Many eukaryotic cell-surface proteins are anchored to the membrane via glycosylphosphatidylinositol (GPI). PGAP1 is a deacylase that removes an acyl-chain from the inositol of GPI anchors in the endoplasmic reticulum immediately after attachment of GPI to proteins. In PGAP1 deficient cells, GPI anchored proteins (GPI-APs) are expressed on the cell surface at normal level but with the abnormal structure. PGAP1 deficiency cases intellectual disability and epilepsy, suggesting that not only the cell surface expression levels of GPI-APs but also the fine structure of GPI-anchors is important for the normal neurological development.
PGAP1