Human Cysteinyl Leukotriene Receptor 1 (CYSLTR1) Protein

Background

CYSLTR1 is a G protein-coupled receptor (GPCR) that binds cysteinyl leukotrienes (CysLTs), including leukotriene C4 (LTC4), leukotriene D4 (LTD4), and leukotriene E4 (LTE4). It is highly expressed in smooth muscle cells, mast cells, eosinophils, and airway epithelial cells. CYSLTR1 signaling plays a central role in allergic and inflammatory responses, particularly in asthma and allergic rhinitis, where it mediates bronchoconstriction, vascular permeability, and mucus production. Activation of CYSLTR1 triggers the phospholipase C (PLC) pathway, leading to calcium mobilization and smooth muscle contraction. CYSLTR1 is also implicated in chronic inflammatory diseases such as atopic dermatitis and cardiovascular disorders. Its overactivation exacerbates tissue damage, airway hyperresponsiveness, and immune cell recruitment. Leukotriene receptor antagonists (LTRAs), such as montelukast and zafirlukast, target CYSLTR1 and are used clinically to manage asthma and allergic inflammation by blocking cysteinyl leukotriene signaling. CYSLTR1 remains a critical therapeutic target for allergic and inflammatory diseases.