title: Identification of a human ortholog of the mouse Dcpp gene locus, encoding a novel member of the CSP-1/Dcpp salivary protein family.
abstract: Salivary fluid, the collective product of numerous major and minor salivary glands, contains a range of secretory proteins that play key defensive, digestive, and gustatory roles in the oral cavity. To understand the distinct protein "signature" contributed by individual salivary glands to salivary secretions, we studied a family of proteins shown by in vitro mRNA translation to be abundantly expressed in mouse sublingual glands. Molecular cloning, Southern blotting, and restriction fragment length polymorphism analyses showed these to represent one known and two novel members of the common salivary protein (CSP-1)/Demilune cell and parotid protein (Dcpp) salivary protein family, the genes for which are closely linked in the T-complex region of mouse chromosome 17. Bioinformatic analysis identified a putative human CSP-1/Dcpp ortholog, HRPE773, expressed predominantly in human salivary tissue, that shows 31% amino acid identity and 45% amino acid similarity to the mouse Dcpp query sequence. The corresponding human gene displays a similar structure to the mouse Dcpp genes and is located on human chromosome 16 in a region known to be syntenic with the T-complex region of mouse chromosome 17. The predicted mouse and human proteins both display classical NH(2)-terminal signal sequences, putative jacalin-related lectin domains, and potential N-linked glycosylation sites, suggesting secretion via sublingual saliva into the oral cavity where they may display antimicrobial activity or provide a defensive coating to enamel. Identification of a human CSP-1/Dcpp ortholog therefore provides a key tool for investigation of salivary protein function in human oral health and disease.
authors.affiliation: Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh Medical School, Edinburgh, UK. j.mullins@ed.ac.uk
authors.forename: John J
authors.initials: JJ
authors.lastname: Mullins
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Mullins
authors.forename: Donald R
authors.initials: DR
authors.lastname: Dunbar
authors.forename: William J
authors.initials: WJ
authors.lastname: Brammar
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Gross
authors.forename: Steven D
authors.initials: SD
authors.lastname: Morley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015139:Blotting, Southern; D002886:Chromosomes, Human, Pair 17; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D011257:Pregnancy Proteins / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012471:Salivary Proteins and Peptides / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D011257:Pregnancy Proteins; D011506:Proteins; D012333:RNA, Messenger; D012471:Salivary Proteins and Peptides; C517340:ZG16B protein, human; C084798:common salivary protein 1, rat; C507434:demilune cell and parotid protein, mouse