This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Horvat, R. D. Articles by Roess, D. A. Search for Related Content PubMed PubMed Citation Articles by Horvat, R. D. Articles by Roess, D. A.

Luteinizing Hormone Receptors Are Self-Associated in Slowly Diffusing Complexes during Receptor Desensitization

Cell and Molecular Biology Program (R.D.H.) Department of Chemistry (B.G.B.) and Department of Physiology (D.A.R.) Colorado State University Fort Collins, Colorado 80523

We have previously shown that rat LH receptors (LHRs) occupied by human CG (hCG) exhibit slow receptor lateral diffusion and are self-associated. Here we have examined whether LHRs become self-associated and enter slowly diffusing structures in response to hormone binding and whether these receptors retain this organization while in the desensitized state. Before hormone exposure, wild-type rat LHRs coupled at the C terminus to enhanced green fluorescent protein (GFP-LHR-wt) exhibited fast lateral diffusion, as assessed by fluorescent photobleaching recovery (FPR) methods, and most receptors were laterally mobile. After 30 min exposure to hCG and subsequent removal of hormone by low pH wash, hormone challenge at any time within the next 4 h produced no increase in cellular cAMP levels. During this time, LHRs were either laterally immobile or exhibited slower lateral diffusion. When LHRs were again responsive to binding of hormone, the rate of receptor lateral diffusion had become significantly faster and the fraction of mobile receptors was again large. Desensitized LHRs were also self-associated and present in microscopically visible clusters on the plasma membrane. Fluorescence energy transfer (FET) methods were used to measure the extent of interaction between receptors coupled to either GFP or to yellow fluorescent protein (YFP). Before hormone treatment, there was essentially no energy transfer between LHRs. After desensitization of the receptors by 30 min exposure to hCG, energy transfer efficiency increased to 18%. Values for FET efficiency between desensitized receptors decreased over time, and receptors were responsive to hormone only after measurable energy transfer had completely disappeared. Together these results suggest that desensitized LHRs exist in large, slowly diffusing structures containing self-associated receptors and that these structures must dissipate before the receptor can again respond to hormone.

This article has been cited by other articles:

				R. Guan, X. Feng, X. Wu, M. Zhang, X. Zhang, T. E. Hebert, and D. L. Segaloff Bioluminescence Resonance Energy Transfer Studies Reveal Constitutive Dimerization of the Human Lutropin Receptor and a Lack of Correlation between Receptor Activation and the Propensity for Dimerization J. Biol. Chem., March 20, 2009; 284(12): 7483 - 7494. [Abstract] [Full Text] [PDF]

				R. M. Thomas, C. A. Nechamen, J. E. Mazurkiewicz, M. Muda, S. Palmer, and J. A. Dias Follice-Stimulating Hormone Receptor Forms Oligomers and Shows Evidence of Carboxyl-Terminal Proteolytic Processing Endocrinology, May 1, 2007; 148(5): 1987 - 1995. [Abstract] [Full Text] [PDF]

				J.-P. Pin, R. Neubig, M. Bouvier, L. Devi, M. Filizola, J. A. Javitch, M. J. Lohse, G. Milligan, K. Palczewski, M. Parmentier, et al. International Union of Basic and Clinical Pharmacology. LXVII. Recommendations for the Recognition and Nomenclature of G Protein-Coupled Receptor Heteromultimers Pharmacol. Rev., March 1, 2007; 59(1): 5 - 13. [Abstract] [Full Text] [PDF]

				A. M. Navratil, T. A. Farmerie, J. Bogerd, T. M. Nett, and C. M. Clay Differential Impact of Intracellular Carboxyl Terminal Domains on Lipid Raft Localization of the Murine Gonadotropin-Releasing Hormone Receptor Biol Reprod, May 1, 2006; 74(5): 788 - 797. [Abstract] [Full Text] [PDF]

				S. M. L. Smith, Y. Lei, J. Liu, M. E. Cahill, G. M. Hagen, B. G. Barisas, and D. A. Roess Luteinizing Hormone Receptors Translocate to Plasma Membrane Microdomains after Binding of Human Chorionic Gonadotropin Endocrinology, April 1, 2006; 147(4): 1789 - 1795. [Abstract] [Full Text] [PDF]

				S. Costagliola, E. Urizar, F. Mendive, and G. Vassart Specificity and promiscuity of gonadotropin receptors Reproduction, September 1, 2005; 130(3): 275 - 281. [Abstract] [Full Text] [PDF]

				L. Cezanne, S. Lecat, B. Lagane, C. Millot, J.-Y. Vollmer, H. Matthes, J.-L. Galzi, and A. Lopez Dynamic Confinement of NK2 Receptors in the Plasma Membrane: IMPROVED FRAP ANALYSIS AND BIOLOGICAL RELEVANCE J. Biol. Chem., October 22, 2004; 279(43): 45057 - 45067. [Abstract] [Full Text] [PDF]

				D. A. Roess and S. M.L. Smith Self-Association and Raft Localization of Functional Luteinizing Hormone Receptors Biol Reprod, December 1, 2003; 69(6): 1765 - 1770. [Abstract] [Full Text] [PDF]

				M. Hunzicker-Dunn, G. Barisas, J. Song, and D. A. Roess Membrane Organization of Luteinizing Hormone Receptors Differs between Actively Signaling and Desensitized Receptors J. Biol. Chem., October 31, 2003; 278(44): 42744 - 42749. [Abstract] [Full Text] [PDF]

				R. Latif, P. Graves, and T. F. Davies Ligand-dependent Inhibition of Oligomerization at the Human Thyrotropin Receptor J. Biol. Chem., November 15, 2002; 277(47): 45059 - 45067. [Abstract] [Full Text] [PDF]

				M. C. Overton and K. J. Blumer The Extracellular N-terminal Domain and Transmembrane Domains 1 and 2 Mediate Oligomerization of a Yeast G Protein-coupled Receptor J. Biol. Chem., October 25, 2002; 277(44): 41463 - 41472. [Abstract] [Full Text] [PDF]

				I. Ji, C. Lee, Y. Song, P. M. Conn, and T. H. Ji Cis- and Trans-Activation of Hormone Receptors: the LH Receptor Mol. Endocrinol., June 1, 2002; 16(6): 1299 - 1308. [Abstract] [Full Text] [PDF]