This gene encodes a member of the mucin family of proteins, which are highly glycosylated macromolecular components of mucus secretions. This family member is the major gel-forming mucin in mucus. It is a major contributor to the lubricating and viscoelastic properties of whole saliva, normal lung mucus and cervical mucus. This gene has been found to be up-regulated in some human diseases, including sinus mucosa of chronic rhinosinusitis (CRS), CRS with nasal polyposis, chronic obstructive pulmonary disease (COPD) and H. pylori-associated gastric disease, and it may be involved in the pathogenesis of these diseases. [provided by RefSeq, Jul 2010],domain: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.,induction:Regulated by all-trans-retinoic acid in a cell-type specific manner.,PTM:Highly glycosylated. C-, N- and O-gylcosylated. 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.,similarity:Contains 1 CTCK (C-terminal cystine knot-like) domain.,similarity:Contains 1 TIL (trypsin inhibitory-like) domain.,similarity:Contains 3 VWFC domains.,similarity:Contains 4 VWFD domains.,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.,
