GPIs

Glycosylphosphatidylinositol (GPI) anchors are complex glycolipids found on the surface of eukaryotic cells. They attach proteins to the outer leaflet of the plasma membrane. This attachment occurs post-translationally, meaning it happens after the protein has been synthesized. A GPI anchor consists of a hydrophobic diacylglycerol tail, a common glycan core, and a phosphoethanolamine bridge linking the glycan to the C-terminus of the protein. The structure of the glycan core can vary, but it typically includes mannose residues. GPI-anchored proteins play diverse roles in cellular processes, including cell adhesion, signal transduction, and immune response. They can be released from the cell surface by specific phospholipases. The study of GPI anchors is important for understanding cell membrane structure and function, as well as for developing potential therapeutic strategies targeting GPI-anchored proteins. Some pathogens, like the parasite Trypanosoma brucei, also utilize GPI anchors, making them targets for drug development.