A novel erythrocyte binding antigen-175 paralogue from Plasmodium falciparum defines a new trypsin-resistant receptor on human erythrocytes

J Biol Chem. 2003 Apr 18;278(16):14480-6. doi: 10.1074/jbc.M211446200. Epub 2003 Jan 29.

Abstract

The recognition and invasion of human erythrocytes by the most lethal malaria parasite Plasmodium falciparum is dependent on multiple ligand-receptor interactions. Members of the erythrocyte binding-like (ebl) family, including the erythrocyte binding antigen-175 (EBA-175), are responsible for high affinity binding to glycoproteins on the surface of the erythrocyte. Here we describe a paralogue of EBA-175 and show that this protein (EBA-181/JESEBL) binds in a sialic acid-dependent manner to erythrocytes. EBA-181 is expressed at the same time as EBA-175 and co-localizes with this protein in the microneme organelles of asexual stage parasites. The receptor binding specificity of EBA-181 to erythrocytes differs from other members of the ebl family and is trypsin-resistant and chymotrypsin-sensitive. Furthermore, using glycophorin B-deficient erythrocytes we show that binding of EBA-181 is not dependent on this sialoglycoprotein. The level of expression of EBA-181 differs among parasite lines, and the importance of this ligand for invasion appears to be strain-dependent as the EBA-181 gene can be disrupted in W2mef parasites, without affecting the invasion phenotype, but cannot be targeted in 3D7 parasites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens / metabolism
  • Antigens, Protozoan / chemistry*
  • Antigens, Protozoan / metabolism*
  • Antigens, Surface
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism
  • Chymotrypsin / pharmacology
  • Electrophoresis, Polyacrylamide Gel
  • Erythrocytes / immunology*
  • Erythrocytes / metabolism
  • Erythrocytes / parasitology*
  • Humans
  • Immunoblotting
  • Ligands
  • Microscopy, Fluorescence
  • Models, Genetic
  • Phenotype
  • Plasmids / metabolism
  • Plasmodium falciparum / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / metabolism
  • Recombination, Genetic
  • Sialoglycoproteins / chemistry
  • Time Factors
  • Transfection
  • Trypsin / pharmacology*

Substances

  • Antigens
  • Antigens, Protozoan
  • Antigens, Surface
  • Carrier Proteins
  • EBA-181 protein, Plasmodium falciparum
  • Ligands
  • Protozoan Proteins
  • Sialoglycoproteins
  • erythrocyte-binding antigen 175, Plasmodium
  • Chymotrypsin
  • Trypsin