Abstract
Pyruvate kinase catalyzes the last step of glycolysis which is important for generating adenosine triphosphate (ATP). Mammals express four major pyruvate kinase (PK) isozymes: muscle (M1), liver (L), erythrocyte (R), and the ubiquitous M2 types. All but the M1 isozyme exhibit positive cooperative kinetic behaviors upon binding the allosteric activator fructose-1,6-diphosphate and in the presence of increasing phosphoenolpyruvate (PEP) concentrations. All four isozymes are inhibited by phenylalanine. The l-PK isozyme activity is also inhibited by phosphorylation in response to glucagon. Consistent with its important role in regulating glucose metabolism and fat synthesis in liver, l-PK is also extensively regulated at the level of transcription. l-PK transcription increases in response to glucose and insulin and decreases in response to glucagon and high fat diets.
Original language | English (US) |
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Title of host publication | Encyclopedia of Biological Chemistry |
Subtitle of host publication | Second Edition |
Publisher | Elsevier Inc. |
Pages | 719-721 |
Number of pages | 3 |
ISBN (Electronic) | 9780123786319 |
ISBN (Print) | 9780123786302 |
DOIs | |
State | Published - Feb 15 2013 |
Keywords
- Allosteric enzyme
- Cancer
- Carbohydrate metabolism
- Fat synthesis
- Gluconeogenesis
- Glycolysis
- Lipogenesis
- Pyruvate kinase
- Regulation of glycolysis
- Warburg effects
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology