Endoplasmic reticulum protein (ERp) 72, a 72 kDa protein localized
to the endoplasmic reticulum, is a member of the protein disulfide
isomerase (PDI) family of proteins . It contains three repeats
of the thioredoxin-like regions that is postulated to represent
three independently acting catalytic domains (CGHC) of PDI activity.
ERp72 contains the sequence at its carboxyl terminus which serves
as its ER retention signal. Together with other ER resident proteins
such as BiP, GRP94, and PDI, they serve as the molecular chaperones
for proper folding of newly translocated and glycolsylated proteins
such as thyroglobulin (Tg)
and human chorionic gonadotropin (hCG)-b. ERp72 expression is regulated by
the level of misfolding proteins in the ER, as the amount of ERp72 increased
in response to epithelial ischemia, a condition that perturbs the maturation
of secretory proteins.
- back - complete