Disruption of the ER α-mannosidase gene in yeast (10, 11) and inhibition of ER Man I in mammalian cells (13, 14) both prevent ERAD.We recently reported the molecular cloning of mouse EDEM (-antitrypsin and accelerates its degradation (15).Collagens are modular triple helical proteins that constitute the major structural components of the extracellular matrix of all animals.They occur as diverse suprastructures such as fibrils, microfibrils, and networks, which serve as self-organizing scaffolds for the attachment of other macromolecular complexes including laminin networks, proteoglycans, and cell surface receptors.Emid2 has 13 cysteine residues in the N-terminal portion of the first noncollagenous region and 2 clusters of gly-X-Y collagen-like repeats.
Correctly folded glycoproteins exit the ER to their final destinations, whereas misfolded glycoproteins are readily degraded (for reviews see Refs. Many terminally misfolded proteins in the ER are degraded by cytoplasmic proteasomes, a mechanism known as ERAD (for reviews see Refs. Experimental evidence in yeast and mammalian cells suggests that ER α1,2-mannosidase I (ER Man I) that primarily removes the middle branch mannose from Man isomer B (Man8B) (8, 9) acts as a signal triggering ERAD of glycoproteins (10–12).
(2002) cloned mouse Emid2, which they called Col26a1, by yeast 2-hybrid analysis using Hsp47 (600943) as bait.
The deduced 438-amino acid protein contains an N-terminal signal sequence, followed by 3 noncollagenous domains separated by 2 collagenous domains.
Immunohistochemical analysis detected mouse Emid2 in the extracellular matrix of testis and ovary. (2002) identified 2 splice variants encoding EMID2, which they designated EMU2.
The deduced proteins contain 441 and 439 amino acids.