Bifunctional coenzyme A synthase (COASY)

**Bifunctional coenzyme A synthase (COASY)** is an enzyme encoded by the *COASY* gene in humans, catalyzing the final two steps of de novo coenzyme A (CoA) biosynthesis from vitamin B5 (pantothenic acid). This enzyme consists of two catalytic domains: 4'-phosphopantetheine adenylyltransferase (PPAT/CoaD) and dephospho-CoA kinase (DPCK/CoaE). COASY is mainly localized to mitochondria but is also found in the cytoplasm and nucleus. Disease-associated loss-of-function mutations result in the ultra-rare neurodegenerative disease COASY protein-associated neurodegeneration (CoPAN/NBIA6), characterized by brain iron accumulation, due to impaired CoA synthesis. COASY also has roles in mitosis and DNA repair, implicating it in multiple cellular pathways. **Note:** The term “COASY mRNA” is not the correct target form for pharmacological modulation; the biologically meaningful and therapeutically relevant entity is the **COASY protein/enzyme**. If a structured format is required, do not list “COASY mRNA” as a canonical target—use the protein/enzymatic form instead.

Other names

CoA synthaseCOASY protein4'-phosphopantetheine adenylyltransferase/dephospho-CoA kinasePPAT/DPCK

metabolic supplementation with riboflavin may compensate for deficiencies in CoA biosynthesis caused by COASY mutations