Two-hybrid analysis of human salivary mucin MUC7 interactions
- Biochim Biophys Acta. 2005 Oct 30;1746(1):65-72. doi: 10.1016/j.bbamcr.2005.08.007.
- 1. Department of Biochemistry, Boston University Medical Center, Boston, MA 02118, USA.
MUC7 is a low molecular weight monomeric Mucin secreted by submandibular, sublingual and minor salivary glands. This Mucin has been implicated in the non-immune host defense system in the oral cavity since it binds and agglutinates a variety of oral microbes. To investigate interactions between this Mucin and Other secretory salivary proteins, a submandibular gland prey library was screened with baits encoding the N- and C-terminal regions of MUC7 in the yeast two-hybrid system. The N-terminal region interacted with several secretory salivary proteins, whereas the C-terminal region did not. Interacting proteins included amylase, acidic proline-rich protein 2, basic proline-rich protein 3, lacrimal proline-rich protein 4, statherin and histatin 1. Formation of complexes between these proteins and the N-terminal region of MUC7 was confirmed in Far Western blotting experiments. Interactions between Mucin and non-mucin proteins in saliva could protect complex partners from proteolysis, modulate the biological activity of complexed proteins or serve as a delivery system for distribution of secretory salivary proteins throughout the oral cavity.