The COOH-terminus of parathyroid hormone-related protein (PTHrP) interacts with β-arrestin 1B1

Abstract Parathyroid hormone-related protein (PTHrP) has a diverse range of proposed biological activities participating in both extracellular and intracellular signaling. In order to identify candidate protein effectors, yeast two-hybrid screens were conducted using mature human PTHrP (residues 1–141) and the COOH-terminus (residues 107–141). Both PTHrP baits interacted with a β-arrestin 1B fragment, an important component of G-protein-coupled receptor desensitization and MAPK signaling. Co-immunoprecipitation, in vitro binding assays and colocalization experiments confirmed this interaction in human cells and this required residues 122–141 of PTHrP. These findings suggest that β-arrestin 1 acts as an effector for a novel function of PTHrP in cytoplasm.