Defender of cell death 1 (DAD1) was initially discovered in BHK21 cells as a negative regulator of programmed cell death, a process important for normal organism development and tissue homeostasis. DAD1 was later shown to be a subunit of the mammalian oligosaccharyltransferase complex and is required for its function and structural integrity. Mice lacking DAD1 express abnormal N-linked glycoproteins and undergo increased apoptotic-associated embryonic death. Furthermore, overexpression of DAD1 mRNA is seen in some human hepatocellular carcinomas, indicating it may also play a role in carcinogenesis. It should be noted that DAD1 is not related to the inhibitor of apoptosis proteins (IAP) family and does not contain any baculoviral IAP repeat (BIR) domains.
DAD-1; Defender against cell death 1; Dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit DAD1; Oligosaccharyl transferase subunit DAD1; oligosaccharyltransferase 2 homolog; oligosaccharyltransferase subunit 2 (non-catalytic); OST2