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Curson JE, Liu L, Luo L, Muusse TW, Lucas RM, Gunther KS, Vajjhala PR, Abrol R, Jones A, Kapetanovic R, Stacey KJ, Stow JL, Sweet MJ. TLR4 phosphorylation at tyrosine 672 activates the ERK/c-FOS signaling module for LPS-induced cytokine responses in macrophages. Eur J Immunol 2023; 53:e2250056. [PMID: 37058370 PMCID: PMC10947571 DOI: 10.1002/eji.202250056] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 03/20/2023] [Accepted: 04/11/2023] [Indexed: 04/15/2023]
Abstract
TLRs engage numerous adaptor proteins and signaling molecules, enabling a complex series of post-translational modifications (PTMs) to mount inflammatory responses. TLRs themselves are post-translationally modified following ligand-induced activation, with this being required to relay the full spectrum of proinflammatory signaling responses. Here, we reveal indispensable roles for TLR4 Y672 and Y749 phosphorylation in mounting optimal LPS-inducible inflammatory responses in primary mouse macrophages. LPS promotes phosphorylation at both tyrosine residues, with Y749 phosphorylation being required for maintenance of total TLR4 protein levels and Y672 phosphorylation exerting its pro-inflammatory effects more selectively by initiating ERK1/2 and c-FOS phosphorylation. Our data also support a role for the TLR4-interacting membrane proteins SCIMP and the SYK kinase axis in mediating TLR4 Y672 phosphorylation to permit downstream inflammatory responses in murine macrophages. The corresponding residue in human TLR4 (Y674) is also required for optimal LPS signaling responses. Our study, thus, reveals how a single PTM on one of the most widely studied innate immune receptors orchestrates downstream inflammatory responses.
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Affiliation(s)
- James E.B. Curson
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Liping Liu
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Lin Luo
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Timothy W. Muusse
- School of Chemistry and Molecular Biosciences (SCMB) and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Richard M. Lucas
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Kimberley S. Gunther
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Parimala R. Vajjhala
- School of Chemistry and Molecular Biosciences (SCMB) and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Rishika Abrol
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Alun Jones
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Ronan Kapetanovic
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
- Friedrich Miescher Institute for Biomedical ResearchBaselSwitzerland
| | - Katryn J. Stacey
- School of Chemistry and Molecular Biosciences (SCMB) and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Jennifer L. Stow
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
| | - Matthew J. Sweet
- Institute for Molecular Bioscience (IMB)IMB Centre for Inflammation and Disease Research and Australian Infectious Diseases Research CentreThe University of QueenslandBrisbaneQueenslandAustralia
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2
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Zhan Y, Zhao CS, Qu X, Xiao Z, Deng C, Li Y. Identification of a novel amphioxus leucine-rich repeat receptor involved in phagocytosis reveals a role for Slit2-N-type LRR in bacterial elimination. J Biol Chem 2023; 299:104689. [PMID: 37044216 DOI: 10.1016/j.jbc.2023.104689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 03/25/2023] [Accepted: 03/31/2023] [Indexed: 04/14/2023] Open
Abstract
The basal chordate amphioxus is a model for tracing the origin and evolution of vertebrate immunity. To explore the evolution of immunoreceptor signaling pathways, we searched the associated receptors of the amphioxus B. belcheri (Bb) homolog of immunoreceptor signaling adaptor protein Grb2. Mass-spectrum analysis of BbGrb2 immunoprecipitates from B. belcheri intestine lysates revealed a folate receptor (FR) domain- and leucine-rich repeat (LRR)-containing protein (FrLRR). Sequence and structural analysis showed that FrLRR is a membrane protein with a predicted curved solenoid structure. The N-terminal Fr domain contains very few folate-binding sites; the following LRR region is a Slit2-type LRR, and a GPI-anchored site was predicted at the C-terminus. RT-PCR analysis showed FrLRR is a transcription-mediated fusion gene of BbFR-like and BbSlit2-N-like genes. Genomic DNA structure analysis implied the B. belcheri FrLRR gene locus and the corresponding locus in B. floridae might be generated by exon shuffling of a Slit2-N-like gene into an FR gene. RT-qPCR, immunostaining and immunoblot results showed that FrLRR was primarily distributed in B. belcheri intestinal tissue. We further demonstrated that FrLRR localized to the cell membrane and lysosomes. Functionally, FrLRR mediated and promoted bacteria-binding and phagocytosis, and FrLRR antibody blocking or Grb2 knockdown inhibited FrLRR-mediated phagocytosis. Interestingly, we found that human Slit2-N (hSlit2-N) also mediated direct bacteria-binding and phagocytosis which was inhibited by Slit2-N antibody blocking or Grb2 knockdown. Together, these results indicate FrLRR and hSlit2-N may function as phagocytotic-receptors to promote phagocytosis through Grb2, implying the Slit2-N-type-LRR-containing proteins play a role in bacterial binding and elimination.
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Affiliation(s)
- Yanli Zhan
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Chen-Si Zhao
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Xuemei Qu
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhihui Xiao
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Chong Deng
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yingqiu Li
- MOE Key Laboratory of Gene Function and Regulation, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
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Lucas RM, Luo L, Stow JL. ERK1/2 in immune signalling. Biochem Soc Trans 2022; 50:1341-1352. [PMID: 36281999 PMCID: PMC9704528 DOI: 10.1042/bst20220271] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 07/30/2023]
Abstract
Extracellular signal-related kinases 1 and 2 (ERK1/2) are the final components of the mitogen-activated protein kinase (MAPK) phosphorylation cascade, an integral module in a diverse array of signalling pathways for shaping cell behaviour and fate. More recently, studies have shown that ERK1/2 plays an essential role downstream of immune receptors to elicit inflammatory gene expression in response to infection and cell or tissue damage. Much of this work has studied ERK1/2 activation in Toll-like receptor (TLR) pathways, providing mechanistic insights into its recruitment, compartmentalisation and activation in cells of the innate immune system. In this review, we summarise the typical activation of ERK1/2 in growth factor receptor pathways before discussing its known roles in immune cell signalling with a focus downstream of TLRs. We examine emerging research uncovering evidence of dysfunctional ERK1/2 signalling in inflammatory diseases and discuss the potential therapeutic benefit of targeting ERK1/2 pathways in inflammation.
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Affiliation(s)
- Richard M. Lucas
- Institute for Molecular Bioscience (IMB) and Centre for Inflammation and Disease Research, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Lin Luo
- Institute for Molecular Bioscience (IMB) and Centre for Inflammation and Disease Research, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Jennifer L. Stow
- Institute for Molecular Bioscience (IMB) and Centre for Inflammation and Disease Research, The University of Queensland, St Lucia, QLD 4072, Australia
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The transmembrane adapter SCIMP recruits tyrosine kinase Syk to phosphorylate Toll-like receptors to mediate selective inflammatory outputs. J Biol Chem 2022; 298:101857. [PMID: 35337798 PMCID: PMC9052152 DOI: 10.1016/j.jbc.2022.101857] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 11/23/2022] Open
Abstract
Innate immune signaling by Toll-like receptors (TLRs) involves receptor phosphorylation, which helps to shape and drive key inflammatory outputs, yet our understanding of the kinases and mechanisms that mediate TLR phosphorylation is incomplete. Spleen tyrosine kinase (Syk) is a nonreceptor protein tyrosine kinase, which is known to relay adaptive and innate immune signaling, including from TLRs. However, TLRs do not contain the conserved dual immunoreceptor tyrosine-based activation motifs that typically recruit Syk to many other receptors. One possibility is that the Syk-TLR association is indirect, relying on an intermediary scaffolding protein. We previously identified a role for the palmitoylated transmembrane adapter protein SCIMP in scaffolding the Src tyrosine kinase Lyn, for TLR phosphorylation, but the role of SCIMP in mediating the interaction between Syk and TLRs has not yet been investigated. Here, we show that SCIMP recruits Syk in response to lipopolysaccharide-mediated TLR4 activation. We also show that Syk contributes to the phosphorylation of SCIMP and TLR4 to enhance their binding. Further evidence pinpoints two specific phosphorylation sites in SCIMP critical for its interaction with Syk-SH2 domains in the absence of immunoreceptor tyrosine-based activation motifs. Finally, using inhibitors and primary macrophages from SCIMP-/- mice, we confirm a functional role for SCIMP-mediated Syk interaction in modulating TLR4 phosphorylation, signaling, and cytokine outputs. In conclusion, we identify SCIMP as a novel, immune-specific Syk scaffold, which can contribute to inflammation through selective TLR-driven inflammatory responses.
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Curson JE, Luo L, Liu L, Burgess BJ, Bokil NJ, Wall AA, Brdicka T, Kapetanovic R, Stow JL, Sweet MJ. An alternative downstream translation start site in the non-TIR adaptor Scimp enables selective amplification of CpG DNA responses in mouse macrophages. Immunol Cell Biol 2022; 100:267-284. [PMID: 35201640 PMCID: PMC9544816 DOI: 10.1111/imcb.12540] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 02/17/2022] [Accepted: 02/22/2022] [Indexed: 01/01/2023]
Abstract
Toll-like receptor (TLR) signaling relies on Toll/interleukin-1 receptor homology (TIR) domain-containing adaptor proteins that recruit downstream signaling molecules to generate tailored immune responses. In addition, the palmitoylated transmembrane adaptor protein family member Scimp acts as a non-TIR-containing adaptor protein in macrophages, scaffolding the Src family kinase Lyn to enable TLR phosphorylation and proinflammatory signaling responses. Here we report the existence of a smaller, naturally occurring translational variant of Scimp (Scimp TV1), which is generated through leaky scanning and translation at a downstream methionine. Scimp TV1 also scaffolds Lyn, but in contrast to full-length Scimp, it is basally rather than lipopolysaccharide (LPS)-inducibly phosphorylated. Macrophages from mice that selectively express Scimp TV1, but not full-length Scimp, have impaired sustained LPS-inducible cytokine responses. Furthermore, in granulocyte macrophage colony-stimulating factor-derived myeloid cells that express high levels of Scimp, selective overexpression of Scimp TV1 enhances CpG DNA-inducible cytokine production. Unlike full-length Scimp that localizes to the cell surface and filopodia, Scimp TV1 accumulates in intracellular compartments, particularly the Golgi. Moreover, this variant of Scimp is not inducibly phosphorylated in response to CpG DNA, suggesting that it may act via an indirect mechanism to enhance TLR9 responses. Our findings thus reveal the use of alternative translation start sites as a previously unrecognized mechanism for diversifying TLR responses in the innate immune system.
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Affiliation(s)
- James Eb Curson
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Lin Luo
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Liping Liu
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Belinda J Burgess
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Nilesh J Bokil
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Adam A Wall
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Tomas Brdicka
- Laboratory of Leukocyte Signaling, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ronan Kapetanovic
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.,Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jennifer L Stow
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience (IMB), IMB Centre for Inflammation and Disease Research, and Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
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Lucas RM, Liu L, Curson JEB, Koh YWH, Tuladhar N, Condon ND, Das Gupta K, Burgener SS, Schroder K, Ingley E, Sweet MJ, Stow JL, Luo L. SCIMP is a spatiotemporal transmembrane scaffold for Erk1/2 to direct pro-inflammatory signaling in TLR-activated macrophages. Cell Rep 2021; 36:109662. [PMID: 34496234 DOI: 10.1016/j.celrep.2021.109662] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/12/2021] [Accepted: 08/13/2021] [Indexed: 02/06/2023] Open
Abstract
Immune cells are armed with Toll-like receptors (TLRs) for sensing and responding to pathogens and other danger cues. The role of extracellular-signal-regulated kinases 1/2 (Erk1/2) in TLR signaling remains enigmatic, with both pro- and anti-inflammatory functions described. We reveal here that the immune-specific transmembrane adaptor SCIMP is a direct scaffold for Erk1/2 in TLR pathways, with high-resolution, live-cell imaging revealing that SCIMP guides the spatial and temporal recruitment of Erk2 to membrane ruffles and macropinosomes for pro-inflammatory TLR4 signaling. SCIMP-deficient mice display defects in Erk1/2 recruitment to TLR4, c-Fos activation, and pro-inflammatory cytokine production, with these effects being phenocopied by Erk1/2 signaling inhibition. Our findings thus delineate a selective role for SCIMP as a key scaffold for the membrane recruitment of Erk1/2 kinase to initiate TLR-mediated pro-inflammatory responses in macrophages.
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Affiliation(s)
- Richard M Lucas
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Liping Liu
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - James E B Curson
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Yvette W H Koh
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Neeraj Tuladhar
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nicholas D Condon
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Kaustav Das Gupta
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Sabrina S Burgener
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Kate Schroder
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Evan Ingley
- Cell Signalling Group, Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Perth, WA 6009, Australia; Discipline of Medical, Molecular and Forensic Sciences, College of Science, Health, Engineering and Education, Murdoch University, Murdoch, WA 6150, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jennifer L Stow
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Lin Luo
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia.
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Src Family Tyrosine Kinases in Intestinal Homeostasis, Regeneration and Tumorigenesis. Cancers (Basel) 2020; 12:cancers12082014. [PMID: 32717909 PMCID: PMC7464719 DOI: 10.3390/cancers12082014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/18/2020] [Accepted: 07/19/2020] [Indexed: 01/11/2023] Open
Abstract
Src, originally identified as an oncogene, is a membrane-anchored tyrosine kinase and the Src family kinase (SFK) prototype. SFKs regulate the signalling induced by a wide range of cell surface receptors leading to epithelial cell growth and adhesion. In the intestine, the SFK members Src, Fyn and Yes regulate epithelial cell proliferation and migration during tissue regeneration and transformation, thus implicating conserved and specific functions. In patients with colon cancer, SFK activity is a marker of poor clinical prognosis and a potent driver of metastasis formation. These tumorigenic activities are linked to SFK capacity to promote the dissemination and tumour-initiating capacities of epithelial tumour cells. However, it is unclear how SFKs promote colon tumour formation and metastatic progression because SFK-encoding genes are unfrequently mutated in human cancer. Here, we review recent findings on SFK signalling during intestinal homeostasis, regeneration and tumorigenesis. We also describe the key nongenetic mechanisms underlying SFK tumour activities in colorectal cancer, and discuss how these mechanisms could be exploited in therapeutic strategies to target SFK signalling in metastatic colon cancer.
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8
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Luo L, Lucas RM, Liu L, Stow JL. Signalling, sorting and scaffolding adaptors for Toll-like receptors. J Cell Sci 2019; 133:133/5/jcs239194. [PMID: 31889021 DOI: 10.1242/jcs.239194] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Toll-like receptors (TLRs) are danger-sensing receptors that typically propagate self-limiting inflammatory responses, but can unleash uncontrolled inflammation in non-homeostatic or disease settings. Activation of TLRs by pathogen- and/or host-derived stimuli triggers a range of signalling and transcriptional pathways to programme inflammatory and anti-microbial responses, including the production of a suite of inflammatory cytokines and other mediators. Multiple sorting and signalling adaptors are recruited to receptor complexes on the plasma membrane or endosomes where they act as scaffolds for downstream signalling kinases and effectors at these sites. So far, seven proximal TLR adaptors have been identified: MyD88, MAL, TRIF (also known as TICAM1), TRAM (TICAM2), SARM (SARM1), BCAP (PIK3AP1) and SCIMP. Most adaptors tether directly to TLRs through homotypic Toll/interleukin-1 receptor domain (TIR)-TIR interactions, whereas SCIMP binds to TLRs through an atypical TIR-non-TIR interaction. In this Review, we highlight the key roles for these adaptors in TLR signalling, scaffolding and receptor sorting and discuss how the adaptors thereby direct the differential outcomes of TLR-mediated responses. We further summarise TLR adaptor regulation and function, and make note of human diseases that might be associated with mutations in these adaptors.
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Affiliation(s)
- Lin Luo
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Richard M Lucas
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Liping Liu
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jennifer L Stow
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research, The University of Queensland, Brisbane, QLD 4072, Australia
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9
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Luo L, Curson JEB, Liu L, Wall AA, Tuladhar N, Lucas RM, Sweet MJ, Stow JL. SCIMP is a universal Toll‐like receptor adaptor in macrophages. J Leukoc Biol 2019; 107:251-262. [DOI: 10.1002/jlb.2ma0819-138rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 08/19/2019] [Accepted: 08/20/2019] [Indexed: 02/06/2023] Open
Affiliation(s)
- Lin Luo
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research The University of Queensland Brisbane Queensland Australia
| | - James E. B. Curson
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research The University of Queensland Brisbane Queensland Australia
| | - Liping Liu
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research The University of Queensland Brisbane Queensland Australia
| | - Adam A. Wall
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research The University of Queensland Brisbane Queensland Australia
| | - Neeraj Tuladhar
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research The University of Queensland Brisbane Queensland Australia
| | - Richard M. Lucas
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research The University of Queensland Brisbane Queensland Australia
| | - Matthew J. Sweet
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research The University of Queensland Brisbane Queensland Australia
| | - Jennifer L. Stow
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation and Disease Research The University of Queensland Brisbane Queensland Australia
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