Chemotactic response of unicellular Tetrahymena to a leukocyte attractant peptide and its repellent derivative: evolutionary conclusions.

Chemotactic properties of the leukocyte chemoattractant N-formyl-Norleucine-Leucine-Phenylalanine (NLP) and its antagonist N-t-BOC-Norleucine-Leucine-Phenylalanine (BOC-NLP) were investigated in unicellular Tetrahymena pyriformis cells. NLP express its attractant character in a two-peak profile of concentration course (maximum at 10(-8)-10(-7) M and 10(-11) M) while BOC-NLP has a constant repellent character (maximum at 10(-12) M). The observed homology of action concurs with our theory about the wide evolutionary background of signal molecules and receptors.