Premium
The N‐terminal domain of GPR61, an orphan G‐protein‐coupled receptor, is essential for its constitutive activity
Author(s) -
Toyooka Masaru,
Tujii Takashi,
Takeda Shigeki
Publication year - 2008
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.21955
Subject(s) - orphan receptor , fusion protein , amino acid , gtpgammas , biology , transmembrane domain , mutant , alanine , receptor , microbiology and biotechnology , biochemistry , g protein , gene , recombinant dna , transcription factor
G‐protein‐coupled receptor 61 (GPR61) is an orphan receptor that is abundantly expressed in the brain, which suggests its involvement in various physiological functions in the central nervous system. It couples with Gs and shows constitutive activity. To investigate the role of the N‐terminal segment in the constitutive activity of GPR61, we measured [ 35 S]GTPγS binding using a GPR61‐Gs fusion protein and derivatives that had a deletion or alanine mutation in the N‐terminal segment. We found that deletion of the N‐terminal 25 amino acids and the V19A mutation in GPR61 impaired its constitutive activity. Moreover, the loss of the constitutive activity of the mutants could be restored by adding a fusion protein containing a C‐terminal CD8 single transmembrane domain and the N‐terminal 48‐amino‐acid segment of GPR61, i.e., CD8‐48. We conclude that the N‐terminal domain of GPR61 is required for maintaining its constitutive activity and functions as a tethered intramolecular ligand. © 2008 Wiley‐Liss, Inc.