9.B.131 The Post-GPI Attachment Protein (P-GAP2) Family
Glycosylphosphatidylinositol (GPI) is a complex glycolipid that serves as a membrane anchor for many cell-surface proteins, such as Thy-1 and CD48. GPI-anchored proteins (GPI-APs) play important roles in many biological processes, such as signal transduction and cell-cell interaction, through their association with lipid rafts. Fatty acid remodeling of GPI-APs in the Golgi apparatus is required for their efficient association with lipid rafts, i.e., the unsaturated fatty acid at the sn-2 position of the PI moiety is exchanged for the saturated fatty acid by PGAP2 and PGAP3 (Murakami et al., 2012). This family may be distantly related to two other TC families, 9.B.14 and 2.A.66 (see the TC# 9.B.131.1.8 entry).