| Function | Catalytic subunit of the glycosylphosphatidylinositol-anchor (GPI-anchor) transamidase (GPI-T) complex that catalyzes the formation of the linkage between a proprotein and a GPI-anchor and participates in GPI anchored protein biosynthesis. Recognizes diverse proproteins at a C-terminal signal peptide (CSP) region that lacks consensus sequence and replaces it with a GPI-anchor via a transamidation reaction. Transamidation catalysis reaction follows a two-phase mechanism. In the acyl-enzyme phase, the carbonyl group of the proproteins's omega-site undergoes a nucleophilic attack forming an enzyme-substrate thioester bond. Followed by a general acid catalysis that allows CSP releasing, regenerating the carbonyl, and forming the acyl-enzyme intermediate. In the GPI-anchor attachment phase, the amino group of the GPI-anchor's ethanolamine phosphate, the one on third mannose (EtNP3), mediates a nucleophilic attack on the carbonyl of the acyl-enzyme intermediate, replacing the CSP, allowing GPI-anchor attachment to the omega-residue, therefore forming the product and freeing the enzyme. |
| Protein Name | Gpi-Anchor TransamidaseGpi-Anchor Transamidase Component Pigk - Catalytic SubunitGpi8 HomologHgpi8Phosphatidylinositol-Glycan Biosynthesis Class K ProteinPig-K |
| Database Links | Reactome: R-HSA-162791 |
| Cellular Localisation | Endoplasmic Reticulum MembraneSingle-Pass Type I Membrane Protein |
| Alternative Antibody Names | Anti-Gpi-Anchor Transamidase antibodyAnti-Gpi-Anchor Transamidase Component Pigk - Catalytic Subunit antibodyAnti-Gpi8 Homolog antibodyAnti-Hgpi8 antibodyAnti-Phosphatidylinositol-Glycan Biosynthesis Class K Protein antibodyAnti-Pig-K antibodyAnti-PIGK antibodyAnti-GPI8 antibody |
Information sourced from Uniprot.org
