Asparagine Linked Glycosylation Protein 3 (ALG3)

ALG3 encodes a member of the ALG3 family. The encoded protein catalyses the addition of the first dol-P-Man derived mannose in an alpha 1,3 linkage to Man5GlcNAc2-PP-Dol. Defects in this gene have been associated with congenital disorder of glycosylation type Id (CDG-Id) characterized by abnormal N-glycosylation.Korner et al. (1999) noted that the human Not56-like protein shares with the yeast ALG3 protein 30% sequence homology, the C-terminal -KKXX ER-retrieval signal, and multiple membrane-spanning helices. Complementation of the glycosylation defect in a yeast strain with a disrupted ALG3 gene by the human Not56-like protein gene demonstrated that NOT56L is the ortholog of the S. cerevisiae ALG3 gene.