This Article Full Text Full Text (PDF) All Versions of this Article: 148/5/1987    most recent Author Manuscript (PDF) Purchase Article View Shopping Cart 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 Thomas, R. M. Articles by Dias, J. A. Search for Related Content PubMed PubMed Citation Articles by Thomas, R. M. Articles by Dias, J. A.

Follice-Stimulating Hormone Receptor Forms Oligomers and Shows Evidence of Carboxyl-Terminal Proteolytic Processing

Wadsworth Center (R.M.T., C.A.N., J.A.D.), David Axelrod Institute for Public Health, New York State Department of Health, and Center for Neuropharmacology and Neuroscience (J.E.M.), Albany Medical College, Albany, New York 12208; Serono Reproductive Biology Institute (M.M., S.P), Serono Inc., Rockland, Massachusetts 02370; and Department of Biomedical Sciences (J.A.D.), State University of New York at Albany, Albany, New York 12201

Address all correspondence and requests for reprints to: James A. Dias, Ph.D., Wadsworth Center, David Axelrod Institute for Public Health, New York State Department of Health, 120 New Scotland Avenue, Albany, New York 12208. E-mail: james.dias{at}wadsworth.org.

FSH receptor (FSHR), a member of the G protein-coupled receptor superfamily, is present in the plasma membrane of ovarian granulosa cells and testicular Sertoli cells. FSH regulates normal ovarian follicle development and spermatogenesis through FSHR. The extracellular domain of FSHR is a weakly associated homodimer in the recently solved crystal structure of FSH in complex with the extracellular domain of FSHR. However, there is currently no biochemical data that demonstrate that FSHR exists as a dimer or higher-order oligomer in cell membranes. A fluorescence resonance energy transfer assay was used to determine whether full-length native FSHR is an oligomer. FSHR-specific monoclonal antibody or Fab fragments, labeled with two different fluorophores, allowed the study of nontagged receptor in situ. Unoccupied FSHR exhibited strong fluorescence resonance energy transfer profiles in situ. Complementary coimmunoprecipitation experiments of myc- or FLAG-tagged FSHR indicated that FSHR forms oligomers early in receptor biosynthesis. No effect of FSH treatment was observed. Thus, immature forms of FSHR, not yet fully processed, were observed to coimmunoprecipitate. An unexpected observation was made that the C-terminal epitope tags are removed from FSHR before arrival at the cell surface. These results provide the first evidence for oligomers of full-length FSHR in situ and for C-terminal proteolytic processing of FSHR and that both events take place during biosynthesis. This may explain how heterozygous mutations in the FSHR gene that affect receptor trafficking may be ameliorated by oligomer formation.

This article has been cited by other articles:

				A. Uribe, T. Zarinan, M. A. Perez-Solis, R. Gutierrez-Sagal, E. Jardon-Valadez, A. Pineiro, J. A. Dias, and A. Ulloa-Aguirre Functional and Structural Roles of Conserved Cysteine Residues in the Carboxyl-Terminal Domain of the Follicle-Stimulating Hormone Receptor in Human Embryonic Kidney 293 Cells Biol Reprod, May 1, 2008; 78(5): 869 - 882. [Abstract] [Full Text] [PDF]

				P. M. Conn, A. Ulloa-Aguirre, J. Ito, and J. A. Janovick G Protein-Coupled Receptor Trafficking in Health and Disease: Lessons Learned to Prepare for Therapeutic Mutant Rescue in Vivo Pharmacol. Rev., September 1, 2007; 59(3): 225 - 250. [Abstract] [Full Text] [PDF]