Different Forms of TFF3 in the Human Saliva: Heterodimerization with IgG Fc Binding Protein (FCGBP)

Int J Mol Sci. 2019 Oct 10;20(20):5000. doi: 10.3390/ijms20205000.

Abstract

The peptide TFF3 is a member of a family of secretory lectins, and is typically synthesized by mucous epithelia together with mucins. It is mainly released from intestinal goblet cells as a high-molecular mass heterodimer with IgG Fc binding protein (FCGBP). Herein, we investigated human saliva by fast protein liquid chromatography (FPLC) and proteomics and identified high- and low-molecular-mass forms of TFF3. Whereas the high-molecular-mass forms represent a heterodimer with FCGBP, the low-molecular-mass forms represent homodimeric TFF3 forms. Proteomic analysis also revealed a C-terminally truncated form of TFF3. We hypothesize that salivary TFF3-FCGBP might play a role in the innate immune defense of the oral cavity and that TFF3 might also bind to microbial glycans. The known interaction of TFF3 with the agglutinin DMBT-1, a typical constituent of human saliva, further supports this protective role.

Keywords: DMBT1; FCGBP; IgG Fc binding protein; TFF3; lectin; mucin; saliva; trefoil factor.

MeSH terms

  • Calcium-Binding Proteins / metabolism
  • Cell Adhesion Molecules / chemistry*
  • Cell Adhesion Molecules / immunology
  • Cell Adhesion Molecules / metabolism*
  • DNA-Binding Proteins / metabolism
  • Dimerization*
  • Humans
  • Immunity, Innate
  • Polysaccharides
  • Protein Interaction Domains and Motifs
  • Proteomics
  • Saliva / immunology
  • Saliva / metabolism*
  • Trefoil Factor-3 / chemistry*
  • Trefoil Factor-3 / immunology
  • Trefoil Factor-3 / metabolism*
  • Tumor Suppressor Proteins / metabolism

Substances

  • Calcium-Binding Proteins
  • Cell Adhesion Molecules
  • DMBT1 protein, human
  • DNA-Binding Proteins
  • FCGBP protein, human
  • Polysaccharides
  • TFF3 protein, human
  • Trefoil Factor-3
  • Tumor Suppressor Proteins