Molecular Endocrinology, Vol 9, 1240-1249, Copyright © 1995 by Endocrine Society

ARTICLES

Mutational analysis of the cytoplasmic tail of the G protein-coupled receptor for parathyroid hormone (PTH) and PTH-related protein: effects on receptor expression and signaling

Z Huang, Y Chen, S Pratt, TH Chen, T Bambino, DM Shoback and RA Nissenson
Endocrine Unit, Veterans Affairs Medical Center, San Francisco, California 94121, USA.

The present studies were undertaken to examine the role of the cytoplasmic tail of the G protein-coupled receptor for PTH and PTH- related protein (PTHrP) on receptor signaling and expression. The wild type (WT) receptor (585 amino acids) and five truncated receptors whose cytoplasmic tails terminated at residues 507, 494, 474, 466, and 458 were expressed in COS-7 cells. Based on [125I]PTHrP binding, mutants T507, T494, and T466 displayed progressively decreased levels of expression, compared with WT. The tailless mutant T458 was not expressed in a functional form, whereas T474 was expressed at a level similar to WT. Comparable results were obtained when expression levels of WT and mutated PTH/PTHrP receptors were evaluated by Western blotting. Binding affinities were similar for all mutated receptors (IC50 = 1-2 nM). Immunocytochemistry showed that WT and mutated receptors were diffusely distributed, presumably at the cell surface, except for the tailless mutant T458, which displayed striking perinuclear localization. T458 did not display an adenylyl cyclase response to PTH, while the other mutants were similar to WT both with respect to their maximal adenylyl cyclase responses to PTH and to their EC50 values. Cai2+ signaling properties of these mutants were assessed as PTH-stimulated 45Ca efflux from Xenopus oocytes that had been injected with in vitro transcribed PTH/PTHrP receptor cRNAs. The WT and mutated receptors (except for T458) responded to PTH with significant (6- to 27-fold) increases in 45Ca efflux.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				M. J. Mahon, T. M. Bonacci, P. Divieti, and A. V. Smrcka A Docking Site for G Protein {beta}{gamma} Subunits on the Parathyroid Hormone 1 Receptor Supports Signaling through Multiple Pathways Mol. Endocrinol., January 1, 2006; 20(1): 136 - 146. [Abstract] [Full Text] [PDF]

				C. Liu, G. Sandford, G. Fei, and J. Nicholas G{alpha} Protein Selectivity Determinant Specified by a Viral Chemokine Receptor-Conserved Region in the C Tail of the Human Herpesvirus 8 G Protein-Coupled Receptor J. Virol., March 1, 2004; 78(5): 2460 - 2471. [Abstract] [Full Text] [PDF]

				M. Castro, F. Dicker, J.-P. Vilardaga, C. Krasel, M. Bernhardt, and M. J. Lohse Dual Regulation of the Parathyroid Hormone (PTH)/PTH-Related Peptide Receptor Signaling by Protein Kinase C and {beta}-Arrestins Endocrinology, October 1, 2002; 143(10): 3854 - 3865. [Abstract] [Full Text] [PDF]

				J.-P. Vilardaga, C. Krasel, S. Chauvin, T. Bambino, M. J. Lohse, and R. A. Nissenson Internalization Determinants of the Parathyroid Hormone Receptor Differentially Regulate beta -Arrestin/Receptor Association J. Biol. Chem., March 1, 2002; 277(10): 8121 - 8129. [Abstract] [Full Text] [PDF]

				M. B. Wheeler, R. W. Gelling, S. A. Hinke, B. Tu, R. A. Pederson, F. Lynn, J. Ehses, and C. H. S. McIntosh Characterization of the Carboxyl-terminal Domain of the Rat Glucose-dependent Insulinotropic Polypeptide (GIP) Receptor. A ROLE FOR SERINES 426 AND 427 IN REGULATING THE RATE OF INTERNALIZATION J. Biol. Chem., August 27, 1999; 274(35): 24593 - 24601. [Abstract] [Full Text] [PDF]

				R. A. Nissenson Editorial: Parathyroid Hormone (PTH)/PTHrP Receptor Mutations in Human Chondrodysplasia Endocrinology, December 1, 1998; 139(12): 4753 - 4755. [Full Text] [PDF]

				A. E. Adams, A. Bisello, M. Chorev, M. Rosenblatt, and L. J. Suva Arginine 186 in the Extracellular N-Terminal Region of the Human Parathyroid Hormone 1 Receptor Is Essential for Contact with Position 13 of the Hormone Mol. Endocrinol., November 1, 1998; 12(11): 1673 - 1683. [Abstract] [Full Text]

				H. M. Sadeghi, G. Innamorati, and M. Birnbaumer An X-Linked NDI Mutation Reveals a Requirement for Cell Surface V2R Expression Mol. Endocrinol., June 1, 1997; 11(6): 706 - 713. [Abstract] [Full Text]

				A. T. Zhou, R. Bessalle, A. Bisello, C. Nakamoto, M. Rosenblatt, L. J. Suva, and M. Chorev Direct mapping of an agonist-binding domain within the parathyroid hormone/parathyroid hormone-related protein receptor by photoaffinity crosslinking PNAS, April 15, 1997; 94(8): 3644 - 3649. [Abstract] [Full Text] [PDF]

				S. K. Mathi, Y. Chan, X. Li, and M. B. Wheeler Scanning of the Glucagon-Like Peptide-1 Receptor Localizes G Protein-Activating Determinants Primarily to the N Terminus of the Third Intracellular Loop Mol. Endocrinol., April 1, 1997; 11(4): 424 - 432. [Abstract] [Full Text]

				Z. Huang, Y. Chen, S. Pratt, T.-H. Chen, T. Bambino, R. A. Nissenson, and D. M. Shoback The N-terminal Region of the Third Intracellular Loop of the Parathyroid Hormone (PTH)/PTH-related Peptide Receptor Is Critical for Coupling to cAMP and Inositol Phosphate/Ca2+ Signal Transduction Pathways J. Biol. Chem., December 27, 1996; 271(52): 33382 - 33389. [Abstract] [Full Text] [PDF]