M. Pagani et al., Endoplasmic reticulum oxidoreductin 1-L beta (ERO1-L beta), a human gene induced in the course of the unfolded protein response, J BIOL CHEM, 275(31), 2000, pp. 23685-23692
Oxidative conditions must be generated in the endoplasmic reticulum (ER) to
allow disulfide bond formation in secretory proteins. A family of conserve
d genes, termed ERO for ER oxidoreductins, plays a key role in this process
. We have previously described the human gene ERO1-L, which complements sev
eral phenotypic traits of the yeast thermo-sensitive mutant erol-1 (Cabibbo
, A., Pagani, M., Fabbri, M., Rocchi, M., Farmery, M. R., Bulleid, N. J., a
nd Sitia, R. (2000) J. Biol. Chem. 275, 4827-4833). Here, we report the clo
ning and characterization of a novel human member of this family, ERO1-L be
ta. Immunofluorescence, endoglycosidase sensitivity, and in vitro translati
on/translocation assays reveal that the products of the ERO1-L beta gene ar
e primarily localized in the ER of mammalian cells. The ability to allow gr
owth at 37 degrees C and to alleviate the "unfolded protein response" when
expressed in erol-1 cells indicates that EBO1-L beta is involved also in ge
nerating oxidative conditions in the ER, ERO1-L and ERO1-L beta display dif
ferent tissue distributions. Furthermore, only ERO1-L beta transcripts are
induced in the course of the unfolded protein response. Our results suggest
a complex regulation of ER redox homeostasis in mammalian cells.