What is the function of mucins?
Mucins are heavily O-glycosylated linear glycoproteins that are secreted by higher organisms to protect and lubricate epithelial cell surfaces. Mucin and mucin-like domains are also involved in modulating immune response, inflammation, adhesion, and tumorigenesis.
How does mucin protect the respiratory system?
Mucus plays a vital role in protecting the lungs from environmental factors, but conversely, in muco-obstructive airway disease, mucus becomes pathologic. In its protective role, mucus entraps microbes and particles removing them from the lungs via the co-ordinated beating of motile cilia.
What are the chemical nature and structure of mucins?
Mucins, major components of the extracellular mucus blanket that protect and lubricate mammalian epithelia, are high-molecular-mass glycoconjugates (154 to > or = 7,000 kDa) with hundreds of oligosaccharide chains in O-glycosidic linkages to a protein backbone.
What is a mucin anatomy?
Mucins are a family of large, heavily glycosylated proteins. Although some mucins are membrane bound due to the presence of a hydrophobic membrane-spanning domain that favors retention in the plasma membrane, the concentration here is on those mucins that are secreted on mucosal surfaces and saliva.
Where are mucins found in the body?
Mucins are large glycoproteins expressed by epithelial membranes and as components of the mucus secretions that cover epithelia in harsh environments – the air–water interface of the respiratory system, the acidic environment of the stomach, the complex environment of the intestinal tract, and secretory epithelial …
What are the types of mucins?
Histochemically mucins are classified into two types: Epithelial mucin (mucins/mucosubstances) and Connective tissue mucin (mucopolysaccharides). Epithelial mucins are further classified as neutral and acidic.
What is mucin production?
Mucin glycoproteins produced by mucus-producing cells in the epithelium or submucosal glands are the major macromolecular constituent of mucus and are responsible for the viscous properties of the mucus gel.
What mucin means?
Definition of mucin : any of various mucoproteins that occur especially in secretions of mucous membranes.
How are mucins made?
Mucins are high-molecular-weight glycoproteins, which are synthesized by major glands (except, parotid gland), and various minor salivary glands (eg, located in palatal, buccal, and labial mucosa) (Oppenheim et al., 2007; Kejriwal et al., 2014; Dawes et al., 2015).
What is the difference between mucin and mucus?
Mucins are glycoproteins which are components of mucus. Mucus comprises only mucins but is associated with other components such as anti-microbial peptides secreted by epithelial cells.
What is mucins in mucosa?
Mucins are found as cell surface (transmembrane) molecules on the luminal aspect of all mucosal epithelial cells and importantly, they also provide the molecular framework of the viscous fluid called mucus, which lies over the top of all mucosal epithelial surfaces.
What are acid mucins?
Acid mucins which carry a negative charge on the mucin molecules and can be classified as either simple (carboxyl group added) or complex (sulfuric acid group added). They are found widely throughout the gastrointestinal and respiratory tracts. Neutral mucins which lack acid groups and carry no charge.