Nucleoside diphosphokinase, an enzyme with step changes in activity during the cell cycle of the fission yeast Schizosaccharomyces pombe. I. Persistence of steps after a block to the DNA-division cycle

1986 ◽  
Vol 86 (1) ◽  
pp. 207-215
Author(s):  
J. Creanor ◽  
J.M. Mitchison
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Normal Cell ◽  
Normal Cell Cycle

In confirmation of earlier results, nucleoside diphosphokinase is shown to be a ‘step’ enzyme in Schizosaccharomyces pombe with a sharp doubling in activity at the beginning of the cell cycle. These doubling steps occur at the same time in the cycle in the smaller cells of the mutant wee1.6. An important result is that the activity steps persist with normal cell cycle timing after a block to the DNA-division cycle imposed by the cycle mutants cdc2.33 and cdc2.33wee1.6. This is clear proof that oscillatory controls of some cell cycle events can persist after the main periodic events of the DNA-division cycle have been abolished.

scholarly journals Oncogenes - the basics

2018 ◽  
Vol 3 (4) ◽  
pp. 35-37
Author(s):  
Arnab Ghosh ◽  
Diasma Ghartimagar ◽  
Sushma Thapa
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Dna Repair ◽  
Tumor Suppressor ◽  
Tumor Suppressor Genes ◽  
Normal Cell ◽  
Tumor Formation ◽  
Precursor Cell ◽  
Single Precursor ◽  
Normal Cell Cycle

Normal cell cycle and cell proliferation are regulated by several genes which can be broadly classified into 4 groups viz, proto-oncogenes, tumor suppressor genes, genes regulating apoptosis and genes involved in DNA repair. These genes may be defective due to different factors. The defective genes may lead to production of abnormal proteins which may lead to disruption of the normal cell cycle and proliferation. A single precursor cell with defective gene proliferates surpassing the normal physiologic regulatory process and leads to tumor formation, so, traditionally,it is said that “tumors are clonal”.

Overexpression Phenotypes of Plk1 and Ndrg2 in Schizosaccharomyces Pombe: Fission Yeast System for Mammalian Gene Study

2005 ◽  
Vol 277-279 ◽  
pp. 1-6 ◽  
Author(s):  
Young Joo Jang ◽  
Young Sook Kil ◽  
Jee Hee Ahn ◽  
Jae Hoon Ji ◽  
Jong Seok Lim ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Rna Splicing ◽  
Mammalian Cells ◽  
Protein Modification ◽  
Genetic System ◽  
Functional Study ◽  
Mammalian Genes

The fission yeast, Schizosaccharomyces pombe is a single-celled free-living fungus that shares many features with cells of more complicated eukaryotes. Many of the genes required for the cell-cycle control, proteolysis, protein modification, and RNA splicing are highly conserved with those of higher eukaryotes. Moreover, fission yeast has the merit of genetics and its genetic system is already well characterized. As such, the current study evaluated the use of a fission yeast system as a tool for the functional study of mammalian genes and attempted to set up an assay system for novel genes. Since the phenotypes of a deletion mutant and the overexpression of a gene are generally analyzed for a functional study of specific genes in yeast, the present study used overexpression phenotypes to study the functions of mammalian genes. Therefore, based on using a thiamine-repressive promoter, two mammalian genes were expressed in fission yeast, and their overexpressed phenotypes compared with those in mammalian cells. The phenotypes resulting from overexpression were analyzed using a FACS, which analyzes the DNA contents, and a microscope. One of the selected genes was the mammalian Polo-like kinase 1 (Plk1), which is activated and plays a role in the mitotic phase of the cell division cycle. The overexpression of various constructs of Plk1 in the HeLa cells caused cell cycle defects, suggesting that the ectopic Plk1s blocked the endogenous Plk1 in the cells. As expected, when the constructs were overexpressed in the fission yeast system, the cells were arrested in mitosis and defected at the end of mitosis. As such, this data suggests that the Plk1-overexpressed phenotypes were similar in the mammalian cells and the fission yeast, thereby enabling the mammalian Plk1 functions to be approximated in the fission yeast. The other selected gene was the N-Myc downstream-regulated gene 2 (ndrg2), which is upregulated during cell differentiation, yet still not well characterized. When the ndrg2 gene was overexpressed in the fission yeast, the cells contained multi-septa. The septa were positioned well, yet their number increased per cell. Therefore, this gene was speculated to block cell division in the last stage of the cell cycle, making the phenotype potentially useful for explaining cell growth and differentiation in mammalian cells. Accordingly, fission yeast is demonstrated to be an appropriate species for the functional study of mammalian genes.

The cell cycle genes cdc22 + and suc22 + of the fission yeast Schizosaccharomyces pombe encode the large and small subunits of ribonucleotide reductase

1993 ◽  
Vol 238-238 (1-2) ◽  
pp. 241-251 ◽  
Author(s):  
Maria-Jose Fernandez Sarabia ◽  
Christopher McInerny ◽  
Pamela Harris ◽  
Colin Gordon ◽  
Peter Fantes
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Ribonucleotide Reductase ◽  
Cell Cycle Genes

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.

scholarly journals Chk1-mediated Cdc25A degradation as a critical mechanism for normal cell cycle progression

2019 ◽  
Vol 132 (2) ◽  
pp. jcs223123 ◽  
Author(s):  
Hidemasa Goto ◽  
Toyoaki Natsume ◽  
Masato T. Kanemaki ◽  
Aika Kaito ◽  
Shujie Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Normal Cell ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Normal Cell Cycle

Octyl gallate and gallic acid isolated from Terminalia bellarica regulates normal cell cycle in human breast cancer cell lines

2018 ◽  
Vol 103 ◽  
pp. 1577-1584 ◽  
Author(s):  
Mary Selesty Sales ◽  
Anita Roy ◽  
Ludas Antony ◽  
Sakhila K. Banu ◽  
Selvaraj Jeyaraman ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Gallic Acid ◽  
Breast Cancer Cell ◽  
Human Breast Cancer ◽  
Normal Cell ◽  
Human Breast Cancer Cell ◽  
Breast Cancer Cell Lines ◽  
Human Breast ◽  
Normal Cell Cycle

scholarly journals The decision to enter mitosis: feedback and redundancy in the mitotic entry network

2009 ◽  
Vol 185 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Arne Lindqvist ◽  
Verónica Rodríguez-Bravo ◽  
René H. Medema
Keyword(s):  
Cell Cycle ◽  
Normal Cell ◽  
Cell Cycle Progression ◽  
Feedback Loops ◽  
Cyclin B ◽  
Cycle Progression ◽  
Mitotic Entry ◽  
Different Levels ◽  
Normal Cell Cycle

The decision to enter mitosis is mediated by a network of proteins that regulate activation of the cyclin B–Cdk1 complex. Within this network, several positive feedback loops can amplify cyclin B–Cdk1 activation to ensure complete commitment to a mitotic state once the decision to enter mitosis has been made. However, evidence is accumulating that several components of the feedback loops are redundant for cyclin B–Cdk1 activation during normal cell division. Nonetheless, defined feedback loops become essential to promote mitotic entry when normal cell cycle progression is perturbed. Recent data has demonstrated that at least three Plk1-dependent feedback loops exist that enhance cyclin B–Cdk1 activation at different levels. In this review, we discuss the role of various feedback loops that regulate cyclin B–Cdk1 activation under different conditions, the timing of their activation, and the possible identity of the elusive trigger that controls mitotic entry in human cells.

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