Pyruvate kinase R isoform (PKR)

Pyruvate kinase R isoform is an enzyme that catalyzes the final rate-limiting step of glycolysis by transferring a phosphate group from phosphoenolpyruvate (PEP) to adenosine diphosphate (ADP), generating one molecule each of pyruvate and ATP[1][4]. The R isoform is specifically expressed in erythrocytes and plays a critical role in maintaining their energy balance. It is encoded by the PKLR gene, which also encodes the liver-specific L isoform[1]. Deficiency or dysfunction of this enzyme leads to hereditary nonspherocytic hemolytic anemia due to impaired ATP generation in red blood cells. The activity of this enzyme can be allosterically regulated by metabolites such as fructose 1,6-bisphosphate and inhibited by ATP and alanine[1]. In cancer biology, altered regulation or expression patterns of pyruvate kinases—including other tissue-specific forms—are associated with changes in cellular metabolism that support tumor growth[2]. The structure-function relationship involves complex allosteric regulation allowing adaptation to metabolic needs; mutations affecting these properties underlie disease phenotypes such as hemolytic anemia[3].

Other names

PKRErythrocyte pyruvate kinasePyruvate kinase, red cell isoformPK-L/R (when referring to the gene encoding both liver and red cell forms)

For experimental activators or correctors of mutant enzyme function: Allosteric activation to increase enzymatic activity and restore glycolytic flux. Stabilization of active conformation.