Two-hybrid analysis of human salivary mucin MUC7 interactions.
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.
Bruno
Lucila S
LS
Department of Biochemistry, Boston University Medical Center, Boston, MA 02118, USA.
Li
Xiaojing
X
Wang
Li
L
Soares
Rodrigo V
RV
Siqueira
Camille C
CC
Oppenheim
Frank G
FG
Troxler
Robert F
RF
Offner
Gwynneth D
GD
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
C083238:MUC7 protein, human; D009077:Mucins; D012471:Salivary Proteins and Peptides