Differential desensitization and internalization of three different bullfrog gonadotropin-releasing hormone receptors

Sujata Acharjee, Kaushik Maiti, Jae Mok Soh, Wook B. Im, Jae Young Seong, Hyuk Bang Kwon

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

We previously demonstrated the presence of three distinct types of the gonadotropin-releasing hormone receptor (GnRHR) in a bullfrog (denoted bfGnRHR-1, bfGnRHR-2, and bfGnRHR-3). The bfGnRHRs exhibited differential tissue distribution and ligand selectivity. In the present study, we demonstrated the desensitization and internalization kinetics of these receptors in both transiently-transfected HEK293 cells and retrovirus-mediated stable cells. The time-course accumulation of the inositol phosphate in response to GnRH revealed that bfGnRHR-1 and -2 were rapidly desensitized, whereas bfGnRHR-3 was slowly desensitized. A comparison of the internalization kinetics revealed the most rapid rate and highest extent of internalization of bfGnRHR-2 among the three receptors. Interestingly, the mechanisms that underlie the receptor internalization appear to differ from each other. Internalization of bfGnRHR-1 was dependent on both dynamin and β-arrestin, whereas those of bfGnRHR-2 and -3 were dependent on dynamin, but not on β-arrestin. These results, therefore, suggest that differential regulatory mechanisms for desensitization and internalization of the GnRHR are involved in diverse cellular and physiological responses to GnRH stimulation.

Original languageEnglish
Pages (from-to)101-107
Number of pages7
JournalMolecules and Cells
Volume14
Issue number1
Publication statusPublished - 2002 Aug 1
Externally publishedYes

    Fingerprint

Keywords

  • β-Arrestin
  • Bullfrog
  • Desensitization
  • Dynamin
  • Gonadotropin-releasing hormone receptor (GnRHR)
  • Internalization

ASJC Scopus subject areas

  • Cell Biology
  • Genetics
  • Molecular Biology

Cite this