EC Number   |
General Information |
Reference |
|---|
   2.4.1.259 | malfunction |
accumulation of D-Man-alpha-(1->2)-D-Man-alpha-(1->2)-D-Man-alpha-(1->3)-[D-Man-alpha-(1->3)-D-Man-alpha-(1->6)]-D-Man-beta-(1->4)-D-GlcNAc-beta-(1->4)-D-GlcNAc-diphosphodolichol in Saccharomyces cerevisiae DELTAalg9 mutant |
636758 |
| 2.4.1.259 | malfunction |
an ALG9-defective (congenital disorders of glycosylation type IL) patient who is homozygous for the p.Y286C (c.860A>G) mutation. This patient presents with psychomotor retardation, axial hypotonia, epilepsy, failure to thrive, inverted nipples, hepatomegaly, and pericardial effusion. Due to theALG9 deficiency, the cells of this patient accumulated the lipid-linked oligosaccharides Man6GlcNAc2-PP-dolichol and Man8GlcNAc2-PP-dolichol. Lipid-linked Man6GlcNAc2 and Man8GlcNAc2 are transferred onto proteins with the same efficiency. In addition, glycoproteins bearing these Man6GlcNAc2 and Man8GlcNAc2 structures efficiently enter in the glucosylation/deglucosylation cycle of the quality control system to assist in protein folding. In comparison with control cells, patients cells degrade misfolded glycoproteins at an increasing rate. The Man8GlcNAc2 isomer C on the patients glycoproteins is found to promote the degradation of misfolded glycoproteins |
708614 |
| 2.4.1.259 | malfunction |
congenital disorders of glycosylation, a deficiency of the ALG9 alpha1,2 mannosyltransferase enzyme, causes an accumulation of lipid-linked-GlcNAc2Man6 and -GlcNAc2Man8 structures, which is paralleled by the transfer of incomplete oligosaccharide precursors to protein. A homozygous point-mutation E523K is detected in the ALG9 gene. The ALG9 defect found in the patient with CDG, who presents with developmental delay, hypotonia, seizures, and hepatomegaly, shows that efficient lipid-linked oligosaccharide synthesis is required for proper human development and physiology |
707031 |
| 2.4.1.259 | physiological function |
inactivation of Alg9 results in impaired maturation and defective glycosylation of polycystin-1 |
759415 |
