Cloned (Comment) | Organism |
---|---|
gene EXT1, recombinant expression of Myc-DKK-tagged enzyme in S2 cells, interaction analysis with GOLPH3 via yeast two-hybrid assay | Drosophila melanogaster |
gene EXT2, recombinant expression of Myc-DKK-tagged enzyme in S2 cells, interaction analysis with GOLPH3 via yeast two-hybrid assay | Drosophila melanogaster |
General Stability | Organism |
---|---|
Rti regulates the stability of EXT isozymes | Drosophila melanogaster |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
Golgi apparatus | EXT isozymes are localized mainly in the cis- and middle-Golgi stacks. Rotini, Rti, mediates the retrograde transport of EXT enzymes within the Golgi complex. Rotini regulates the sub-compartmental distribution of EXTs in the Golgi | Drosophila melanogaster | 5794 | - |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Drosophila melanogaster | Q9V730 | gene EXT1 | - |
Drosophila melanogaster | Q9Y169 | gene ext2 | - |
Synonyms | Comment | Organism |
---|---|---|
extosin | - |
Drosophila melanogaster |
General Information | Comment | Organism |
---|---|---|
malfunction | mutations in the tumor suppressor genes EXT1 and EXT2 disturb heparan sulfate proteoglycan biosynthesis and cause multiple osteochondroma. A reduction in Rti shifts the steady-state distribution of EXTs to the trans-Golgi. These accumulated EXTs tend to be degraded and their re-entrance towards the route for polymerizing GAG chains is disengaged. Conversely, EXTs are mislocalized towards the transitional endoplasmic reticulum/cis-Golgi when Rti is overexpressed. Both loss of function and overexpression of rti result in incomplete heparan sulfate proteoglycans and perturb Hedgehog signaling | Drosophila melanogaster |
physiological function | exostosin (EXT) genes encode glycosyltransferases required for glycosaminoglycan chain polymerization in the biosynthesis of heparan sulfate proteoglycans. Synthesis of heparan sulfate proteoglycans requires sequential enzymatic modifications of glycoproteins in the Golgi. Drosophila Golgi phosphoprotein 3, GOLPH3 or rotini, Rti, regulates the biosynthesis of heparan sulfate proteoglycans by modulating the retrograde trafficking of exostosins. Rti regulates the stability of EXTs. Proper function of EXTs depends not only on their enzymatic activities but also on their sub-compartmental distributions | Drosophila melanogaster |