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Leukotriene Receptor
The leukotriene (LT) receptors are G protein-coupled receptors that bind and are activated by the leukotrienes. They include the following proteins: * Leukotriene B4 receptors (BLTRs) – bind to and are activated by LTB4: ** BLT1 ( Leukotriene B4 receptor 1) – ** BLT2 ( Leukotriene B4 receptor 2) – * Cysteinyl leukotriene receptors (CysLTRs) – bind to and are activated by LTC4, LTD4, and LTE4: ** CysLT1 ( Cysteinyl leukotriene receptor 1) – ** CysLT2 ( Cysteinyl leukotriene receptor 2) – The recently elucidated CysLTE, represented by GPR99/OXGR1, may constitute a third CysLTR. See also * Eicosanoid receptor * Oxoeicosanoid receptor * Prostaglandin receptor * Thromboxane receptor The thromboxane receptor (TP) also known as the prostanoid TP receptor is a protein that in humans is encoded by the ''TBXA2R'' gene, The thromboxane receptor is one among the five classes of prostanoid receptors and was the first eicosanoid re ... References External links IUPH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G Protein-coupled Receptor
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related proteins that are cell surface receptors that detect molecules outside the cell and activate cellular responses. Coupling with G proteins, they are called seven-transmembrane receptors because they pass through the cell membrane seven times. Text was copied from this source, which is available under Attribution 2.5 Generic (CC BY 2.5) license. Ligands can bind either to extracellular N-terminus and loops (e.g. glutamate receptors) or to the binding site within transmembrane helices (Rhodopsin-like family). They are all activated by agonists although a spontaneous auto-activation of an empty receptor can also be observed. G protein-coupled receptors are found only in eukaryotes, including yeast, choanoflagellates, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteinyl Leukotriene Receptor 1
Cysteinyl leukotriene receptor 1, also termed CYSLTR1, is a receptor for cysteinyl leukotrienes (LT) (see leukotrienes#Cysteinyl leukotrienes). CYSLTR1, by binding these cysteinyl LTs (CysLTs; viz, LTC4, LTD4, and to a much lesser extent, LTE4) contributes to mediating various allergic and hypersensitivity reactions in humans as well as models of the reactions in other animals. Gene The human gene maps to the X chromosome at position Xq13-Xq21, contains three exons with the entire open reading frame located in exon 3, and codes for a protein composed of 337 amino acids. The ''CYSLTR1'' gene promoter region is distanced from 665 to 30 bp upstream of its transcription start site. Expression CYSLTR1 mRNA is expressed in lung smooth muscle, lung macrophages, monocytes, eosinophils, basophils, neutrophils, platelets, T cells, B lymphocytes, pluripotent hematopoietic stem cells (CD34+), mast cells, pancreas, small intestine, prostate, interstitial cells of the nasal mucosa, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thromboxane Receptor
The thromboxane receptor (TP) also known as the prostanoid TP receptor is a protein that in humans is encoded by the ''TBXA2R'' gene, The thromboxane receptor is one among the five classes of prostanoid receptors and was the first eicosanoid receptor cloned. The TP receptor derives its name from its preferred endogenous ligand thromboxane A2. Gene The gene responsible for directing the synthesis of the thromboxane receptor, ''TBXA2R'', is located on chromosome 19 at position p13.3, spans 15 kilobases, and contains 5 exons. ''TBXA2R'' codes for a member of the G protein-coupled super family of seven-transmembrane receptors. Heterogeneity Molecular biology findings have provided definitive evidence for two human TP receptor subtypes. The originally cloned TP from placenta (343 amino acids in length) is known as the α isoform and the splice variant cloned from endothelium (with 407 amino acids), termed the β isoform. The first 328 amino acids are the same for both isoforms, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostaglandin Receptor
Prostaglandin receptors or prostanoid receptors represent a sub-class of cell surface membrane receptors that are regarded as the primary receptors for one or more of the classical, naturally occurring prostanoids viz., prostaglandin D2, (i.e. PGD2), PGE2, PGF2alpha, prostacyclin (PGI2), thromboxane A2 (TXA2), and PGH2. They are named based on the prostanoid to which they preferentially bind and respond, e.g. the receptor responsive to PGI2 at lower concentrations than any other prostanoid is named the Prostacyclin receptor (IP). One exception to this rule is the receptor for thromboxane A2 (TP) which binds and responds to PGH2 and TXA2 equally well. All of the prostanoid receptors are G protein-coupled receptors belonging to the Subfamily A14 of the rhodopsin-like receptor family except for the Prostaglandin DP2 receptor which is more closely related in amino acid sequence and functionality to chemotactic factor receptors such as the receptors for C5a and leukotriene B4. Prostan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxoeicosanoid Receptor
Oxoeicosanoid receptor 1 (OXER1) also known as G-protein coupled receptor 170 (GPR170) is a protein that in humans is encoded by the OXER1 gene located on human chromosome 2p21; it is the principal receptor for the 5-Hydroxyicosatetraenoic acid family of carboxy fatty acid metabolites derived from arachidonic acid. The receptor has also been termed hGPCR48, HGPCR48, and R527 but OXER1 is now its preferred designation. OXER1 is a G protein-coupled receptor (GPCR) that is structurally related to the hydroxy-carboxylic acid (HCA) family of G protein-coupled receptors whose three members are HCA1 (GPR81), HCA2 ( Niacin receptor 1), and HCA3 ( Niacin receptor 2); OXER1 has 30.3%, 30.7%, and 30.7% amino acid sequence identity with these GPCRs, respectively. It is also related (30.4% amino acid sequence identity) to the recently defined receptor, GPR31, for the hydroxyl-carboxy fatty acid 12-HETE. Species and tissue distribution Orthologs of OXER1 are found in various mammalian s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eicosanoid Receptor
Most of the eicosanoid receptors are integral membrane protein G protein-coupled receptors (GPCRs) that bind and respond to eicosanoid signaling molecules. Eicosanoids are rapidly metabolized to inactive products and therefore are short-lived. Accordingly, the eicosanoid-receptor interaction is typically limited to a local interaction: cells, upon stimulation, metabolize arachidonic acid to an eicosanoid which then binds cognate receptors on either its parent cell (acting as an Autocrine signalling molecule) or on nearby cells (acting as a Paracrine signalling molecule) to trigger functional responses within a restricted tissue area, e.g. an inflammatory response to an invading pathogen. In some cases, however, the synthesized eicosanoid travels through the blood (acting as a hormone-like messenger) to trigger systemic or coordinated tissue responses, e.g. prostaglandin (PG) E2 released locally travels to the hypothalamus to trigger a febrile reaction (see ). An example of a no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPR99
2-Oxoglutarate receptor 1 (OXGR1), also known as cysteinyl leukotriene receptor E (CysLTE) and GPR99, is a protein that in humans is encoded by the (also termed ''GPR99'') gene. The Gene has recently been nominated as a receptor not only for 2-oxogluterate (see alpha-Ketoglutaric acid) but also for the three cysteinyl leukotrienes (CysLTs), particularly leukotriene E4 (LTE4) and to far lesser extents LTC4 and LTE4. Recent studies implicate GPR99 as a cellular receptor which is activated by LTE4 thereby causing these cells to contribute to mediating various allergic and hypersensitivity responses. History In 2001, a gene projected to code for a G protein-like receptor protein was reported; the gene's apparent protein product was classified as an orphan receptor (i.e., a receptor whose activating ligand and function were unknown) and named ''GPR80''. The projected amino acid sequence of the protein encoded by the ''GPR80'' gene bore similarities to a purinergic receptor, P2Y1, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteinyl Leukotriene Receptor 2
Cysteinyl leukotriene receptor 2, also termed CYSLTR2, is a receptor for cysteinyl leukotrienes (LT) (see leukotrienes#Cysteinyl leukotrienes). CYSLTR2, by binding these cysteinyl LTs (CysLTs; viz, LTC4, LTD4, and to a much lesser extent, LTE4) contributes to mediating various allergic and hypersensitivity reactions in humans. However, the first discovered receptor for these CsLTs, cysteinyl leukotriene receptor 1 (CysLTR1), appears to play the major role in mediating these reactions. Gene The human gene maps to the long arm of chromosome 13 at position 13q14, a chromosomal region that has long been linked to asthma and other allergic diseases. The gene consists of four exons with all introns located in the genes' 5' UTR region and the entire coding region located in the last exon. CysLTR2'' encodes a protein composed of 347 amino acids and shows only modest similarity to the ''CysLTR1'' gene in that its protein shares only 31% amino acid identity with the CysLTR1 protein. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukotriene E4
Leukotriene E4 (LTE4) is a cysteinyl leukotriene involved in inflammation. It is known to be produced by several types of white blood cells, including eosinophils, mast cells, tissue macrophages, and basophils, and recently was also found to be produced by platelets adhering to neutrophils. It is formed from the sequential conversion of LTC4 to LTD4 and then to LTE4, which is the final and most stable cysteinyl leukotriene. Compared to the short half lives of LTC4 and LTD4, LTE4 is relatively stable and accumulates in breath condensation, in plasma, and in urine, making it the dominant cysteinyl leukotriene detected in biologic fluids. Therefore, measurements of LTE4, especially in the urine, are commonly monitored in clinical research studies. Increased production and excretion of LTE4 has been linked to several respiratory diseases, and urinary LTE4 levels are increased during severe asthma attacks and are especially high in people with aspirin-induced asthma Aspirin exacerba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukotriene
Leukotrienes are a family of eicosanoid inflammatory mediators produced in leukocytes by the oxidation of arachidonic acid (AA) and the essential fatty acid eicosapentaenoic acid (EPA) by the enzyme arachidonate 5-lipoxygenase. Leukotrienes use lipid signaling to convey information to either the cell producing them (autocrine signaling) or neighboring cells (paracrine signaling) in order to regulate immune responses. The production of leukotrienes is usually accompanied by the production of histamine and prostaglandins, which also act as inflammatory mediators. One of their roles (specifically, leukotriene D4) is to trigger contractions in the smooth muscles lining the bronchioles; their overproduction is a major cause of inflammation in asthma and allergic rhinitis. Leukotriene antagonists are used to treat these disorders by inhibiting the production or activity of leukotrienes. History and name The name ''leukotriene'', introduced by Swedish biochemist Bengt Samuelss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukotriene D4
Leukotriene D4 (LTD4) is one of the leukotrienes. Its main function in the body is to induce the contraction of smooth muscle, resulting in bronchoconstriction and vasoconstriction. It also increases vascular permeability. LTD4 is released by basophils. Other leukotrienes that function in a similar manner are leukotrienes C4 and E4. Pharmacological agents that inhibit the function of these leukotrienes are leukotriene receptor antagonists (e.g., zafirlukast Zafirlukast is an orally administered leukotriene receptor antagonist (LTRA) used for the chronic treatment of asthma. While zafirlukast is generally well tolerated, headache and stomach upset often occur. Some rare side effects can occur, which ..., montelukast) and are useful for asthmatic individuals. References Eicosanoids {{biochemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukotriene C4
Leukotriene C4 (LTC4) is a leukotriene. LTC4 has been extensively studied in the context of allergy and asthma. In cells of myeloid origin such as mast cells, its biosynthesis is orchestrated by translocation to the nuclear envelope along with co-localization of cytosolic phospholipase A2 (cPLA2), Arachidonate 5-lipoxygenase (5-LO), 5-lipoxygenase-activating protein (FLAP) and LTC4 synthase (LTC4S), which couples glutathione to an LTA4 intermediate. The MRP1 transporter then secretes cytosolic LTC4 and cell surface proteases further metabolize it by sequential cleavage of the γ-glutamyl and glycine residues off its glutathione segment, generating the more stable products LTD4 and LTE4. All three leukotrienes then bind at different affinities to two G-protein coupled receptors: CYSLTR1 and CYSLTR2, triggering pulmonary vasoconstriction and bronchoconstriction. In cells of non-haematopoietic lineage, endoplasmic reticulum (ER) stress and chemotherapy induce LTC4 biosynthesi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
