Cloning of mammalian Ire1 reveals diversity in the ER stress responses

Cells modify their gene expression pattern in response to stress signals emanating from the endoplasmic reticulum (ER). The well‐characterized aspect of this response consists of the activation of genes that encode protein chaperones and other ER resident proteins, and is conserved between mammals and yeast. In mammalian cells, however, ER stress also activates other pathways, including the expression of the transcription factor CHOP/GADD153 and its downstream target genes. ER stress is also linked to the development of programmed cell death, a phenomenon in which CHOP plays an important role. Here we report on the cloning of a murine homolog of yeast IRE1, an essential upstream component of the ER stress‐response in yeast. The mammalian Ire1 is located in the ER membrane and its over‐expression in mammalian cells activates both the endogenous ER chaperone GRP78/BiP and CHOP‐encoding genes. Over‐expression of a dominant‐negative form of Ire1 blocks the induction of GRP78/BiP and CHOP in response to the ER stress induced by tunicamycin treatment. Over‐expression of murine Ire1 also leads to the development of programmed cell death in transfected cells. These results indicate that a single upstream component, Ire1, plays a role in multiple facets of the ER stress‐response in mammalian cells.

[1]  N. Mandahl,et al.  Fusion of CHOP to a novel RNA-binding protein in human myxoid liposarcoma , 1993, Nature.

[2]  K. Mori,et al.  Unconventional Splicing of HAC1/ERN4 mRNA Required for the Unfolded Protein Response , 1998, The Journal of Biological Chemistry.

[3]  J. Sambrook,et al.  A transmembrane protein with a cdc2+ CDC28 -related kinase activity is required for signaling from the ER to the nucleus , 1993, Cell.

[4]  A. Dorner,et al.  The stress response in Chinese hamster ovary cells. Regulation of ERp72 and protein disulfide isomerase expression and secretion. , 1990, The Journal of biological chemistry.

[5]  T. W. Fawcett,et al.  Regulation of the C/EBP-related gene gadd153 by glucose deprivation , 1993, Molecular and cellular biology.

[6]  X. Wang,et al.  Inhibition of adipogenesis by the stress‐induced protein CHOP (Gadd153). , 1995, The EMBO journal.

[7]  L. Zon,et al.  Role of SAPK/ERK kinase-1 in the stress-activated pathway regulating transcription factor c-Jun , 1994, Nature.

[8]  J. Trueman,et al.  The mouse Plk gene: structural characterization, chromosomal localization and identification of a processed Plk pseudogene. , 1997, Gene.

[9]  A. Zetterberg,et al.  Selective killing induced by an inhibitor of N-linked glycosylation. , 1993, Journal of cell science.

[10]  R. Kaufman,et al.  Immunoglobulin Binding Protein (BiP) Function Is Required to Protect Cells from Endoplasmic Reticulum Stress but Is Not Required for the Secretion of Selective Proteins* , 1997, The Journal of Biological Chemistry.

[11]  J. Sambrook,et al.  Protein folding in the cell , 1992, Nature.

[12]  Xiaozhong Wang,et al.  CHOP is implicated in programmed cell death in response to impaired function of the endoplasmic reticulum. , 1998, Genes & development.

[13]  C. Sander,et al.  A hybrid protein kinase‐RNase in an interferon‐induced pathway? , 1993, FEBS letters.

[14]  P. Silver,et al.  Amino terminus of the yeast GAL4 gene product is sufficient for nuclear localization. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[15]  P. Walter,et al.  Translational attenuation mediated by an mRNA intron , 1997, Current Biology.

[16]  N. Holbrook,et al.  The molecular response to reductive stress in LLC-PK1 renal epithelial cells: coordinate transcriptional regulation of gadd153 and grp78 genes by thiols. , 1997, Cell stress & chaperones.

[17]  R. Kaufman,et al.  Protein Serine/Threonine Phosphatase Ptc2p Negatively Regulates the Unfolded-Protein Response by Dephosphorylating Ire1p Kinase , 1998, Molecular and Cellular Biology.

[18]  T. Shenk,et al.  Use of a membrane-localized green fluorescent protein allows simultaneous identification of transfected cells and cell cycle analysis by flow cytometry. , 1997, Cytometry.

[19]  Peter Walter,et al.  The Transmembrane Kinase Ire1p Is a Site-Specific Endonuclease That Initiates mRNA Splicing in the Unfolded Protein Response , 1997, Cell.

[20]  K. Mori,et al.  Palindrome with Spacer of One Nucleotide Is Characteristic of thecis-Acting Unfolded Protein Response Element inSaccharomyces cerevisiae * , 1998, The Journal of Biological Chemistry.

[21]  Amy S. Lee,et al.  Generation of a Mammalian Cell Line Deficient in Glucose-regulated Protein Stress Induction through Targeted Ribozyme Driven by a Stress-inducible Promoter (*) , 1995, The Journal of Biological Chemistry.

[22]  S. Komiyama,et al.  Molecular cloning of a human cDNA encoding a novel protein, DAD1, whose defect causes apoptotic cell death in hamster BHK21 cells , 1993, Molecular and cellular biology.

[23]  Xiaozhong Wang,et al.  Signals from the stressed endoplasmic reticulum induce C/EBP-homologous protein (CHOP/GADD153) , 1996, Molecular and cellular biology.

[24]  K. Mori,et al.  Endoplasmic reticulum stress-induced mRNA splicing permits synthesis of transcription factor Hac1p/Ern4p that activates the unfolded protein response. , 1997, Molecular biology of the cell.

[25]  D. Ron,et al.  CHOP, a novel developmentally regulated nuclear protein that dimerizes with transcription factors C/EBP and LAP and functions as a dominant-negative inhibitor of gene transcription. , 1992, Genes & development.

[26]  A. Friedman.  GADD153/CHOP, a DNA damage-inducible protein, reduced CAAT/enhancer binding protein activities and increased apoptosis in 32D c13 myeloid cells. , 1996, Cancer research.

[27]  J. Nikawa,et al.  Saccharomyces cerevisiae IRE2/HAC1 is involved in IRE1-mediated KAR2 expression. , 1996, Nucleic acids research.

[28]  Peter Walter,et al.  Transcriptional induction of genes encoding endoplasmic reticulum resident proteins requires a transmembrane protein kinase , 1993, Cell.

[29]  J. Sambrook,et al.  The presence of malfolded proteins in the endoplasmic reticulum signals the induction of glucose-regulated proteins , 1988, Nature.

[30]  R. Kaufman,et al.  A stress response pathway from the endoplasmic reticulum to the nucleus requires a novel bifunctional protein kinase/endoribonuclease (Ire1p) in mammalian cells. , 1998, Genes & development.

[31]  P. Walter,et al.  A Novel Mechanism for Regulating Activity of a Transcription Factor That Controls the Unfolded Protein Response , 1996, Cell.

[32]  L. Philipson,et al.  CHOP (GADD153) and its oncogenic variant, TLS-CHOP, have opposing effects on the induction of G1/S arrest. , 1994, Genes & development.

[33]  O. Larsson,et al.  Inhibition of N-linked glycosylation using tunicamycin causes cell death in malignant cells: role of down-regulation of the insulin-like growth factor 1 receptor in induction of apoptosis. , 1997, Cancer research.

[34]  J. Fargnoli,et al.  Mammalian genes coordinately regulated by growth arrest signals and DNA-damaging agents , 1989, Molecular and cellular biology.

[35]  M. W. Clark,et al.  The subnuclear localization of tRNA ligase in yeast , 1987, The Journal of cell biology.

[36]  M. Ptashne,et al.  A vector for expressing GAL4(1-147) fusions in mammalian cells. , 1989, Nucleic acids research.

[37]  S. Komiyama,et al.  Molecular Cloning of a Human cDNA Encoding a Novel Protein , DAD 1 , Whose Defect Causes Apoptotic Cell Death in Hamster BHK 21 Cells , 1993 .

[38]  B. Price,et al.  Gadd45 and Gadd153 messenger RNA levels are increased during hypoxia and after exposure of cells to agents which elevate the levels of the glucose-regulated proteins. , 1992, Cancer research.

[39]  P. Walter,et al.  The unfolded protein response coordinates the production of endoplasmic reticulum protein and endoplasmic reticulum membrane. , 1997, Molecular biology of the cell.

[40]  G K Lewis,et al.  Isolation of monoclonal antibodies specific for human c-myc proto-oncogene product , 1985, Molecular and cellular biology.

[41]  F. Mollinedo,et al.  Inhibition of N‐linked glycosylation induces early apoptosis in human promyelocytic HL‐60 cells , 1995, Journal of cellular physiology.

[42]  R. Larson,et al.  Fusion of the dominant negative transcription regulator CHOP with a novel gene FUS by translocation t(12;16) in malignant liposarcoma , 1993, Nature Genetics.

[43]  H. Zinszner,et al.  Identification of novel stress‐induced genes downstream of chop , 1998, The EMBO journal.

[44]  N. Lenny,et al.  Regulation of endoplasmic reticulum stress proteins in COS cells transfected with immunoglobulin mu heavy chain cDNA. , 1991, The Journal of biological chemistry.

[45]  D. Kelleher,et al.  The essential OST2 gene encodes the 16-kD subunit of the yeast oligosaccharyltransferase, a highly conserved protein expressed in diverse eukaryotic organisms , 1995, The Journal of cell biology.

[46]  P. Walter,et al.  Oligomerization and phosphorylation of the Ire1p kinase during intracellular signaling from the endoplasmic reticulum to the nucleus. , 1996, The EMBO journal.

[47]  Amy S. Lee,et al.  The glucose-regulated proteins (GRP78 and GRP94): functions, gene regulation, and applications. , 1994, Critical reviews in eukaryotic gene expression.

[48]  P. Walter,et al.  tRNA Ligase Is Required for Regulated mRNA Splicing in the Unfolded Protein Response , 1996, Cell.

[49]  R. Kaufman,et al.  The Unfolded Protein Response Pathway in Saccharomyces cerevisiae , 1996, The Journal of Biological Chemistry.

[50]  Amy S. Lee.  Coordinated regulation of a set of genes by glucose and calcium ionophores in mammalian cells , 1987 .

[51]  G. Yancopoulos,et al.  Identification of functional receptors for ciliary neurotrophic factor on neuronal cell lines and primary neurons , 1990, Neuron.