LPP4

LPP4, short for lipid phosphate phosphatase 4, is a member of the lipid phosphate phosphatase (LPP) family. In humans, the PLPP4 gene encodes this enzyme, which is involved in the regulation of extracellular lipid signaling by removing phosphate groups from lipid phosphates. LPP4 is part of a group of membrane-associated enzymes that modulate levels of lipid signaling molecules outside the cell, thereby influencing downstream cellular responses.

In terms of structure and localization, LPP4 is considered a multi-pass transmembrane protein with catalytic motifs characteristic of the LPP family. The catalytic region is oriented toward the extracellular milieu, which enables dephosphorylation of extracellular lipid phosphate substrates. This localization supports a role in shaping the extracellular lipid environment that can affect signaling pathways related to cell behavior.

Substrates attributed to LPP enzymes often include lysophosphatidic acid (LPA) and other lipid phosphates, and LPP4 is thought to participate in dephosphorylating such molecules to modulate signaling pathways. Through these reactions, LPP4 can influence processes like cell proliferation, migration, and vascular or tissue remodeling, though the exact substrate specificity and physiological impact of LPP4 can vary by tissue and organism.

Expression and regulation of LPP4 have been observed across multiple tissues in humans and model organisms, indicating a broadly relevant role in lipid signaling. Research continues to define its precise functions, regulatory mechanisms, and potential involvement in disease contexts. Some studies have explored associations with cancer, metabolic disorders, and inflammatory conditions, but clinical implications remain to be fully established.