Pterin-4 alpha-carbinolamine dehydratase 1 (PCBD1)

Pterin-4 alpha-carbinolamine dehydratase 1 (PCBD1) is an enzyme essential in the recycling of **tetrahydrobiopterin (BH4)**, a critical cofactor for enzymes involved in **amino acid metabolism** and **neurotransmitter synthesis**. Besides its enzymatic role, PCBD1 also acts as a **dimerization cofactor (transcriptional coactivator)** for hepatocyte nuclear factors HNF1A (and HNF1B), thereby regulating gene transcription involved in renal magnesium handling (FXYD2), glucose metabolism, and other cellular processes. Mutations in PCBD1 can cause a rare form of **tetrahydrobiopterin deficiency** leading to hyperphenylalaninemia and have been associated with **hypomagnesemia** and, less commonly, glucose intolerance or MODY diabetes. The enzyme forms homodimers or tetramers and interacts with key transcription factors and metabolic enzymes but has no currently known direct therapeutic targeting drugs.

Other names

Pterin-4 alpha-carbinolamine dehydrataseDimerization cofactor of hepatocyte nuclear factor 1-alphaDimerization cofactor of HNF1DCoHPCBDPCDPHSPhenylalanine hydroxylase-stimulating proteinPterin carbinolamine dehydratase4-alpha-hydroxy-tetrahydropterin dehydratase6-pyruvoyl-tetrahydropterin synthase/dimerization cofactor of HNF1 alphaPterin-4a-carbinolamine dehydratase (dimerization cofactor of hepatic nuclear factor 1-alpha)

Potential mechanisms relate to enzyme supplementation (conceptual, not in clinical use) or modulation of cofactor (tetrahydrobiopterin, BH4) recycling; indirectly, transcriptional modulation via HNF1A/B pathways.