Salivary secretions contain two distinct mucins, a high molecular weight mucin named MG1 and a low molecular weight mucin named MG2. Mucins protect oral surfaces against desiccation, form a selectively permeable diffusion barrier between underlying surfaces and the external environment, lubricate hard and soft tissues to minimize mechanical injury, facilitate speech and swallowing and provide a physical barrier to protect against colonization of potentially harmful microbes and viruses. We have shown that MG1 is actually a mixture of mucin gene products, containing MUC4, MUC5B and a novel salivary mucin (NSM), whereas MG2 is a single gene product encoded in the MUC7 gene. MG1 and MG2 are differentially expressed in major and minor salivary glands and the overall goal of this project is to understand their structural features and functional properties.
The specific aims of this project are to: 1. determine the structural organization and sequence of mucin gene products comprising MG1 by characterization of a novel salivary mucin (NSM) and elucidating the C-terminal sequence of MUC4. 2. investigate the biosynthesis and assembly of MUC4, MUC5B and NSM using mucin constructs expressed in COS-7 cells. 3. evaluate interactions of MG2 with oral microbes and investigate MG2 heterotypic complexes with other salivary proteins in the yeast two hybrid system. 4. study expression of trefoil peptides in major and minor salivary glands using immunohistochemistry and in situ hybridization. 5. examine MG1 and MG2 levels in salivary secretions and whole saliva and determine secretion profiles using mucin-specific capture ELISAs.

National Institute of Health (NIH)
National Institute of Dental & Craniofacial Research (NIDCR)
Research Project (R01)
Project #
Application #
Study Section
Oral Biology and Medicine Subcommittee 1 (OBM)
Program Officer
Kousvelari, Eleni
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Boston University
Schools of Medicine
United States
Zip Code
Oppenheim, Frank G; Helmerhorst, Eva J; Lendenmann, Urs et al. (2012) Anti-candidal activity of genetically engineered histatin variants with multiple functional domains. PLoS One 7:e51479
Komatsu, Tomoko; Salih, Erdjan; Helmerhorst, Eva J et al. (2011) Influence of histatin 5 on Candida albicans mitochondrial protein expression assessed by quantitative mass spectrometry. J Proteome Res 10:646-55
Li, Xiaojing; Wang, Li; Nunes, David P et al. (2005) Suppression of MUC1 synthesis downregulates expression of the epidermal growth factor receptor. Cancer Biol Ther 4:968-73
Ruhl, S; Rayment, S A; Schmalz, G et al. (2005) Proteins in whole saliva during the first year of infancy. J Dent Res 84:29-34
Bruno, Lucila S; Li, Xiaojing; Wang, Li et al. (2005) Two-hybrid analysis of human salivary mucin MUC7 interactions. Biochim Biophys Acta 1746:65-72
Li, J; Helmerhorst, E J; Leone, C W et al. (2004) Identification of early microbial colonizers in human dental biofilm. J Appl Microbiol 97:1311-8
Li, J; Helmerhorst, E J; Troxler, R F et al. (2004) Identification of in vivo pellicle constituents by analysis of serum immune responses. J Dent Res 83:60-4
Soares, Rodrigo V; Lin, Thomas; Siqueira, Camille C et al. (2004) Salivary micelles: identification of complexes containing MG2, sIgA, lactoferrin, amylase, glycosylated proline-rich protein and lysozyme. Arch Oral Biol 49:337-43
Li, J; Helmerhorst, E J; Yao, Y et al. (2004) Statherin is an in vivo pellicle constituent: identification and immuno-quantification. Arch Oral Biol 49:379-85
Piludu, Marco; Rayment, Sean A; Liu, Bing et al. (2003) Electron microscopic immunogold localization of salivary mucins MG1 and MG2 in human submandibular and sublingual glands. J Histochem Cytochem 51:69-79

Showing the most recent 10 out of 30 publications