| First Author | Watanabe R | Year | 2000 |
| Journal | EMBO J | Volume | 19 |
| Issue | 16 | Pages | 4402-11 |
| PubMed ID | 10944123 | Mgi Jnum | J:138284 |
| Mgi Id | MGI:3804747 | Doi | 10.1093/emboj/19.16.4402 |
| Citation | Watanabe R, et al. (2000) Initial enzyme for glycosylphosphatidylinositol biosynthesis requires PIG-P and is regulated by DPM2. EMBO J 19(16):4402-11 |
| abstractText | Glycosylphosphatidylinositols (GPIs) are attached to the C-termini of many proteins, thereby acting as membrane anchors. Biosynthesis of GPI is initiated by GPI-N-acetylglucosaminyltransferase (GPI-GnT), which transfers N-acetylglucosamine from UDP- N-acetylglucosamine to phosphatidylinositol. GPI-GnT is a uniquely complex glycosyltransferase, consisting of at least four proteins, PIG-A, PIG-H, PIG-C and GPI1. Here, we report that GPI-GnT requires another component, termed PIG-P, and that DPM2, which regulates dolichol-phosphate-mannose synthase, also regulates GPI-GnT. PIG-P, a 134-amino acid protein having two hydrophobic domains, associates with PIG-A and GPI1. PIG-P is essential for GPI-GnT since a cell lacking PIG-P is GPI-anchor negative. DPM2, but not two other components of dolichol-phosphate-mannose synthase, associates with GPI-GnT through interactions with PIG-A, PIG-C and GPI1. Lec15 cell, a null mutant of DPM2, synthesizes early GPI intermediates, indicating that DPM2 is not essential for GPI-GnT; however, the enzyme activity is enhanced 3-fold in the presence of DPM2. These results reveal new essential and regulatory components of GPI-GnT and imply co-regulation of GPI-GnT and the dolichol-phosphate-mannose synthase that generates a mannosyl donor for GPI. |
