Characterization of the pharmacology, signal transduction and internalization of the fluorescent PACAP ligand, fluor-PACAP, on NIH/3T3 cells expressing PAC1

• Published in: Peptides (New York, N.Y. : 1980) N.Y. : 1980), 2001-06, Vol.22 (6), p.861-866
• Main Authors: Germano, Patrizia M., Stalter, James, Le, Sang V., Wu, Mark, Yamaguchi, Dean J., Scott, David, Pisegna, Joseph R.
• Format: Article
• Language: English
• Subjects: 3T3 Cells; Adenylyl Cyclases - metabolism; Animals; Binding, Competitive; Confocal microscopy; Cyclic AMP - metabolism; DNA, Complementary - metabolism; Dose-Response Relationship, Drug; Fluo-PACAP; Fluorescent Dyes - pharmacology; Hydrazines - pharmacology; Immunohistochemistry; Ligands; Mice; Microscopy, Confocal; Neuropeptides - chemistry; Neuropeptides - pharmacology; NIH; PAC1; PACAP; Pharmacology; Pituitary Adenylate Cyclase-Activating Polypeptide; Protein Binding; Signal Transduction; Time Factors; Transfection
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/S0196-9781(01)00410-7

Fluor-PACAP, a fluorescent derivative of PACAP-27, has been confirmed to share a high affinity for PAC1 receptors transfected into NIH/3T3 cells and to have comparable pharmacological characteristics to the unconjugated, native form. Through competitive binding with 125I-PACAP-27, the two ligands exhibited similar dose- dependent inhibition. Additional examination of the efficacy of activating adenylyl cyclase revealed that both ligands analogously stimulated the production of cyclic AMP. Furthermore, PAC1 internalization visualized by our Fluor-PACAP, is compareable to that performed with the radioligand, 125I-PACAP-27, with maximal internalization achieved within thirty minutes. Thus, Fluor-PACAP exhibits intracellular signaling abilities homologous to the native ligand.