biostudies-literatureLi XANCI NIH HHS3446-53https://www.ebi.ac.uk/biostudies/studies/S-EPMC361074biostudies-literatureUnknown11(7)GRP78, a 78-kDa protein localized in the endoplasmic reticulum (ER), has been implicated in protein processing and stress protection. Its promoter contains a 36-bp region which is conserved among GRP genes across species and has the ability to compete for trans-acting factors mediating GRP gene expression. Integration of about 800 tandem copies of this sequence into the genome of a Chinese hamster ovary cell line (DG44) results in transfectants with the following phenotypes: (i) the induction level of GRP78 by the calcium ionophore A23187 and tunicamycin is reduced 4- and 2-fold, respectively, (ii) the induction levels of two other ER luminal protein genes, GRP94 and ERp72, are simultaneously down-regulated, (iii) the growth rate of these cells is half that of transfectants without the ampMolecular and cellular biologyCompetitive inhibition of a set of endoplasmic reticulum protein genes (GRP78, GRP94, and ERp72) retards cell growth and lowers viability after ionophore treatment.PMC361074R37 CA27607Li XALee ASfalseCompetitive inhibition of a set of endoplasmic reticulum protein genes (GRP78, GRP94, and ERp72) retards cell growth and lowers viability after ionophore treatment.GRP78, a 78-kDa protein localized in the endoplasmic reticulum (ER), has been implicated in protein processing and stress protection. Its promoter contains a 36-bp region which is conserved among GRP genes across species and has the ability to compete for trans-acting factors mediating GRP gene expression. Integration of about 800 tandem copies of this sequence into the genome of a Chinese hamster ovary cell line (DG44) results in transfectants with the following phenotypes: (i) the induction level of GRP78 by the calcium ionophore A23187 and tunicamycin is reduced 4- and 2-fold, respectively, (ii) the induction levels of two other ER luminal protein genes, GRP94 and ERp72, are simultaneously down-regulated, (iii) the growth rate of these cells is half that of transfectants without the amp1991-01-01T00:00:00Z1991 Jul2025-04-04T09:47:11.006Z2019-03-27T00:50:09ZS-EPMC361074204666310.1128/mcb.11.7.3446-3453.1991