Phosphomannose Isomerase (PMI) (磷酸甘露糖异构酶 (PMI))

Phosphomannose isomerase (PMI/MPI), phosphomannose mutase (PMM), and GDP-Man pyrophosphorylase (GMPP) are the three crucial enzymes involved in the biosynthesis of GDP-Man, which is required for cell wall mannan biosynthesis and protein glycosylation. UDP-glucose (UDP-Glc), UDP-GlcNAc, and GDP-Man are the three precursors required for cell wall biosynthesis. PMI catalyzes the conversion between fructose-6-phosphate (Fru6P) and mannose-6-phosphate (Man6P)^[1]. This enzyme is present in mammals, bacteria, and fungi and plays an important role in cell wall synthesis, viability, and cell signaling. PMI deficiency is associated with congenital disorder of glycosylation. PMI inhibition combined with mannose supplementation might help normalize N-glycosylation and improve CDG-Ia pathology^[2].