Control of gasdermin D oligomerization and pyroptosis by the Ragulator-Rag-mTORC1 pathway
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA742124 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR14933920.fastq.gz | Fastqsanger.gz | |||
| SRR14933921.fastq.gz | Fastqsanger.gz |
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Project description:The process of pyroptosis is mediated by inflammasomes and a downstream effector known as gasdermin D (GSDMD). Upon cleavage by inflammasome-associated caspases, the N-terminal domain of GSDMD forms membrane pores that promote cytolysis. Numerous proteins promote GSDMD cleavage, but none are known to be required for pore formation after GSDMD cleavage. Herein, we report a forward genetic screen that identified the Ragulator-Rag complex as being necessary for GSDMD pore formation and pyroptosis in macrophages. Mechanistic analysis revealed that Ragulator-Rag is not required for GSDMD cleavage upon inflammasome activation, but rather promotes GSDMD oligomerization in the plasma membrane. Defects in GSDMD oligomerization and pore formation can be rescued by mitochondrial poisons that stimulate reactive oxygen species (ROS) production, and ROS modulation impacts the ability of inflammasome pathways to promote pore formation downstream of GSDMD cleavage. These findings reveal an unexpected link between key regulators of immunity (inflammasome-GSDMD) and metabolism (Ragulator-Rag).
2021-06-29 | GSE179089 | GEO
Project description:The process of pyroptosis is mediated by inflammasomes and a downstream effector known as gasdermin D (GSDMD). Upon cleavage by inflammasome-associated caspases, the N-terminal domain of GSDMD forms membrane pores that promote cytolysis. Numerous proteins promote GSDMD cleavage, but none are known to be required for pore formation after GSDMD cleavage. Herein, we report a forward genetic screen that identified the Ragulator-Rag complex as being necessary for GSDMD pore formation and pyroptosis in macrophages. Mechanistic analysis revealed that Ragulator-Rag is not required for GSDMD cleavage upon inflammasome activation but rather promotes GSDMD oligomerization in the plasma membrane. Defects in GSDMD oligomerization and pore formation can be rescued by mitochondrial poisons that stimulate reactive oxygen species (ROS) production, and ROS modulation impacts the ability of inflammasome pathways to promote pore formation downstream of GSDMD cleavage. These findings reveal an unexpected link between key regulators of immunity (inflammasome-GSDMD) and metabolism (Ragulator-Rag).
| S-EPMC8380731 | biostudies-literature
Project description:The Rag GTPases recruit the master kinase mTORC1 to lysosomes to regulate cell growth and proliferation in response to amino acid availability. The nucleotide state of Rag heterodimers is critical for their association with mTORC1. Our cryo-EM structure of RagA/RagC in complex with mTORC1 shows the details of RagA/C binding to the RAPTOR subunit of mTORC1 and explains why only the RagAGTP/RagCGDP nucleotide state binds mTORC1. Previous kinetic studies suggested that GTP binding to one Rag locks the heterodimer to prevent GTP binding to the other. Our crystal structures and dynamics show the mechanism for this locking, and explain how oncogenic hotspot mutations disrupt this process. In contrast to allosteric activation by RHEB, Rag heterodimer binding does not change mTORC1 conformation and activates mTORC1 by targeting it to lysosomes.
2019-10-11 | PXD015778 | Pride
Project description:Control of gasdermin D oligomerization and pyroptosis by the Ragulator-Rag-mTORC1 pathway
| PRJNA739880 | ENA
Project description:Gasdermin D (GSDMD) is the executioner of pyroptosis, which is important for host defense against pathogen infection. After activation, caspase-mediated cleavage of GSDMD liberates an N-terminal fragment (GSDMD-NT), which oligomerizes and forms pores in the plasma membrane, leading to cell death and subsequent release of proinflammatory cytokines. How this process is spatiotemporally controlled to promote pyroptosis in cells has been a fundamental, unaddressed question. Here, we identify GSDMD as a substrate for reversible S-palmitoylation on cysteine 192 (Cys192) in response to lipopolysaccharide (LPS) stimulation. We found that the palmitoyl acyltransferase DHHC7palmitoylates GSDMD to direct its cleavage by caspases in pyroptosis by promoting the interaction of GSDMD and caspases. We further show that after GSDMD cleavage, palmitoylation of GSDMD-NTpromotes its plasma membrane translocation and binding, and then acyl protein thioesterase 2 (APT2) depalmitoylates GSDMD-NT to unmask the Cys192 residue to promote oxidation-mediated oligomerization and pyroptosis. Perturbation of either palmitoylation or depalmitoylation suppresses pyroptosis, extends the survival of mice from LPS-induced lethal septic shock and sensitizes mice to bacterial infection. Thus. our findings reveal a model through which a palmitoylation-depalmitoylationrelay spatially and temporally controls GSDMD activation in pyroptosis.
2024-02-25 | GSE252893 | GEO
Project description:Gasdermin D (GSDMD) is the executioner of pyroptosis, which is important for host defense against pathogen infection. After activation, caspase-mediated cleavage of GSDMD liberates an N-terminal fragment (GSDMD-NT), which oligomerizes and forms pores in the plasma membrane, leading to cell death and subsequent release of proinflammatory cytokines. How this process is spatiotemporally controlled to promote pyroptosis in cells has been a fundamental, unaddressed question. Here, we identify GSDMD as a substrate for reversible S-palmitoylation on cysteine 192 (Cys192) in response to lipopolysaccharide (LPS) stimulation. We found that the palmitoyl acyltransferase DHHC7palmitoylates GSDMD to direct its cleavage by caspases in pyroptosis by promoting the interaction of GSDMD and caspases. We further show that after GSDMD cleavage, palmitoylation of GSDMD-NTpromotes its plasma membrane translocation and binding, and then acyl protein thioesterase 2 (APT2) depalmitoylates GSDMD-NT to unmask the Cys192 residue to promote oxidation-mediated oligomerization and pyroptosis. Perturbation of either palmitoylation or depalmitoylation suppresses pyroptosis, extends the survival of mice from LPS-induced lethal septic shock and sensitizes mice to bacterial infection. Thus. our findings reveal a model through which a palmitoylation-depalmitoylationrelay spatially and temporally controls GSDMD activation in pyroptosis.
2024-02-25 | GSE252911 | GEO
Project description:Alcoholic hepatitis (AH) continues to be a disease with high mortality and no efficacious medical treatment. Although severe AH is presented as acute on chronic liver failure, what underlies this transition from chronic alcoholic steatohepatitis (ASH) to AH, is largely unknown. To address this question, unbiased RNA-seq and proteomic analyses were performed on livers of the recently developed AH mouse model which exhibits the shift to AH from chronic ASH upon weekly alcohol binge, and these results are compared with gene expression profiling data from AH patients. This cross-analysis has identified Casp11 (CASP4 in man) as a commonly upregulated gene known to be involved in non-canonical inflammasome pathway. Immunoblotting confirms CASP11/4 activation in AH mice but not in chronic ASH. Gasdermin-D (GSDMD) which induces pyroptosis (lytic cell death caused by bacterial infection) downstream of CASP11/4 activation, is also activated in AH livers. CASP11 deficiency reduces GSDMD activation, bacterial load in the liver, and the severity of AH. Conversely, the deficiency of IL-18, the key anti-microbial cytokine, aggravates hepatic bacterial load, GSDMD activation, and AH. Further, hepatocyte-specific expression of constitutively active GSDMD worsens hepatocellular lytic death and PMN inflammation. These results implicate pyroptosis induced by CASP11/4-GSDMD pathway in the pathogenesis of AH.
2017-03-31 | GSE97234 | GEO
Project description:Immune checkpoint blockade (ICB) therapy has demonstrated promising clinical results in oncology and is currently one of the most sought-after immunotherapies for tumors. However, there are a number of issues with ICB therapy, including low response rates and a lack of effective efficacy predictors. Gasdermin-mediated pyroptosis is a typical form of inflammatory death mode, but it is unclear whether ICB treatment can trigger its occurrence or whether gasdermin expression has any effect on the response rate to ICB treatment. Herein, we discovered that high expression of gasdermin protein was associated with a favorable tumor immune microenvironment and a favorable prognosis in head and neck squamous cell carcinoma (HNSCC), and taking advantage of the mouse HNSCC cell line 4MOSC1 (responsive to CTLA-4 blockade) and 4MOSC2 (resistant to CTLA-4 blockade) orthotopic models, we also demonstrated that CTLA-4 blockade treatment induced gasdermin-mediated pyroptosis of tumor cells and that the expression of gasdermin was positively associated with the effectiveness of CTLA-4 blocking treatment. Mechanistically, through RNA sequencing, flow cytometry, ELISA, Western blotting and RT-PCR, we discovered that CTLA-4 blockade activated CD8+ T cells in the tumor and increased the levels of the cytokines TNF-α and IFN-γ in the tumor microenvironment, and that TNF-α and IFN-γ synergistically activated the STAT1/IRF1 axis, inducing tumor cell pyroptosis and the release of large amounts of inflammatory substances and chemokines such as CXCL10.
2023-04-01 | GSE201367 | GEO
Project description:As a new type of cell death mediated by Gasdermin (GSDM) family, pyroptosis has increasingly become a research hotspot in the fields of biology and medicine. Studies have found that a variety of drugs (such as etoposide and traditional Chinese medicine extracts) can effectively inhibit the occurrence and development of tumors by activating caspase family and GSDM protein family to induce pyroptosis. Promoting pyroptosis has become an effective method for the treatment of tumors, but the research on its regulatory mechanism is still lacking. In order to explore the key molecular pathways of etoposide-induced pyroptosis, transcriptome sequencing analysis was performed
2024-11-20 | GSE266073 | GEO
Project description:The pore-forming protein gasdermin D (GSDMD) executes lytic cell death called pyroptosis to eliminate the replicative niche of intracellular pathogens. Evolution favors pathogens that circumvent this host defense mechanism. Here, we show that the Shigella ubiquitin ligase IpaH7.8 functions as an inhibitor of GSDMD. Shigella is an enteroinvasive bacterium that causes hemorrhagic gastroenteritis in primates, but not rodents. IpaH7.8 contributes to species specificity by ubiquitinating human, but not mouse, GSDMD and targeting it for proteasomal degradation. Accordingly, infection of human epithelial cells with IpaH7.8-deficient Shigella flexneri results in increased GSDMD-dependent cell death compared with wild type. Consistent with pyroptosis contributing to murine disease resistance, eliminating GSDMD from NLRC4-deficient mice, which are already sensitized to oral infection with Shigella flexneri, leads to further enhanced bacterial replication and increased disease severity. This work highlights a species-specific pathogen arms race focused on maintenance of host cell viability.
2022-03-01 | MSV000088966 | MassIVE