Galectin-1, a natural ligand for the receptor-type protein tyrosine phosphatase CD45

Immunol Lett. 1999 Apr 15;67(3):193-202. doi: 10.1016/s0165-2478(99)00012-7.


Galectin-1 binds preferentially to N-acetyllactosamine residues on oligosaccharides associated with several cell surface glycoconjugates. In the present work, placental galectin-1 has been identified to be a natural ligand for the receptor-type protein tyrosine phosphatase CD45. The binding of galectin-1 to CD45 was detected by affinity chromatography of NP 40 solubilized Jurkat T cell membranes on galectin-1 agarose followed by immunoblotting of the galectin-1 agarose bound fraction applying monoclonal antibodies to CD45 isoforms. The PTPase activity of the galectin-1 agarose binding membrane fraction could be inhibited by sodium orthovanadate. Preincubation of Jurkat T cell membrane preparations with galectin-1 decreased the membrane-associated PTPase activity in a concentration-dependent manner. Incubation of Jurkat cells with galectin-1 suppressed the immunoprecipitated PTPase activity of CD45. Galectin-1 stimulates the cell surface expression of phosphatidylserine an early indicator of apoptosis. In CD45+ Jurkat T cells, galectin-1 induces higher levels of phosphatidylserine when compared with CD45- Jurkat cells. These observations indicate that galectin-1-mediated ligation of CD45 is involved in the induction of apoptosis in Jurkat T cells.

MeSH terms

  • Apoptosis
  • Flow Cytometry
  • Galectin 1
  • Hemagglutinins / isolation & purification
  • Hemagglutinins / metabolism*
  • Humans
  • Immunoblotting
  • Jurkat Cells
  • Leukocyte Common Antigens / metabolism*
  • Ligands
  • Phosphatidylserines / metabolism
  • Protein Tyrosine Phosphatases / metabolism*


  • Galectin 1
  • Hemagglutinins
  • Ligands
  • Phosphatidylserines
  • Leukocyte Common Antigens
  • Protein Tyrosine Phosphatases