MUC5B
Domain
The CTCK domain mediates interchain disulfide bonds with another molecule of MUC5B.
The cysteine residues in the Cys-rich subdomain repeats are not involved in disulfide bonding.
Function
Gel-forming mucin that is thought to contribute to the lubricating and viscoelastic properties of whole saliva and cervical mucus.
Involvement in disease
Interstitial lung disease 2
ILD2
A form of interstitial lung disease, a heterogeneous group of diseases affecting the distal part of the lung and characterized by a progressive remodeling of the alveolar interstitium. The disease spectrum ranges from idiopathic interstitial pneumonia or pneumonitis to idiopathic pulmonary fibrosis, that is associated with an increased risk of developing lung cancer. Clinical features of interstitial lung disease include dyspnea, clubbing of the fingers, and restrictive lung capacity. ILD2 inheritance is autosomal dominant.
None
Disease susceptibility is associated with variants affecting the gene represented in this entry. A common polymorphism in the promoter of MUC5B is associated with familial interstitial pneumonia and idiopathic pulmonary fibrosis, suggesting that dysregulated MUC5B expression in the lung may be involved in the pathogenesis of pulmonary fibrosis (PubMed:21506741).
Post-translational modifications
Highly glycosylated. C-, N- and O-glycosylated. C-mannosylated in the Cys-rich subdomains probably on the first Trp residue of the WXXW motif. Highly O-glycosylated in the Ser/Thr-rich tandem repeat (TR) region. The repeat region is about 59% O-glycosylated with a high abundance of NeuAc(2)Hex(1)HexNac1-ol.
Tissue Specificity
Expressed on surface airway epithelia. Expressed mainly in mucous cells of submucosal glands of airway tissues. Highly expressed in the sublingual gland. Also found in submaxillary glands, endocervix, gall bladder, and pancreas.
Cellular localization
- Secreted
Alternative names
MUC5, MUC5B, Mucin-5B, MUC-5B, Cervical mucin, High molecular weight salivary mucin MG1, Sublingual gland mucin