Protein synthesis and its relation to the DNA-division cycle in the fission yeast Schizosaccharomyces pombe

1984 ◽  
Vol 69 (1) ◽  
pp. 199-210
Author(s):  
J. Creanor ◽  
J.M. Mitchison
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Protein Content ◽  
Fission Yeast ◽  
Nuclear Division ◽  
Restrictive Temperature ◽  
Tentative Conclusion ◽  
Synchronous Cultures

The rate of protein synthesis has been measured with pulse labels of [3H]tryptophan in synchronous and asynchronous cultures of cdc mutants of Schizosaccharomyces pombe shifted up to the restrictive temperature. The cell cycle related fluctuations in rate that occur in normal synchronous cultures vanish when nuclear division is blocked in synchronous cultures of cdc2 and cdc10. But they persist in cdc11 where nuclear division continues and cleavage is stopped. We conclude that nuclear division affects the rate of synthesis and that this effect is inhibitory and probably persists for the last 40% of the cycle. When nuclear division has been blocked, the rate of synthesis continues to increase until a plateau is reached where the rate remains constant. Three size mutants of cdc2 reach the plateau at the same average protein content per cell although their initial protein contents vary over a threefold range. Comparison of these results with those from cdc10 leads to the tentative conclusion that the plateau starts when the cells reach a critical protein/DNA ratio.

Oxygen uptake during the cell cycle of the fission yeast Schizosaccharomyces pombe

1978 ◽  
Vol 33 (1) ◽  
pp. 399-411
Author(s):  
J. Creanor
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Oxygen Uptake ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Nuclear Division ◽  
Synchronous Culture ◽  
Synchronous Cultures ◽  
The Many

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.

Carbon dioxide evolution during the cell cycle of the fission yeast Schizosaccharomyces pombe

1978 ◽  
Vol 33 (1) ◽  
pp. 385-397
Author(s):  
J. Creanor
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Nuclear Division ◽  
Complete Medium ◽  
Co2 Evolution ◽  
Carbon Dioxide Evolution ◽  
Synchronous Cultures ◽  
Constant Addition

The rate of CO2 evolution was measured in synchronous cultures of the fission yeast Schizosaccharomyces pombe growing in a minimal medium. The rate of CO2 evolution was found to double sharply at about the time of nuclear division (0.75 of the way through the cell cycle). For the remainder of the cell cycle the rate remained constant. Addition of inhibitors of DNA synthesis or nuclear division did not affect the pattern of CO2 evolution in synchronous cultures. Similarly, in an induced synchronous culture, in which DNA synthesis, nuclear division and cell division—but not growth, were synchronized, CO2 evolution showed a continuous pattern and not the step-wise increase associated with the normal synchronous cultures. When S. pombe was grown in a complete medium, the evolution of CO2 in a synchronous cultures was shown to increase in a continuous manner but at a rate faster than the growth of the culture.

Nucleoside diphosphokinase and cell cycle control in the fission yeast Schizosaccharomyces pombe

1983 ◽  
Vol 60 (1) ◽  
pp. 355-365
Author(s):  
J.R. Dickinson
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Enzyme Activity ◽  
Dna Replication ◽  
Schizosaccharomyces Pombe ◽  
S Phase ◽  
Restrictive Temperature ◽  
Wild Type ◽  
Synchronous Cultures ◽  
In The Wild

Centrifugal elutriation was used to prepare synchronous cultures of Schizosaccharomyces pombe. Nucleoside diphosphokinase activity was measured throughout the cell cycle. In the wild-type strain (972) nucleoside diphosphokinase activity doubled in a stepwise fashion. The midpoint of the rise in enzyme activity was at 0.65 of a cycle, 0.29 of a cycle before the next S phase. Synchronous cultures of the mutant wee 1–6 were also prepared. In this strain S phase is delayed, occurring about 0.3 cycle later than in the wild-type. In wee 1–6 the midpoint of the stepwise doubling in nucleoside diphosphokinase activity occurred at 0.084; showing that the rise in enzyme activity is also delayed. Addition of cycloheximide to an exponentially growing culture caused an immediate inhibition of protein synthesis, yet nucleoside diphosphokinase activity continued to increase exponentially for a further 300 min. This indicates that the stepwise doubling of nucleoside diphosphokinase activity during the cell cycle is not achieved by a simple control on protein synthesis. Two temperature-sensitive cdc- mutants were also used: cdc2-33, a mutant whose single genetic lesion results in the twin defects of a loss of mitotic control and a loss of commitment to the cell cycle; and cdc 10–129, which has a defect in DNA replication. In both mutants a temperature shift-up of an asynchronously growing culture from the permissive (25 degrees C) to the restrictive temperature (36.5 degrees C) results in a rapid inhibition of DNA replication. In both mutants nucleoside diphosphokinase continues to increase exponentially. Therefore, although nucleoside diphosphokinase is required for DNA replication, apparently DNA replication is not required for an increase in nucleoside diphosphokinase activity.

Patterns of protein synthesis during the cell cycle of the fission yeast Schizosaccharomyces pombe

1982 ◽  
Vol 58 (1) ◽  
pp. 263-285
Author(s):  
J. Creanor ◽  
J.M. Mitchison
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Messenger Rna ◽  
Model Fitting ◽  
Selection Procedure ◽  
Periodic Pattern ◽  
Synchronous Cultures ◽  
Metabolic Pool ◽  
Cdc 2

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.

Arginase and sucrase potential in the fission yeast Schizosaccharomyces pombe

1980 ◽  
Vol 46 (1) ◽  
pp. 399-431
Author(s):  
T. Benitez ◽  
P. Nurse ◽  
J.M. Mitchison
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Gene Dosage ◽  
Critical Ratio ◽  
Restrictive Temperature ◽  
Wild Type ◽  
Synchronous Cultures ◽  
Short Period

The induction potentials of 2 enzymes, sucrase and arginase, have been measured in asynchronous and synchronous cultures of the fission yeast Schizosaccharomyces pombe. The effect on potential of inhibiting DNA synthesis is asynchronous cultures has been studied using 2 temperature-sensitive dcd mutants, one blocked in DNA replication and the other blocked in mitosis. The results show that despite inhibition of DNA synthesis, sucrase and arginase potential both continue to increase exponentially for at least a generation of growth after shifting the cdc mutants from the permissive to the restrictive temperature. A second method of inhibiting DNA synthesis, using deoxyadenosine, has also been tested. Cells treated with deoxyadenosine stop the increase in potential for a short period. However, experiments carried out using a cdc mutant together with deoxyadenosine show that the block to the increase in potential is due to a side effect of the inhibitor. It appears that increase in potential is not dependent upon continued DNA replication, and that gene dosage does not control potential in the normal cell cycle. This conclusion is supported by measurements on mutants of different cell sizes. potential is proportional to size (protein content per cell is asynchronous culture) and not to DNA content. Although potential is not gene limited in normal cells, it does appear to be so in the abnormally large cells produced by a cdc block. If cdc mutants of different sizes are grown asynchronously, and DNA synthesis is inhibited by a shift to the restrictive temperature, there is no increase in potential. This critical ratio is different for the 2 enzymes, but for each enzyme it is similar in all the mutants tested. When large cells (produced by a mutant block for 4.5 h) are shifted down in temperature, there are synchronous rounds of DNA synthesis and division and also step doublings in potential. In synchronous cultures of wild type cells, both enzymes show a stepwise doubling of potential at 0.2 of a cycle after DNA replication. In synchronous cultures of cdc mutants blocked either in replication or in mitosis, the potential steps continue with the normal timing observed in wild type cells. This shows that the steps are not dependent on the events of the DNA-division cycle but are controlled by another mechanism. Attainment of a critical size might be part of this mechanism, but tests with size mutants argue against this.

scholarly journals Mitochondrial adenosine triphosphatase of the fission yeast, Schizosaccharomyces pombe 972h−. Changes in activity and oligomycin-sensitivity during the cell cycle of catabolite-repressed and -de-repressed cells

1977 ◽  
Vol 162 (1) ◽  
pp. 39-46 ◽  
Author(s):  
S W Edwards ◽  
D Lloyd
Keyword(s):  
Cell Cycle ◽  
Atpase Activity ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Adenosine Triphosphatase ◽  
Total Activity ◽  
Stages Of Growth ◽  
Synchronous Cultures ◽  
A Cell ◽  
In Cells

1. Changes in activity of ATPase (adenosine triphosphatase) during the cell cycle of Schizosaccharomyces pombe were analysed in cell-free extracts of cells harvested from different stages of growth of synchronous cultures and also after cell-cycle fractionation. 2. Oligomycin-sensitive ATPase oscillates in both glucose-repressed synchronous cultures and shows four maxima of activity approximately equally spaced through the cell cycle. The amplitude of the oscillations accounts for between 13 and 80% of the total activity at different times in the cell cycle. 3. Oligomycin sensitivity varies over a fourfold range at different stages of the cell cycle. 4. The periodicity of maximum oligomycin sensitivity is one-quarter of a cell cycle. 5. These results were confirmed for the first three-quarters of the cell cycle by cell-cycle fractionation. 6. In cells growing synchronously with glycerol, ATPase activity increases in a stepwise pattern, with two steps per cell cycle; the first of these occurs at 0.54 of the cell cycle and the second at 0.95. 7. These results are discussed in relation to previously obtained data on the development of mitochondrial activities during the cell cycle.

Changes in the rate of oxygen consumption in synchronous cultures of the fission yeast Schizosaccharomyces pombe

1990 ◽  
Vol 96 (3) ◽  
pp. 429-433
Author(s):  
B. Novak ◽  
J.M. Mitchison
Keyword(s):  
Cell Cycle ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Oxygen Electrode ◽  
Co2 Production ◽  
Synchronous Cultures ◽  
Rate Of Oxygen Consumption

Oxygen consumption was measured with an oxygen electrode in synchronous cultures of S. pombe. There were changes during the cell cycle in the rate of oxygen uptake, which are most clearly shown as oscillations in acceleration curves (rate of the rate of uptake). Under various conditions of selection and induction synchrony the acceleration curves are similar to those found earlier for CO2 production. As with CO2 production, the oscillations continued after a block to the DNA-division cycle. There were, however, two differences between oxygen uptake and CO2 production. The oxygen oscillations were more marked and also were out of phase by half a cycle. The respiratory coefficient therefore changes through the cycle.

Nucleoside diphosphokinase, an enzyme with step changes in activity during the cell cycle of the fission yeast Schizosaccharomyces pombe. II. Dissociation of the steps from the DNA-division cycle after induction synchronization

1989 ◽  
Vol 93 (1) ◽  
pp. 185-189
Author(s):  
J. Creanor ◽  
J.M. Mitchison
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Doubling Time ◽  
Phase Relations ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Normal Cycle ◽  
Short Cycle ◽  
Cycle Times

Synchrony was induced in cultures of the mitotic mutant cdc2.33 of Schizosaccharomyces pombe by shifting up an asynchronous culture to the restrictive temperature for a period of 3.5-4.5 h and then shifting down to the permissive temperature. The resulting synchronous divisions had short cycle times, down to 50% of the normal cycle. The oscillatory control of nucleoside diphosphokinase activity was also synchronized by the shift-down and the activity rose in a step pattern. Unlike the situation in the normal cycle, this step pattern was dissociated from the shortened cell cycle and had a longer period and different phase relations. It may be that the normal entrainment or coupling between the cell cycle and the activity control fails if the cell cycle is too short. The period of the activity control (equal to the protein doubling time at the restrictive temperature) appears to be temperature-compensated.

scholarly journals The Prpl  + Gene Required for Pre-mRNA Splicing in Schizosaccharomyces pombe Encodes a Protein That Contains TPR Motifs and Is Similar to Prp6p of Budding Yeast

Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 101-115 ◽  
Author(s):  
Seiichi Urushiyama ◽  
Tokio Tani ◽  
Yasumi Ohshima
Keyword(s):  
Cell Cycle ◽  
Amino Acid ◽  
Schizosaccharomyces Pombe ◽  
Protein Interactions ◽  
Nuclear Export ◽  
Cell Cycle Progression ◽  
Synthetic Lethality ◽  
Cell Cycle Control ◽  
Mrna Splicing ◽  
Restrictive Temperature

Abstract The prp (pre-mRNA processing) mutants of the fission yeast Schizosaccharomyces pombe have a defect in pre-mRNA splicing and accumulate mRNA precursors at a restrictive temperature. One of the prp mutants, prp1-4, also has a defect in poly(A)+ RNA transport. The prp1  + gene encodes a protein of 906 amino acid residues that contains 19 repeats of 34 amino acids termed tetratrico peptide repeat (TPR) motifs, which were proposed to mediate protein-protein interactions. The amino acid sequence of Prplp shares 29.6% identity and 50.6% similarity with that of the PRP6 protein of Saccharomyces cerevisiae, which is a component of the U4/U6 snRNP required for spliceosome assembly. No functional complementation was observed between S. pombe prp1  + and S. cerevisiae PRP6. We examined synthetic lethality of prp1-4 with the other known prp mutations in S. pombe. The results suggest that Prp1p interacts either physically or functionally with Prp4p, Prp6p and Prp13p. Interestingly, the prp1  + gene was found to be identical with the zer1  + gene that functions in cell cycle control. These results suggest that Prp1p/Zer1p is either directly or indirectly involved in cell cycle progression and/or poly(A)+ RNA nuclear export, in addition to pre-mRNA splicing.

Sign in / Sign up

Export Citation Format

Share Document