G protein-coupled receptor 30 (GPR30) forms a plasma membrane complex with membrane-associated guanylate kinases (MAGUKs) and protein kinase A-anchoring protein 5 (AKAP5) that constitutively inhibits cAMP production.
J Biol Chem
; 289(32): 22117-27, 2014 Aug 08.
Article
em En
| MEDLINE
| ID: mdl-24962572
ABSTRACT
GPR30, or G protein-coupled estrogen receptor, is a G protein-coupled receptor reported to bind 17ß-estradiol (E2), couple to the G proteins Gs and Gi/o, and mediate non-genomic estrogenic responses. However, controversies exist regarding the receptor pharmacological profile, effector coupling, and subcellular localization. We addressed the role of the type I PDZ motif at the receptor C terminus in receptor trafficking and coupling to cAMP production in HEK293 cells and CHO cells ectopically expressing the receptor and in Madin-Darby canine kidney cells expressing the native receptor. GPR30 was localized both intracellularly and in the plasma membrane and subject to limited basal endocytosis. E2 and G-1, reported GPR30 agonists, neither stimulated nor inhibited cAMP production through GPR30, nor did they influence receptor localization. Instead, GPR30 constitutively inhibited cAMP production stimulated by a heterologous agonist independently of Gi/o. Moreover, siRNA knockdown of native GPR30 increased cAMP production. Deletion of the receptor PDZ motif interfered with inhibition of cAMP production and increased basal receptor endocytosis. GPR30 interacted with membrane-associated guanylate kinases, including SAP97 and PSD-95, and protein kinase A-anchoring protein (AKAP) 5 in the plasma membrane in a PDZ-dependent manner. Knockdown of AKAP5 or St-Ht31 treatment, to disrupt AKAP interaction with the PKA RIIß regulatory subunit, decreased inhibition of cAMP production, and St-Ht31 increased basal receptor endocytosis. Therefore, GPR30 forms a plasma membrane complex with a membrane-associated guanylate kinase and AKAP5, which constitutively attenuates cAMP production in response to heterologous agonists independently of Gi/o and retains receptors in the plasma membrane.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Estrogênio
/
AMP Cíclico
/
Receptores Acoplados a Proteínas G
/
Guanilato Quinases
/
Proteínas de Ancoragem à Quinase A
/
Proteínas de Membrana
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2014
Tipo de documento:
Article