1993 — 2001 |
Ron, David |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Adipocyte Growth and Pathogenesis of Liposarcoma @ New York University School of Medicine
DESCRIPTION: This project explores the molecular mechanisms involved in cellular transformation by the chimeric transcriptional regulatory protein TLS-CHOP that is encoded by the t(12:16) chromosomal rearrangement common to most myxoid and round cell liposarcomas. It is hypothesized that transformation in liposarcoma proceeds by two parallel pathways: (1) The CHOP component of the oncoprotein directs it to one set of target genes, and the TLS component deregulates their expression; (2) TLS-CHOP impinges on the normal function of the RNA-binding protein TLS, interfering with the proper expression of another set of target genes. The second component is predicted to be common to sarcomas that contain a TLS (or EWS) component in their causative oncoprotein. Members of both sets of target genes are hypothesized to function as effectors of the process of transformation. The goals of this project are, thus, to identify TLS-CHOP target genes, delineate the mechanism of their deregulation in liposarcoma, and determine their role in transformation. This will involve identifying genes contacted by TLS-CHOP and genes that are normally regulated by TLS, as well as identifying proteins that participate as partners in the process by which TLS-CHOP carried out its function. The latter include the direct cellular contingents of TLS and CHOP, as well as the products of genes that modify transformation indirectly. The identification of TLS-CHOP and TLS target genes will rely on the comparative analysis of the expression pattern of genes in cells that do and do not contain active forms of these regulators. The direct contingents of TLS and CHOP will be identified by biochemical and genetic means, whereas the identification of genes that modify the process of transformation by TLS-CHOP will be attained by a genetic screen of tumors derived in genetically-modified mice that will be developed as animal models for tumorigenesis by the oncoprotein.
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0.954 |
1993 — 1997 |
Ron, David |
R29Activity Code Description: Undocumented code - click on the grant title for more information. |
Metabolic Regulation in the Acute-Phase Response
The rat angiotensinogen gene will be used to study the mechanisms by which changes in gene expression in liver and adipose tissue are induced during the acute-phase. Tumor necrosis factor and interleukin-1 are elevated during the acute-phase, these inflammatory cytokines activate rat angiotensinogen gene transcription through a previously identified cis-acting promoter element that binds a family of CCAAT/Enhancer Binding Protein (C/EBP)-like proteins. The composition of this family of proteins is altered during the acute-phase, suggesting a role for C/EBP- like proteins in mediating effects of cytokines on gene expression. The levels of one member, LAP, increase whereas C/EBP and a newly identified inhibitor, CHOP-10, fall. Experiments to characterize the mechanisms and consequences of cytokine-induced changes in C/EBP-family members are proposed. Because C/EBP-binding sites are important to the expression of genes that play a role in metabolic regulation, these studies will advance our understanding of the molecular pathogenesis of some of the symptoms associated with the acute-phase (such as weight loss) and provide insights into interactions between the immune system and the renin-angiotensin system. Members of the family of C/EBP-like proteins readily dimerize through a leucine zipper domain. Novel probes, consisting of the dimerization domain of LAP and C/EBP fused to a high affinity protein kinase-A phosphorylation site, will be labeled in vitro and used to detect acute- phase induced changes in C/EBP-like proteins immobilized on nitrocellulose blots. Bacterially expressed C/EBP and LAP coupled to a solid support will be used as an affinity matrix for microscale purification of dimerizing proteins from nuclear extracts. These experiments will identify proteins that are candidates for playing a role in regulating gene transcription during the acute-phase. The probe will be used to isolate cDNA clones encoding new C/EBP-like proteins of relevance to the acute-phase. The newly identified proteins will be analyzed for their ability to alter the behavior of the C/EBP-like complex in vitro and in transfected cells, in vivo. Characterization of the proteins will be guided by several hypotheses: a) Some dimerization partners will exhibit specificity for C/EBP and LAP. b) Dimerization can be altered by hormonally-induced post-translational modification (predominantly changes in phosphorylation state). c) Dimerization can affect the DNA binding properties of the heteromeric complex, its transactivation potency, as well as the stability and intracellular localization of the dimerizing partners. It is predicted that these mechanisms are utilized for transduction of hormonal signals into changes in gene expression. The biochemical models will be complemented by the studies on albino-lethal mice (an animal model for tyrosinemia type I) which overexpress CHOP-10 and exhibit severe defects in activating genes important in intermediary metabolism.
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0.954 |
1996 — 2000 |
Ron, David |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Cellular Response to Nonmutagenic Carcinogens @ New York University School of Medicine |
0.948 |
1999 — 2009 |
Ron, David |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. R37Activity Code Description: To provide long-term grant support to investigators whose research competence and productivity are distinctly superior and who are highly likely to continue to perform in an outstanding manner. Investigators may not apply for a MERIT award. Program staff and/or members of the cognizant National Advisory Council/Board will identify candidates for the MERIT award during the course of review of competing research grant applications prepared and submitted in accordance with regular PHS requirements. |
Metabolic Regulation in the Acute Phase @ New York University School of Medicine
Nutritional deprivation of cells plays an important role in human diseases ranging from stroke and ischemic heart disease to the cachexia of cancer and chronic infection. In addition to their ability to react to lack of specific nutrients, cells have evolved more general stress-response pathways that are activated by many forms of cellular malnutrition and other metabolic perturbations. The gene encoding the transcription factor CHOP/GADD153 is induced by a pathway that is activated when cells are deprived of oxygen, energy sources or essential amino-acids. Chop gene knock-out in mice and other experiments indicate that this pathway regulates adaptation to malnutrition in terms of changes in cell growth, differentiation and programmed cell death. Therefore, there is reason to believe that manipulating this response may impact on a broad range of medical conditions associated with cellular malnutrition. The goal of this study is to identify components of the signaling pathways that regulate Chop expression in starved cells and, utilizing genetic tools, to define their role in effecting cellular adaptation to this stressful state. Previous experiments implicate a stress-signal emanating from the endoplasmic reticulum (ER) in Chop induction in response to nutritional and metabolic stress. We have cloned two novel murine genes that are candidates for playing a role in regulating responses to ER stress in mammalian cells. The first, Ire1, encodes a murine homologue of the yeast protein Ire1p, implicated in activating gene expression in response to ER stress in that organism. The second, Perk, plays a role in attenuating translation in response to the accumulation of unfolded proteins in the ER and as such would be expected to play a role in reducing stress in that compartment. We will examine the hypothesis that Ire1 positively regulates Chop expression whereas Perk, by attenuating ER stress, negatively regulates it. We will examine the consequences of interfering with signaling by these two proteins in the context of mouse models of human diseases associated with ER stress. These will include a stroke model, models for renal acute tubular necrosis and mouse models for Pelizaeus-Merzbacher Leukodystrophy. A screen for other genes regulating Chop's response to malnutrition will also be carried out and these new components of the pathway will be examined functionally in cellular assays. If successful, these studies will shed light on basic biological principles that regulate the function of the secretory pathway in mammalian cells and on a poorly understood but broadly-utilized stress-response that is activated in many disease states. The anchoring of these studies in animal-based disease models will hopefully provide clues as to the likely outcome of interfering with the function of specific components of the pathway. This information will be invaluable for rational selection of targets for therapeutic interventions that rely on manipulating the cellular response to ER stress.
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0.948 |
2001 — 2005 |
Ron, David |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
The Cellular Response to Non-Mutagenic Carcinogens @ New York University School of Medicine
DESCRIPTION: (Adapted from the Applicant's Abstract): Chronic low level exposure to environmental toxins impacts on human health by promoting the development of what might otherwise be regarded as normal aging related diseases. Abnormally folded proteins, endogenous proteotoxins, have recently been shown to contribute significantly to degenerative diseases affecting the central and peripheral nervous system, liver, endocrine glands and other organs. Environmental toxins have the potential to modify protein structure directly or indirectly and therefore proteotoxicity is hypothesized to contribute to pathogenesis of many environmentally induced disorders such as Parkinson's disease, Motor Neuron Disease and Cancer. The goal of this program is to define the manner by which environmentally induced changes in protein structure are recognized, to understand how such stress signals are transduced to specific responses and to place these responses in the context of cellular physiology. These studies will impact on environmental health in two ways: First, revealing the details of the cellular adaptation to environmentally-induced proteotoxicity will identify aspects of the response that may be modified to therapeutic ends. Second, by reducing environmentally induced proteotoxicity to its essential molecular components (in much the same way as certain classes of mutagens have been reduced to defined interactions with DNA and chromatin), these studies will provide precise tools for identifying new environmental hazards. Experimentally, the focus will be on stress responses to arsenite, a prototypical toxin thought to exert many of its effects by modifying protein structure. The signaling pathways that link arsenite exposure to the early event of eIF2a phosphorylation will be defined and, utilizing the power of targeted mutagenesis in the mouse, the consequences of interfering with this pathway will be defined functionally. Phosphorylation of eIF2a is an upstream signal that controls stress-induced gene expression. The complement of genes controlled by this pathway will be revealed, using a combination of bioinformatics and functional genomics. The last aim is to use the power of genetic screens to define early events in a signaling pathway that specifically responds to arsenite and activates a novel arsenite-induced gene, Airap/aip- 1. Identification of these early steps will likely provide molecular clues as to the nature of the proximal macromolecular targets of environmental proteotoxicity.
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0.948 |
2002 — 2004 |
Ron, David |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Endoplasmic Reticulum Stress and Parkinson's Disease @ New York University School of Medicine
DESCRIPTION (provided by applicant) Recent observations suggest that abnormal conformations of proteins that are normal constituents of the dopaminergic neuron participate in death of this cell type in Parkinson Disease (PD). Some rare forms of PD can be linked to mutations that cause such proteotoxicity, either directly by affecting the primary structure of the protein converting it to a proteotoxin (e.g. a-SYN mutations) or indirectly, by affecting cellular processes that impact on the accumulation of proteotoxins (e.g. PARK2 mutations). However, such mutations are found in only a small fraction of PD patients, raising the question of how proteotoxicity is triggered in other cases. Recent experiments from our lab indicate that 6-hydroxydopamine and Rotenone, toxins implicated in experimental and environmental PD, cause an imbalance between the folding capacity of the endoplasmic reticulum (ER) and the load of client proteins placed on that organelle (so called ER stress). Uncompensated ER stress can promote proteotoxicity by competing for limited capacity of the ubiquitin proteasomal system and by producing ROS that can alter protein structure. Neurons are naturally prone to ER stress because of their extensive secretory activity and because of their highly elaborate membrane enclosed processes, which must be maintained by high rates of ER trafficking of client proteins. ER stress is normally counteracted by the unfolded protein response (UPR), an adaptive cellular signaling pathway that is activated specifically by ER stress. Impaired UPR signaling sensitizes cells specifically to the effect of ER stress. Therefore, we propose to test the role of ER stress in the development of PD by examining the effect of mutations that impair signaling in the UPR on an established model of experimental PD and on a component of genetic PD. We will determine if in mice lacking the key UPR gene, PERK dopaminergic neurons are hypersensitive to 6-hydroxydopamine. We will seek to identify the defect in ER function imparted by 6-hydroxydopamine and relate it, if possible, to the known ability of the toxin to inhibit mitochondrial complex-1. Finally, we will critically examine PARK2's role in ER-associated degradation of proteins. If the proposed experiments support a role for ER stress in the development of PD, this will effect a paradigmatic shift in our thinking about the pathogenesis of this common disorder.
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0.948 |
2006 |
Ron, David |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Drug-Like Small Molecule Modulators of Integrated Stress @ New York University School of Medicine
[unreadable] DESCRIPTION (provided by applicant): Protein misfolding in the early secretory pathway exerts it pathological affects by two distinct mechanisms: Retention and degradation of misfolded mutant proteins by the endoplasmic reticulum's (ER) quality control machinery leads to loss-of-function phenotypes (exemplified by lysosomal storage diseases). Production and accumulation of the misfolded protein threatens the integrity of the organelle by causing ER stress, leading to cell dysfunction and death, which is believed to contribute to neurodegenerative disorders, diabetes mellitus and other diseases of aging. The protein folding environment in the ER is controlled by a small number of signal transduction pathways and these respond to ER stress in a stereotyped fashion, mediating the unfolded protein response (UPR). Recent evidence suggests that the level of signaling in the UPR is defined by global parameters and by the averaged needs of the ER's diverse protein clientele. It is unlikely therefore that the UPR is finely tuned to the specific exigencies of any one mutation-causing disease. Evidence for this has recently presented itself as circumstances in which knockout of normal genes that function in the UPR improved survival under conditions of ER stress. Such examples of failure of homeostasis indicate that the UPR can be manipulated therapeutically in pathophysiological conditions. Regulated phosphorylation and dephosphorylation of translation initiation factor 2a (elF2a) is a well understood and potentially malleable arm of the UPR, referred to as the integrated stress response (ISR). We propose to identify drug like small molecules that will enhance and others that will reduce the ISR's activity. Transient inhibition of the ISR might overwhelm the quality control mechanism of the ER and promote trafficking of enzymatically active mutant proteins to their functional compartment, alleviating the associated loss of function phenotypes. ISR inactivation might also prove beneficial in the cell culture based production of biotherapeutics used to treat diseases caused by misfolding by enzyme replacement therapy. Activators of the ISR are likely to protect cells and organs against the lethal consequences of ER stress and may prove useful in treating diseases of aging. To accomplish these goals we will develop high throughput screens (HTS) for compounds that inhibit the ER stress inducible elF2a kinase PERK and secondary screens to evaluate the potency, specificity, bioavailability and off-target effects of the compounds. In a parallel strand we will develop HTS assays for inhibitors of elF2a dephosphorylation and others for activators of elF2a kinases, which function by non-canonical mechanisms and activate the ISR without causing stress. The long-term goal of this proposal is therefore to create a pharmacological platform for manipulating the cellular response to misfolded proteins. Given the pervasive role of protein misfolding in human diseases, such agents are likely to become part of the therapeutic armamentarium of future physicians. [unreadable] [unreadable] [unreadable]
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0.948 |
2006 |
Ron, David |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Environmentally-Induced Protein Malfoding @ New York University School of Medicine
[unreadable] DESCRIPTION (provided by applicant): Protein malfolding plays an important role neurodegenerative conditions, such as Parkinson's Disease, Alzheimer's Disease and Motor Neuron Disease. Accumulating evidence suggests that environmental agents may contribute to the pathophysiology of these common disorders by perturbing protein folding, either directly or indirectly through their effects on cell metabolism. However, little is known about how cells adapt to the threat of environmentally-induced proteotoxicity. This study will exploit arsenic as a model for an environmental toxin that adversely affects protein folding and one that represents an important public health hazard affecting multiple organ systems. Two recently-identified adaptations to arsenic exposure will serve as this study's point of departure: (1) Regulated attenuation of new protein synthesis. (2) Modification of the cell's protein degradation apparatus to better accommodate it to arsenic-induced proteotoxicity. Stress-induced phosphorylation of translation initiation factor 2a (elF2a) attenuates protein synthesis and activates a salubrious gene expression program known as the Integrated Stress Response (ISR), which reduces the stress caused by arsenic-induced protein malfolding. Therefore, elF2a phosphorylation has emerged as an important component of cellular unfolded protein responses (UPR). Phosphatases that dephosphorylate elF2a will be characterized in an effort to identify specific biochemical steps whose inhibition activates the ISR. The physiological significance of inhibiting elF2a phosphatases will be tested in mouse models of neurodegenerative diseases. These studies will uncover the promise and potential limitations of therapeutic strategies to protect against proteotoxicity by inhibiting elF2a phosphatases. AIRAP, a novel arsenite induced protein, adapts the proteasome's regulatory cap to the conditions in cells experiencing arsenite-induced proteotoxicity and thereby promotes the cell's ability to deal with malfolded proteins. In an effort to understand how the intracellular protein degradation machinery adapts to proteotoxicity, arsenite-induced and AIRAP-dependent changes in the composition of the proteasome will be characterized by proteomic approaches. Gene knock out experiments in mouse and worms will be used to create experimental systems lacking AIRAP, and these will be applied as tools to identify arsenite-modified proteins whose degradation depends on AIRAP induction and AIRAP integration into the 19S proteasome regulatory particle. In vitro biochemical assays of purified proteasomes containing AIRAP will be used to characterize functionally proteasomal adaptation to environmentally-induced protein malfolding. The goal of this research program is to reduce the cellular adaptations to protein malfolding induced by environmental toxins to their molecular constituents. This will lay the groundwork for identifying relevant bio- markers of exposure and for future preventive and therapeutic interventions against neurodegeneration. [unreadable] [unreadable] [unreadable]
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0.948 |
2007 — 2010 |
Ron, David |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Drug-Like Small Molecule Modulators of the Integrated Stress Response @ New York University School of Medicine
DESCRIPTION (provided by applicant): Protein misfolding in the early secretory pathway exerts it pathological affects by two distinct mechanisms: Retention and degradation of misfolded mutant proteins by the endoplasmic reticulum's (ER) quality control machinery leads to loss-of-function phenotypes (exemplified by lysosomal storage diseases). Production and accumulation of the misfolded protein threatens the integrity of the organelle by causing ER stress, leading to cell dysfunction and death, which is believed to contribute to neurodegenerative disorders, diabetes mellitus and other diseases of aging. The protein folding environment in the ER is controlled by a small number of signal transduction pathways and these respond to ER stress in a stereotyped fashion, mediating the unfolded protein response (UPR). Recent evidence suggests that the level of signaling in the UPR is defined by global parameters and by the averaged needs of the ER's diverse protein clientele. It is unlikely therefore that the UPR is finely tuned to the specific exigencies of any one mutation-causing disease. Evidence for this has recently presented itself as circumstances in which knockout of normal genes that function in the UPR improved survival under conditions of ER stress. Such examples of failure of homeostasis indicate that the UPR can be manipulated therapeutically in pathophysiological conditions. Regulated phosphorylation and dephosphorylation of translation initiation factor 2a (elF2a) is a well understood and potentially malleable arm of the UPR, referred to as the integrated stress response (ISR). We propose to identify drug like small molecules that will enhance and others that will reduce the ISR's activity. Transient inhibition of the ISR might overwhelm the quality control mechanism of the ER and promote trafficking of enzymatically active mutant proteins to their functional compartment, alleviating the associated loss of function phenotypes. ISR inactivation might also prove beneficial in the cell culture based production of biotherapeutics used to treat diseases caused by misfolding by enzyme replacement therapy. Activators of the ISR are likely to protect cells and organs against the lethal consequences of ER stress and may prove useful in treating diseases of aging. To accomplish these goals we will develop high throughput screens (HTS) for compounds that inhibit the ER stress inducible elF2a kinase PERK and secondary screens to evaluate the potency, specificity, bioavailability and off-target effects of the compounds. In a parallel strand we will develop HTS assays for inhibitors of elF2a dephosphorylation and others for activators of elF2a kinases, which function by non-canonical mechanisms and activate the ISR without causing stress. The long-term goal of this proposal is therefore to create a pharmacological platform for manipulating the cellular response to misfolded proteins. Given the pervasive role of protein misfolding in human diseases, such agents are likely to become part of the therapeutic armamentarium of future physicians.
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0.948 |
2007 — 2009 |
Ron, David |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Pathophysiology of Environmentally-Induced Protein Malfolding @ New York University School of Medicine
[unreadable] DESCRIPTION (provided by applicant): Protein malfolding plays an important role neurodegenerative conditions, such as Parkinson's Disease, Alzheimer's Disease and Motor Neuron Disease. Accumulating evidence suggests that environmental agents may contribute to the pathophysiology of these common disorders by perturbing protein folding, either directly or indirectly through their effects on cell metabolism. However, little is known about how cells adapt to the threat of environmentally-induced proteotoxicity. This study will exploit arsenic as a model for an environmental toxin that adversely affects protein folding and one that represents an important public health hazard affecting multiple organ systems. Two recently-identified adaptations to arsenic exposure will serve as this study's point of departure: (1) Regulated attenuation of new protein synthesis. (2) Modification of the cell's protein degradation apparatus to better accommodate it to arsenic-induced proteotoxicity. Stress-induced phosphorylation of translation initiation factor 2a (elF2a) attenuates protein synthesis and activates a salubrious gene expression program known as the Integrated Stress Response (ISR), which reduces the stress caused by arsenic-induced protein malfolding. Therefore, elF2a phosphorylation has emerged as an important component of cellular unfolded protein responses (UPR). Phosphatases that dephosphorylate elF2a will be characterized in an effort to identify specific biochemical steps whose inhibition activates the ISR. The physiological significance of inhibiting elF2a phosphatases will be tested in mouse models of neurodegenerative diseases. These studies will uncover the promise and potential limitations of therapeutic strategies to protect against proteotoxicity by inhibiting elF2a phosphatases. AIRAP, a novel arsenite induced protein, adapts the proteasome's regulatory cap to the conditions in cells experiencing arsenite-induced proteotoxicity and thereby promotes the cell's ability to deal with malfolded proteins. In an effort to understand how the intracellular protein degradation machinery adapts to proteotoxicity, arsenite-induced and AIRAP-dependent changes in the composition of the proteasome will be characterized by proteomic approaches. Gene knock out experiments in mouse and worms will be used to create experimental systems lacking AIRAP, and these will be applied as tools to identify arsenite-modified proteins whose degradation depends on AIRAP induction and AIRAP integration into the 19S proteasome regulatory particle. In vitro biochemical assays of purified proteasomes containing AIRAP will be used to characterize functionally proteasomal adaptation to environmentally-induced protein malfolding. The goal of this research program is to reduce the cellular adaptations to protein malfolding induced by environmental toxins to their molecular constituents. This will lay the groundwork for identifying relevant bio- markers of exposure and for future preventive and therapeutic interventions against neurodegeneration. [unreadable] [unreadable] [unreadable]
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0.948 |
2007 |
Ron, David |
R03Activity Code Description: To provide research support specifically limited in time and amount for studies in categorical program areas. Small grants provide flexibility for initiating studies which are generally for preliminary short-term projects and are non-renewable. |
Screening For Inhibitors of the Integrated Stress Response @ New York University School of Medicine
[unreadable] DESCRIPTION (provided by applicant): A large number of biologically important proteins, such as hormones, enzymes and cell surface receptors undergo early steps of their biogenesis in the endoplasmic reticulum (ER). Defects and variations in efficiency of this process are believed to contribute to important human diseases. For example, misfolding and degradation accounts for lack of enzymes in lysosomal storage diseases or membrane transporters in certain kidney diseases. The protein folding environment in the ER is regulated by signal transduction pathways that together constitute the ER unfolded protein response (UPR), which responds to misfolded protein stress in the organelle. Relatively crude genetic manipulation of these pathways has shown that modulating the protein folding environment in the ER can have important pathophysiological consequences: For example, evidence suggests that loosening the quality control in the ER might allow mildly misfolded proteins that are otherwise functional to escape ER retention and degradation and contribute to essential cellular functions and thereby ameliorate severe phenotypes of loss-of-function mutations. Other studies show that cancer cells from human tumors are particularly reliant on their UPR for survival, suggesting that UPR inhibitors may have selective toxicity against cancer. Therefore, availability of pharmacological probes to modulate signaling in the UPR will provide much needed tools to test the suitability of the pathway as a target for therapeutic intervention in diseases of protein misfolding and cancer. Phosphorylation of translation initiation factor 2a (eIF2a) by the ER stress activated protein kinase PERK is a well understood and potentially malleable arm of the UPR that is referred to as the integrated stress response (ISR). Robust cell-based assays for activity of the ISR have been developed. These entail measurements of the magnitude of translation repression attendant upon PERK activation and eIF2a phosphorylation and a complementary assay that reports on the activity of the gene expression program that is initiated by eIF2a phosphorylation. The assays in question have been miniaturized and converted to a homogenous format suitable for high throughput screens (HTS) for small molecules ("probes") that when added to cells, would either block PERK activity, impair the downstream steps required for eIF2a phosphorylation or the conversion eIF2a phosphorylation signal to the activation of gene expression. Tertiary assays have been developed to pinpoint the site of action of any inhibitory molecules discovered by the HTS. An HTS campaign using these assays is expected to yield potent cell penetrant small molecules that inhibit the ISR at various points in vivo. Unlike the genetic approaches, which tend to produce relatively discontinuous dose responses, small molecule inhibitors are predicted to have continuous dose-response relationships with lengthy monotonic phases. These feature will be exploited by the research community to test the hypothesis that gentle and partial inhibition of the ISR might promote the secretion of otherwise misfolded proteins and selectively compromise the viability of tumor models. Our understanding of the processes by which proteins attain their proper structure has increased markedly in recent years and with that understanding come the prospects of intervening in the process of protein folding to therapeutic ends. This study focuses on one pathway by which cells regulate their capacity to fold proteins in the secretory compartment and is designed to identify drug-like compounds that modulate signaling in that pathway by inhibiting one of its key components, an enzyme called PERK. If successful, this study will tell us whether or not PERK inhibitors have potential utility in treating diseases of protein misfolding, such as lysosomal storage diseases and various cancers. [unreadable] [unreadable] [unreadable] [unreadable] [unreadable]
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0.948 |