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  • Glycoproteins
  • The role of cell surface glycoproteins in determining in vivo blood-borne arrest and survival characteristics of murine melanoma sublines of low (B16-F1) or high (B16-F10) potential to form experimental lung metastases after injection i.v. was assessed after inhibiting tumor cell protein glycosylation with tunicamycin. (aacrjournals.org)
  • Together, our findings reveal the importance of Arabidopsis ( Arabidopsis thaliana ) OST3/6 for the efficient glycosylation of specific glycoproteins involved in different physiological processes and shed light on the composition and function of the plant OST complex. (plantphysiol.org)
  • This invention relates to viral proteins and glycoproteins, to compositions containing these proteins, to methods of preparing the proteins, and to their use in detecting viral infection. (google.es)
  • It appears that tunicamycin inhibits the incorporation of mannose and N -acetylglucosamine into a number of mammary glycoproteins by inhibiting the formation of lipid-linked intermediates, but does not inhibit the incorporation of N -acetylgalactosamine into casein. (biochemj.org)
  • inhibits
  • However, when ER stress is prolonged or too severe, ATF4 may contribute to apoptosis by promoting expression of CHOP (C/EBP homologous protein), a transcription factor that inhibits expression of BCL‐2 while upregulating pro‐apoptotic BIM (BCL‐2 interacting protein), thus triggering the activation of the mitochondria‐dependent apoptotic pathway. (embopress.org)
  • These findings implicate GADD34-mediated dephosphorylation of eIF2α in a negative feedback loop that inhibits stress-induced gene expression, and that might promote recovery from translational inhibition in the unfolded protein response. (rupress.org)
  • The latter is required for the formation of the eukaryotic translational preinitiation complexes, and its sequestration in an inactive complex with phosphorylated eIF2α inhibits the initiation step of protein synthesis. (rupress.org)
  • Thus tunicamycin selectively inhibits the incorporation of N -acetylglucosamine into glycoprotein. (biochemj.org)
  • secretion
  • Many of the characteristic proteins of the UPR are up-regulated in animal cells specialized for secretion, including plasma cells, pancreatic β cells, hepatocytes, and osteoblasts ( 18 ). (pnas.org)
  • In many bacterial pathogens, the type 3 secretion system (T3SS) and associated effector proteins are utilized to hijack host immune surveillance, further allowing survival of the bacteria in hostile host environments. (frontiersin.org)
  • The lumen is an oxidative environment, critical for formation of disulfide bonds and proper folding of proteins destined for secretion or display on the cell surface. (100md.com)
  • Ire1
  • Release from BiP activates the ribonuclease domain of Ire1 to cleave the mRNA precursor encoding the transcription factor X-box binding protein 1 (XBP1) mRNA to its mature form, the XBP1 mRNA. (pnas.org)
  • Only a few homologs of proteins centrally involved in the UPR in other systems have been identified in plants: Ire1 ( 11 - 13 ), eIF2α ( 14 , 15 ), and p58 IPK ( 16 ). (pnas.org)
  • The intrinsic ribonuclease activity of Ire1 also results in production of XBP-1, a transcription factor that induces expression of genes involved in restoring protein folding or degrading unfolded proteins. (100md.com)
  • ATF6
  • We recently found that the basic leucine zipper protein ATF6 isolated as a CCACG-binding protein is synthesized as a transmembrane protein in the ER, and ER stress-induced proteolysis produces a soluble form of ATF6 that translocates into the nucleus. (asm.org)
  • Disulfide-bonded ATF6 is reduced upon treatment of cells with not only the reducing reagent dithiothreitol but also the glycosylation inhibitor tunicamycin, and the extent of reduction correlates with that of activation. (asm.org)
  • ER stress-induced reduction is specific to ATF6 as the oligomeric status of a second ER membrane-bound transcription factor, LZIP/Luman, is not changed upon tunicamycin treatment and LZIP/Luman is well cleaved by S1P in the absence of ER stress. (asm.org)
  • ATF6 is constitutively synthesized as a precursor form designated pATF6(P), a type II transmembrane protein with its bZIP domain facing the cytoplasm ( 12 , 13 ). (asm.org)
  • thapsigargin
  • Here, we report that bortezomib interferes with the UPR and sensitizes pancreatic cancer cells to apoptosis stimulated by the classic ER stress inducers tunicamycin and thapsigargin. (aacrjournals.org)
  • glycoprotein
  • Tunicamycin-treated B16-F1 and B16-F10 cells adhered at lower rates to endothelial cells such that after 24 to 36 hr of drug (0.5 µg/ml) treatment adhesion was almost completely blocked, suggesting that tunicamycin-induced cell surface glycoprotein changes in B16 melanoma cells may interfere with tumor cell-host cell interactions that lead to arrest and survival of blood-borne malignant cells. (aacrjournals.org)
  • 1. Tunicamycin inhibited the incorporation of d -[2- 3 H]mannose into dolichol-linked oligosaccharide and glycoprotein of lactating-rabbit mammary explants by approximately the same extent (approx. (biochemj.org)
  • 2. The incorporation of radioactivity from N -acetyl- d -[1- 14 C]glucosamine into dolichol-linked oligosaccharide was inhibited by tunicamycin to 32% of the control value, whereas the incorporation of the radiolabel into glycoprotein was only inhibited to 72% of the control value. (biochemj.org)
  • intracellular
  • This intracellular signaling, known as the unfolded protein response (UPR), is mediated by the cis -acting ER stress response element (ERSE) in mammals. (asm.org)
  • Effect of 2-fluoropalmitate, cerulenin and tunicamycin on the palmitoylation and intracellular translocation of myelin proteolipid protein. (noneto.com)
  • homeostasis
  • Under such ER stress conditions, homeostasis of protein folding in the ER is maintained by interorganelle signaling from the ER to the nucleus, a process called the unfolded protein response (UPR) ( 20 , 30 ). (asm.org)
  • Connexin 30 (Cx30), a member of the large gap-junction protein family, plays a role in the homeostasis of the epidermis and inner ear through gap junctional intercellular communication (GJIC). (biologists.org)
  • subunits
  • In yeast, the OST complex is composed of a single STT3 protein and eight additional subunits ( Knauer and Lehle, 1999a ). (plantphysiol.org)
  • Consistent with our hypothesis that PIs induce the accumulation of misfolded ER-processed proteins, we found that the amount of immunoglobulin subunits retained within MM cells correlated with their sensitivity to PIs. (bloodjournal.org)
  • Heterotrimeric G proteins, consisting of Gα, Gβ, and Gγ subunits, are a conserved signal transduction mechanism in eukaryotes. (plantphysiol.org)
  • The classical heterotrimeric G protein consists of a GDP/GTP-binding Gα subunit with GTPase activity bound to an obligate dimer formed by Gβ and Gγ subunits. (plantphysiol.org)
  • However, Arabidopsis heterotrimeric G proteins have been implicated in a surprisingly large number of phenotypes, which is seemingly contradictory given the relative scarcity of subunits. (plantphysiol.org)
  • evolutionarily conserved
  • Autophagy or "self-eating" is an evolutionarily conserved lysosome-dependent system in eukaryotes that regulates the turnover of cellular proteins and organelles. (hindawi.com)
  • Disturbances in the normal functions of the ER lead to an evolutionarily conserved cell stress response, the unfolded protein response, which is aimed initially at compensating for damage but can eventually trigger cell death if ER dysfunction is severe or prolonged. (100md.com)
  • pathway
  • 27 In fact the detection of large amounts of monoclonal immunoglobulin or light chain in the serum or urine is one of the diagnostic features of MM. 28 Conditions that disrupt protein folding in the ER, such as a chemical insult or nutrient deprivation, activate a stress signaling pathway known as the unfolded protein response (UPR). (bloodjournal.org)
  • yeast
  • which indicates that Ost3p and Ost6p might prevent fast protein folding to achieve optimal glycosylation efficiency on a subset of proteins in yeast. (plantphysiol.org)
  • To detect interacting pairs of human proteins systematically, a protein matrix of 4456 baits and 5632 preys was screened by automated yeast two-hybrid (Y2H) interaction mating. (genes2cognition.org)
  • Furthermore, a completely different model was presented recently based on the crystal structure, in which the luminal domain of yeast Ire1p binds directly to unfolded proteins to be oligomerized ( 6 ). (asm.org)
  • oligosaccharide
  • This is due to the blockage of the transference of the 14 residue core oligosaccharide (containing two N-acetylglucosamine, nine mannose, and three glucose residues) from a dolichol phosphate donor molecule to certain asparagine (Asn) residues on the proteins. (noneto.com)
  • proteasome
  • Most soluble misfolded proteins are cleared through the ubiquitin-proteasome system, which involves action of a cascade of three canonical ubiquitin enzymes: E1 ubiquitin-activating enzyme initiates the reaction by using ATP to covalently activate and then conjugate the ubiquitin to an E2 ubiquitin-conjugating enzyme. (frontiersin.org)
  • Arabidopsis
  • In addition to GPA1, the sole canonical Arabidopsis ( Arabidopsis thaliana ) Gα subunit, Arabidopsis has three related proteins: the extra-large GTP-binding proteins XLG1, XLG2, and XLG3. (plantphysiol.org)
  • thus
  • A number of physiological processes and environmental factors which contain micro organism, metabolic aspects, medication, hypoxia and inflammation promote the secretory action of these cells, thus inducing stress on the protein high quality handle equipment. (kletterwiki.de)
  • Under conditions of prolonged ER stress, TFEB and TFE3 contribute to cell death, thus revealing an unexpected role for these proteins in controlling cell fate. (embopress.org)
  • This leads to a global translational attenuation, thus reducing protein burden within the ER (Wek et al , 2006 ). (embopress.org)
  • Thus, XLG-Gβγ heterotrimers provide additional signaling modalities for tuning plant G protein responses and increase the repertoire of G protein heterotrimer combinations from three to 12. (plantphysiol.org)
  • influx
  • Translation of mRNAs is also initially inhibited, reducing the influx of new proteins into the ER for hours until mRNAs encoding UPR proteins are produced. (100md.com)
  • subunit
  • Taken together, these observations imply that the Gβ protein, which forms a stable heterodimer with the Gγ subunit, is involved in the signaling events that trigger UPR-associated cell death. (pnas.org)
  • GADD34 formed a complex with the catalytic subunit of protein phosphatase 1 (PP1c) that specifically promoted the dephosphorylation of eIF2α in vitro. (rupress.org)
  • However, G protein subunit numbers in diploid plant genomes are greatly reduced as compared with animals and do not correlate with the diversity of functions and phenotypes in which heterotrimeric G proteins have been implicated. (plantphysiol.org)
  • consequent
  • The protein then travels to the Golgi apparatus for the consequent steps of glycosylation and must be bound by mannose-6-phosphate in order to attach itself to the mannose-6-phosphate receptor. (noneto.com)