DAD1

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.

Full Name

Defender Against Cell Death 1

Function

Subunit of the oligosaccharyl transferase (OST) complex that catalyzes the initial transfer of a defined glycan (Glc3Man9GlcNAc2 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 (PubMed:22467853).

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 (By similarity).

Required for the assembly of both SST3A- and SS3B-containing OST complexes. Loss of the DAD1 protein triggers apoptosis (PubMed:22467853).

Biological Process

Apoptotic process Source: UniProtKB-KW
Blastocyst development Source: Ensembl
Negative regulation of apoptotic process Source: ProtInc
Protein glycosylation Source: UniProtKB
Protein N-linked glycosylation Source: ARUK-UCL
Protein N-linked glycosylation via asparagine Source: Reactome
Regulation of protein stability Source: ARUK-UCL
Response to drug Source: Ensembl
Response to nutrient Source: Ensembl
Viral protein processing Source: Reactome

Cellular Location

Endoplasmic reticulum membrane

Topology

Cytoplasmic: 2-30
Helical: 31-51
Lumenal: 52
Helical: 53-73
Cytoplasmic: 74-92
Helical: 93-113