Phospholipid phosphatase 3

Phospholipid phosphatase 3 (PLPP3) is a magnesium-independent plasma membrane phosphatase that catalyzes the dephosphorylation of diverse glycerolipid and sphingolipid phosphate esters, including phosphatidate, lysophosphatidate, sphingosine 1-phosphate, and ceramide 1-phosphate (UniProt: O14495). Through this activity, it regulates the availability of bioactive lipid mediators and modulates signal transduction across multiple cellular processes.

PLPP3 functions in vascular homeostasis by controlling extracellular sphingosine-1-phosphate levels, thereby influencing endothelial cell migration, adhesion, and survival. It also maintains cerebellar development and function through lipid homeostasis, and acts in early secretory pathway compartments. Additionally, PLPP3 participates in Wnt signaling and beta-catenin stabilization, affecting cell proliferation and differentiation, as well as integrin-mediated cell-cell adhesion (UniProt: O14495).

PLPP3 is upregulated in Alzheimer's disease brain tissue relative to age-matched controls in post-mortem human samples (Chaparral AD proteomics), with a mean log2 fold-change of 1.101 across quantified subcellular fractions. This elevation suggests altered lipid phosphate metabolism may contribute to AD pathophysiology, though the functional significance of this upregulation requires further investigation.