scholarly journals RNA-binding proteins and heat-shock protein 90 are constituents of the cytoplasmic capping enzyme interactome

2018 ◽  
Vol 293 (43) ◽  
pp. 16596-16607 ◽  
Author(s):  
Jackson B. Trotman ◽  
Bernice A. Agana ◽  
Andrew J. Giltmier ◽  
Vicki H. Wysocki ◽  
Daniel R. Schoenberg
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Mammalian Cells ◽  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Capping Enzyme ◽  
Eukaryotic Mrnas

The N7-methylguanosine cap is added in the nucleus early in gene transcription and is a defining feature of eukaryotic mRNAs. Mammalian cells also possess cytoplasmic machinery for restoring the cap at uncapped or partially degraded RNA 5′ ends. Central to both pathways is capping enzyme (CE) (RNA guanylyltransferase and 5′-phosphatase (RNGTT)), a bifunctional, nuclear and cytoplasmic enzyme. CE is recruited to the cytoplasmic capping complex by binding of a C-terminal proline-rich sequence to the third Src homology 3 (SH3) domain of NCK adapter protein 1 (NCK1). To gain broader insight into the cellular context of cytoplasmic recapping, here we identified the protein interactome of cytoplasmic CE in human U2OS cells through two complementary approaches: chemical cross-linking and recovery with cytoplasmic CE and protein screening with proximity-dependent biotin identification (BioID). This strategy unexpectedly identified 66 proteins, 52 of which are RNA-binding proteins. We found that CE interacts with several of these proteins independently of RNA, mediated by sequences within its N-terminal triphosphatase domain, and we present a model describing how CE-binding proteins may function in defining recapping targets. This analysis also revealed that CE is a client protein of heat shock protein 90 (HSP90). Nuclear and cytoplasmic CEs were exquisitely sensitive to inhibition of HSP90, with both forms declining significantly following treatment with each of several HSP90 inhibitors. Importantly, steady-state levels of capped mRNAs decreased in cells treated with the HSP90 inhibitor geldanamycin, raising the possibility that the cytotoxic effect of these drugs may partially be due to a general reduction in translatable mRNAs.

scholarly journals Synergism of Heat Shock Protein 90 and Histone Deacetylase Inhibitors in Synovial Sarcoma

Sarcoma ◽  
2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Anne Nguyen ◽  
Le Su ◽  
Belinda Campbell ◽  
Neal M. Poulin ◽  
Torsten O. Nielsen
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Synovial Sarcoma ◽  
Histone Deacetylase ◽  
Histone Deacetylase Inhibitors ◽  
Hdac Inhibitors ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Therapeutic Benefit ◽  
Multiple Time

Current systemic therapies have little curative benefit for synovial sarcoma. Histone deacetylase (HDAC) inhibitors and the heat shock protein 90 (Hsp90) inhibitor 17-AAG have recently been shown to inhibit synovial sarcoma in preclinical models. We tested combinations of 17-AAG with the HDAC inhibitor MS-275 for synergism by proliferation and apoptosis assays. The combination was found to be synergistic at multiple time points in two synovial sarcoma cell lines. Previous studies have shown that HDAC inhibitors not only induce cell death but also activate the survival pathway NF-κB, potentially limiting therapeutic benefit. As 17-AAG inhibits activators of NF-κB, we tested if 17-AAG synergizes with MS-275 through abrogating NF-κB activation. In our assays, adding 17-AAG blocks NF-κB activation by MS-275 and siRNA directed against histone deacetylase 3 (HDAC3) recapitulates the effects of MS-275. Additionally, we find that the NF-κB inhibitor BAY 11-7085 synergizes with MS-275. We conclude that agents inhibiting NF-κB synergize with HDAC inhibitors against synovial sarcoma.

Heat shock protein 90 inhibitors attenuate LPS-induced endothelial hyperpermeability

2008 ◽  
Vol 294 (4) ◽  
pp. L755-L763 ◽  
Author(s):  
Anuran Chatterjee ◽  
Connie Snead ◽  
Gunay Yetik-Anacak ◽  
Galina Antonova ◽  
Jingmin Zeng ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Heat Shock ◽  
Lung Injury ◽  
Heat Shock Protein ◽  
Adherens Junction ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Barrier Dysfunction ◽  
Focal Adhesion Protein ◽  
Endothelial Hyperpermeability

Endothelial hyperperme ability leading to vascular leak is an important consequence of sepsis and sepsis-induced lung injury. We previously reported that heat shock protein (hsp) 90 inhibitor pretreatment improved pulmonary barrier dysfunction in a murine model of sepsis-induced lung injury. We now examine the effects of hsp90 inhibitors on LPS-mediated endothelial hyperpermeability, as reflected in changes in transendothelial electrical resistance (TER) of bovine pulmonary arterial endothelial cells (BPAEC). Vehicle-pretreated cells exposed to endotoxin exhibited a concentration-dependent decrease in TER, activation of pp60Src, phosphorylation of the focal adhesion protein paxillin, and reduced expression of the adherens junction proteins, vascular endothelial (VE)-cadherin and β-catenin. Pretreatment with the hsp90 inhibitor, radicicol, prevented the decrease in TER, maintained VE-cadherin and β-catenin expression, and inhibited activation of pp60Src and phosphorylation of paxillin. Similarly, when BPAEC hyperpermeability was induced by endotoxin-activated neutrophils, pretreatment of neutrophils and/or endothelial cells with radicicol protected against the activated neutrophil-induced decrease in TER. Increased paxillin phosphorylation and decreased expression of β-catenin and VE-cadherin were also observed in mouse lungs 12 h after intraperitoneal endotoxin and attenuated in mice pretreated with radicicol. These results suggest that hsp90 plays an important role in sepsis-associated endothelial barrier dysfunction.

scholarly journals Inhibition of heat shock protein 90 prolongs survival of mice with BCR-ABL-T315I–induced leukemia and suppresses leukemic stem cells

Blood ◽  
2007 ◽  
Vol 110 (2) ◽  
pp. 678-685 ◽  
Author(s):  
Cong Peng ◽  
Julia Brain ◽  
Yiguo Hu ◽  
Ami Goodrich ◽  
Linghong Kong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Kinase Inhibitors ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Myelogenous Leukemia ◽  
Leukemia Stem Cells

Abstract Development of kinase domain mutations is a major drug-resistance mechanism for tyrosine kinase inhibitors (TKIs) in cancer therapy. A particularly challenging example is found in Philadelphia chromosome–positive chronic myelogenous leukemia (CML) where all available kinase inhibitors in clinic are ineffective against the BCR-ABL mutant, T315I. As an alternative approach to kinase inhibition, an orally administered heat shock protein 90 (Hsp90) inhibitor, IPI-504, was evaluated in a murine model of CML. Treatment with IPI-504 resulted in BCR-ABL protein degradation, decreased numbers of leukemia stem cells, and prolonged survival of leukemic mice bearing the T315I mutation. Hsp90 inhibition more potently suppressed T315I-expressing leukemia clones relative to the wild-type (WT) clones in mice. Combination treatment with IPI-504 and imatinib was more effective than either treatment alone in prolonging survival of mice simultaneously bearing both WT and T315I leukemic cells. These results provide a rationale for use of an Hsp90 inhibitor as a first-line treatment in CML by inhibiting leukemia stem cells and preventing the emergence of imatinib-resistant clones in patients. Rather than inhibiting kinase activity, elimination of mutant kinases provides a new therapeutic strategy for treating BCR-ABL–induced leukemia as well as other cancers resistant to treatment with tyrosine kinase inhibitors.

Induction of the heat shock response in Arabidopsis by heat shock protein 70 inhibitor VER-155008

2019 ◽  
Vol 46 (10) ◽  
pp. 925
Author(s):  
Erina Matsuoka ◽  
Naoki Kato ◽  
Masakazu Hara
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Heat Shock Response ◽  
Wheat Germ ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Wheat Germ Extract ◽  
Chlorophyll Contents ◽  
Shock Response ◽  
Human Hsp70

The heat shock protein 90 (HSP90) inhibitor, geldanamycin, is a chemical inducer of the heat shock response (HSR) in Arabidopsis. Geldanamycin is thought to activate the heat shock signal by dissociating the HSP90-heat shock factor (HSF) complex. Recent studies have indicated that plant HSP70 is also associated with HSF, suggesting that inhibition of HSP70 may induce the HSR. However, no studies have been conducted to test this hypothesis. Here, we found that a specific HSP70 inhibitor VER-155008 activated the promoter of a small HSP gene (At1 g53540, HSP17.6C-CI) of Arabidopsis, which was shown to be activated by geldanamycin and other HSP90 inhibitors. The production of HSP17.6C-CI, HSP70 and HSP90.1 proteins in Arabidopsis was enhanced by the addition of VER-155008. The reduction of chlorophyll contents by heat shock was ameliorated by VER-155008. Chaperone analyses indicated that VER-155008 inhibited the chaperone activities of wheat germ extract and human HSP70/HSP40, respectively. These results suggest that the inhibition of HSP70 by VER-155008 enhanced the heat tolerance of Arabidopsis by inducing the HSR in the plant.

scholarly journals Potential role of heat shock protein 90 in regulation of hyperthermia-driven differentiation of neural stem cells

2019 ◽  
Author(s):  
Lei Wang ◽  
Yi Zhuo ◽  
Zhengwen He ◽  
Ying Xia ◽  
Ming Lu
Keyword(s):  
Stem Cells ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Neural Stem Cells ◽  
Time Window ◽  
Heat Shock Protein 90 ◽  
Hsp90 Inhibitor ◽  
Control Group ◽  
Transcriptional Level ◽  
Hyperthermic Treatment

AbstractObjectiveOur previous studies indicated that hyperthermia may play a role in differentiation of neural stem cells and that hypoxia inducible factor-1(HIF-1) was critical in this process. Heat shock protein 90 (Hsp90) is one of the most common heat-related proteins and involved in HIF-1 expression by regulating its activity and stabilization. Here, we hypothesized that HSP90 may be involved in regulation of hyperthermia-driven differentiation of neural stem cells(NSCs). We also investigated whether the HSP90 activity exert its regulatory action via HIF-1 pathway and the transcriptional level of the target genes of HIF-1.MethodThe cultured NSCs were divided into three groups: an hyperthermic treatment group(40NSC) which NSCs was induced under 40°C temperature; a control group(37NSC) which NSCs was induced under 37°C temperature; an hyperthermic treatment and HSP90-inhibited group(40NSC+GA) which NSCs was induced with 0.5μM HSP90 inhibitor Geldanamycin(GA) under 40°C temperature. We examined cells HSPa and HIF-1a expression during a time window of 5 days(12h, 1d, 3d, 5d) post-differentiation. The expression HSPα, HIF-1α, VEGF (vascular endothelial growth factor) and erythmpoietin(EPO) of during a time window was evaluated by RT-qPCR. The proportion of Tuj-1 positive differentiated cells were observed by flow cytometry.ResultHyperthermia promoted neuronal differentiation of NSC, and this effect could be blocked by HSP90 inhibitor GA. We observed the up-regulation of HSP90 during hyperthermia treatment, and that the protein levels of HIF-1α changed depending of the GA treatment. GA could not inhibited HSP90α expression but suppressed HSP activity and decreased the expression HIF-1α protein. Inhibition of HIF-1α expression by GA could consequently affect expression of its targeted genes such as VEGF and EPO.ConclusionHyperthermia promote differentiation of NSCs into neurons. HSP90 involved in the regulation of hyperthermia-driven differentiation of NSC, and the mechanism is related to HIF-1α and its downstream gene activation.

Activity of the heat shock protein 90 (HSP90) inhibitor, SNX-2112, in pediatric cancer cell lines.

2010 ◽  
Vol 28 (15_suppl) ◽  
pp. 9565-9565
Author(s):  
D. C. Chinn ◽  
W. S. Holland ◽  
J. M. Yoon ◽  
T. Zwerdling ◽  
P. C. Mack
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Cell Lines ◽  
Cancer Cell ◽  
Pediatric Cancer ◽  
Heat Shock Protein 90 ◽  
Cancer Cell Lines ◽  
Hsp90 Inhibitor

scholarly journals Inhibition of Heat Shock Protein 90 in the Spinal Cord Improves the Therapeutic Index of Morphine

2021 ◽  
Author(s):  
David I Duron ◽  
Katherin A Gabriel ◽  
Jessica L Bowden ◽  
Christopher S Campbell ◽  
Sanket Mishra ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Side Effects ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Dose Reduction ◽  
Heat Shock Protein 90 ◽  
Therapeutic Index ◽  
Hsp90 Inhibitor ◽  
Tail Flick ◽  
Reduction Strategy

Opioid drugs are the gold standard for treating acute and chronic pain, but are limited by negative side effects, including tolerance, constipation, and addiction. New approaches are thus greatly needed to improve opioid therapy and decrease side effects. Our investigations have revealed Heat shock protein 90 (Hsp90) as a critical regulator of opioid receptor signaling, and that inhibition of spinal cord Hsp90 boosts opioid anti-nociception. These findings led us to hypothesize that spinal Hsp90 inhibitor treatment could improve the therapeutic index of opioids, boosting anti-nociception while improving or not altering side effects, enabling a dose-reduction strategy. To test this hypothesis, we injected the Hsp90 inhibitor KU-32 by the intrathecal route into male and female CD-1 mice. We then tested these mice for their response to morphine in a battery of anti-nociception and side effect models. We found that spinal KU-32 treatment increased the anti-nociceptive potency of morphine by 2-4 fold in the tail flick, post-surgical paw incision, and HIV peripheral neuropathy pain models. At the same time, morphine anti-nociceptive tolerance was reduced from 21 fold to 2.9 fold by KU-32 treatment, and established morphine tolerance could be rescued by KU-32 injection. Reward as measured by conditioned place preference and constipation were both unchanged. These results support our hypothesis, and suggest that Hsp90 inhibitors could be a novel approach to improve the therapeutic index of opioids, enable a dose-reduction strategy, and lead to fewer side effects during pain therapy.

Sign in / Sign up

Export Citation Format

Share Document