Identification, cloning and characterisation of a new gene required for full pyruvate decarboxylase activity in Saccharomyces cerevisiae

1989 ◽  
Vol 15 (3) ◽  
pp. 171-175 ◽  
Author(s):  
Anthony P. H. Wright ◽  
Hong-Lan Png ◽  
Brian S. Hartley
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pyruvate Decarboxylase ◽  
Decarboxylase Activity ◽  
New Gene

scholarly journals Physiological Properties of Saccharomyces cerevisiae from Which Hexokinase II Has Been Deleted

2001 ◽  
Vol 67 (4) ◽  
pp. 1587-1593 ◽  
Author(s):  
Jasper A. Diderich ◽  
Léonie M. Raamsdonk ◽  
Arthur L. Kruckeberg ◽  
Jan A. Berden ◽  
Karel Van Dam
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Repression ◽  
Adenine Nucleotides ◽  
Pyruvate Decarboxylase ◽  
Decarboxylase Activity ◽  
Diauxic Shift ◽  
Wild Type ◽  
Hexokinase Ii ◽  
In The Wild ◽  
Fructose 1,6 Bisphosphate

ABSTRACT Hexokinase II is an enzyme central to glucose metabolism and glucose repression in the yeast Saccharomyces cerevisiae. Deletion of HXK2, the gene which encodes hexokinase II, dramatically changed the physiology of S. cerevisiae. The hxk2-null mutant strain displayed fully oxidative growth at high glucose concentrations in early exponential batch cultures, resulting in an initial absence of fermentative products such as ethanol, a postponed and shortened diauxic shift, and higher biomass yields. Several intracellular changes were associated with the deletion of hexokinase II. Thehxk2 mutant had a higher mitochondrial H+-ATPase activity and a lower pyruvate decarboxylase activity, which coincided with an intracellular accumulation of pyruvate in the hxk2 mutant. The concentrations of adenine nucleotides, glucose-6-phosphate, and fructose-6-phosphate are comparable in the wild type and the hxk2 mutant. In contrast, the concentration of fructose-1,6-bisphosphate, an allosteric activator of pyruvate kinase, is clearly lower in the hxk2mutant than in the wild type. The results suggest a redirection of carbon flux in the hxk2 mutant to the production of biomass as a consequence of reduced glucose repression.

Modification of thiamine pyrophosphate dependent enzyme activity by oxythiamine in Saccharomyces cerevisiae cells

2005 ◽  
Vol 51 (10) ◽  
pp. 833-839 ◽  
Author(s):  
Adam Tylicki ◽  
Jan Czerniecki ◽  
Pawel Dobrzyn ◽  
Agnieszka Matanowska ◽  
Anna Olechno ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pyruvate Dehydrogenase ◽  
Specific Activity ◽  
Pyruvate Decarboxylase ◽  
Yeast Cells ◽  
Thiamine Pyrophosphate ◽  
Decarboxylase Activity ◽  
Mitochondrial Enzymes ◽  
Oxoglutarate Dehydrogenase ◽  
Cytosolic Enzymes

Oxythiamine is an antivitamin derivative of thiamine that after phosphorylation to oxythiamine pyro phos phate can bind to the active centres of thiamine-dependent enzymes. In the present study, the effect of oxythiamine on the viability of Saccharomyces cerevisiae and the activity of thiamine pyrophosphate dependent enzymes in yeast cells has been investigated. We observed a decrease in pyruvate decarboxylase specific activity on both a control and an oxythiamine medium after the first 6 h of culture. The cytosolic enzymes transketolase and pyruvate decarboxylase decreased their specific activity in the presence of oxythiamine but only during the beginning of the cultivation. However, after 12 h of cultivation, oxythiamine-treated cells showed higher specific activity of cytosolic enzymes. More over, it was established by SDS–PAGE that the high specific activity of pyruvate decarboxylase was followed by an increase in the amount of the enzyme protein. In contrast, the mitochondrial enzymes, pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase complexes, were inhibited by oxythiamine during the entire experiment. Our results suggest that the observed strong decrease in growth rate and viability of yeast on medium with oxythiamine may be due to stronger in hibition of mitochondrial pyruvate dehydrogenase than of cytosolic enzymes.Key words: pyruvate dehydrogenase, 2-oxoglutarate dehydrogenase, transketolase, pyruvate decarboxylase, activity, oxythiamine, inhibition.

CDC55, a Saccharomyces cerevisiae gene involved in cellular morphogenesis: identification, characterization, and homology to the B subunit of mammalian type 2A protein phosphatase

1991 ◽  
Vol 11 (11) ◽  
pp. 5767-5780
Author(s):  
A M Healy ◽  
S Zolnierowicz ◽  
A E Stapleton ◽  
M Goebl ◽  
A A DePaoli-Roach ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Phosphatase ◽  
Protein A ◽  
Cdna Clones ◽  
Restrictive Temperature ◽  
B Subunit ◽  
Bud Emergence ◽  
New Gene ◽  
Cold Sensitive ◽  
Polymerase Chain

Microscopic screening of a collection of cold-sensitive mutants of Saccharomyces cerevisiae led to the identification of a new gene, CDC55, which appears to be involved in the morphogenetic events of the cell cycle. CDC55 maps between CDC43 and CHC1 on the left arm of chromosome VII. At restrictive temperature, the original cdc55 mutant produces abnormally elongated buds and displays a delay or partial block of septation and/or cell separation. A cdc55 deletion mutant displays a cold-sensitive phenotype like that of the original isolate. Sequencing of CDC55 revealed that it encodes a protein of about 60 kDa, as confirmed by Western immunoblots using Cdc55p-specific antibodies. This protein has greater than 50% sequence identity to the B subunits of rabbit skeletal muscle type 2A protein phosphatase; the latter sequences were obtained by analysis of peptides derived from the purified protein, a polymerase chain reaction product, and cDNA clones. An extragenic suppressor of the cdc55 mutation lies in BEM2, a gene previously identified on the basis of an apparent role in bud emergence.

scholarly journals Pyruvate decarboxylase activity is regulated by the Ser/Thr protein phosphatase Sit4p in the yeastSaccharomyces cerevisiae

2013 ◽  
Vol 13 (6) ◽  
pp. 518-528 ◽  
Author(s):  
Leandro José de Assis ◽  
Russolina Benedeta Zingali ◽  
Claudio Akio Masuda ◽  
Silas Pessini Rodrigues ◽  
Monica Montero-Lomelí
Keyword(s):  
Protein Phosphatase ◽  
Pyruvate Decarboxylase ◽  
Decarboxylase Activity

scholarly journals Overproduction of Threonine Aldolase Circumvents the Biosynthetic Role of Pyruvate Decarboxylase in Glucose-Limited Chemostat Cultures of Saccharomyces cerevisiae

2003 ◽  
Vol 69 (4) ◽  
pp. 2094-2099 ◽  
Author(s):  
Antonius J. A. van Maris ◽  
Marijke A. H. Luttik ◽  
Aaron A. Winkler ◽  
Johannes P. van Dijken ◽  
Jack T. Pronk
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Alternative Pathway ◽  
Pyruvate Decarboxylase ◽  
Lysine Biosynthesis ◽  
Carbon Limitation ◽  
Growth Media ◽  
Nutritional Requirement ◽  
Acetyl Coa ◽  
Threonine Aldolase ◽  
Chemostat Cultures

ABSTRACT Pyruvate decarboxylase-negative (Pdc−) mutants of Saccharomyces cerevisiae require small amounts of ethanol or acetate to sustain aerobic, glucose-limited growth. This nutritional requirement has been proposed to originate from (i) a need for cytosolic acetyl coenzyme A (acetyl-CoA) for lipid and lysine biosynthesis and (ii) an inability to export mitochondrial acetyl-CoA to the cytosol. To test this hypothesis and to eliminate the C2 requirement of Pdc− S. cerevisiae, we attempted to introduce an alternative pathway for the synthesis of cytosolic acetyl-CoA. The addition of l-carnitine to growth media did not restore growth of a Pdc− strain on glucose, indicating that the C2 requirement was not solely due to the inability of S. cerevisiae to synthesize this compound. The S. cerevisiae GLY1 gene encodes threonine aldolase (EC 4.1.2.5), which catalyzes the cleavage of threonine to glycine and acetaldehyde. Overexpression of GLY1 enabled a Pdc− strain to grow under conditions of carbon limitation in chemostat cultures on glucose as the sole carbon source, indicating that acetaldehyde formed by threonine aldolase served as a precursor for the synthesis of cytosolic acetyl-CoA. Fractionation studies revealed a cytosolic localization of threonine aldolase. The absence of glycine in these cultures indicates that all glycine produced by threonine aldolase was either dissimilated or assimilated. These results confirm the involvement of pyruvate decarboxylase in cytosolic acetyl-CoA synthesis. The Pdc− GLY1 overexpressing strain was still glucose sensitive with respect to growth in batch cultivations. Like any other Pdc− strain, it failed to grow on excess glucose in batch cultures and excreted pyruvate when transferred from glucose limitation to glucose excess.

scholarly journals AFR1 acts in conjunction with the alpha-factor receptor to promote morphogenesis and adaptation.

1993 ◽  
Vol 13 (11) ◽  
pp. 6876-6888 ◽  
Author(s):  
J B Konopka
Keyword(s):  
Saccharomyces Cerevisiae ◽  
G Protein Signaling ◽  
Receptor Desensitization ◽  
Protein Signaling ◽  
Developmentally Regulated ◽  
Pheromone Receptor ◽  
Complex Processes ◽  
C Terminus ◽  
Alpha Factor ◽  
New Gene

Mating pheromone receptors activate a G-protein signaling pathway that induces changes in transcription, cell division, and morphogenesis needed for the conjunction of Saccharomyces cerevisiae. The C terminus of the alpha-factor pheromone receptor functions in two complex processes, adaptation and morphogenesis. Adaptation to alpha-factor may occur through receptor desensitization, and alpha-factor-induced morphogenesis forms the conjugation bridge between mating cells. A plasmid overexpression strategy was used to isolate a new gene, AFR1, which acts together with the receptor C terminus to promote adaptation. The expression of AFR1 was highly induced by alpha-factor. Unexpectedly, cells lacking AFR1 showed a defect in alpha-factor-stimulated morphogenesis that was similar to the morphogenesis defect observed in cells producing C-terminally truncated alpha-factor receptors. In contrast, AFR1 overexpression resulted in longer projections of morphogenesis, which suggests that this gene may directly stimulate morphogenesis. These results indicate that AFR1 encodes a developmentally regulated function that coordinates both the regulation of receptor signaling and the induction of morphogenesis during conjugation.

scholarly journals Relationship of DFG16 to the Rim101p pH Response Pathway in Saccharomyces cerevisiae and Candida albicans

2005 ◽  
Vol 4 (5) ◽  
pp. 890-899 ◽  
Author(s):  
Karen J. Barwell ◽  
Jacob H. Boysen ◽  
Wenjie Xu ◽  
Aaron P. Mitchell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Candida Albicans ◽  
Proteolytic Processing ◽  
Multivesicular Bodies ◽  
Ph Response ◽  
New Gene ◽  
Escrt Complex ◽  
Membrane Spanning ◽  
Relationship Of ◽  
G Protein Coupled

ABSTRACT Many fungal pH responses depend upon conserved Rim101p/PacC transcription factors, which are activated by C-terminal proteolytic processing. The means by which environmental pH is sensed by this pathway are not known. Here, we report a screen of the Saccharomyces cerevisiae viable deletion mutant library that has yielded a new gene required for processed Rim101p accumulation, DFG16. An S. cerevisiae dfg16Δ mutant expresses Rim101p-repressed genes at elevated levels. In addition, Candida albicans dfg16Δ/dfg16Δ mutants are defective in alkaline pH-induced filamentation, and their defect is suppressed by expression of truncated Rim101-405p. Thus, Dfg16p is a functionally conserved Rim101p pathway member. Many proteins required for processed Rim101p accumulation are members of the ESCRT complex, which functions in the formation of multivesicular bodies (MVBs). Staining with the dye FM4-64 indicates that the S. cerevisiae dfg16Δ mutant does not have an MVB defect. We find that two transcripts, PRY1 and ASN1, respond to mutations that affect both the Rim101p and MVB pathways but not to mutations that affect only one pathway. The S. cerevisiae dfg16Δ mutation does not affect PRY1 and ASN1 expression, thus confirming that Dfg16p function is restricted to the Rim101p pathway. Dfg16p is homologous to Aspergillus nidulans PalH, a component of the well-characterized PacC processing pathway. We verify that the previously recognized PalH homolog, Rim21p, also functions in the S. cerevisiae Rim101p pathway. Dfg16p is predicted to have seven membrane-spanning segments and a long hydrophilic C-terminal region, as expected if Dfg16p were a G-protein-coupled receptor.

Pyruvate decarboxylase encoded by the PDC1 gene contributes, at least partially, to the decarboxylation of α-ketoisocaproate for isoamyl alcohol formation in Saccharomyces cerevisiae

2001 ◽  
Vol 92 (1) ◽  
pp. 83-85 ◽  
Author(s):  
Hiroyuki Yoshimoto ◽  
Tomoyuki Fukushige ◽  
Toshihiko Yonezawa ◽  
Yoshiko Sakai ◽  
Katsuya Okawa ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pyruvate Decarboxylase ◽  
Isoamyl Alcohol ◽  
Alcohol Formation
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