scholarly journals Changes in respiratory activities during the cell-cycle of the fission yeast Schizosaccharomyces pombe 972h- growing in the presence of glycerol

1974 ◽  
Vol 144 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Robert K. Poole ◽  
David Lloyd

1. The specific activities of cytochrome c oxidase, catalase, succinate dehydrogenase, succinate–cytochrome c oxidoreductase, NADH–cytochrome c oxidoreductase, and NADPH–cytochrome c oxidoreductase in mid-exponential-phase batch cultures of glycerol-grown Schizosaccharomyces pombe indicated that the organisms were catabolite-de-repressed. 2. In cultures growing synchronously in the presence of glycerol as sole carbon source, the respiration rate showed two abrupt increases at about 0.45 and 0.95 of the cell-cycle and remained constant in the periods between successive rises. 3. Catalase, succinate dehydrogenase, NADH–cytochrome c oxidoreductase and acid p-nitrophenyl-phosphatase all showed peak patterns of expression in synchronous cultures. 4. Cytochrome c oxidase and cytochromes a+a3 both showed step patterns of expression with two rises per cell-cycle. 5. Cytochromes c548, b554 and b560 all followed similar time-courses in step patterns of expression, but these were distinct from, and more complex than, that of cytochromes a+a3. 6. These results are compared with those previously obtained with glucose-grown cultures, and the part played by catabolite repression in the expression of respiratory activities in the cell-cycle is assessed.

1973 ◽  
Vol 136 (1) ◽  
pp. 195-207 ◽  
Author(s):  
R. K. Poole ◽  
D. Lloyd

1. Increased specific activities of cytochrome c oxidase, catalase, succinate dehydrogenase, succinate–cytochrome c oxidoreductase, NADH–cytochrome c oxidoreductase and malate dehydrogenase were observed during glucose de-repression of Schizosaccharomyces pombe. 2. The cell-cycle of this organism was analysed by three different methods: (a) harvesting of cells at intervals from a synchronous culture, (b) separation of cells by rate-zonal centrifugation into different size classes and (c) separation of cells by isopycnic-zonal centrifugation into different density classes. 3. Measurement of enzyme activities during the cell-cycle showed that all the enzymes assayed [cytochrome c oxidase, catalase, acid p-nitrophenylphosphatase, NADH-dehydrogenase, NADH–cytochrome c oxidoreductase, NADPH–cytochrome c oxidoreductase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase (NADP) and fumarate hydratase] show periodic expression as ‘peaks’. 4. Cytochrome c oxidase shows a single maximum at 0.67 of a cycle, whereas succinate dehydrogenase exhibits two maxima separated by 0.5 of a cell-cycle. 5. All other enzymes assayed showed two distinct maxima per cell-cycle; for catalase, malate dehydrogenase and NADPH–cytochrome c oxidoreductase there is the possibility of multiple fluctuations. 6. The single maximum of cytochrome c oxidase appears at a similar time in the cycle to one maximum of each of the other enzymes studied, except for NADH dehydrogenase. 7. These results are discussed with reference to previous observations on the expression of enzyme activities during the cell-cycle of yeasts.


1974 ◽  
Vol 138 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Robert K. Poole ◽  
David Lloyd ◽  
Britton Chance

1. Spectrophotometric analysis of intact cells of Schizosaccharomyces pombe, harvested from exponentially growing cultures during the phase of glucose repression, revealed the presence of cytochromes a+a3, c and at least two species of cytochrome b. 2. An absorption maximum at 554nm at 77°K, previously attributed to cytochrome c1, has been identified as a b-type cytochrome. 3. CO-difference spectra reveal the presence of cytochromes P-420 and P-450 in addition to cytochrome a3. 4. The cell cycle was analysed by separation of cells into classes representing successive stages in the cell cycle by isopycnic zonal centrifugation. 5. Cytochromes c548, b554 and b560 each exhibited a single broad maximum of synthesis during the cell cycle. 6. Amounts of cytochromes a+a3 and b563 (tentatively identified as cytochrome bT by its reaction on pulsing anaerobic cell suspensions with O2) oscillated in phase, and showed two maxima during the cycle; the second maximum of cytochromes a+a3 was coincident with a maximum of activity of enzymically active cytochrome c oxidase. 7. The amount of cytochrome P-420 decreased during the first three-quarters of the cell-cycle, whereas that of cytochrome P-450 increased during this period. 8. The discrepancy between spectrophotometric and enzymic assay of cytochrome c oxidase, the changing ratio of cytochrome a3/cytochrome a and the relationship between changes in cellular content of cytochromes and previous observations on respiratory oscillations during the cell cycle are discussed.


2011 ◽  
pp. 329-336 ◽  
Author(s):  
J.-L. WU ◽  
Q.-P. WU ◽  
Y.-P. PENG ◽  
J.-M. ZHANG

Accumulation of oxidative damage has been implicated to be a major causative factor in the decline in physiological functions that occur during the aging process. The mitochondrial respiratory chain is a powerful source of reactive oxygen species (ROS), considered as the pathogenic agent of many diseases and aging. L-malate, a tricarboxylic acid cycle intermediate, plays an important role in transporting NADH from cytosol to mitochondria for energy production. Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. In the present study we focused on the effect of L-malate on the activities of electron transport chain in young and aged rats. We found that mitochondrial membrane potential (MMP) and the activities of succinate dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats were significantly decreased when compared to young control rats. Supplementation of L-malate to aged rats for 30 days slightly increased MMP and improved the activities of NADH-dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats when compared with aged control rats. In young rats, L-malate administration increased only the activity of NADH-dehydrogenase. Our result suggested that L-malate could improve the activities of electron transport chain enzymes in aged rats


Author(s):  
Harvey B. Sarnat ◽  
José Marín-García

ABSTRACT:Muscle biopsy provides the best tissue to confirm a mitochondrial cytopathy. Histochemical features often correlate with specific syndromes and facilitate the selection of biochemical and genetic studies. Ragged-red fibres nearly always indicate a combination defect of respiratory complexes I and IV. Increased punctate lipid within myofibers is a regular feature of Kearns-Sayre and PEO, but not of MELAS and MERRF. Total deficiency of succinate dehydrogenase indicates a severe defect in Complex II; total absence of cytochrome-c-oxidase activity in all myofibres correlates with a severe deficiency of Complex IV or of coenzyme-Q10. The selective loss of cytochrome-c-oxidase activity in scattered myofibers, particularly if accompanied by strong succinate dehydrogenase staining in these same fibres, is good evidence of mitochondrial cytopathy and often of a significant mtDNA mutation, though not specific for Complex IV disorders. Glycogen may be excessive in ragged-red zones. Ultrastructure provides morphological evidence of mitochondrial cytopathy, in axons and endothelial cells as well as myocytes. Abnormal axonal mitochondria may contribute to neurogenic atrophy of muscle, a secondary chronic feature. Quantitative determinations of respiratory chain enzyme complexes, with citrate synthase as an internal control, confirm the histochemical impressions or may be the only evidence of mitochondrial disease. Biological and technical artifacts may yield falsely low enzymatic activities. Genetic studies screen common point mutations in mtDNA. The brain exhibits characteristic histopathological alterations in mitochondrial diseases. Skin biopsy is useful for mitochondrial ultrastructure in smooth erector pili muscles and axons; skin fibroblasts may be grown in culture. Mitochondrial alterations occur in many nonmitochondrial diseases and also may be induced by drugs and toxins.


1978 ◽  
Vol 33 (1) ◽  
pp. 399-411
Author(s):  
J. Creanor

Oxygen uptake was measured in synchronous cultures of the fission yeast Schizosaccharomyces pombe. The rate of oxygen uptake was found to increase in a step-wise manner at the beginning of the cycle and again in the middle of the cycle. The increases in rate were such that overall, oxygen uptake doubled in rate once per cell cycle. Addition of inhibitors of DNA synthesis or nuclear division to a synchronous culture did not affect the uptake of oxygen. In an induced synchronous culture, in which DNA synthesis, cell division, and nuclear division, but not ‘growth’ were synchronized, oxygen uptake increased continuously in rate and did not show the step-wise rises which were shown in the selection-synchronized culture. These results were compared with previous measurements of oxygen uptake in yeast and an explanation is suggested for the many different patterns which have been reported.


Biochemistry ◽  
1981 ◽  
Vol 20 (19) ◽  
pp. 5369-5373 ◽  
Author(s):  
T. Somasundaram ◽  
J. Jayaraman

1970 ◽  
Vol 7 (2) ◽  
pp. 523-530
Author(s):  
C. J. BOSTOCK

The effect of different concentrations of 2-phenyl ethanol (PE) on growth and DNA synthesis of Schizosaccharomyces pombe is described. o.3% PE inhibits the entry of cells into S phase, but allows a doubling in the number of cells in the culture. The effect of o.2% PE on random and synchronous cultures of S. pombe shows that, in the continued presence of the inhibitor, the S phase is moved to a different point in the cell cycle. Cells continue to grow in the presence of o.2% PE with a G1 phase occupying a significant portion of the cell cycle. This differs from normal growth when the G1 phase is absent.


1982 ◽  
Vol 58 (1) ◽  
pp. 263-285
Author(s):  
J. Creanor ◽  
J.M. Mitchison

The rate of protein synthesis through the cell cycle of Schizosaccharomyces pombe has been determined from the incorporation of pulses of [3H]tryptophan in synchronous cultures prepared by selection in an elutriating rotor. This selection procedure caused minimal perturbations as judged by asynchronous control cultures, which had also been put through the rotor. The rate of synthesis showed a periodic pattern rather than a smooth exponential increase. There was a sharp increase in the rate at an ‘acceleration point’ at about 0.9 of the cycle. Model-fitting by a novel procedure suggests that the average single cell has an increasing rate of protein synthesis for the first 60% of the cycle and a constant rate for the remaining 40%. The same pattern was shown in less extensive experiments with [3H]leucine and [3H]phenylalanine. It was also shown in a series of size mutants, which indicates that the pattern is not size-related, in contrast to earlier work on the rates of synthesis of messenger RNA. However, one large mutant (cdc 2.M35r20) had a significantly earlier acceleration point. Care was taken to justify the assumption that the rate of incorporation of tryptophan was a valid measure of the rate of protein synthesis. A tryptophan auxotroph was used to eliminate the problem of endogenous supply and the size of the metabolic pool was measured through the cycle. This pool did not show cell-cycle related fluctuations. An operational model of the pools is presented.


1976 ◽  
Vol 21 (3) ◽  
pp. 497-521
Author(s):  
R.S. Fraser ◽  
F. Moreno

The rates of polyadenylated messenger RNA and ribosomal RNA synthesis were measured in synchronously dividing cultures of fission yeast (Schizosaccharomyces pombe). Control asynchronous cultures, which had been exposed to the conditions used for preparing synchronous cultures, were investigated to check for effects of the synchronization procedure itself on RNA synthesis. After each period of DNA synthesis in synchronous culture, the rates of messenger and ribosomal RNA synthesis doubled, suggesting that gene number controls the rate of messenger and ribosomal RNA synthesis. This was confirmed by experiments with asynchronous, exponential-phase cultures in which DNA synthesis was inhibited by hydroxyurea. Both synchronous culture and hydroxyurea experiments suggested that there is a delay of 15 min (0-1 of the cell generation time) between replication of the DNA and transcription of both gene copies. A pattern of protein accumulation was calculated from changes in the rate of polyadenylated messenger RNA synthesis during synchronous culture. The simulated pattern indicates that protein is accumulated linearly, with a doubling in the rate of accumulation once per cell cycle. The simulated pattern of protein accumulation is very similar to measurements previously reported by other workers of changes in activities of 3 enzymes in synchronous cultures. It is suggested that the doubling of the rate of messenger RNA synthesis, as a consequence of the replication of the DNA once per cycle, provides the basis of a mechanism for control of the doubling of other cellular constituents during the cell cycle.


1973 ◽  
Vol 132 (3) ◽  
pp. 609-621 ◽  
Author(s):  
T. G. Cartledge ◽  
D. Lloyd

1. During anaerobic glucose de-repression the respiration rate of whole cells of Saccharomyces carlsbergensis remained constant and was insensitive to antimycin A but was inhibited by 30% by KCN. Aeration of cells for 1 h led to increased respiration rate which was inhibited by 80% by antimycin A or KCN. 2. Homogenates were prepared from sphaeroplasts of anaerobically grown, glucose de-repressed cells and the distribution of marker enzymes was investigated after zonal centrifugation on sucrose gradients containing MgCl2. These homogenates contained no detectable cytochrome c oxidase or catalase activity. The complex density distributions of NADH– and NADPH–cytochrome c oxidoreductases and adenosine triphosphatase(s) [ATPase(s)] were very different from those of anaerobically grown, glucose-repressed cells. 3. The specific activity of total ATPase was lowered and sensitivity to oligomycin decreased from 58 to 7% during de-repression. 4. Cytochrome c oxidase and catalase activities were detectable in homogenates of cells after 10min aeration. Zonal centrifugation indicated complex, broad sedimentable distributions of all enzyme activities assayed; the peaks of activity were at 1.27g/ml. 5. Centrifugation of homogenates of cells adapted for 30min and 3 h indicated a shift of density of the major sedimentable peak from 1.25g/ml (30min) to 1.235g/ml (3 h). After 30min adaptation a minor zone of oligomycin-sensitive ATPase and 15% of the total cytochrome c oxidase activities were detected at ρ=1.12g/l; these particles together with those of higher density containing cytochrome c oxidase, ATPase and NADH–cytochrome c oxidoreductase activities were all sedimented at 105g-min. 6. Electron microscopy indicated that the mitochondria-like structures of anaerobically grown, glucose-de-repressed cells were similar to those of repressed cells. After 10min of respiratory adaptation highly organized mitochondria were evident which resembled the condensed forms of mitochondria of aerobically grown, glucose-de-repressed cells. High-density zonal fractions of homogenates of cells after adaptation also contained numerous electron-dense vesicles 0.05–0.2μm in diameter. 7. The possibility that the `promitochondria' of anaerobically grown cells may not be the direct structural precursors of fully functional mitochondria is discussed.


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