This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kohlhaw, G. B. Search for Related Content PubMed PubMed Citation Articles by Kohlhaw, G. B.

Leucine Biosynthesis in Fungi: Entering Metabolism through the Back Door

Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907

After exploring evolutionary aspects of branched-chain amino acid biosynthesis, the review focuses on the extended leucine biosynthetic pathway as it operates in Saccharomyces cerevisiae. First, the genes and enzymes specific for the leucine pathway are considered: LEU4 and LEU9 (encoding the -isopropylmalate synthase isoenzymes), LEU1 (isopropylmalate isomerase), and LEU2 (ß-isopropylmalate dehydrogenase). Emphasis is given to the unusual distribution of the branched-chain amino acid pathway enzymes between mitochondrial matrix and cytosol, on the newly defined role of Leu5p, and on regulatory mechanisms governing gene expression and enzyme activity, including new evidence for the metabolic importance of the regulation of -isopropylmalate synthase by coenzyme A. Next, structure-function relationships of the transcriptional regulator Leu3p are addressed, defining its dual role as activator and repressor and discussing evidence in support of the self-masking model. Recent data pointing at a more extended Leu3p regulon are discussed. An overview of the layered controls of the extended leucine pathway is provided that includes a description of the newly recognized roles of Ilv5p and Bat1p in maintaining mitochondrial integrity. Finally, branched-chain amino acid biosynthesis and its regulation in other fungi are summarized, the question of leucine as metabolic signal is addressed, and possible directions of future research in this area are outlined.

This article has been cited by other articles:

• Godard, P., Urrestarazu, A., Vissers, S., Kontos, K., Bontempi, G., van Helden, J., Andre, B. (2007). Effect of 21 Different Nitrogen Sources on Global Gene Expression in the Yeast Saccharomyces cerevisiae. Mol. Cell. Biol. 27: 3065-3086 [Abstract] [Full Text]  
• MacPherson, S., Larochelle, M., Turcotte, B. (2006). A Fungal Family of Transcriptional Regulators: the Zinc Cluster Proteins. Microbiol. Mol. Biol. Rev. 70: 583-604 [Abstract] [Full Text]  
• Liu, X., Noll, D. M., Lieb, J. D., Clarke, N. D. (2005). DIP-chip: Rapid and accurate determination of DNA-binding specificity. Genome Res. 15: 421-427 [Abstract] [Full Text]  
• de Koning, A. P., Keeling, P. J. (2004). Nucleus-Encoded Genes for Plastid-Targeted Proteins in Helicosporidium: Functional Diversity of a Cryptic Plastid in a Parasitic Alga. Eukaryot Cell 3: 1198-1205 [Abstract] [Full Text]  
• Saldanha, A. J., Brauer, M. J., Botstein, D. (2004). Nutritional Homeostasis in Batch and Steady-State Culture of Yeast. Mol. Biol. Cell 15: 4089-4104 [Abstract] [Full Text]