INPP5E

INPP5E, also known as inositol polyphosphate-5-phosphatase E, is an enzyme encoded by the INPP5E gene in humans. This enzyme belongs to the 5-phosphatase family and plays a crucial role in the metabolism of phosphoinositides. Specifically, INPP5E dephosphorylates phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) at the 5-position, converting it to phosphatidylinositol 4-phosphate (PI(4)P). This action is vital for regulating the intracellular levels of various phosphoinositide species, which act as second messengers in numerous cellular signaling pathways.

The activity of INPP5E is implicated in a variety of cellular processes, including cell proliferation, migration, and differentiation. Its role in controlling PI(4,5)P2 levels makes it a key player in pathways such as actin cytoskeleton organization and membrane trafficking. Aberrant INPP5E activity has been linked to certain diseases, particularly neurological disorders. Mutations in the INPP5E gene have been identified as a cause of Joubert syndrome, a rare genetic disorder characterized by a specific brain malformation known as the molar tooth sign, along with other developmental abnormalities affecting breathing, eye movements, and cognitive function. Research continues to explore the precise mechanisms by which INPP5E functions and its broader implications in human health and disease.