EC Number   |
Protein Variants |
Reference |
|---|
   2.4.1.261 | E523K |
the ALG9 defect defines a form of congenital disorders of glycosylation named CDG-IL. The patient with this ALG9 defect, who presents with developmental delay, hypotonia, seizures, and hepatomegaly |
707031 |
| 2.4.1.261 | R100W |
residue R100 is located near the end of the largest luminal loop between the first two predicted transmembrane segments and is absolutely conserved in all known ALG9 enzymes. Mutation suppresses a dwarf mutant, bri1-9, the phenotypes of which are caused by endoplasmic reticulum retention and endoplasmic reticulum-associated degradation of a brassinosteroid receptor, BRASSINOSTEROID-INSENSITIVE 1, BR1. The mutation prevents the Glc3Man9GlcNAc2 assembly and inhibits the endoplasmic reticulum-associated degradation of bri1-9. Overexpression of EBS4 in the R100W bri1-9 mutant, which encodes the Arabidopsis ortholog of the yeast ALG12 catalyzing the ER luminal alpha1,6 Man addition, adds an alpha1,6 Man to the truncated N-glycan precursor accumulated in R100W bri1-9, promotes the bri1-9 endoplasmic reticulum-associated degradation, and neutralizes the R100W suppressor phenotype |
723648 |
| 2.4.1.261 | Y286C |
patient, who is homozygous for the ALG9 mutation p.Y286C, deleterious effect Y286C on the ALG9 function. Compared the complementation efficiency of the wild-type and mutant ALG9 cDNA in yeast cells deficient for alg9. In an assay, the growth efficiency of the transformed yeast double mutant alg9 wbp1-2 is tested. Deficiency in lipid-linked oligosaccharide biosynthesis (alg9) in combination with reduced oligosaccharyltransferase activity (wbp1-2) results in a temperature-sensitive phenotype at 30°C. At this restrictive temperature, both the normal and mutant ALG9 cDNAs are able to restore growth. The HsALG9 transformants perform similar to the yeast alg9. The complementation with the mutant construct (HsALG9 (Y286C)) is less efficient, resulting is a reduced growth restoration. This difference becomes more prominent when the transformants are grown at 32°C. The hypoglycosylation of the alg9 yeast strain is reflected in the presence of CPY glycoforms lacking one or two N-linked oligosacharides. The human ALG9 cDNA complements the yeast mutation partially, as shown by the improved glycosylation of CPY. The complementation efficiency of the HsALG9 (Y286C) is less efficient and almost comparable to the empty vector |
707037 |
