PACAP-38 is a chemorepellent and an agonist for the lysozyme receptor in tetrahymena thermophila.
Pituitary adenylate cyclase activating peptide (PACAP-38) is a peptide hormone which functions in many mammalian systems, including the nervous and digestive systems. Using in vivo behavioral studies, we have found that this hormone functions as a chemore-pellent in Tetrahymena thermophila with an EC50 of 10 nM. Cells previously adapted to PACAP-38 were found to be adapted to lysozyme and vice versa. Furthermore, the in vivo behavioral activity of PACAP-38 was blocked by addition of the anti-lysozyme receptor antibody, 5545. Chemorepellent activity of PACAP-38 was also inhibited by the addition of neomycin sulfate (inhibition constant Ki = 0.080 micromol x l(-1)), a competitive inhibitor of lysozyme binding to its receptor. PACAP-38 is a more potent and specific agonist for the lysozyme receptor than either intact lysozyme or CB2, a 24-amino acid fragment of lysozyme.
Mace
S R
SR
Cedarville College, Department of Science and Mathematics, OH 45134, USA.
Dean
J G
JG
Murphy
J R
JR
Rhodes
J L
JL
Kuruvilla
H G
HG
D000222:Adaptation, Physiological / Q000187:drug effects; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D003429:Cross Reactions; D009113:Muramidase / Q000494:pharmacology; D009355:Neomycin / Q000494:pharmacology; D009479:Neuropeptides / Q000494:pharmacology*; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D015800:Protozoan Proteins / Q000276:immunology / Q000378:metabolism; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D011979:Receptors, Pituitary Hormone / Q000819:agonists / Q000276:immunology / Q000378:metabolism*; D015290:Second Messenger Systems / Q000187:drug effects; D015398:Signal Transduction / Q000502:physiology; D016808:Tetrahymena thermophila / Q000737:chemistry / Q000187:drug effects*
D000906:Antibodies; D009479:Neuropeptides; D018377:Neurotransmitter Agents; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011500:Protein Synthesis Inhibitors; D015800:Protozoan Proteins; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D011979:Receptors, Pituitary Hormone; D009113:Muramidase; D009355:Neomycin