mucin-7; MUC-7; salivary mucin-7; apo-MG2 (MUC7, MG2)

Function

• may function in a protective capacity by promoting the clearance of bacteria in the oral cavity & aiding in mastication, speech, & swallowing
• binds P aeruginosa pili

Structure

• N- & O-glycosylated. contains fucose, mannose, galactose, N-acetylglucosamine & N-acetylgalactosamine
• monomer

Compartment

secreted

Expression

• expressed in salivary gland tissues & only in those that contain mucous acinar cells (e.g. sublingual gland & submandibular gland) & not in salivary glands containing only serous acinar cells (e.g. parotid gland)

Pathology

• the MUC7*5 allele associated with susceptibility to asthma

Polymorphism

• the most common allele, MUC7*6, contains a tandem repeat domain comprising 6 repeats each composed of 23 amino acids
• these repeats are very similar but not identical
• in a large cohort of 375 individuals from a variety of ethnic backgrounds, 3 different alleles were detected, MUC7*6 being the most common, in all populations studied, followed by MUC7*5 (5 repeats), with frequency varying from 0.05 in Africans to 0.22 in East Asians
• MUC7*8 (8 repeats), a novel rare allele, was identified in 1 Northern European individual

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=4589
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:4589
• OMIM: https://mirror.omim.org/entry/158375
• OMIM: https://mirror.omim.org/entry/600807
• UniProt: http://www.uniprot.org/uniprot/Q8TAX7.html