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MetaCyc Pathway: L-alanine degradation III
Inferred from experiment

Enzyme View:

Pathway diagram: L-alanine degradation III

This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Superclasses: Degradation/Utilization/AssimilationAmino Acids DegradationProteinogenic Amino Acids DegradationL-alanine Degradation

Some taxa known to possess this pathway include : Candida maltosa, Canis lupus familiaris, Homo sapiens, Rattus norvegicus

Expected Taxonomic Range: Eukaryota

In eukaryotes, L-alanine is degraded through transamination to pyruvate by alanine aminotransferase. Pyruvate is transported into the mitochondrion where it is oxidatively decarboxylated by the pyruvate dehydrogenase complex to carbon dioxide and acetyl-CoA (as shown in the pathway link). Acetyl-CoA enters the TCA cycle .

Biosynthetically, pyruvate is involved in gluconeogenesis (see MetaCyc pathway gluconeogenesis I) and is also a precursor of the pyruvate family of amino acids: alanine, valine, leucine and isoleucine. In plants and bacteria, it is also a precursor of isoprenoids (see MetaCyc pathway methylerythritol phosphate pathway I).

Alanine aminotransferase is a commonly used diagnostic marker in humans. It is produced mainly in the liver and its presence in serum is an indicator of liver disease [Sherman91]. The enzyme is present as isozymes in both the cytosol and mitochondrion. Expression of the isozymes varies among tissues and is species-specific (in [Rajamohan06]).

In bacteria, alanine is converted to pyruvate by oxidative deamination ( [Gottschalk86]) (see MetaCyc pathway L-alanine degradation IV). An alanine aminotransferase has been identified in the archaeon Pyrococcus furiosus and is thought to function biosynthetically, transaminating pyruvate with glutamate [Ward00] (see MetaCyc pathway pyruvate fermentation to acetate and alanine.

Variants: L-alanine degradation I, L-alanine degradation II (to D-lactate), L-alanine degradation IV

Revised 11-Dec-2006 by Fulcher CA, SRI International


Gottschalk86: Gottschalk, G "Bacterial Metabolism, Second Edition." Springer-Verlag, New York. 1986.

Rajamohan06: Rajamohan F, Nelms L, Joslin DL, Lu B, Reagan WJ, Lawton M (2006). "cDNA cloning, expression, purification, distribution, and characterization of biologically active canine alanine aminotransferase-1." Protein Expr Purif 48(1);81-9. PMID: 16495081

Sherman91: Sherman KE (1991). "Alanine aminotransferase in clinical practice. A review." Arch Intern Med 151(2);260-5. PMID: 1992953

Umemura94: Umemura I, Yanagiya K, Komatsubara S, Sato T, Tosa T (1994). "Purification and some properties of alanine aminotransferase from Candida maltosa." Biosci Biotechnol Biochem 58(2);283-7. PMID: 7764540

Vedavathi04: Vedavathi M, Girish KS, Kumar MK (2004). "Isolation and characterization of cytosolic alanine aminotransferase isoforms from starved rat liver." Mol Cell Biochem 267(1-2);13-23. PMID: 15663181

Ward00: Ward DE, Kengen SW, van Der Oost J, de Vos WM (2000). "Purification and characterization of the alanine aminotransferase from the hyperthermophilic Archaeon pyrococcus furiosus and its role in alanine production." J Bacteriol 2000;182(9);2559-66. PMID: 10762259

Yang02: Yang RZ, Blaileanu G, Hansen BC, Shuldiner AR, Gong DW (2002). "cDNA cloning, genomic structure, chromosomal mapping, and functional expression of a novel human alanine aminotransferase." Genomics 79(3);445-50. PMID: 11863375

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Felbeck80: Felbeck H, Grieshaber MK (1980). "Investigations on some enzymes involved in the anaerobic metabolism of amino acids of Arenicola marina L." Comparative Biochemistry and Physiology Part B: Comparative Biochemistry 66(2);205-213.

Ishiguro91: Ishiguro M, Takio K, Suzuki M, Oyama R, Matsuzawa T, Titani K (1991). "Complete amino acid sequence of human liver cytosolic alanine aminotransferase (GPT) determined by a combination of conventional and mass spectral methods." Biochemistry 30(43);10451-7. PMID: 1931970

Kim10b: Kim SH, Schneider BL, Reitzer L (2010). "Genetics and regulation of the major enzymes of alanine synthesis in Escherichia coli." J Bacteriol 192(20);5304-11. PMID: 20729367

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Liepman03: Liepman AH, Olsen LJ (2003). "Alanine aminotransferase homologs catalyze the glutamate:glyoxylate aminotransferase reaction in peroxisomes of Arabidopsis." Plant Physiol 131(1);215-27. PMID: 12529529

Rey84: Rey, M, Garnet, H (1984). "A physiological study of Panicum maximum infected by Phyllachora paspalicola." Can. J. Bot. Vol 62: 2283-2289.

Schweiger84: Schweiger G, Buckel W (1984). "On the dehydration of (R)-lactate in the fermentation of alanine to propionate by Clostridium propionicum." FEBS Lett 1984;171(1);79-84. PMID: 6586495

Sohocki97: Sohocki MM, Sullivan LS, Harrison WR, Sodergren EJ, Elder FF, Weinstock G, Tanase S, Daiger SP (1997). "Human glutamate pyruvate transaminase (GPT): localization to 8q24.3, cDNA and genomic sequences, and polymorphic sites." Genomics 40(2);247-52. PMID: 9119391

Son92: Son D, Sugiyama T (1992). "Molecular cloning of an alanine aminotransferase from NAD-malic enzyme type C4 plant Panicum miliaceum." Plant Mol Biol 20(4);705-13. PMID: 1450385

Tao08: Tao Y, Ferrer JL, Ljung K, Pojer F, Hong F, Long JA, Li L, Moreno JE, Bowman ME, Ivans LJ, Cheng Y, Lim J, Zhao Y, Ballare CL, Sandberg G, Noel JP, Chory J (2008). "Rapid synthesis of auxin via a new tryptophan-dependent pathway is required for shade avoidance in plants." Cell 133(1);164-76. PMID: 18394996

Wang87: Wang MD, Buckley L, Berg CM (1987). "Cloning of genes that suppress an Escherichia coli K-12 alanine auxotroph when present in multicopy plasmids." J Bacteriol 169(12);5610-4. PMID: 2890623

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.5 on Sat Apr 30, 2016, BIOCYC11A.