An essential role for the interferon-inducible, double-stranded RNA-activated protein kinase PKR in the tumor necrosis factor-induced apoptosis in U937 cells.

Yeung, Michael C.; Li, Jun; Lau, Alan F.

doi:10.1073/pnas.93.22.12451

Cited by 159 publications

(126 citation statements)

References 21 publications

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“…Using this trans-dominant negative property of the catalytically inactive PKR, we have shown that a functional PKR pathway is required to induce apoptosis in response to serum deprivation or TNF␣ treatment. Our results confirm and extend recent observations that implicate PKR as a general transducer of the apoptotic response (6,32,33,35). Although it was appreciated for many years that dsRNA in the presence of interferon is toxic to cells, it was only recently suggested that PKR mediates the apoptotic response to dsRNA upon vaccinia virus (6,35,39) and influenza virus (40) infection.…”

Section: Discussionsupporting

confidence: 81%

“…It is most likely that poly(I)⅐poly(C) alone did not affect NIH3T3 cells due to their low levels of PKR. These results are in agreement with previous observations (32,33) and support the idea that dsRNA is toxic to NIH3T3 cells that have a functional PKR pathway.…”

Section: Eif-2␣ Phosphorylation Mediates Pkr-dependent Apoptosissupporting

confidence: 83%

“…addition, forced expression of wild-type PKR was sufficient to induce apoptosis; this is also consistent with previous observations (33). PKR activation was also previously demonstrated to occur in response to stress conditions, such as activation of the heat shock response, presence of unfolded protein in the endoplasmic reticulum, growth factor depletion, and increases in cytosolic calcium (23,(41)(42)(43).…”

Section: Eif-2␣ Phosphorylation Mediates Pkr-dependent Apoptosissupporting

confidence: 77%

“…Although it was appreciated for many years that dsRNA in the presence of interferon is toxic to cells, it was only recently suggested that PKR mediates the apoptotic response to dsRNA upon vaccinia virus (6,35,39) and influenza virus (40) infection. Recent observations also support the idea that TNF␣-induced apoptosis requires a functional PKR pathway, whereas either expression of antisense PKR mRNA or deletion of the PKR gene reduced the apoptotic response to TNF␣ (32,33). We have demonstrated that apoptotic responses to TNF␣, serum deprivation, and interferon treatment with poly(I)⅐poly(C) require a functional PKR pathway by expression of a trans-dominant negative mutant of PKR.…”

Section: Discussionsupporting

confidence: 56%

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Phosphorylation of Eukaryotic Translation Initiation Factor 2 Mediates Apoptosis in Response to Activation of the Double-stranded RNA-dependent Protein Kinase

Srivastava¹,

Kumar²,

Kaufman³

1998

Journal of Biological Chemistry

361

322

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The interferon-inducible, double-stranded (ds) RNAdependent serine/threonine protein kinase (PKR) plays a role in viral pathogenesis, cell growth, and differentiation and is implicated as a tumor suppressor gene. Expression of a trans-dominant negative, catalytically inactive mutant PKR protected NIH3T3 cells from apoptosis in response to either treatment with tumor necrosis factor ␣ (TNF␣), serum deprivation. In cells expressing mutant PKR, TNF␣, but not dsRNA induced transcription from a nuclear factor B-dependent promoter, demonstrating specificity for dsRNA in signaling through the PKR pathway. Serum or plateletderived growth factor addition to serum-deprived mutant PKR-expressing cells induced transcription of the early response genes c-fos and c-jun, indicating that the immediate early response signaling was intact. Overexpression of wild-type PKR in a transient DNA transfection system was sufficient to induce apoptosis. TNF␣-induced apoptosis correlated with increased phosphorylation of the ␣ subunit of eukaryotic translation initiation factor 2 (eIF-2␣), the primary physiological substrate of the PKR. Furthermore, forced expression of a nonphosphorylatable S51A mutant eIF-2␣ partially protected cells from TNF␣-induced apoptosis, and expression of a S51D mutant eIF-2␣, a mutant that mimics phosphorylated eIF-2␣, was sufficient to induce apoptosis. Taken together, these studies identify a novel requirement for PKR in stress-induced apoptosis that is mediated through eIF-2␣ phosphorylation.

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Section: Discussionsupporting

confidence: 81%

Section: Eif-2␣ Phosphorylation Mediates Pkr-dependent Apoptosissupporting

confidence: 83%

Section: Eif-2␣ Phosphorylation Mediates Pkr-dependent Apoptosissupporting

confidence: 77%

Section: Discussionsupporting

confidence: 56%

See 2 more Smart Citations

Phosphorylation of Eukaryotic Translation Initiation Factor 2 Mediates Apoptosis in Response to Activation of the Double-stranded RNA-dependent Protein Kinase

Srivastava¹,

Kumar²,

Kaufman³

1998

Journal of Biological Chemistry

361

322

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“…Caspase Assay U937 cells (ATCC) sensitive to TNF-α-induced apoptosis 7 were cultured in RPMI 1640 medium containing 10% fetal bovine serum at 37 °C and 5% CO 2 /O 2 . Cells were grown in every other well of a 384-well NUNC sterile, clear plate (25,000 cells/well, 25 µL/well) for 18 h. Solutions of the carbohydrates at the indicated concentrations (0.01 -4000 µM in sterile PBS) were pre-incubated with TNF-α (1 µL/well of a 125 ng/mL solution in sterile PBS) at rt.…”

Section: S6mentioning

confidence: 99%

Discovery of a TNF-α Antagonist Using Chondroitin Sulfate Microarrays

2006

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Conjugation of CS Oligosaccharides to 1,2-(Bisaminooxy)ethane for Microarray ProductionOzonolysis of the anomeric allyl group and linkage of CS compounds 1-4 1,2 to 1,2-(bisaminooxy)ethane 3 proceeded as follows: oligosaccharide (0.51 µmol) was dissolved in MeOH (500 µL) and cooled to -78 °C. O 3 was bubbled through the reaction until a blue color persisted (1 min). The reaction was then purged with N 2 until colorless, quenched with Ph 3 P beads (3 mg), and gradually warmed to rt over 12 h. It was filtered and the product concentrated to afford the desired aldehyde as a white solid. The aldehyde (0.51 µmol) was then reacted for 14 h at rt with 1,2-(bisaminooxy)ethane hydrochloride (1.4 mg, 15 µmol) that had been dissolved in H 2 O (100 µL) and pH adjusted to 5.0 with 1 M NaOH. The resulting oxime product was purified using a SepPak C18 column (500 mg, H 2 O) and Sephadex G-10 (CS-E The relative concentrations of the aminooxy oligosaccharides were calibrated to one another using the carbazole assay for uronic acid residues. 4 Briefly, the acid borate reagent (1.5 mL of 0.80 g sodium tetraborate, 16.6 mL H 2 O, and 83.3 mL H 2 SO 4 ) was added to 20-mL glass vials with Teflon caps. The Carbohydrate MicroarraysSolutions of the aminooxy oligosaccharides (in 300 mM NaH 2 PO 4 , pH 5.0, 10 µL/well in a 384-well plate) were arrayed on Hydrogel Aldehyde slides (NoAb Biodiscoveries) by using a Microgrid II arrayer (Biorobotics) to deliver sub-nanoliter volumes at rt and 50% humidity. Concentrations of carbohydrates ranged from 0 -500 µM. The resulting arrays were incubated in a 70% humidity chamber at rt for 12 h and then stored in a low humidity, dust-free dessicator. The pH and reaction time were Non-specific attachment of CS oligosaccharides lacking the aminooxy linker (e.g., compounds 1-4) was not observed. Prior to use, the arrays were outlined with a hydrophobic pen (Super Pap Pen, Research Products International) to create a boundary for the protein treatments and rinsed three times with H 2 O. The slides were then blocked by treatment with NaBH 4 (125 mg) in 140 mM NaCl, 2.7 mM KCl, 5.4 mM Na 2 HPO 4 , and 1.8 mM KH 2 PO 4 (phosphate buffered saline, PBS, 50 mL) at rt for 5 min with gentle rocking and washed five times for 3 min with PBS. For all incubations, the slides were placed in a covered pipette tip box. Human TNF-α (Peprotech), FGF-1 (R&D Systems; both reconstituted to 2 µM in 0.1% Triton X-100 in PBS), cell culture supernatant containing monoclonal anti-CS-A antibody, or cell culture supernatant containing monoclonal anti-CS-E antibody (both 1:1 in 0.1% Triton X-100 in PBS) were spotted onto the slides in 250 µL quantities, and incubated statically at rt for 2 h. The slides were then washed as previously described and incubated with the appropriate primary antibody [anti-TNF-α (Peprotech) or anti-FGF-1 (R&D Systems); 1:1000 in 0.1% Triton X-100 in PBS] for 2 h at rt with gentle rocking. Following the incubation, the slides were washed as previously described and treated in the dark at rt with a seconda...

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Properties of soy protein isolate/poly(ethylene‐co‐ethyl acrylate‐co‐maleic anhydride) blends

Zhong

Sun

2003

J of Applied Polymer Sci

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Blends of soy protein isolate (SPI) with 10, 20, 30, 40, and 50% poly(ethylene-co-ethyl acrylate-co-maleic anhydride) (PEEAMA), with or without addition of 2.0 wt % methylene diphenyl diisocyanate (MDI), were prepared by mixing with an intensive mixer at 150°C for 5 min, and then milling through a 1-mm sieve. Blends were then compression-molded into a tensile bar at 140°C. Thermal and mechanical properties and water absorption of the blends were studied by differential scanning calorimetry (DSC), dynamical mechanic analysis (DMA), a test of modulus and tensile strength (with an Instron tensile tester), a water absorption test, and scanning electron microscopy (SEM). The blends showed two composition-dependent glass transition temperatures. Furthermore, as the SPI content increased, the melting temperature of PEEAMA remained constant but the heat of fusion decreased. These results indicate that SPI and PEEAMA were partially miscible. Morphology observations support these results. Increasing the PEEAMA content resulted in decreases in the modulus and tensile strengths and increases in the elongation and toughness of the blends. Water absorption of the blends also decreased with increased PEEAMA content. Incorporating MDI further decreased the water absorption of the blends. The mechanism of water sorption of SPI was relaxation controlled, and that of the blends was diffusion controlled.

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An essential role for the interferon-inducible, double-stranded RNA-activated protein kinase PKR in the tumor necrosis factor-induced apoptosis in U937 cells.

Cited by 159 publications

References 21 publications

Phosphorylation of Eukaryotic Translation Initiation Factor 2 Mediates Apoptosis in Response to Activation of the Double-stranded RNA-dependent Protein Kinase

Phosphorylation of Eukaryotic Translation Initiation Factor 2 Mediates Apoptosis in Response to Activation of the Double-stranded RNA-dependent Protein Kinase

Discovery of a TNF-α Antagonist Using Chondroitin Sulfate Microarrays

Properties of soy protein isolate/poly(ethylene‐co‐ethyl acrylate‐co‐maleic anhydride) blends

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