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Metabolic Fate of the Increased Yeast Amino Acid Uptake Subsequent to Catabolite Derepression
Joint Authors
Hothersall, John S.
Ahmed, Aamir
Source
Issue
Vol. 2013, Issue 2013 (31 Dec. 2013), pp.1-7, 7 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2013-02-04
Country of Publication
Egypt
No. of Pages
7
Main Subjects
Abstract EN
Catabolite repression (CCR) regulates amino acid permeases in Saccharomyces cerevisiae via a TOR-kinase mediated mechanism.
When glucose, the preferred fuel in S.
cerevisiae, is substituted by galactose, amino acid uptake is increased.
Here we have assessed the contribution and metabolic significance of this surfeit of amino acid in yeast undergoing catabolite derepression (CDR).
L-[U-14C]leucine oxidation was increased 15 ± 1 fold in wild type (WT) strain grown in galactose compared to glucose.
Under CDR, leucine oxidation was (i) proportional to uptake, as demonstrated by decreased uptake and oxidation of leucine in strains deleted of major leucine permeases and (ii) entirely dependent upon the TCA cycle, as cytochrome c1 (Cyt1) deleted strains could not grow in galactose.
A regulator of amino acid carbon entry into the TCA cycle, branched chain ketoacid dehydrogenase, was also increased 29 ± 3 fold under CCR in WT strain.
Protein expression of key TCA cycle enzymes, citrate synthase (Cs), and Cyt1 was increased during CDR.
In summary, CDR upregulation of amino acid uptake is accompanied by increased utilization of amino acids for yeast growth.
The mechanism for this is likely to be an increase in protein expression of key regulators of the TCA cycle.
American Psychological Association (APA)
Hothersall, John S.& Ahmed, Aamir. 2013. Metabolic Fate of the Increased Yeast Amino Acid Uptake Subsequent to Catabolite Derepression. Journal of Amino Acids،Vol. 2013, no. 2013, pp.1-7.
https://search.emarefa.net/detail/BIM-473444
Modern Language Association (MLA)
Hothersall, John S.& Ahmed, Aamir. Metabolic Fate of the Increased Yeast Amino Acid Uptake Subsequent to Catabolite Derepression. Journal of Amino Acids No. 2013 (2013), pp.1-7.
https://search.emarefa.net/detail/BIM-473444
American Medical Association (AMA)
Hothersall, John S.& Ahmed, Aamir. Metabolic Fate of the Increased Yeast Amino Acid Uptake Subsequent to Catabolite Derepression. Journal of Amino Acids. 2013. Vol. 2013, no. 2013, pp.1-7.
https://search.emarefa.net/detail/BIM-473444
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-473444