Pyruvate dehydrogenase E1 (PDH E1)

Pyruvate dehydrogenase E1 is the primary regulatory component of the multi-enzyme pyruvate dehydrogenase complex (PDC), which catalyzes the rate-limiting step in aerobic glucose oxidation. It facilitates the oxidative decarboxylation of pyruvate to form acetyl-CoA, effectively linking the glycolytic pathway to the tricarboxylic acid (TCA) cycle within the mitochondrial matrix (UniProt P08559). The enzyme exists as a heterotetramer of two alpha and two beta subunits, with its activity strictly controlled by reversible phosphorylation mediated by pyruvate dehydrogenase kinases (PDKs) and phosphatases (PDPs) (Patel et al., 2014). Genetic mutations in the PDHA1 gene, which encodes the E1-alpha subunit, are the most common cause of pyruvate dehydrogenase deficiency, leading to lactic acidosis and severe neurological impairment such as Leigh syndrome (StatPearls, 2023). In oncology, PDH E1 is often suppressed in cancer cells to favor glycolysis over oxidative phosphorylation, a phenomenon known as the Warburg effect, making its reactivation a potential therapeutic strategy (Stacpoole, 2017). Conversely, inhibitors like devimistat (CPI-613) target the E1 and E2 subunits to disrupt the altered mitochondrial metabolism of tumor cells (Pardee et al., 2014). Beyond cancer, the enzyme is a focal point for research in metabolic diseases like type 2 diabetes and sepsis, where metabolic flexibility is compromised (Gray et al., 2014).

Other names

Pyruvate dehydrogenase (lipoamide) alpha 1Pyruvate decarboxylasePDHE1E1 component of the pyruvate dehydrogenase complexPDHA1PDHB

The E1 subunit catalyzes the thiamine pyrophosphate (TPP)-dependent oxidative decarboxylation of pyruvate, resulting in the formation of a hydroxyethyl-TPP intermediate and the release of CO2; the acetyl group is then transferred to the lipoamide moiety of the E2 subunit (UniProt P08559; Patel et al., 2014).