Phosphatidylserine decarboxylase proenzyme, mitochondrial (PISD)

Phosphatidylserine decarboxylase proenzyme, mitochondrial (PISD) is an essential enzyme localized mainly to the inner mitochondrial membrane in eukaryotic cells. It catalyzes the decarboxylation of phosphatidylserine to phosphatidylethanolamine, a crucial step in the biosynthesis of major membrane phospholipids. PISD is initially synthesized as a proenzyme that undergoes autoendoproteolytic cleavage, generating active alpha and beta subunits; this process and subsequent enzyme activity depend on conserved catalytic residues forming a classic serine protease triad. The function of PISD is vital for the maintenance of mitochondrial structure and integrity, as well as for inter-organelle phospholipid trafficking and potentially, lipid droplet biogenesis. Genetic deficiency or pharmacological inhibition of this enzyme leads to profound mitochondrial dysfunction and can be lethal in model organisms. Because of its central metabolic role and regulatory mechanisms, PISD is under investigation as a target for antimicrobial and anticancer therapy, although safety concerns due to its essential nature must be addressed.

Other names

Phosphatidylserine decarboxylase beta chainPhosphatidylserine decarboxylase alpha chainPSDPSDCPSSCdJ858B16.2LIBFDJ858B16Phosphatidylserine decarboxylase proenzyme, mitochondrial

Enzyme inhibitors (disrupt maturation of the proenzyme or decarboxylase reaction to block enzymatic activity) - Lipid analogs (competing substrates or inhibitors interacting with the active site; disrupting PS binding)