ABSTRACT
Mucin secretion in the airway epithelium acts as an essential barrier process that protects the upper respiratory tract from inhaled particles, environmental pathogens and toxicants. However, dysregulated mucin secretion contributes to pathophysiologic conditions such as rhinitis, asthma, and chronic obstructive pulmonary disease etc. The study on mucin hypersecretion has long been worked, but the exact molecular composition and mechanism for exocytic machinery remain mostly to be elucidated. The regulated mucin secretion, highly coordinated process, is mediated by the cooperative interaction of several proteins existing in the secretory granule, cytoplasm, and plasma membrane. This review provides the information on molecular components of the core exocytic machinery and their functional roles for mucin exocytosis in airway secretory cells.