High impact information on ALG3

• A cDNA (ALG-3) encoding the last 103 amino acids of PS2 has been identified as a potent inhibitor of apoptosis [1].
• These aberrant protein-linked oligosaccharides were processed by the addition of outer chain residues in the alg3, alg5, and alg6 mutants [2].
• When compared with alg3 sec18 and wild-type core mannans, Deltaalg9 N-glycans reveal a regulatory role for the Alg3p-dependent alpha1,3-linked Man in subsequent oligosaccharide-lipid and glycoprotein glycan maturation [3].
• The delta och1 mnn1 alg3 mutants accumulated Man5GlcNAc2 and Man8GlcNAc2 in total cell mannoprotein, confirming the lack of outer chain addition to the incomplete corelike oligosaccharide and the leaky phenotype of the alg3 mutation [4].
• Thus, the vast majority of the N-linked glycosylation in the ER of alg3 yeast (> 75%) occurs by transfer of Man5GlcNAc2 without prior addition of the 3 glucoses normally found on the lipid-linked precursor [5].

Biological context of ALG3

• Finally, analysis of the P. pastoris alg3 deletion mutant in the presence and absence of the outer chain initiating Och1p alpha-1,6-mannosyltransferase activity suggests that the PpOch1p has a broader substrate specificity compared to its S. cerevisiae counterpart [6].

Anatomical context of ALG3

• Glycoprotein biosynthesis in the alg3 Saccharomyces cerevisiae mutant. I. Role of glucose in the initial glycosylation of invertase in the endoplasmic reticulum [5].
• Preparations that were highly enriched in either Glc(3)Man(9)GlcNAc(2)-PP-Dol or Man(9)GlcNAc(2)-PP-Dol were obtained from porcine pancreas and a Man(5)GlcNAc(2)-PP-Dol preparation was obtained from an alg3 yeast culture [7].
• A novel yeast gene, RHK1, is involved in the synthesis of the cell wall receptor for the HM-1 killer toxin that inhibits beta-1,3-glucan synthesis [8].

Associations of ALG3 with chemical compounds

• The inactivation of the nonessential ALG3 gene results in the accumulation of lipid-linked Man5GlcNac2 and protein-bound carbohydrates which are completely Endo H resistant [9].
• The accumulation of Man(6)GlcNAc(2)-PP-dolichol in the Saccharomyces cerevisiae Deltaalg9 mutant reveals a regulatory role for the Alg3p alpha1,3-Man middle-arm addition in downstream oligosaccharide-lipid and glycoprotein glycan processing [3].

Other interactions of ALG3

• Structure of Saccharomyces cerevisiae alg3, sec18 mutant oligosaccharides [10].
• Not45 shows significant homology to yeast ALG3 protein acting as a dolichol mannosyltransferase in the asparagine-linked glycosylation [11].

References