N4BP1 negatively regulates NF-κB by binding and inhibiting NEMO oligomerization
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE165916 | GEO | 2021/02/08
REPOSITORIES: GEO
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Project description:Human mutations in the death receptor Fas or its ligand FasL cause autoimmune lymphoproliferative syndrome (ALPS), whereas mutations in caspase-8 or its adaptor FADD â which mediate cell death downstream of Fas/FasL â cause severe immunodeficiency in addition to ALPS. Mouse models have corroborated a role for FADD-caspase-8 in promoting inflammatory responses, but the mechanisms underlying immunodeficiency remain undefined. Here, we identify NEDD4-binding protein 1 (N4BP1) as a suppressor of cytokine production that is cleaved and inactivated by caspase-8. N4BP1 deletion in mice significantly increased production of select cytokines upon Toll-like receptor (TLR) 1/2, TLR7, or TLR9 stimulation, but not upon TLR3 or TLR4 engagement. N4BP1 did not suppress TLR3 or TLR4 responses in wild-type macrophages owing to TRIF- and caspase-8-dependent cleavage of N4BP1. Notably, impaired TLR3 and TLR4 cytokine responses of caspase-8-deficient macrophages were largely rescued by co-deletion of N4BP1. Thus, persistence of intact N4BP1 in caspase-8-deficient macrophages impairs their ability to mount robust cytokine responses. Tumor necrosis factor (TNF), like TLR3 or TLR4 agonists, also induced caspase-8-dependent cleavage of N4BP1, thereby licensing TRIF-independent TLRs to produce higher levels of inflammatory cytokines. Illustrating the importance of this function of TNF in vivo, TNF blockade increased the mortality of mice infected with Streptococcus Pneumoniae, but did not do so when infected mice lacked N4BP1. Collectively, our results identify N4BP1 as a potent suppressor of cytokine responses; reveal N4BP1 cleavage by Caspase-8 as a point of signal integration during inflammation; and offer an explanation for immunodeficiency caused by FADD-caspase-8 mutations.
2020-09-10 | GSE157786 | GEO
Project description:Human mutations in the death receptor Fas or its ligand FasL cause autoimmune lymphoproliferative syndrome (ALPS), whereas mutations in caspase-8 or its adaptor FADD â which mediate cell death downstream of Fas/FasL â cause severe immunodeficiency in addition to ALPS. Mouse models have corroborated a role for FADD-caspase-8 in promoting inflammatory responses, but the mechanisms underlying immunodeficiency remain undefined. Here, we identify NEDD4-binding protein 1 (N4BP1) as a suppressor of cytokine production that is cleaved and inactivated by caspase-8. N4BP1 deletion in mice significantly increased production of select cytokines upon Toll-like receptor (TLR) 1/2, TLR7, or TLR9 stimulation, but not upon TLR3 or TLR4 engagement. N4BP1 did not suppress TLR3 or TLR4 responses in wild-type macrophages owing to TRIF- and caspase-8-dependent cleavage of N4BP1. Notably, impaired TLR3 and TLR4 cytokine responses of caspase-8-deficient macrophages were largely rescued by co-deletion of N4BP1. Thus, persistence of intact N4BP1 in caspase-8-deficient macrophages impairs their ability to mount robust cytokine responses. Tumor necrosis factor (TNF), like TLR3 or TLR4 agonists, also induced caspase-8-dependent cleavage of N4BP1, thereby licensing TRIF-independent TLRs to produce higher levels of inflammatory cytokines. Illustrating the importance of this function of TNF in vivo, TNF blockade increased the mortality of mice infected with Streptococcus Pneumoniae, but did not do so when infected mice lacked N4BP1. Collectively, our results identify N4BP1 as a potent suppressor of cytokine responses; reveal N4BP1 cleavage by Caspase-8 as a point of signal integration during inflammation; and offer an explanation for immunodeficiency caused by FADD-caspase-8 mutations.
2020-09-09 | GSE148066 | GEO
Project description:The cell death protease caspase-8 plays an essential role in controlling inflammation, as severe immunodeficiency results from its loss. We previously found that caspase-8 promotes inflammatory responses by cleaving NEDD4-binding protein 1 (N4BP1), a suppressor of cytokine production, but the underlying mechanisms remained unclear. Here we find that N4BP1 curtails the duration, rather than initial induction, of proinflammatory signaling through a mechanism involving noncanonical IKK (ncIKK)-mediated inhibition of the canonical IkB kinase (IKK) complex, a crosstalk event among the IKK family facilitated by N4BP1. Accordingly, co-deletion of the ncIKKs or their adaptor protein TANK largely phenocopied deletion of N4BP1, augmenting cytokine responses by macrophages upon engagement of TRIF-independent toll-like receptors (TLR) 1/2, TLR7, or TLR9. Like N4BP1, TANK was largely prevented from inhibiting the TRIF-dependent TLR4 response due to caspase-8. Biochemically, N4BP1 binds both the canonical and noncanonical IKK complexes, in a manner promoted by linear and/or K63-linked polyubiquitin chain binding by N4BP1 and independent of its RNAse activity. Consistent with this, a knock-in mutant of N4BP1 with diminished ubiquitin chain-binding capacity led to increased proinflammatory cytokine responses. These findings thereby unveil a mechanism of late-phase inflammatory gene control, whereby N4BP1 prevents persistent IKK activity through ncIKK-mediated inhibition. This molecular crosstalk among caspase-8, N4BP1, and the IKKs and ncIKKs may have implications for our understanding of genetic immune diseases caused by mutations in caspase-8 or TBK1 and suggest a novel ‘guarding’ mechanism against pathogens that attempt to subvert the ncIKKs.
2024-04-01 | GSE218956 | GEO
Project description:The cell death protease caspase-8 plays an essential role in controlling inflammation, as severe immunodeficiency results from its loss. We previously found that caspase-8 promotes inflammatory responses by cleaving NEDD4-binding protein 1 (N4BP1), a suppressor of cytokine production, but the underlying mechanisms remained unclear. Here we find that N4BP1 curtails the duration, rather than initial induction, of proinflammatory signaling through a mechanism involving noncanonical IKK (ncIKK)-mediated inhibition of the canonical IkB kinase (IKK) complex, a crosstalk event among the IKK family facilitated by N4BP1. Accordingly, co-deletion of the ncIKKs or their adaptor protein TANK largely phenocopied deletion of N4BP1, augmenting cytokine responses by macrophages upon engagement of TRIF-independent toll-like receptors (TLR) 1/2, TLR7, or TLR9. Like N4BP1, TANK was largely prevented from inhibiting the TRIF-dependent TLR4 response due to caspase-8. Biochemically, N4BP1 binds both the canonical and noncanonical IKK complexes, in a manner promoted by linear and/or K63-linked polyubiquitin chain binding by N4BP1 and independent of its RNAse activity. Consistent with this, a knock-in mutant of N4BP1 with diminished ubiquitin chain-binding capacity led to increased proinflammatory cytokine responses. These findings thereby unveil a mechanism of late-phase inflammatory gene control, whereby N4BP1 prevents persistent IKK activity through ncIKK-mediated inhibition. This molecular crosstalk among caspase-8, N4BP1, and the IKKs and ncIKKs may have implications for our understanding of genetic immune diseases caused by mutations in caspase-8 or TBK1 and suggest a novel ‘guarding’ mechanism against pathogens that attempt to subvert the ncIKKs.
2024-04-01 | GSE218955 | GEO
Project description:The cell death protease caspase-8 plays an essential role in controlling inflammation, as severe immunodeficiency results from its loss. We previously found that caspase-8 promotes inflammatory responses by cleaving NEDD4-binding protein 1 (N4BP1), a suppressor of cytokine production, but the underlying mechanisms remained unclear. Here we find that N4BP1 curtails the duration, rather than initial induction, of proinflammatory signaling through a mechanism involving noncanonical IKK (ncIKK)-mediated inhibition of the canonical IkB kinase (IKK) complex, a crosstalk event among the IKK family facilitated by N4BP1. Accordingly, co-deletion of the ncIKKs or their adaptor protein TANK largely phenocopied deletion of N4BP1, augmenting cytokine responses by macrophages upon engagement of TRIF-independent toll-like receptors (TLR) 1/2, TLR7, or TLR9. Like N4BP1, TANK was largely prevented from inhibiting the TRIF-dependent TLR4 response due to caspase-8. Biochemically, N4BP1 binds both the canonical and noncanonical IKK complexes, in a manner promoted by linear and/or K63-linked polyubiquitin chain binding by N4BP1 and independent of its RNAse activity. Consistent with this, a knock-in mutant of N4BP1 with diminished ubiquitin chain-binding capacity led to increased proinflammatory cytokine responses. These findings thereby unveil a mechanism of late-phase inflammatory gene control, whereby N4BP1 prevents persistent IKK activity through ncIKK-mediated inhibition. This molecular crosstalk among caspase-8, N4BP1, and the IKKs and ncIKKs may have implications for our understanding of genetic immune diseases caused by mutations in caspase-8 or TBK1 and suggest a novel ‘guarding’ mechanism against pathogens that attempt to subvert the ncIKKs.
2024-04-01 | GSE219005 | GEO
Project description:The cell death protease caspase-8 plays an essential role in controlling inflammation, as severe immunodeficiency results from its loss. We previously found that caspase-8 promotes inflammatory responses by cleaving NEDD4-binding protein 1 (N4BP1), a suppressor of cytokine production, but the underlying mechanisms remained unclear. Here we find that N4BP1 curtails the duration, rather than initial induction, of proinflammatory signaling through a mechanism involving noncanonical IKK (ncIKK)-mediated inhibition of the canonical IkB kinase (IKK) complex, a crosstalk event among the IKK family facilitated by N4BP1. Accordingly, co-deletion of the ncIKKs or their adaptor protein TANK largely phenocopied deletion of N4BP1, augmenting cytokine responses by macrophages upon engagement of TRIF-independent toll-like receptors (TLR) 1/2, TLR7, or TLR9. Like N4BP1, TANK was largely prevented from inhibiting the TRIF-dependent TLR4 response due to caspase-8. Biochemically, N4BP1 binds both the canonical and noncanonical IKK complexes, in a manner promoted by linear and/or K63-linked polyubiquitin chain binding by N4BP1 and independent of its RNAse activity. Consistent with this, a knock-in mutant of N4BP1 with diminished ubiquitin chain-binding capacity led to increased proinflammatory cytokine responses. These findings thereby unveil a mechanism of late-phase inflammatory gene control, whereby N4BP1 prevents persistent IKK activity through ncIKK-mediated inhibition. This molecular crosstalk among caspase-8, N4BP1, and the IKKs and ncIKKs may have implications for our understanding of genetic immune diseases caused by mutations in caspase-8 or TBK1 and suggest a novel ‘guarding’ mechanism against pathogens that attempt to subvert the ncIKKs.
2024-04-01 | GSE218957 | GEO
Project description:The cell death protease caspase-8 plays an essential role in controlling inflammation, as severe immunodeficiency results from its loss. We previously found that caspase-8 promotes inflammatory responses by cleaving NEDD4-binding protein 1 (N4BP1), a suppressor of cytokine production, but the underlying mechanisms remained unclear. Here we find that N4BP1 curtails the duration, rather than initial induction, of proinflammatory signaling through a mechanism involving noncanonical IKK (ncIKK)-mediated inhibition of the canonical IkB kinase (IKK) complex, a crosstalk event among the IKK family facilitated by N4BP1. Accordingly, co-deletion of the ncIKKs or their adaptor protein TANK largely phenocopied deletion of N4BP1, augmenting cytokine responses by macrophages upon engagement of TRIF-independent toll-like receptors (TLR) 1/2, TLR7, or TLR9. Like N4BP1, TANK was largely prevented from inhibiting the TRIF-dependent TLR4 response due to caspase-8. Biochemically, N4BP1 binds both the canonical and noncanonical IKK complexes, in a manner promoted by linear and/or K63-linked polyubiquitin chain binding by N4BP1 and independent of its RNAse activity. Consistent with this, a knock-in mutant of N4BP1 with diminished ubiquitin chain-binding capacity led to increased proinflammatory cytokine responses. These findings thereby unveil a mechanism of late-phase inflammatory gene control, whereby N4BP1 prevents persistent IKK activity through ncIKK-mediated inhibition. This molecular crosstalk among caspase-8, N4BP1, and the IKKs and ncIKKs may have implications for our understanding of genetic immune diseases caused by mutations in caspase-8 or TBK1 and suggest a novel ‘guarding’ mechanism against pathogens that attempt to subvert the ncIKKs.
2024-04-01 | GSE218954 | GEO
Project description:The model was constructed to describe TLR4 induced NF-κB activation in native bone marrow-derived macrophages. It included processes of ligand (lipopolysaccharide) recognition, formation of dimer receptor complex and further signal transduction through TRAF6/TAK1 complex that leads to the activation of IKKα/β kinase, which in turn enables the NF-κB transcription factor phosphorylation and translocation in the cell nucleus, and induction of IkB and WIP1 (as an example of induced protein that promotes NF-κB dephosphorylation 2) gene transcription. Models were based on the current knowledge of TLR signaling framework, protein interactions within the TLR4 pathway, and up-to-date mathematical models describing Toll receptor activation.
The major important additions were made to TLR4 signaling description:
1) Receptor dimerization process
2) The existence of a basal nuclear NF-κB level (translocation)
3) NF-κB phosphorylation by IKK complex
2019-03-27 | MODEL1809230001 | BioModels
Project description:N4BP1 negatively regulates NF-κB by binding and inhibiting NEMO oligomerization
| PRJNA698568 | ENA
Project description:In response to DNA double strand breaks (DSBs), the ATM kinase activates NF-κB factors to stimulate gene expression changes that promote survival and allow time for cells to repair damage. In cell lines, ATM can activate NF-κB transcription factors via two independent, convergent mechanisms. One is ATM-mediated phosphorylation of nuclear NF-κB essential modulator (Nemo) protein, which leads to monoubiquitylation and export of Nemo to the cytoplasm where it engages the IκB kinase (IKK) complex to activate NF-κB. Another is DSB-triggered migration of ATM into the cytoplasm where it promotes monoubiquitylation of Nemo and resulting IKK-mediated activation of NF-κB. ATM has many other functions in the DSB response beyond activation of NF-κB, and Nemo activates NF-κB downstream of diverse stimuli, including developmental or proinflammatory stimuli such as lipopolysaccharides (LPS). To elucidate the in vivo role of DSB-induced, ATM-dependent changes in expression of NF-κB-responsive genes, we generated mice expressing phosphomutant Nemo protein lacking consensus SQ sites for phosphorylation by ATM or related kinases. We demonstrate that these mice are viable/healthy, fertile, and exhibit overall normal B and T lymphocyte development. Moreover, treatment of their B lineage cells with LPS induces normal NF-κB-regulated gene expression changes. Furthermore, in marked contrast to results from a pre-B cell line, primary B lineage cells expressing phosphomutant Nemo treated with the genotoxic drug etoposide induce normal ATM- and Nemo-dependent changes in expression of NF-κB-regulated genes. Our data demonstrate that ATM-dependent phosphorylation of Nemo SQ motifs in vivo is dispensable for DSB-signaled changes in expression of NF-κB-regulated genes.
2024-08-08 | GSE264315 | GEO