. Author manuscript; available in PMC: 2007 Oct 23.

Published in final edited form as: FEBS Lett. 2007 Apr 25;581(19):3641–3651. doi: 10.1016/j.febslet.2007.04.045

Table 1.

Summary of function and disease relevance of ER chaperones, co-chaperones and folding enzymes

Protein	Localization	Function	Knockout mouse model	Diseases	Reference
GRP78/BiP	ER lumen ER transmembrane Cell surface Nucleus	Chaperone, Ca²⁺-binding, ER stress sensor, UPR regulator Anti-apoptosis	Embryonic lethality at E3.5 due to failure of embryo peri-implantation	Cancer Alzheimer’s disease Parkinson’s disease Prion diseases Atherosclerosis	[34,57,65,71,75–78,107]
SIL1	ER lumen	Co-chaperone, nucleotide exchange factor for GRP78	Woozy mouse associated with cerebellar purkinje cell degeneration and ataxia	Marinesco-Sjögren syndrome	[58–60]
GRP94/gp96	ER lumen Cell surface transmembrane	Chaperone, Ca²⁺-binding Anti-apoptosis Tumor immunity	Embryonic lethality	Cancer Prion diseases Autoimmune disease	[65,71,86,87,89]
GRP170/ORP150	ER lumen	Chaperone, potential nucleotide exchange factor for GRP78	Embryonic lethality	Alzheimer’s disease	[57,61,129]
GRP58/ERp57	ER lumen Nucleus Cytosol	Thio-oxidoreductase to catalyze disulfide bond formation of glycoprotein	Embryonic lethality (traditional knockout); Grp58⁻^/⁻ B cells are defective in antigen presentation (conditional knockout in B cells).	Prion diseases Alzheimer’s disease	[35,62,92,130,131]
PDI	ER lumen Cell surface	Thio-oxidoreductase to catalyze disulfide bond formation	N.D.	Alzheimer’s disease Parkinson’s disease	[55,92,132]