Advertisement

Acta Biologica Hungarica

, Volume 59, Supplement 2, pp 241–243 | Cite as

Functions of a GnRH Receptor Heterodimer of the Ascidian, Ciona intestinalis

  • T. SakaiEmail author
  • M. Aoyama
  • T. Kusakabe
  • M. Tsuda
  • H. Satake
Open Access
Short Communication

Abstract

Gonadotropin-releasing hormone (GnRH) is a ten-amino acid peptide hormone that plays pivotal roles in reproduction in vertebrates and octopus. Recently, six GnRH forms (t-GnRH-3-8) and four GnRH receptor subtypes (Ci-GnRHR-1-4) were identified in the protochordate, Ciona intestinalis. In this study, we show the functional modulation of Ci-GnRHR-1 via heterodimerization with the orphan receptor subtype, Ci-GnRHR-4. The dimerization between Ci-GnRHR-1 and R-4 was detected by co-immunoprecipitation and immunoblot analysis. Binding assays confirmed the binding of t-GnRHs to Ci-GnRHR-1 but not to R-4, and verified no alternation in ligand-binding affinity between Ci-GnRHR-1 homodimer and Ci-GnRHR1&4 heterodimer. The heterodimer was found to stimulate the elevation of intracellular calcium, time-extension of ERK phosphorylation, and up-regulation of cell proliferation, all in a ligand specific manner, compared with the Ci-GnRHR-1 homodimer. In combination, these results indicated that Ci-GnRHR-4 is not an inactive receptor, but a modulatory factor for Ci-GnRHR-1 in C. intestinalis.

Keywords

GnRH G protein-coupled receptors (GPCR) heterodimer 

References

  1. 1.
    Millar, R. P. et al. (2004) Gonadotropin-releasing hormone receptors. Endocrine Reviews. 25, 235–275.CrossRefGoogle Scholar
  2. 2.
    Satake, H., Sakai, T. (2006) Impact of heterodimers between G-protein-coupled receptors for peptides: New promising targets or burdensome issues in drug development? PharmaChem. October, 22–25.Google Scholar
  3. 3.
    Tello, J. A. et al. (2005) Tunicate Gonadotropin-releasing hormone (GnRH) peptides selectively activate Ciona intestinalis GnRH receptors and the green monkey type II GnRH receptor. Endocrinology. 146, 4061–4073.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest 2008

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  • T. Sakai
    • 1
    Email author
  • M. Aoyama
    • 1
  • T. Kusakabe
    • 2
  • M. Tsuda
    • 2
  • H. Satake
    • 1
  1. 1.Suntory Institute for Bioorganic ResearchOsakaJapan
  2. 2.Graduate School of Life ScienceUniversity of HyogoHyogoJapan

Personalised recommendations