PTDSS1 Gene: Function, Mutations, and Associated Diseases | Biomedical Resource

The PTDSS1 gene encodes phosphatidylserine synthase 1, an enzyme that catalyzes the base-exchange reaction converting phosphatidylcholine to phosphatidylserine. This enzyme is critical for the biosynthesis of phosphatidylserine, a phospholipid essential for cell membrane integrity and signaling. PTDSS1 is ubiquitously expressed and plays a role in apoptosis, cell signaling, and membrane dynamics. Mutations in PTDSS1 are associated with Lenz-Majewski syndrome, a rare genetic disorder characterized by skeletal abnormalities and intellectual disability.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Phospholipid metabolism

• Glycerophospholipid biosynthesis

PTDSS1 is a 473-amino acid protein localized to the endoplasmic reticulum and mitochondria-associated membranes. It catalyzes the exchange of L-serine with the polar head group of phosphatidylcholine or phosphatidylethanolamine to produce phosphatidylserine. The enzyme requires calcium ions for activity and is involved in the regulation of cellular phosphatidylserine levels, which are crucial for apoptosis and membrane asymmetry. Structural studies indicate that the active site is on the cytoplasmic side of the membrane, and the protein forms homodimers. PTDSS1 is ubiquitously expressed, with higher levels in brain and liver, and its dysregulation is linked to rare genetic disorders.