Airway epithelial secretory machinery

The airway epithelial secretory machinery is a coordinated system of proteins and organelles responsible for the regulated exocytosis of mucins and other protective factors from specialized cells, such as goblet cells and submucosal gland cells. This machinery relies on a core set of proteins including the SNARE (Soluble N-ethylmaleimide-sensitive factor Attachment protein REceptor) complex—specifically Syntaxin-3, SNAP-23, and VAMP-8—alongside regulatory proteins like Munc13-2, Munc18, and Synaptotagmin-2 (Davis & Dickey, 2008, Annual Review of Physiology). These components facilitate the docking, priming, and fusion of large mucin-containing granules with the apical plasma membrane in response to agonists like ATP or inflammatory mediators (Fahy & Dickey, 2010, NEJM). In chronic airway diseases such as asthma and COPD, the machinery is often upregulated or hyper-responsive, leading to pathological mucus hypersecretion and airway obstruction. Therapeutic targeting of this system, such as through the inhibition of the MARCKS protein which tethers granules to the cytoskeleton, aims to reduce excessive mucus release without completely abolishing the baseline secretion necessary for lung defense (Kim et al., 2015, American Journal of Respiratory Cell and Molecular Biology).

Other names

Mucus secretory apparatusAirway secretory pathwayExocytotic machinery of airway goblet cellsMucin secretory complex

Inhibition of vesicle docking and fusion, cleavage of SNARE proteins (e.g., SNAP-23), inhibition of MARCKS-mediated granule translocation, and disruption of Munc13-2-dependent priming of secretory granules.