| First Author | Rodeheffer C | Year | 2002 |
| Journal | Biochim Biophys Acta | Volume | 1573 |
| Issue | 3 | Pages | 258-70 |
| PubMed ID | 12417408 | Mgi Jnum | J:80110 |
| Mgi Id | MGI:2429811 | Doi | 10.1016/s0304-4165(02)00392-6 |
| Citation | Rodeheffer C, et al. (2002) Targeted mutations in beta1,4-galactosyltransferase I reveal its multiple cellular functions. Biochim Biophys Acta 1573(3):258-70 |
| abstractText | beta1,4-Galactosyltransferase I (GalT I) is one of the most extensively studied glycosyltransferases. It is localized in the trans-Golgi compartment of most eukaryotic cells, where it participates in the elongation of oligosaccharide chains on glycoproteins and glycolipids. GalT I has also been reported in non-Golgi locations, most notably the cell surface, where it has been suggested to function non-biosynthetically as a receptor for extracellular glycoside substrates. Cloning of the GalT I cDNAs revealed that the gene encodes two similar proteins that differ only in the length of their cytoplasmic domains. Whether these different GalT I proteins, or isoforms, have similar or different biological roles is a matter of active investigation. The functions of the GalT I proteins have been addressed by targeted mutations that eliminate either both GalT I isoforms or just the long GalT I isoform. Eliminating both GalT I proteins abolishes most, but not all, GalT activity, an observation that led to the realization that other GalT family members must exist. The loss of both GalT I isoforms leads to neonatal lethality due to a wide range of phenotypic abnormalities that are most likely the result of decreased galactosylation. When the long isoform of GalT I is eliminated, galactosylation proceeds grossly normal via the short GalT I isoform, but specific defects in cell interactions occur that are thought to depend upon a non-biosynthetic function of the long GalT I isoform. |
