mucin-5B; MUC-5B; mucin-5 subtype B, tracheobronchial; high molecular weight salivary mucin MG1; sublingual gland mucin; cervical mucin (MUC5B, MUC5)

Function

• gel-forming mucin that is thought to contribute to the lubricating & viscoelastic properties of whole saliva & cervical mucus

Structure

• highly glycosylated
• S-, N- & O-gylcosylated
• S- mannosylated in the Cys-rich subdomains probably on the first Trp of the WXXW motif
• highly O-glycosylated in the Ser/Thr-rich tandem repeat region; the repeat region is about 59% O-glycosylated with a high abundance of neuAc(2)hex(1)hexNac1-ol
• the Cys in the Cys-rich subdomain repeats are not involved in disulfide bonding
• contains 1 CTCK (C-terminal cystine knot-like) domain
• contains 1 TIL (trypsin inhibitory-like) domain
• contains 3 VWFC domains
• contains 4 VWFD domains

Compartment

secreted

Expression

• 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, & pancreas
• regulated by all-trans-retinoic acid (cell-type specific)

More general terms

• mucin
• secreted protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=727897
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:727897
• OMIM: https://mirror.omim.org/entry/600770
• UniProt: http://www.uniprot.org/uniprot/Q9HC84.html