The cytokine TNF can trigger highly proinflammatory RIPK1-dependent cell death. Here, we show that the two adapter proteins, TANK and AZI2, suppress TNF-induced cell death by regulating the activation of TBK1 kinase. Mice lacking either TANK or AZI2 do not show an overt phenotype. Conversely, animals deficient in both adapters are born in a sub-Mendelian ratio and suffer from severe multi-organ inflammation, excessive antibody production, male sterility, and early mortality, which can be rescued by TNFR1 deficiency and significantly improved by expressing a kinase-dead form of RIPK1. Mechanistically, TANK and AZI2 both recruit TBK1 to the TNF receptor signaling complex, but with distinct kinetics due to interaction with different complex components. While TANK binds directly to the adapter NEMO, AZI2 is recruited later via deubiquitinase A20. In summary, our data show that TANK and AZI2 cooperatively sustain TBK1 activity during different stages of TNF receptor assembly to protect against autoinflammation.

• MeSH
• adaptorové proteiny signální transdukční * metabolismus   genetika   MeSH
• buněčná smrt MeSH
• endopeptidasy MeSH
• intracelulární signální peptidy a proteiny metabolismus   genetika   MeSH
• lidé MeSH
• myši inbrední C57BL MeSH
• myši knockoutované * MeSH
• myši MeSH
• protein-serin-threoninkinasy interagující s receptory * metabolismus   genetika   MeSH
• protein-serin-threoninkinasy * metabolismus   genetika   MeSH
• receptory TNF - typ I * metabolismus   genetika   MeSH
• signální transdukce MeSH
• TNF-alfa * metabolismus   MeSH
• TNFAIP3 metabolismus   genetika   MeSH
• zánět metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

T cells are pivotal in the adaptive immune defense, necessitating a delicate balance between robust response against infections and self-tolerance. Their activation involves intricate cross-talk among signaling pathways triggered by the T-cell antigen receptors (TCR) and co-stimulatory or inhibitory receptors. The molecular regulation of these complex signaling networks is still incompletely understood. Here, we identify the adaptor protein ABIN1 as a component of the signaling complexes of GITR and OX40 co-stimulation receptors. T cells lacking ABIN1 are hyper-responsive ex vivo, exhibit enhanced responses to cognate infections, and superior ability to induce experimental autoimmune diabetes in mice. ABIN1 negatively regulates p38 kinase activation and late NF-κB target genes. P38 is at least partially responsible for the upregulation of the key effector proteins IFNG and GZMB in ABIN1-deficient T cells after TCR stimulation. Our findings reveal the intricate role of ABIN1 in T-cell regulation.

• MeSH
• adaptorové proteiny signální transdukční * metabolismus   genetika   MeSH
• aktivace lymfocytů imunologie   genetika   MeSH
• cytotoxické T-lymfocyty * imunologie   metabolismus   MeSH
• diabetes mellitus 1. typu imunologie   genetika   metabolismus   MeSH
• glukokortikoidy indukovaný protein související s TNRF MeSH
• interferon gama metabolismus   MeSH
• lidé MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• NF-kappa B metabolismus   MeSH
• receptory antigenů T-buněk metabolismus   MeSH
• receptory OX40 metabolismus   genetika   MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Interleukin-17A (IL-17A) is a key mediator of protective immunity to yeast and bacterial infections but also drives the pathogenesis of several autoimmune diseases, such as psoriasis or psoriatic arthritis. Here we show that the tetra-transmembrane protein CMTM4 is a subunit of the IL-17 receptor (IL-17R). CMTM4 constitutively associated with IL-17R subunit C to mediate its stability, glycosylation and plasma membrane localization. Both mouse and human cell lines deficient in CMTM4 were largely unresponsive to IL-17A, due to their inability to assemble the IL-17R signaling complex. Accordingly, CMTM4-deficient mice had a severe defect in the recruitment of immune cells following IL-17A administration and were largely resistant to experimental psoriasis, but not to experimental autoimmune encephalomyelitis. Collectively, our data identified CMTM4 as an essential component of IL-17R and a potential therapeutic target for treating IL-17-mediated autoimmune diseases.

• MeSH
• encefalomyelitida autoimunitní experimentální * genetika   MeSH
• interleukin-17 metabolismus   MeSH
• lidé MeSH
• myši MeSH
• proteiny obsahující MARVEL doménu genetika   MeSH
• psoriatická artritida * MeSH
• psoriáza * MeSH
• receptory interleukinu-17 genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Bardet-Biedl syndrome (BBS) is a pleiotropic ciliopathy caused by dysfunction of primary cilia. More than half of BBS patients carry mutations in one of eight genes encoding for subunits of a protein complex, the BBSome, which mediates trafficking of ciliary cargoes. In this study, we elucidated the mechanisms of the BBSome assembly in living cells and how this process is spatially regulated. We generated a large library of human cell lines deficient in a particular BBSome subunit and expressing another subunit tagged with a fluorescent protein. We analyzed these cell lines utilizing biochemical assays, conventional and expansion microscopy, and quantitative fluorescence microscopy techniques: fluorescence recovery after photobleaching and fluorescence correlation spectroscopy. Our data revealed that the BBSome formation is a sequential process. We show that the pre-BBSome is nucleated by BBS4 and assembled at pericentriolar satellites, followed by the translocation of the BBSome into the ciliary base mediated by BBS1. Our results provide a framework for elucidating how BBS-causative mutations interfere with the biogenesis of the BBSome.

• MeSH
• Bardetův-Biedlův syndrom genetika   metabolismus   patologie   MeSH
• buněčné linie MeSH
• cilie metabolismus   MeSH
• CRISPR-Cas systémy genetika   MeSH
• cytoplazma metabolismus   MeSH
• editace genu MeSH
• fluorescenční mikroskopie MeSH
• FRAP MeSH
• lidé MeSH
• mutace MeSH
• podjednotky proteinů genetika   metabolismus   MeSH
• proteiny asociované s mikrotubuly nedostatek   genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

IL-17 mediates immune protection from fungi and bacteria, as well as it promotes autoimmune pathologies. However, the regulation of the signal transduction from the IL-17 receptor (IL-17R) remained elusive. We developed a novel mass spectrometry-based approach to identify components of the IL-17R complex followed by analysis of their roles using reverse genetics. Besides the identification of linear ubiquitin chain assembly complex (LUBAC) as an important signal transducing component of IL-17R, we established that IL-17 signaling is regulated by a robust negative feedback loop mediated by TBK1 and IKKε. These kinases terminate IL-17 signaling by phosphorylating the adaptor ACT1 leading to the release of the essential ubiquitin ligase TRAF6 from the complex. NEMO recruits both kinases to the IL-17R complex, documenting that NEMO has an unprecedented negative function in IL-17 signaling, distinct from its role in NF-κB activation. Our study provides a comprehensive view of the molecular events of the IL-17 signal transduction and its regulation.

• MeSH
• adaptorové proteiny signální transdukční genetika   metabolismus   MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• kinasa I-kappa B genetika   metabolismus   MeSH
• lidé MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• receptory interleukinu-17 genetika   metabolismus   MeSH
• signální transdukce * MeSH
• zpětná vazba fyziologická * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The linear-ubiquitin chain assembly complex (LUBAC) modulates signalling via various immune receptors. In tumour necrosis factor (TNF) signalling, linear (also known as M1) ubiquitin enables full gene activation and prevents cell death. However, the mechanisms underlying cell death prevention remain ill-defined. Here, we show that LUBAC activity enables TBK1 and IKKε recruitment to and activation at the TNF receptor 1 signalling complex (TNFR1-SC). While exerting only limited effects on TNF-induced gene activation, TBK1 and IKKε are essential to prevent TNF-induced cell death. Mechanistically, TBK1 and IKKε phosphorylate the kinase RIPK1 in the TNFR1-SC, thereby preventing RIPK1-dependent cell death. This activity is essential in vivo, as it prevents TNF-induced lethal shock. Strikingly, NEMO (also known as IKKγ), which mostly, but not exclusively, binds the TNFR1-SC via M1 ubiquitin, mediates the recruitment of the adaptors TANK and NAP1 (also known as AZI2). TANK is constitutively associated with both TBK1 and IKKε, while NAP1 is associated with TBK1. We discovered a previously unrecognized cell death checkpoint that is mediated by TBK1 and IKKε, and uncovered an essential survival function for NEMO, whereby it enables the recruitment and activation of these non-canonical IKKs to prevent TNF-induced cell death.

• MeSH
• buněčná smrt účinky léků   MeSH
• buňky A549 MeSH
• fosforylace účinky léků   MeSH
• HeLa buňky MeSH
• kinasa I-kappa B metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• myši knockoutované MeSH
• protein-serin-threoninkinasy interagující s receptory metabolismus   MeSH
• protein-serin-threoninkinasy metabolismus   MeSH
• receptory TNF - typ I metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• TNF-alfa farmakologie   MeSH
• ubikvitinace účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Virtual memory T cells are foreign antigen-inexperienced T cells that have acquired memory-like phenotype and constitute 10-20% of all peripheral CD8+ T cells in mice. Their origin, biological roles, and relationship to naïve and foreign antigen-experienced memory T cells are incompletely understood. By analyzing T-cell receptor repertoires and using retrogenic monoclonal T-cell populations, we demonstrate that the virtual memory T-cell formation is a so far unappreciated cell fate decision checkpoint. We describe two molecular mechanisms driving the formation of virtual memory T cells. First, virtual memory T cells originate exclusively from strongly self-reactive T cells. Second, the stoichiometry of the CD8 interaction with Lck regulates the size of the virtual memory T-cell compartment via modulating the self-reactivity of individual T cells. Although virtual memory T cells descend from the highly self-reactive clones and acquire a partial memory program, they are not more potent in inducing experimental autoimmune diabetes than naïve T cells. These data underline the importance of the variable level of self-reactivity in polyclonal T cells for the generation of functional T-cell diversity.

• MeSH
• buněčná diferenciace * MeSH
• CD8-pozitivní T-lymfocyty imunologie   MeSH
• homeostáza MeSH
• imunologická paměť * MeSH
• myši MeSH
• receptory antigenů T-buněk analýza   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Transmembrane adaptor proteins (TRAPs) are structurally related proteins that have no enzymatic function, but enable inducible recruitment of effector molecules to the plasma membrane, usually in a phosphorylation dependent manner. Numerous surface receptors employ TRAPs for either propagation or negative regulation of the signal transduction. Several TRAPs (LAT, NTAL, PAG, LIME, PRR7, SCIMP, LST1/A, and putatively GAPT) are known to be palmitoylated that could facilitate their localization in lipid rafts or tetraspanin enriched microdomains. This review summarizes expression patterns, binding partners, signaling pathways, and biological functions of particular palmitoylated TRAPs with an emphasis on the three most recently discovered members, PRR7, SCIMP, and LST1/A. Moreover, we discuss in silico methodology used for discovery of new family members, nature of their binding partners, and microdomain localization.

• MeSH
• adaptorové proteiny signální transdukční metabolismus   MeSH
• leukocyty metabolismus   fyziologie   MeSH
• lidé MeSH
• lipoylace MeSH
• membránové mikrodomény metabolismus   MeSH
• membránové proteiny metabolismus   MeSH
• signální transdukce * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

When a BCR on a mature B cell is engaged by its ligand, the cell becomes activated, and the Ab-mediated immune response can be triggered. The initiation of BCR signaling is orchestrated by kinases of the Src and Syk families. However, the proximal BCR-induced phosphorylation remains incompletely understood. According to a model of sequential activation of kinases, Syk acts downstream of Src family kinases (SFKs). In addition, signaling independent of SFKs and initiated by Syk has been proposed. Both hypotheses lack sufficient evidence from relevant B cell models, mainly because of the redundancy of Src family members and the importance of BCR signaling for B cell development. We addressed this issue by analyzing controlled BCR triggering ex vivo on primary murine B cells and on murine and chicken B cell lines. Chemical and Csk-based genetic inhibitor treatments revealed that SFKs are required for signal initiation and Syk activation. In addition, ligand and anti-BCR Ab-induced signaling differ in their sensitivity to the inhibition of SFKs.

• MeSH
• aktivace enzymů imunologie   MeSH
• buněčné linie MeSH
• intracelulární signální peptidy a proteiny metabolismus   fyziologie   MeSH
• kultivované buňky MeSH
• kur domácí MeSH
• modely u zvířat MeSH
• myši inbrední C57BL MeSH
• myši transgenní MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• receptory antigenů B-buněk metabolismus   fyziologie   MeSH
• receptory pre-B lymfocytů metabolismus   fyziologie   MeSH
• signální transdukce imunologie   MeSH
• skupina kinas odvozených od src-genu metabolismus   fyziologie   MeSH
• tyrosinkinasy metabolismus   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Transmembrane adaptor proteins are membrane-anchored proteins consisting of a short extracellular part, a transmembrane domain, and a cytoplasmic part with various protein-protein interaction motifs but lacking any enzymatic activity. They participate in the regulation of various signaling pathways by recruiting other proteins to the proximity of cellular membranes where the signaling is often initiated and propagated. In this work, we show that LST1/A, an incompletely characterized protein encoded by MHCIII locus, is a palmitoylated transmembrane adaptor protein. It is expressed specifically in leukocytes of the myeloid lineage, where it localizes to the tetraspanin-enriched microdomains. In addition, it binds SHP-1 and SHP-2 phosphatases in a phosphotyrosine-dependent manner, facilitating their recruitment to the plasma membrane. These data suggest a role for LST1/A in negative regulation of signal propagation.

• MeSH
• buněčná membrána metabolismus   MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• hlavní histokompatibilní komplex fyziologie   MeSH
• Jurkat buňky MeSH
• lidé MeSH
• membránové proteiny chemie   genetika   metabolismus   MeSH
• molekulární sekvence - údaje MeSH
• myeloidní buňky cytologie   metabolismus   MeSH
• plakiny metabolismus   MeSH
• primární buněčná kultura MeSH
• pseudopodia metabolismus   MeSH
• sekvence aminokyselin MeSH
• signální transdukce fyziologie   MeSH
• terciární struktura proteinů fyziologie   MeSH
• transport proteinů fyziologie   MeSH
• tyrosinfosfatasa nereceptorového typu 11 metabolismus   MeSH
• tyrosinfosfatasa nereceptorového typu 6 metabolismus   MeSH
• U937 buňky MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH