ERO1 Like Protein Beta (ERO1Lb)

Oxidative conditions must be generated in the endoplasmic reticulum (ER) to allow disulfide bond formation in secretory proteins. ERO1-L complements several phenotypic traits of the yeast thermo-sensitive mutant ero1-1. Immunofluorescence, endoglycosidase sensitivity, and in vitro translation/translocation assays reveal that the products of the ERO1-Lbeta gene are primarily localized in the ER of mammalian cells. The ability to allow growth at 37 degrees C and to alleviate the "unfolded protein response" when expressed in ero1-1 cells indicates that ERO1-Lbeta is involved also in generating oxidative conditions in the ER. ERO1-L and ERO1-Lbeta display different tissue distributions. ERO1-Lbeta transcripts are induced in the course of the unfolded protein response.