Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P11021 (BiP)
 2,049 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The promoter of the human gene encoding the stress-responsive protein polypeptide-binding protein/78 kDa glucose-regulated protein (BiP/GRP78) was isolated from Burkitt's lymphoma cells by PCR. This promoter DNA segment (termed BiP670) or one of its 5' deletion derivatives was fused to the bacterial chloramphenicol acetyltransferase gene and introduced into HeLa cells for transient expression. BiP670 retained transcriptional activity at both the basal and Ca2+ ionophore A23187-inducible levels. However, there was no significant increase in promoter activity following a 5 h induction with 7 microM-A23187, and less than 5-fold induction at 15 h. In contrast, the steady-state mRNA level was induced by 18-fold at 5 h. The in vivo transactivation assays with BiP670 5' deletion derivatives indicate that the putative A23187-inducible element is located within a 70 bp DNA segment (i.e. spanning -39 to -107 bp upstream of the transcriptional initiation site). Using an in vitro gel mobility shift assay, A23187-inducible nuclear factors were identified from HeLa cell extracts. DNA-binding competition experiments also suggest that the 70 bp DNA segment contains a potential sequence motif for the binding of the A23187-inducible nuclear factors.
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PMID:Cloning of a functional Burkitt's lymphoma polypeptide-binding protein/78 kDa glucose-regulated protein (BiP/GRP78) gene promoter by the polymerase chain reaction, and its interaction with inducible cellular factors. 138 10

Hemin induces nonterminal differentiation of human K562 erythroleukemia cells, which is accompanied by the expression of certain erythroid cell-specific genes, such as the embryonic and fetal globins, and elevated expression of the stress genes hsp70, hsp90, and grp78/BiP. Previous studies revealed that, as during heat shock, transcriptional induction of hsp70 in hemin-treated cells is mediated by activation of heat shock transcription factor (HSF), which binds to the heat shock element (HSE). We report here that hemin activates the DNA-binding activity of HSF2, whereas heat shock induces predominantly the DNA-binding activity of a distinct factor, HSF1. This constitutes the first example of HSF2 activation in vivo. Both hemin and heat shock treatments resulted in equivalent levels of HSF-HSE complexes as analyzed in vitro by gel mobility shift assay, yet transcription of the hsp70 gene was stimulated much less by hemin-induced HSF than by heat shock-induced HSF. Genomic footprinting experiments revealed that hemin-induced HSF and heat shock-induced HSF, HSF2, and HSF1, respectively, occupy the HSE of the human hsp70 promoter in a similar yet not identical manner. We speculate that the difference in occupancy and/or in the transcriptional abilities of HSF1 and HSF2 accounts for the observed differences in the stimulation of hsp70 gene transcription.
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PMID:Activation of heat shock factor 2 during hemin-induced differentiation of human erythroleukemia cells. 150 7

A cDNA library was constructed from size-fractionated poly(A)+ RNA prepared from a murine pre-B-cell hybridoma expressing high levels of immunoglobulin heavy chain binding protein (BiP) and mu heavy chains. Transformed bacterial colonies were screened for recombinant plasmids containing cDNA coding for BiP by hybrid-selected mRNA translation. A clone, pMBiP, containing a 736-base-pair insert was shown to encode the protein. Translation in vitro of hybridoma mRNA selected by hybridization to the pMBiP cDNA yielded a single polypeptide of BiP-like size. The authenticity of this mRNA was verified by comparing the peptides obtained by the limited proteolysis of its in vitro translation product with those obtained from the in vivo produced BiP. Likewise, the authenticity of the cDNA insert was verified by an RNase A protection assay of heteroduplex molecules obtained by annealing a uniformly labeled single-strand copy of the cDNA clone with the same mRNA selected by hybridization and tested by translation. The nucleotide sequence of this clone enabled us to deduce the carboxyl-terminal 142 amino acids of BiP and to establish its kinship with the 70-kDa heat shock protein family. The finding of a single copy of the BiP gene in DNA blots of mouse and rat implies that the BiP-related RNA transcripts constitutively expressed in various murine tissues and cell lines are indeed products of the same gene. These findings imply that BiP plays a more general role than previously anticipated on the basis of the discovery of its association with immunoglobulin heavy chains.
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PMID:cDNA cloning of the immunoglobulin heavy chain binding protein. 289 72

The inducible, higher eukaryotic transcription factor NF-kappa B is activated by a variety of external stimuli including inflammatory cytokines, viral and bacterial infection and UV irradiation. Here we show that internal stress, caused by the accumulation of proteins in the endoplasmic reticulum (ER), also induces NF-kappa B DNA binding as well as kappa B-dependent gene expression. This was observed upon expression of immunoglobulin mu chains in the absence of light chains and by treatment of cells with several agents known to cause ER stress, such as tunicamycin, brefeldin A, 2-deoxyglucose and thapsigsargin. The transcription factor AP-1 was weakly induced under similar conditions. Overexpression of NF-kappa B subunits did not influence expression of the gene encoding grp78/BiP, a protein induced by various forms of ER stress. Likewise, the glucosidase inhibitor castanospermine, which induced grp78/BiP expression, failed to activate NF-kappa B, while the antioxidant dithiothreitol augmented grp78/BiP expression but prevented activation of NF-kappa B. Hence, NF-kappa B participates in a novel ER-nuclear signal transduction pathway distinct from the unfolded-protein-response described previously. We provide evidence that the ER can produce at least two distinct signals in response to a functional impairment. One is emitted by the presence of unfolded proteins, the other in response to overloading of the organelle, for example through the overexpression of secretory proteins.
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PMID:A novel signal transduction pathway from the endoplasmic reticulum to the nucleus is mediated by transcription factor NF-kappa B. 778 11

Microsomal-type cytochrome P450s are integral membrane proteins bound to the membrane through their N-terminal transmembrane hydrophobic segment, the signal anchor sequence. To elucidate the determinants that enable the P450s to be located in the ER, we constructed cDNAs encoding chimeric proteins in which a secretory form of carboxyesterase, carboxyesterase Sec, was connected to the N-terminus of the full-length or truncated forms of a microsomal-type P450, P450(M1), and the constructed plasmids were expressed in COS cells. Since carboxyesterase Sec is an N-glycosylated secretory protein, endo H treatment could be used to determine whether these chimeric proteins were located in the ER or not. Carboxyesterase Sec with the N-terminal 20 amino acids, containing the transmembrane region, of P450(M1), was located in the ER, as determined from the endo H sensitivity of the expressed protein and immunofluorescence staining of the cells. As the expressed protein exhibited carboxyesterase activity, it was not retained in the ER through the BiP-dependent quality control system recognizing unfolded proteins. Another chimeric protein construct in which carboxyesterase Sec was connected to the C-terminal region of rat UDP-glucuronosyltransferase (UDP-GT), that contained a double-lysin ER retention motif, was also located in the ER, as determined from the endo H sensitivity and immunofluorescence staining. On the other hand, the sugar moiety of the carboxyesterase Sec connected to the transmembrane segment of UDP-GT, Sec/GTd, was partially resistant to the endo H treatment. From the results of immunofluorescent staining and cell fractionation, it was concluded that the Sec/GTd product was located in the Golgi apparatus. These observations indicated that the N-terminal hydrophobic segment of P450(M1) is sufficient for the ER membrane retention, whereas the transmembrane segment of UDP-GT is not. To determine whether microsomal P450s are recycled between the ER and Golgi compartments or not, a DNA construct encoding cathepsin D connected to the N-terminus of P450(M1) was prepared and expressed in COS cells. The fusion protein was phosphorylated, but the phosphorylation was sensitive to alkaline phosphatase. As a control, authentic cathepsin D was subjected to phosphorylation of its oligosaccharide chain that was resistant to the alkaline phosphatase treatment. Since GlcNAc-P-transferase, which forms the alkaline phosphatase-resistant phosphodiester in the sugar chains of lysosome-targeting proteins, is located in the Golgi apparatus, it was concluded that the oligosaccharide chain of the cathepsin D portion of the fusion protein was not phosphorylated, and that the chimeric protein did not go to the Golgi apparatus.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The transmembrane region of microsomal cytochrome P450 identified as the endoplasmic reticulum retention signal. 779 74

Members of the 70-kD heat shock protein family have been found in all free-living organisms investigated and in major compartments of eukaryotic cells where they are essential to a wide range of functions, including protein folding and targeting. We have isolated a mitochondrial homolog (mtHSP70) from rat liver using ATP agarose affinity chromatography. Its identity was confirmed on the basis of immunological analysis and Ca(2+)-dependent autophosphorylation. Using protein sequence obtained from the amino termius and nine endo Lys-C peptide fragments, we have employed oligonucleotides to isolate a full-length cDNA clone. The open reading frame encodes a protein of 679 amino acids and calculated M(r) 73,913 daltons. The sequence has a high degree of identity with other members of the HSP70 family, including Escherichia coli DnaK (51%), Saccharomyces cerevisiae SSC1p (65%), the constitutive cytosolic HSP70 from rat, HSC70 (46%), and the rat endoplasmic reticulum isoform, BiP, (49%). The cDNA encodes a precursor protein with a 46-amino-acid signal peptide that is absent from the protein isolated from rat liver. The protein also shows a high degree of identity (98%) with a protein isolated from mouse and human tissues (PBP74, Domanico et al., 1993; mortalin, Wadhwa et al., 1993a; CSA, Michikawa et al., 1993a); however, the intracellular localization of these proteins is uncertain. We show that the precursor of mtHSP70 is efficiently imported into isolated mitochondria from rat liver and processed from 74 kD to the mature 69-kD protein.
DNA Cell Biol 1994 Dec
PMID:cDNA cloning and efficient mitochondrial import of pre-mtHSP70 from rat liver. 781 87

The sec71-1 and sec72-1 mutations were identified by a genetic assay that monitored membrane protein integration into the endoplasmic reticulum (ER) membrane of the yeast Saccharomyces cerevisiae. The mutations inhibited integration of various chimeric membrane proteins and translocation of a subset of water soluble proteins. In this paper we show that SEC71 encodes the 31.5-kDa transmembrane glycoprotein (p31.5) and SEC72 encodes the 23-kDa protein (p23) of the Sec63p-BiP complex. SEC71 is therefore identical to SEC66 (HSS1), which was previously shown to encode p31.5. DNA sequence analyses reveal that sec71-1 cells contain a nonsense mutation that removes approximately two-thirds of the cytoplasmic C-terminal domain of p31.5. The sec72-1 mutation shifts the reading frame of the gene encoding p23. Unexpectedly, the sec71-1 mutant lacks p31.5 and p23. Neither mutation is lethal, although sec71-1 cells exhibit a growth defect at 37 degrees C. These results show that p31.5 and p23 are important for the trafficking of a subset of proteins to the ER membrane.
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PMID:Nonlethal sec71-1 and sec72-1 mutations eliminate proteins associated with the Sec63p-BiP complex from S. cerevisiae. 784 22

The synthesis of complex biological structures such as antibodies using recombinant DNA technology is a major biotechnological advance. Active murine antibody (IgG) oligomers, composed of two heavy (H) and two light (L) polypeptide chains, have been expressed and secreted by the baculovirus-insect cell expression system. Unfortunately, expression of the functional antibodies is accompanied by the formation of abnormal protein complexes and aggregates in which the polypeptide chains are bound together into incorrect associations. The formation of these abnormal complexes or protein aggregates in insect cells may be caused by insufficient intracellular levels of two catalytic proteins, immunoglobulin binding protein (BiP or GRP78), and protein disulfide isomerase (PDI). Consequently, we obtained the genes coding for murine BiP and PDI and cloned the genes into the baculovirus vector (Autographa californica nuclear polyhedrosis virus) to obtain AcBB-BiP and AcBB-PDI. Infection of Spodoptera frugiperda (Sf-9) insect cells with these two baculoviruses yielded recombinant proteins of the correct size that were recognized by antibodies to these proteins. Cloning these genes into the baculovirus vector is one approach to engineering the assembly pathway in order to lower aggregation and increase production of functionally active proteins and oligomers.
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PMID:Engineering the assembly pathway of the baculovirus-insect cell expression system. 801 Jun 71

BiP/GRP78 is a member of the HSP70 family involved in the folding and assembly of proteins in the endoplasmic reticulum. Using PCR amplification of DNA from human x rodent somatic hybrids that segregate human chromosomes in conjunction with fluorescence in situ hybridization, we have assigned GRP78 to chromosome 9q34. This is in agreement with the localization of murine and bovine homologues based on the high degree of synteny in this region. Several interesting genes and disorders map to this region and are discussed.
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PMID:Localization of the gene encoding human BiP/GRP78, the endoplasmic reticulum cognate of the HSP70 family, to chromosome 9q34. 802 Sep 77

The endoplasmic reticulum (ER) of eukaryotic cells contains an abundant 78,000-Da protein (BiP) that is involved in the translocation, folding, and assembly of secretory and transmembrane proteins. In the yeast Saccharomyces cerevisiae, as in mammalian cells, BiP mRNA is synthesized at a high basal rate and is further induced by the presence of increased amounts of unfolded proteins in the ER. However, unlike mammalian BiP, yeast BiP is also induced severalfold by heat shock, albeit in a transient fashion. To identify the regulatory sequences that respond to these stimuli in the yeast KAR2 gene that encodes BiP, we have cloned a 1.3-kb segment of DNA from the region upstream of the sequences coding for BiP and fused it to a reporter gene, the Escherichia coli beta-galactosidase gene. Analysis of a series of progressive 5' truncations as well as internal deletions of the upstream sequence showed that the information required for accurate transcriptional regulation of the KAR2 gene in S. cerevisiae is contained within a approximately 230-bp XhoI-DraI fragment (nucleotides -245 to -9) and that this fragment contains at least two cis-acting elements, one (heat shock element [HSE]) responding to heat shock and the other (unfolded protein response element [UPR]) responding to the presence of unfolded proteins in the ER. The HSE and UPR elements are functionally independent of each other but work additively for maximum induction of the yeast KAR2 gene. Lying between these two elements is a GC-rich region that is similar in sequence to the consensus element for binding of the mammalian transcription factor Sp1 and that is involved in the basal expression of the KAR2 gene. Finally, we provide evidence suggesting that yeast cells monitor the concentration of free BiP in the ER and adjust the level of transcription of the KAR2 gene accordingly; this effect is mediated via the UPR element in the KAR2 promoter.
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PMID:The promoter region of the yeast KAR2 (BiP) gene contains a regulatory domain that responds to the presence of unfolded proteins in the endoplasmic reticulum. 842 9


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