 ; Kim et al 2001 ; Panagaki et al 2019 , 2020 ).…”

Section: Gene Expression Proteomic and Metabolomic Profiling Of Ds Amentioning

confidence: 99%

“…Electron microscopy analysis of fetal DS hearts provided a deeper understanding of mitochondrial abnormalities in DS. Most of the DS mitochondria were characterized by morphological alterations, such as increased fragmentation, bigger size, irregular shape, and cristae’s patterns (Schapira 1999 ; Piccoli et al 2013 ; Kim et al 2001 ; Panagaki et al 2019 , 2020 ). Similar changes have been reported in hypoxic conditions, namely increased ROS production, together with a decrease in the activity in mitochondrial complexes and mitochondrial fragmentation (Lee et al 2020a , b ).…”

Section: Gene Expression Proteomic and Metabolomic Profiling Of Ds Amentioning

confidence: 99%

“…The malate-aspartate shuttle mechanism serves to move the reduced NADH across the membrane in the form of other reduced molecules (Nelson et al 2008 ). However, in DS, the electron transport chain is directly inhibited {as discussed later, recent data suggest that one of the reasons is that Complex IV activity is suppressed by the increased hydrogen sulfide [H 2 S] production, resulting from increased cystathionine-beta-synthase [CBS] and 3-mercaptopyruvate sulfurtransferase [3-MST] expression in DS cells (Panagaki et al 2019 , 2020 )}. Hence, NADH molecules remain in the cytosol and oxidized in the process of lactic fermentation to regenerate NADH molecules produced in glycolysis.…”

Section: Gene Expression Proteomic and Metabolomic Profiling Of Ds Amentioning

confidence: 99%

“…Three principal enzymes, cystathionine--lyase (CSE), cystathionine-β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST) are responsible for mammalian H 2 S biogenesis (Szabo and Papapetropoulos 2017 ; Zuhra et al 2020 ). CBS (encoded on chromosome 21) and 3-MST (encoded on chromosome 1) are both upregulated in DS cells (Panagaki et al 2019 ; Panagaki et al 2020 ; reviewed in Szabo 2020 ); accordingly, DS cells produce high levels of CBS. Indeed, early clinical observations have demonstrated that DS individuals have elevated plasma and urinary levels of H 2 S and its metabolites (Belardinelli et al 2001 ; Kamoun et al 2003 ).…”

Section: Potential Mechanisms Responsible For the Development Of Pseumentioning

confidence: 99%

“…Indeed, early clinical observations have demonstrated that DS individuals have elevated plasma and urinary levels of H 2 S and its metabolites (Belardinelli et al 2001 ; Kamoun et al 2003 ). As reviewed recently (Szabo 2020 ), when cellular H 2 S levels are increased beyond an optimal concentration, H 2 S produce inhibitory bioenergetic effects (in principle, via inhibition of mitochondrial Complex IV, but also through other mechanisms) (Panagaki et al 2019 , 2020 ; Szabo 2020 ; Nicholls et al 2013 ). 1 Indeed, pharmacological inhibition or genetic silencing of CBS can restore mitochondrial function and cellular proliferation in DS fibroblasts (Panagaki et al 2019 ) and it can improve neurological function in DS mice (Marechal et al 2019 ).…”

Section: Potential Mechanisms Responsible For the Development Of Pseumentioning

confidence: 99%

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Meta-analysis of metabolites involved in bioenergetic pathways reveals a pseudohypoxic state in Down syndrome

Pecze

Randi

Szabó

2020

Mol Med

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Clinical observations and preclinical studies both suggest that Down syndrome (DS) may be associated with significant metabolic and bioenergetic alterations. However, the relevant scientific literature has not yet been systematically reviewed. The aim of the current study was to conduct a meta-analysis of metabolites involved in bioenergetics pathways in DS to conclusively determine the difference between DS and control subjects. We discuss these findings and their potential relevance in the context of pathogenesis and experimental therapy of DS. Articles published before July 1, 2020, were identified by using the search terms “Down syndrome” and “metabolite name” or “trisomy 21” and “metabolite name”. Moreover, DS-related metabolomics studies and bioenergetics literature were also reviewed. 41 published reports and associated databases were identified, from which the descriptive information and the relevant metabolomic parameters were extracted and analyzed. Mixed effect model revealed the following changes in DS: significantly decreased ATP, CoQ10, homocysteine, serine, arginine and tyrosine; slightly decreased ADP; significantly increased uric acid, succinate, lactate and cysteine; slightly increased phosphate, pyruvate and citrate. However, the concentrations of AMP, 2,3-diphosphoglycerate, glucose, and glutamine were comparable in the DS vs. control populations. We conclude that cells of subjects with DS are in a pseudo-hypoxic state: the cellular metabolic and bio-energetic mechanisms exhibit pathophysiological alterations that resemble the cellular responses associated with hypoxia, even though the supply of the cells with oxygen is not disrupted. This fundamental alteration may be, at least in part, responsible for a variety of functional deficits associated with DS, including reduced exercise difference, impaired neurocognitive status and neurodegeneration.

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Section: Gene Expression Proteomic and Metabolomic Profiling Of Ds Amentioning

confidence: 99%

Section: Gene Expression Proteomic and Metabolomic Profiling Of Ds Amentioning

confidence: 99%

Section: Gene Expression Proteomic and Metabolomic Profiling Of Ds Amentioning

confidence: 99%

Section: Potential Mechanisms Responsible For the Development Of Pseumentioning

confidence: 99%

Section: Potential Mechanisms Responsible For the Development Of Pseumentioning

confidence: 99%

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Meta-analysis of metabolites involved in bioenergetic pathways reveals a pseudohypoxic state in Down syndrome

Pecze

Randi

Szabó

2020

Mol Med

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Evolution of Chloroplast and Mitochondrial DNA in Plants and Algae

Palmer¹

1985

Molecular Evolutionary Genetics

164

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Structure, composition, and distribution of plastid nucleoids in Narcissus pseudonarcissus

Hansmann

Falk

Ronai

et al. 1985

Planta

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The size, frequency and distribution of the nucleoids of chloroplasts (cl-nucleoids) and chromoplasts (cr-nucleoids) of the daffodil have been investigated in situ using the DNA-specific fluorochrome 4'6-diamidino-2-phenylindole. Chromoplasts contain fewer nucleoids (approx. 4) than chloroplasts (> 10), and larger chromoplasts (cultivated form, approx. 4) contain more than smaller ones (wild type, approx. 2). During chromoplast development the nucleoid number decreases in parallel with the chlorophyll content. Each nucleoid contains 2-3 plastome copies on average. In chloroplasts the nucleoids are evenly distributed, whereas they are peripherally located in chromoplasts. The fine structure of isolated cl-and cr-nucleoids, purified either by Sepharose 4B-CL columns or by metrizamide gradients, was investigated electron microscopically. The cl-nucleoids consist of a central protein-rich core with 'naked' DNA-loops protruding from it. In cr-nucleoids, on the other hand, the total DNA is tightly packed within the proteinaceous core. The protein-containing core region of the nucleoids is made up of knotty and fibrillar sub-structures with diameters of 18 and 37 nm, respectively. After proteinase treatment, or incressing ion concentration, most of the proteins are removed and the DNA is exposed even in the case of cr-nucleoids, the stability of which proved to be greater than that of cl-nucleoids. The chemical composition of isolated plastid nucleoids has been determined qualitatively and quantitatively. Chromoplast-nucleoids contain, relative to the same DNA quantity, about six times as much protein as cl-nucleoids. Accordingly the buoyant density of cr-nucleoids in metrizamide gradients is higher than that of cl-nucleoids. In addition to DNA and protein, RNA could be found in the nucleoid fraction. No pigments were present. The cr-and cl-nucleoids have many identical proteins. There are, however, also characteristic differences in their protein pattern which are possibly related to the different expression of the genomes of chloroplasts and chromoplasts. Nucleoids of both plastid types contain some proteins which also occur in isolated envelope membranes (probably partly in the outer membrane) and thus possibly take part in binding the DNA to membranes.

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Configurations indicative of functional sites in spinach chloroplast DNA

Cited by 4 publications

References 22 publications

Meta-analysis of metabolites involved in bioenergetic pathways reveals a pseudohypoxic state in Down syndrome

Meta-analysis of metabolites involved in bioenergetic pathways reveals a pseudohypoxic state in Down syndrome

Evolution of Chloroplast and Mitochondrial DNA in Plants and Algae

Structure, composition, and distribution of plastid nucleoids in Narcissus pseudonarcissus

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