3. Yeast Metabolism

  1. Prof. Dr. Horst Feldmann1,2

Published Online: 26 SEP 2012

DOI: 10.1002/9783527659180.ch3

Yeast: Molecular and Cell Biology, Second Edition

Yeast: Molecular and Cell Biology, Second Edition

How to Cite

Feldmann, H. (ed) (2012) Yeast Metabolism, in Yeast: Molecular and Cell Biology, Second Edition, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany. doi: 10.1002/9783527659180.ch3

Editor Information

  1. 1

    Adolf Butenandt Institute, Molecular Biology, Ludwig-Maximilians-Universität M¨nchen, Schillerstr. 44, 80336 M¨nchen, Germany

  2. 2

    Ludwig-Thoma-Strasse 22B, 85232 Bergkirchen, Germany

Publication History

  1. Published Online: 26 SEP 2012
  2. Published Print: 22 AUG 2012

ISBN Information

Print ISBN: 9783527332526

Online ISBN: 9783527659180

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Keywords:

  • yeastmetabolism;
  • energy;
  • catabolism;
  • gluconeogenesis;
  • transition metals

Summary

• The principal knowledge of the metabolic capabilities will help us understand the peculiarities that yeast reveals in the breakdown of organic compounds, production of new cell-specific components, and generation of energy necessary in anabolic pathways. First, we consider the major sources for energy production in S. cerevisiae – the hexose carbon compounds. Since this yeast (as well as many others) can adapt its metabolism to aerobic or aerobic conditions, we have to differentiate between respiration and oxidative phosphorylation, on the one hand, and alcoholic fermentation, on the other hand. In this context, we describe the effects of glucose repression and diauxie. The possibilities of how yeast utilizes other hexose sugars, non-hexose carbon sources, or complex carbon sources are outlined. Gluconeogenesis and carbohydrate biosynthesis are explained in view of yeast's potential to store different forms of carbohydrate for retrieval of energy. Following this, we deal with the utilization and manufacturing of “unusual” hexoses and amino sugars that play an important role in the biosynthesis of cell-specific macromolecules. A particular section is devoted to yeast compounds that contain inositol as a constituent, such as InsPs and the various phosphatidylinositol derivatives. The regular order of post-translational N- and O-linked glycosylation of proteins is presented in some detail. Similar attention is given to the structural carbohydrates that have an outstanding role in yeast cell wall organization.

• Next, we consider fatty acid and lipid metabolism, which in yeast reveals some specific features. In discussing the glycolipids, we focus on sphingolipids and GPI, which latter have a dominant role as lipid membrane anchors. This section includes a survey of the isoprenoid derivatives, which are particularly synthesized and utilized in yeast.

• Nitrogen metabolism considers the utilization of organic and inorganic sources in catabolic pathways, whereby the fact that yeasts can live on ammonium as a sole nitrogen source comes as a real surprise. Employing urea as a nitrogen source is restricted to yeast species other than S. cerevisiae. Yeast has the capacity to biosynthesize virtually all amino acids from simple carbon sources plus a nitrogen source, assimilation of sulfur from sulfate for the few sulfur-containing amino acids (cysteine, methionine, homocysteine), together with constituents from some cofactors. One of the most important activities in nitrogen metabolism concerns protein biosynthesis. We do not present a detailed picture in this overview, but point out further reading/references pertinent to this extremely important field.

• The following section then presents a concise overview of the manufacturing and breakdown of nucleotide compounds in yeast, most of whose features are common to all organisms. Except in degradation pathways, there are some unusual aspects in fungi. We add a description of nucleotide-modifying enzymes, which have been studied in S. cerevisiae in great detail.

• Sections dealing with the metabolism of phosphorus (phosphate) and sulfur in yeast as well as the capabilities of yeast to synthesize most of its “vitamins” and cofactors from endogenous sources complement our metabolic excursion.