Reactome: A Curated Pathway Database

phosphoenolpyruvate + ADP => pyruvate + ATP (R-HSA-71670)

Species Homo sapiens


Cytosolic pyruvate kinase catalyzes the transfer of a high-energy phosphate from phosphoenolpyruvate to ADP, forming pyruvate and ATP. This reaction, an instance of substrate-level phosphorylation, is essentially irreversible under physiological conditions.

Four isozymes of human pyruvate kinase have been described, L, R, M1 and M2. Isozymes L and R are encoded by alternatively spliced transcripts of the PKLR gene; isozymes M1 and M2 are encoded by alternatively spliced transcripts of PKM2. In the body, L pyruvate kinase is found in liver (Tani et al. 1988), R in red blood cells (Kanno et al. 1991), M1 in muscle, heart and brain (Takenaka et al. 1991), and M2 in early fetal tissues and tumors (e.g., Lee et al. 2008). In all cases, the active form of the enzyme is a homotetramer, activated by fructose 1,6-bisphosphate (Valentini et al. 2002; Dombrauckas et al. 2005). Mutations in PKLR have been associated with hemolytic anemias (e.g., Zanella et al. 2005).

Locations in the PathwayBrowser
Additional Information
Compartment cytosol
Components of this entry
Input entries
Output entries
Catalyst Activity
PhysicalEntity Activity Active Units
pyruvate kinase tetramer pyruvate kinase activity (0004743)
Cross References
Database Identifier
Rhea 18160, 18159
This entry is regulated by
Regulation type Name
allosteric activation
allosteric inhibition