Phosphoglycerate Dehydrogenase (PHGDH)

3-Phosphoglycerate dehydrogenase (PHGDH; EC 1.1.1.95) catalyzes the transition of 3-phosphoglycerate into 3-phosphohydroxypyruvate, which is the first and rate-limiting step in the phosphorylated pathway of serine biosynthesis, using NAD+/NADH as a cofactor. The deduced 533-amino acid protein, with a molecular mass of 56.8 kD, shares 94% sequence identity with rat liver 3-PGDH. Northern blot analysis detected a major 2.1-kb transcript at high levels in prostate, testis, ovary, brain, liver, kidney, and pancreas and at low levels in thymus, colon, and heart. A 710-bp transcript appeared as a weaker band in most tissues in which the 2.1-kb mRNA was expressed, was more significant than the 2.1-kb mRNA in heart, and was the only transcript present in skeletal muscle.