CD91 interacts with mannan-binding lectin (MBL) through the MBL-associated serine protease-binding site

FEBS J. 2010 Dec;277(23):4956-64. doi: 10.1111/j.1742-4658.2010.07901.x. Epub 2010 Nov 5.

Abstract

CD91 plays an important role in the scavenging of apoptotic material, possibly through binding to soluble pattern-recognition molecules. In this study, we investigated the interaction of CD91 with mannan-binding lectin (MBL), ficolins and lung surfactant proteins. Both MBL and L-ficolin were found to bind CD91. The MBL-CD91 interaction was time- and concentration-dependent and could be inhibited by known ligands of CD91. MBL-associated serine protease 3 (MASP-3) also inhibited binding between MBL and CD91, suggesting that the site of interaction is located at or near the MASP-MBL interaction site. This was confirmed by using MBL mutants deficient for MASP binding that were unable to interact with CD91. These findings demonstrate that MBL and L-ficolin interact with CD91, strongly suggesting that they have the potential to function as soluble recognition molecules for scavenging microbial and apoptotic material by CD91.

MeSH terms

  • Amino Acid Substitution
  • Antigens, CD / chemistry*
  • Antigens, CD / metabolism*
  • Binding Sites / genetics
  • Calcium / metabolism
  • Humans
  • In Vitro Techniques
  • Kinetics
  • Lectins / chemistry
  • Lectins / metabolism
  • Ligands
  • Low Density Lipoprotein Receptor-Related Protein-1
  • Mannose-Binding Lectin / chemistry*
  • Mannose-Binding Lectin / genetics
  • Mannose-Binding Lectin / metabolism*
  • Mannose-Binding Protein-Associated Serine Proteases / chemistry*
  • Mannose-Binding Protein-Associated Serine Proteases / metabolism*
  • Mutagenesis, Site-Directed
  • Mutant Proteins / chemistry
  • Mutant Proteins / genetics
  • Mutant Proteins / metabolism
  • Protein Binding
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Surface Plasmon Resonance

Substances

  • Antigens, CD
  • LRP1 protein, human
  • Lectins
  • Ligands
  • Low Density Lipoprotein Receptor-Related Protein-1
  • MBL2 protein, human
  • Mannose-Binding Lectin
  • Mutant Proteins
  • Recombinant Proteins
  • ficolin
  • MASP1 protein, human
  • Mannose-Binding Protein-Associated Serine Proteases
  • Calcium