Evidence for the activation of PAR-2 by the sperm protease, acrosin: expression of the receptor on oocytes Academic Article uri icon


  • Proteinase-activated receptor-2 (PAR-2) is a member of a family of G-protein-coupled, seven-transmembrane domain receptors that are activated by proteolytic cleavage. The receptor is expressed in a number of different tissues and potential physiological activators identified thus far include trypsin and mast cell tryptase. Acrosin, a trypsin-like serine proteinase found in spermatozoa of all mammals, was found to cleave a model peptide fluorescent quenched substrate representing the cleavage site of PAR-2. This substrate was cleaved with kinetics similar to those of the known PAR-2 activators, trypsin and mast cell tryptase. Acrosin was also shown to induce significant intracellular calcium responses in Chinese hamster ovary cells stably expressing intact human PAR-2, most probably due to activation of the receptor. Immunohistochemical studies using PAR-2 specific antibodies indicated that the receptor is expressed by mouse oocytes, which suggests that acrosin may play additional role(s) in the fertilization process via the activation of PAR-2 on oocytes.


  • Smith, Rosealee
  • Jenkins, Alison
  • Lourbakos, Afrodite
  • Thompson, Philip
  • Ramakrishnan, Vanitha
  • Tomlinson, Jim
  • Deshpande, Usha
  • Johnson, David A
  • Jones, Roy
  • Mackie, Eleanor J
  • Pike, Robert N

publication date

  • November 10, 2000