cysteinyl leukotriene receptor activity

Definition

Target type: molecularfunction

Combining with a cysteinyl leukotriene to initiate a change in cell activity. Cysteinyl leukotrienes are leukotrienes that contain a peptide group based on cysteine. [GOC:ai, ISBN:0198506732]

Cysteinyl leukotriene receptors (CysLTRs), also known as leukotriene D4 receptors (LTD4Rs), are G protein-coupled receptors (GPCRs) that mediate the biological effects of cysteinyl leukotrienes (CysLTs), a family of potent lipid mediators involved in inflammatory and allergic responses. CysLTs, including leukotriene D4 (LTD4), leukotriene E4 (LTE4), and leukotriene C4 (LTC4), are produced by various cell types, particularly mast cells, during immune responses and allergic reactions. Upon binding to CysLTRs, CysLTs activate downstream signaling pathways, primarily through the G protein Gq, leading to a cascade of intracellular events, including:

* **Activation of phospholipase C (PLC):** Gq activation stimulates PLC, which hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol (DAG) and inositol trisphosphate (IP3).
* **Calcium release:** IP3 binds to its receptors on the endoplasmic reticulum, triggering the release of calcium ions (Ca2+) into the cytosol.
* **Activation of protein kinase C (PKC):** DAG activates PKC, a serine/threonine kinase involved in various cellular processes.
* **Activation of mitogen-activated protein kinases (MAPKs):** CysLTR activation can also activate MAPK signaling pathways, including ERK, JNK, and p38, leading to the regulation of gene expression and cell proliferation.

These intracellular events culminate in the physiological responses associated with CysLTR activation, including:

* **Bronchoconstriction:** CysLTs are potent bronchoconstrictors, contributing to the airway narrowing and difficulty breathing characteristic of asthma and other respiratory conditions.
* **Vascular permeability:** CysLTs increase vascular permeability, allowing fluid and immune cells to leak into tissues, leading to inflammation and edema.
* **Chemotaxis:** CysLTs attract and activate immune cells, such as neutrophils, eosinophils, and macrophages, to the site of inflammation.
* **Mucus production:** CysLTs stimulate mucus secretion in the airways, contributing to airway obstruction and difficulty breathing.

The CysLTR signaling pathway plays a critical role in the pathogenesis of allergic and inflammatory diseases, including asthma, rhinitis, and atopic dermatitis. Therefore, CysLTR antagonists, such as montelukast and zafirlukast, have become important therapeutic agents for the treatment of these conditions. These antagonists block the binding of CysLTs to their receptors, effectively inhibiting the downstream signaling events and reducing the inflammatory and allergic responses.
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Proteins (2)

Compounds (28)