Search results for TLR2

Showing 21 results out of 57

×

Species

Types

Compartments

Reaction types

Search properties

Species

Types

Compartments

Reaction types

Search properties

Protein (3 results from a total of 3)

Identifier: R-HSA-167992
Species: Homo sapiens
Compartment: plasma membrane
Primary external reference: UniProt: TLR2: O60603
Identifier: R-HSA-9637646
Species: Homo sapiens
Compartment: plasma membrane
Primary external reference: UniProt: TLR2: O60603
Identifier: R-HSA-6804777
Species: Homo sapiens
Compartment: secretory granule membrane
Primary external reference: UniProt: TLR2: O60603

Reaction (5 results from a total of 27)

Identifier: R-HSA-9637638
Species: Homo sapiens
Compartment: cytosol, plasma membrane
Mtb secreted Mtb 6 kDa early secretory antigenic target (esxA) binds to toll-like-receptor 2 (TLR2), inhibiting the human immune reponse (Pathak et al. 2007).
Identifier: R-HSA-9637641
Species: Homo sapiens
Compartment: cytosol, plasma membrane
Mtb Rv2779c protein binds to toll-like-receptor 2 (TLR2), inhibiting the human immune reponse (Liu et al. 2015).
Identifier: R-HSA-168951
Species: Homo sapiens
Compartment: plasma membrane
The TLR2:TLR1 complex recognizes Neisserial PorB and Mycobacterial triacylated lipoproteins and peptides, amongst others.
Identifier: R-HSA-166072
Species: Homo sapiens
Compartment: plasma membrane, cytosol
MyD88 binds to IRAK (IL-1 receptor-associated kinase) and the receptor heterocomplex (the signaling complex) and thereby mediates the association of IRAK with the receptor. MyD88 therefore couples a serine/threonine protein kinase to the receptor complex.
Identifier: R-HSA-2559414
Species: Homo sapiens
Compartment: plasma membrane, cytosol
Bruton's tyrosine kinase (BTK) is a cytoplasmic protein tyrosine kinase, which plays an essential role in B cell receptor (BCR) signaling (Brunner C et al. 2005). BTK has been also implicated in TLR signaling (Lee KG et al. 2012, Jefferies CA et al. 2003; Doyle SL et al. 2007). Interaction studies revealed that BTK can associate with intracellular TIR-domains of TLRs 4, 6, 8 and 9. Furthermore, BTK was found to interact with other proteins involved in TLR2/4 signaling - MyD88, MAL and IRAK-1 (Jefferies CA et al. 2003)

Loss of BTK function causes X-linked agammaglobulinemia (XLA), a rare primary immunode?ciency disease with severe defects in early B-cell development resulting in an almost complete absence of peripheral B cells and severely reduced serum levels of immunoglobulins of all classes (Väliaho J et al. 2006). Affected individuals suffer from recurrent bacterial and enteroviral infections. It remains unclear whether XLA patients have normal or impared TLR signaling functions. LPS-stimulated monocytes from XLA patients were found to produce reduced amounts of TNFalpha (Horwood NJ et al. 2003), These data contradict a study that showed enhanced amounts of TNFalpha and IL6 comparing to control cells, starting at 6 hours and extending for 48 hours (Marron TU et al. 2012). The other group reported similar expression TNFalpha upon TLR4 triggering, compared with healthy control cells (Perez de Diego R et al. 2006). Thus, the effect of BTK deficiency on TLR-mediated inflammation needs to be further clarified.

Complex (5 results from a total of 14)

Identifier: R-HSA-9037685
Species: Homo sapiens
Compartment: plasma membrane
Identifier: R-HSA-168946
Species: Homo sapiens
Compartment: plasma membrane
Identifier: R-HSA-168949
Species: Homo sapiens
Compartment: plasma membrane
Identifier: R-HSA-181226
Species: Homo sapiens
Compartment: plasma membrane
Identifier: R-HSA-2559462
Species: Homo sapiens
Compartment: plasma membrane

Pathway (5 results from a total of 10)

Identifier: R-HSA-5603041
Species: Homo sapiens
Interleukin-1 receptor-associated kinase 4 (IRAK4) is a serine/threonine kinase, that mediates activation of transcriptional factors such as NFkB and AP1 downstream of IL-1 receptors and all toll like receptors (TLR) except for TLR3 (Suzuki N et al. 2002). IRAK4 is recruited to the TLR receptor complex through a homophilic interaction of the death domains of IRAK4 and adaptor myeloid differentiation factor 88 protein (MyD88) (Motshwene PG et al. 2009; Lin SC et al. 2010). Studies have identified patients with an autosomal recessive (AR) form of IRAK4 deficiency, a health condition with clinical manifestation in infancy or early childhood, that predisposes affected patients to recurrent pyogenic bacterial infection (e.g., Streptococcus pneumoniae and Staphylococcus aureus) (Picard C et al. 2003; Ku CL et al. 2007; Picard C et al. 2010; Picard C et al. 2011). Leukocytes derived from IRAK4-deficient patients display a lack of production of inflammatory cytokines such as TNF alpha, IL-6 and IL-1 beta by whole blood or a lack of CD62 ligand (CD62L) shedding from granulocytes following activation with the most TLR agonists including those of TLR1/2 (Pam3CSK4), TLR2/6 (Pam2CSK4) and TLR4 (LPS) (Picard C et al. 2003; McDonald DR et al. 2006; Ku CL et al. 2007). However, LPS-induced TLR4-mediated production of some cytokines (IL8 and MIP-1beta) was reduced but not abolished (Ku CL et al. 2007). LPS-stimulated induction of type I IFN via MyD88-IRAK4 independent signaling axis was normal or weakly affected suggesting that TLR4 could induce some responses in IRAK4 deficient patients(Yang K et al. 2005).

Patients with AR IRAK4 deficiency were found to bear homozygous or compound heterozygous mutations in the IRAK4 gene (Picard C et al. 2003; Ku CL et al. 2007; McDonald DR et al. 2006). Here we describe selected mutations, that have been functionally characterized. Cell-based assay as well as in vitro protein-interaction analyses with IRAK4 variants showed that the loss-of-function of defective IRAK4 is caused by either loss of protein production (reported for IRAK4 Q293X and E402X) or an impaired interaction with MyD88 as shown for missence mutation IRAK4 R12C (Ku CL et al. 2007; Yamamoto T et al. 2014).

Besides defective TLR2/4 mediated signaling, the Reactome module describes the impact of functional deficiency of IRAK4 on TLR5 pathways. The module does not include defective TLR7, TLR8 and TLR9 signaling events, which are associated mostly with viral infections, although studies using patient-derived blood cells showed abolished cytokine production by peripheral blood mononuclear cells (PBMCs) and lack of CD62 ligand (CD62L) shedding from granulocytes in response to TLR7-9 agonists (McDonald DR et al. 2006; von Bernuth H et al. 2006; Ku CL et al. 2007). In addition to the TLR-NFkB signaling axis, endosomic TLR7-9 activates IFN-alpha/beta and IFN-gamma responses and these are also impaired in IRAK4-deficient PBMC (Yang K et al. 2005). Nevertheless, IFN-alpha/beta and -gamma production in IRAK-4-deficient blood cells in response to 9 of 11 viruses was normal or weakly affected, suggesting that IRAK-4-deficient patients may control viral infections by TLR7-9-independent production of IFNs such as IRAK4-independent antiviral RIGI and MDA5 pathways (Yang K et al. 2005). So it is not yet possible to annotate a definitive molecular pathway between IRAK-4 deficiency and changes in TLR7-9 signaling.

Identifier: R-HSA-5602498
Species: Homo sapiens
Myeloid differentiation primary response (MyD88) is an adaptor protein that mediates intracellular signaling pathways evoked by all Toll-like receptors (TLRs) except for TLR3 and by several interleukin-1 receptors (IL-1Rs) (Medzhitov R et al. 1998). Upon ligand binding, TLRs hetero- or homodimerize and recruit MyD88 through their respective TIR domains. Then, MyD88 oligomerizes via its death domain (DD) and TIR domain and interacts with the interleukin-1 receptor-associated kinases (IRAKs) to form the Myddosome complex (MyD88:IRAK4:IRAK1/2) (Motshwene PG et al. 2009; Lin SC et al. 2010). The Myddosome complex transmits the signal leading to activation of transcription factors such as nuclear factor-kappaB (NFkB) and activator protein 1 (AP1).

Studies have identified patients with autosomal recessive (AR) form of MyD88 deficiency caused by homozygous or compound heterozygous mutations in MYD88 gene leading to abolished protein production (von Bernuth et al. 2008). AR MyD88 deficiency is a type of a primary immunodeficiency characterized by greater susceptibility to pyogenic bacteria (such as Streptococcus pneumoniae, Staphylococcus aureus or Pseudomonas aeruginosa) manifested in infancy and early childhood. Patients with MyD88 deficiency show delayed or weak signs of inflammation (Picard C et al. 2010; Picard C et al. 2011).

Functional assessment of MyD88 deficiency revealed that cytokine responses were impaired in patient-derived blood cells upon stimulation with the agonists of TLR2 and TLR4 (PAM2CSK4 and LPS respectively), although some were produced in response to LPS. (von Bernuth et al. 2008). NFkB luciferase reporter gene assays using human embryonic kidney 293 (HEK293T) cells showed that MyD88 variants, S34Y, E52del, E53X, L93P, R98C, and R196C, were compromised in their ability to enhance NFkB activation (Yamamoto T et al. 2014). The molecular basis for the observed functional effects (reported for selected mutations) probably faulty Myddosome formation due to impaired MyD88 oligomerization and/or interaction with IRAK4 (George J et al. 2011; Nagpal K et al. 2011; Yamamoto T et al. 2014).

While MyD88-deficiency might be expected to perturb MyD88?IRAK4 dependent TLR7 and TLR8 signaling events associated with the sensing viral infections, patients with MyD88 and IRAK4 deficiencies have so far not been reported to be susceptible to viral infection.

Identifier: R-HSA-181438
Species: Homo sapiens
TLR2 is involved in recognition of peptidoglycan from gram-positive bacteria, bacterial lipoproteins, mycoplasma lipoprotein and mycobacterial products. It is quite possible that recognition of at least some other TLR2 ligands may be assisted by additional accessory proteins, particularly in association with TLR1 or TLR6. TLR2 is expressed constitutively on macrophages, dendritic cells, and B cells, and can be induced in some other cell types, including epithelial cells. TLR1 and TLR6, on the other hand, are expressed almost ubiquitously (Muzio et al. 2000). TLR2 may be a sensor and inductor of specific defense processes, including oxidative stress and cellular necrosis initially spurred by microbial compounds.
Identifier: R-HSA-168179
Species: Homo sapiens
TLR1 is expressed by monocytes. TLR1 and TLR2 cotranslationally form heterodimeric complexes on the cell surface and in the cytosol. The TLR2:TLR1 complex recognizes Neisserial PorB and Mycobacterial triacylated lipoproteins and peptides, amongst others, triggering up-regulation of nuclear factor-kappaB production and apoptotic cascades. Such cooperation between TLR1 and TLR2 on the cell surface of normal human peripheral blood mononuclear cells, for instance, leads to the activation of pro-inflammatory cytokine secretion (Sandor et al. 2003).
Identifier: R-HSA-168188
Species: Homo sapiens
TLR2 and TLR4 recognize different bacterial cell wall components. While TLR4 is trained onto Gram-negative lipopolysaccharide components, TLR2 - in combination with TLR6 - plays a major role in recognizing peptidoglycan wall products from Gram-positive bacteria, as well as Mycobacterial diacylated lipopeptides. In particular, TLR6 appears to participate in discriminating the subtle differences between dipalmitoyl and tripalmitoyl cysteinyl residues (Okusawa et al. 2004).

Set (2 results from a total of 2)

Identifier: R-ALL-517854
Compartment: plasma membrane
Identifier: R-ALL-517843
Compartment: extracellular region

Icon (1 results from a total of 1)

Species: Homo sapiens
Representation of Toll-like 2 binding TLR1 or TLR6
Cite Us!