Continuous Culture and Intermediary Carbon Metabolism

McDonald, I.; Tsai, Chien-Sheng

doi:10.1016/b978-0-12-514085-0.50015-4

Cited by 11 publications

(9 citation statements)

References 108 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The increased proportion of anucleate cells presumably reflects a corresponding increase in asymmetric chromosome segregation during mitosis in the double-deletion strain. However, branched and multiseptated cells, a defect commonly seen in nutritionally deprived cells (42), may be the result of an extremely low growth rate, leading to an uncoupling of temporal events that coordinate cellular growth and mitosis. In the remaining 51% of ⌬abp1 ⌬cbh1 cells, about one-quarter (12%) had typical C-shaped chromatin masses FIG.…”

Section: Resultsmentioning

confidence: 99%

Fission Yeast Homologs of Human CENP-B Have Redundant Functions Affecting Cell Growth and Chromosome Segregation

Baum

Clarke

2000

Molecular and Cellular Biology

View full text Add to dashboard Cite

Two functionally important DNA sequence elements in centromeres of the fission yeast Schizosaccharomyces pombe are the centromeric central core and the K-type repeat. Both of these DNA elements show internal functional redundancy that is not correlated with a conserved DNA sequence. Specific, but degenerate, sequences in these elements are bound in vitro by the S. pombe DNA-binding proteins Abp1p (also called Cbp1p) and Cbhp, which are related to the mammalian centromere DNA-binding protein CENP-B. In this study, we determined that Abp1p binds to at least one of its target sequences within S. pombe centromere II central core (cc2) DNA with an affinity (K s ‫؍‬ 7 ؋ 10 9 M ؊1) higher than those of other known centromere DNA-binding proteins for their cognate targets. In vivo, epitope-tagged Cbhp associated with centromeric K repeat chromatin, as well as with noncentromeric regions. Like abp1 ؉ /cbp1 ؉ , we found that cbh ؉ is not essential in fission yeast, but a strain carrying deletions of both genes (⌬abp1 ⌬cbh) is extremely compromised in growth rate and morphology and missegregates chromosomes at very high frequency. The synergism between the two null mutations suggests that these proteins perform redundant functions in S. pombe chromosome segregation. In vitro assays with cell extracts with these proteins depleted allowed the specific assignments of several binding sites for them within cc2 and the K-type repeat. Redundancy observed at the centromere DNA level appears to be reflected at the protein level, as no single member of the CENP-B-related protein family is essential for proper chromosome segregation in fission yeast. The relevance of these findings to mammalian centromeres is discussed.The faithful inheritance of a cell's genetic blueprint depends on flawless chromosome segregation at each cell division. Mistakes that result in gain or loss of chromosomes (aneuploidy) are associated with death and disease in humans. Aneuploidy is estimated to be the cause of 25% of spontaneous abortions, is the leading cause of mental retardation, and is associated with certain types of cancers, including most colorectal tumors (9,26,36). Proper segregation in mitosis and meiosis is governed by the centromere, a multifunctional region on each chromosome that is the site of sister chromatid cohesion, kinetochore assembly, and spindle attachment and is subject to cell cycle surveillance (reviewed in references 1 and 16) and epigenetic regulation (reviewed in references 13 and 34). Despite the functional similarities of centromeres in various organisms, wide variation is seen in the underlying centromeric DNA sequences that nucleate assembly of the kinetochore. Not surprisingly, the centromere appears to be a target of species divergence.With the exception of the budding yeasts, which utilize small "point" centromeres (Ͻ0.2 kb), other organisms as diverse as fission yeast (Schizosaccharomyces pombe), Drosophila, and humans contain large "regional" centromeres (40 to 5,000 kb) that are characterized by the presence of re...

show abstract

Section: Resultsmentioning

confidence: 99%

Fission Yeast Homologs of Human CENP-B Have Redundant Functions Affecting Cell Growth and Chromosome Segregation

Baum

Clarke

2000

Molecular and Cellular Biology

View full text Add to dashboard Cite

show abstract

“…Since trehalose-6-P does not affect glucose phosphorylating activity in extracts of Schizosaccharomyces pombe [6] we have initiated a study of the characteristics of the hexokinase(s) of this yeast. Surprisingly, although S. pombe has been widely used in molecular and cell biology studies, there is scarce information on its glycolytic enzymes and their regulation [7]. We present here our results on the isolation of the genes encoding two hexokinases from this yeast, their expression and the kinetic characteristics of the encoded enzymes.…”

Section: Introductionmentioning

confidence: 94%

Schizosaccharomyces pombe possesses an unusual and a conventional hexokinase: biochemical and molecular characterization of both hexokinases

Petit¹,

Blázquez²,

Gancedo³

1996

FEBS Letters

View full text Add to dashboard Cite

Two hexokinases were characterized in Schizosaccharomyces pombe: hexokinase 1, with a low phosphorylation coefficient on glucose (K m 8.5 mM) and hexokinase 2, a kinetically conventional hexokinase. Genes hxkl ÷ and hxk2 + encoding these enzymes were cloned and sequenced. Disruption of hxkl + had no effect on growth but disruption of hxk2 ÷ doubled the generation time in glucose. Spores carrying the double disruption hxkl ÷ hxk2 ÷ did not grow on glucose or fructose after one week. Expression of hxkl + increased strongly during growth in fructose or glycerol. Expression of hxk2 + was highest during growth in glycerol. A NADP-dependent glucose dehydrogenase was detected, but not a glucokinase.

show abstract

“…It is assumed, not reported, that analogous metabolic pathways operate in both yeasts (McDonald and Tsai 1989), though some metabolic differences have been documented (Fiechter et al 198 1 ;May and Sloan 198 1). Schizosaccharomyces pombe grows diauxically in the D-glucose batch media .…”

Section: Introductionmentioning

confidence: 95%

Enzyme activities of D-glucose metabolism in the fission yeast Schizosaccharomyces pombe

Tsai¹,

Shi²,

Beehler³

et al. 1992

Can. J. Microbiol.

View full text Add to dashboard Cite

The activities of key enzymes that are members of D-glucose metabolic pathways in Schizosaccharomyces pombe undergoing respirative, respirofermentative, and fermentative metabolisms are monitored. The steady-state activities of glycolytic enzymes, except phosphofructokinase, decrease with a reduced efficiency in D-glucose utilization by yeast continuous culture. On the other hand, the enzymic activities of pentose monophosphate pathway reach the maximum when the cell mass production of the cultures is optimum. Enzymes of tricarboxylate cycle exhibit the maximum activities at approximately the washout rate. The steady-state activity of pyruvate dehydrogenase complex increases rapidly when D-glucose is efficiently utilized. By comparison, the activity of pyruvate decarboxylase begins to increase only when ethanol production occurs. Depletion of dissolved oxygen suppresses the activity of pyruvate dehydrogenase complex but facilitates that of pyruvate decarboxylase. Acetate greatly enhances the acetyl CoA synthetase activity. Similarly, ethanol stimulates alcohol dehydrogenase and aldehyde dehydrogenase activities. Evidence for the existence of alcohol dehydrogenase isozymes in the fission yeast is presented.

show abstract

Continuous Culture and Intermediary Carbon Metabolism

Cited by 11 publications

References 108 publications

Fission Yeast Homologs of Human CENP-B Have Redundant Functions Affecting Cell Growth and Chromosome Segregation

Fission Yeast Homologs of Human CENP-B Have Redundant Functions Affecting Cell Growth and Chromosome Segregation

Schizosaccharomyces pombe possesses an unusual and a conventional hexokinase: biochemical and molecular characterization of both hexokinases

Enzyme activities of D-glucose metabolism in the fission yeast Schizosaccharomyces pombe

Contact Info

Product

Resources

About