RelevanceMalic enzyme catalyzes the oxidative decarboxylation of malate to pyruvate using either NAD+ or NADP+ as a cofactor. Mammalian tissues contain 3 distinct isoforms of malic enzyme: a cytosolic NADP(+)-dependent isoform, a mitochondrial NADP(+) dependent isoform, and a mitochondrial NAD(+) dependent isoform. This gene encodes a mitochondrial NADP(+) dependent isoform. Multiple alternatively spliced transcript variants have been found for this gene, but the biological validity of some variants has not been determined. ME3 is expressed predominantly in organs with a low division rate. Its catalytic activity is (S) malate + NADP+ = pyruvate + CO2 + NADPH.