Recombinant human Dolichyl-diphosphooligosaccharide–protein glycosyltransferase subunit DAD1 protein

Uniprot Id

P61803

Target Species

Human

Target Name

DAD1

Target Full Name

Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit DAD1

Target Function

Subunit of the oligosaccharyl transferase (OST) complex that catalyzes the initial transfer of a defined glycan (Glc(3)Man(9)GlcNAc(2) in eukaryotes) from the lipid carrier dolichol-pyrophosphate to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains, the first step in protein N-glycosylation. N-glycosylation occurs cotranslationally and the complex associates with the Sec61 complex at the channel-forming translocon complex that mediates protein translocation across the endoplasmic reticulum (ER). All subunits are required for a maximal enzyme activity. Required for the assembly of both SST3A- and SS3B-containing OST complexes. Loss of the DAD1 protein triggers apoptosis.

Target Subcellular Location

Endoplasmic reticulum membrane; Multi-pass membrane protein.

Target Protein Families

DAD/OST2 family

Target Research Area

Apoptosis

Target Synonyms

DAD1; Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit DAD1; Oligosaccharyl transferase subunit DAD1; Defender against cell death 1; DAD-1

Target Background

DAD1, the defender against apoptotic cell death, was initially identified as a negative regulator of programmed cell death in the temperature sensitive tsBN7 cell line. The DAD1 protein disappeared in temperature-sensitive cells following a shift to the nonpermissive temperature, suggesting that loss of the DAD1 protein triggered apoptosis. DAD1 is believed to be a tightly associated subunit of oligosaccharyltransferase both in the intact membrane and in the purified enzyme, thus reflecting the essential nature of N-linked glycosylation in eukaryotes.