title: Two-hybrid analysis of human salivary mucin MUC7 interactions.
abstract: 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.
authors.affiliation: Department of Biochemistry, Boston University Medical Center, Boston, MA 02118, USA.
authors.forename: Lucila S
authors.initials: LS
authors.lastname: Bruno
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Rodrigo V
authors.initials: RV
authors.lastname: Soares
authors.forename: Camille C
authors.initials: CC
authors.lastname: Siqueira
authors.forename: Frank G
authors.initials: FG
authors.lastname: Oppenheim
authors.forename: Robert F
authors.initials: RF
authors.lastname: Troxler
authors.forename: Gwynneth D
authors.initials: GD
authors.lastname: Offner
mesh_terms: D000595:Amino Acid Sequence; D026481:Blotting, Far-Western; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D009077:Mucins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D015203:Reproducibility of Results; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012463:Saliva / Q000737:chemistry*; D012471:Salivary Proteins and Peptides; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques
chemical_list: C083238:MUC7 protein, human; D009077:Mucins; D012471:Salivary Proteins and Peptides