Regulator of G protein signaling 4 suppresses basal and thyrotropin releasing-hormone (TRH)-stimulated signaling by two mouse TRH receptors, TRH-R(1) and TRH-R(2).
Endocrinology
; 142(3): 1188-94, 2001 Mar.
Article
em En
| MEDLINE
| ID: mdl-11181534
ABSTRACT
We cloned the mouse TRH receptor type 2 (mTRH-R2) gene, which is 92% identical with rat TRH-R2 and 50% identical with mTRH-R1 at the amino acid level, and identified an intron within the coding sequence that is not present in the TRH-R1 gene structure. Similar to its rat homolog, mTRH-R2 binds TRH with an affinity indistinguishable from mTRH-R1, signals via the phosphoinositide pathway like mTRH-R1, but exhibits a higher basal signaling activity than mTRH-R1. We found that regulator of G protein signaling 4 (RGS4), which differentially inhibits signaling by other receptors that couple to Gq, inhibits TRH-stimulated signaling via mTRH-R1 and mTRH-R2 to similar extents. In contrast, other RGS proteins including RGS7, RGS9, and GAIP had no effect on signaling by mTRH-R1 or mTRH-R2 demonstrating the specificity of RGS4 action. Interestingly, RGS4 markedly inhibited basal signaling by mTRH-R2. Inhibition of basal signaling of mTRH-R2 by RGS4 suggests that modulation of agonist-independent signaling may be an important mechanism of regulation of G protein-coupled receptor activity under normal physiologic circumstances.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
/
Hormônio Liberador de Tireotropina
/
Receptores do Hormônio Liberador da Tireotropina
/
Proteínas RGS
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Endocrinology
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Alemanha