• Asian Journal of Turfgrass Science
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• v.11 no.1
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• pp.59-72
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• 1997

The influence of respiration on photosythetic electron transport were investigated in the Wid type and psaB mutants from Syneehocystis sp. PCC6803. The amount of glucose uptake in the wild type was proportional to the glucose concentration added in wild type and less than that of psaB mutants in the dark. It was suggested that psaB mutants more depend on the glucose than the wild type. It was investigated how the activities of isocitrate dehydrogenase(IDH) and glucose-6-phos-phate dehydrogenase(G6PDH) were changed. The activities of IDH were very low. While, the ac-tivities of G6PDH were much higher than that of IDH. These results agree to the reports that ex-ogenous glucose was dismilated aerobically via Oxidative Pentose Phosphate Pathway in heterotrophic cyanobacteria. PsaB mutants showed high G6PDH activity in the presence of glucose as well as in the dark and high respiratory activities especially in the dark. It was also investigated how photosynthetic electron transport activities were changed. PsaB mutants showed higher photosynthetic electron tranasport activities than wild type in the presence of glucose as well as in the dark. In the results, it was proposed that photosynthetic electron transport between PS I and PS U was complemented by respiratory electron transport through the NADPH generated by Dxidative Pentose Phophate Pathway in psaB mutant from Synechocystis sp. PCC6803. Key words: Photosynthetic electron transport, Respiration, Synechoystis sp. PCC6803, psaB mutant, Glucose uptake, IDH, G6PDH, Respiratory electron transport activity.

• Molecules and Cells
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• v.25 no.2
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• pp.158-162
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• 2008

Recent molecular genetics studies have revealed that cyclic electron transport around photosystem I is essential for normal photosynthesis and growth of plants. Chloroplastic NAD(P)H dehydorgenase (NDH) complex, a homologue of the complex I in respiratory electron transport, is involved in one of two cyclic pathways. Recent studies on the function and structure of the NDH complex are reviewed.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.149-155
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• 2010

Expression of the genes for carotenoid bio-synthesis (crt) is dependent on light, but little is known about the underlying mechanism of light sensing and signalling in the cyanobacterium Synechocystis sp. PCC 6803 (hereafter, Synechocystis). In the present study, we investigated the light-induced increase in the transcript levels of Synechocystis crt genes, including phytoene synthase (crtB), phytoene desaturase (crtP), ${\zeta}$-carotene desaturase (crtQ), and ${\beta}$-carotene hydroxylase (crtR), during a darkto-light transition period. During the dark-to-light shift, the increase in the crt transcript levels was not affected by mutations in cyanobacterial photoreceptors, such as phytochromes (cph1, cph2 and cph3) and a cryptochrome-type photoreceptor (ccry), or respiratory electron transport components NDH and Cyd/CtaI. However, treatment with photosynthetic electron transport inhibitors significantly diminished the accumulation of crt gene transcripts. Therefore, the light induction of the Synechocystis crt gene expression is most likely mediated by photosynthetic electron transport rather than by cyanobacterial photoreceptors during the dark-to-light transition.

• Molecules and Cells
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• v.40 no.4
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• pp.307-313
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• 2017

Caloric restriction (CR) has been shown to extend lifespan and prevent cellular senescence in various species ranging from yeast to humans. Many effects of CR may contribute to extend lifespan. Specifically, CR prevents oxidative damage from reactive oxygen species (ROS) by enhancing mitochondrial function. In this study, we characterized 33 single electron transport chain (ETC) gene-deletion strains to identify CR-induced chronological lifespan (CLS) extension mechanisms. Interestingly, defects in 17 of these 33 ETC gene-deleted strains showed loss of both respiratory function and CR-induced CLS extension. On the contrary, the other 16 respiration-capable mutants showed increased CLS upon CR along with increased mitochondrial membrane potential (MMP) and intracellular adenosine triphosphate (ATP) levels, with decreased mitochondrial superoxide generation. We measured the same parameters in the 17 non-respiratory mutants upon CR. CR simultaneously increased MMP and mitochondrial superoxide generation without altering intracellular ATP levels. In conclusion, respiration is essential for CLS extension by CR and is important for balancing MMP, ROS, and ATP levels.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.264-267
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• 1990

Representative synthetic piericidin-like compounds, such as hydroxypyridine and hydroxyquinoline derivatives, which showed high inhibition activity against NADH-ubiquinone oxidoreductase on the respiratory chain revealed good fungicide activity. Especially, hydrolrypyridine ones showed high activity against rice blast (Pyricularia oryzae) and barley powdery mildew (Erysiphe graminis).

• Archives of Pharmacal Research
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• v.26 no.11
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• pp.951-959
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• 2003

A series of typical (chlorpromazine, haloperidol and thioridazine) and atypical (risperidone, quetiapine, clozapine and olanzapine) antipsychotics were tested for effects on integrated bioenergetic functions of isolated rat liver mitochondria. Polarographic measurement of oxygen consumption in freshly isolated mitochondria showed that electron transfer activity at respiratory complex I is inhibited by chlorpromazine, haloperidol, risperidone, and quetiapine, but not by clozapine, olanzapine, or thioridazine. Chlorpromazine and thioridazine act as modest uncouplers of oxidative phosphorylation. The typical neuroleptics inhibited NADH-coenzyme Q reductase in freeze-thawed mitochondria, which is a direct measure of complex I enzyme activity. The inhibition of NADH-coenzyme Q reductase activity by the atypicals risperidone and quetiapine was 2-4 fold less than that for the typical neuroleptics. Clozapine and olanzapine had only slight effects on NADH-coenzyme Q reductase activity, even at 200 $\mu$ M. The relative potencies of these neuroleptic drugs as inhibitors of mitochondrial bioenergetic function is similar to their relative potencies as risk factors in the reported incidence of extrapyramidal symptoms, including tardive dyskinesia (TD). This suggests that compromised bioenergetic function may be involved in the cellular pathology underlying TD.

• Tuberculosis and Respiratory Diseases
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• v.41 no.6
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• pp.663-669
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• 1994

Kartagener's sydrome is an autosomaly inherited recessive condition characterized by situs inversus, bronchiectasis, and chronic sinusitis. And recently it was recognized as a subclass of dyskinetic cilia syndrome which caused by a defect in mucociliary transport owing to immotile or dyskinetic beating of cilia. Electron microsopy of cilia from sperm tails, nasal and bronchial epithelium of patients reveals the partial or complete absence of dynein arms. Our four patients were diagnosed as a Kartagener's syndrome by classic triad. We carried out electron microscopy of cilia of the nasal mucosa. And many other tests were done. One patient had squamous cell carcinoma of the lung, and another one patient revealed features of adult respiratory distress syndrome at admission. All patients improved with conservative therapy such as physiotherapy, bronchodilater, antibiotics except one patient who mechanical ventilation was required. A brief review of literature was made.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.364-370
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• 1987

The $O_2^-$ level of the extract from young rice leaves, which was cold treated for 2 days and then placed at room temperature for a period of time significantly higher than that from tissues untreated. $O_2^-$ level in leaves was practically unchanged during cold treatment for 48 hours. But it started to increase to arrive at maximum in 8 hours, once the plants were placed under room temperature. The abnormal production of $O_2^-$ in mitochondria during postchilling process was interpreted as a biochemical consequence of accumulation of glycolysis product(s) in cytosol and/or NADH in mitochondrial matrix due to disruption of catabolic balance at low temperature. Mitochondria isolated from the chilling injured tissue was found to have lost considerably their respiratory activity. This fact may imply the involvement of intramitochondrial accumulation of $O_2^-$ in the inactivation of electron transport chain system. The observation that mitochondria in the presence of the $O_2^--producing$ enzymatic system (Xanthine/Xanthine oxidase) lost their respiratory activity supports this inference. It was also found in this work that Superoxide dismutase (SOD) is a substrate inducible enzyme, and that SOD is a possible protective agent in plant cell against chilling injury.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.153-157
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• 1991

Intracellular enzymes of an extreme halophilic bacterium, Halobacterium sp. HE10, isolated from a saltern in Korea was investigated. The membrane-bound enzyme, NADH dehydrogenase, involved in electron transport system was stimulated by the addition of 2.0 M NaCl. The respiratory enzyme activities such as NADH oxidase and NADH dehydrogenase was decreased on removal of $Na^+$ ion and restored when replaced with cations like $K^+$, $Li^+$and $NH_{4}^{+}$ ions. Furthermore, their activities were affected by the anions such like carbonate, acetate, sulfate, chloride and nitrate at the presence of $Na^+$ion. Lactate dehydrogenase activity was highest at the asturated solution of NaCl and isocitrate dehydrogenase activity was a maximum level at 1.0 M NaCl. These results suggested that the enzyme activites of the respiratory chain in Halobacterium sp. EH10 was stimulated by the presence of $Na^+$ ion.

• Korean Journal of Microbiology
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• v.5 no.1
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• pp.15-19
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• 1967

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Physiological activities such as growth rate, reproduction, endogenous and glucose respiration, photosynthetic activity and biosythesis of chlorophyll of the micro-element definition cells were measured. It generally, growth rate, respiratory and photosynthetic activities, and biosynthesis of chlorophyll of the micro-element deficient cells decreased more or less, compared with those of the normal cells. The growth of the algal cells in an iron-free medium were retarded severely with the chlorosis, and the photosynthetic activity of the cells decreased remarkably even though the low content of chlorophyll in the cells owing to the iron-deficiency is considered. Therefore, it is deduced that iron takes part in the photosynthetic process itself, possibly by its participation in the photo phosphorylation coupled with electron transport. Respiratory activity of boron-deficient cells showed the most severe decrease whereas those of the molybdenum-deficient cells showed very slight decrease in spite of severe growth retardation.