Negative reciprocity between angiotensin II type 1 and dopamine D1 receptors in rat renal proximal tubule cells.
Am J Physiol Renal Physiol
; 295(4): F1110-6, 2008 Oct.
Article
em En
| MEDLINE
| ID: mdl-18701624
ABSTRACT
Sodium excretion is bidirectionally regulated by dopamine, acting on D1-like receptors (D1R) and angiotensin II, acting on AT1 receptors (AT1R). Since sodium excretion has to be regulated with great precision within a short frame of time, we tested the short-term effects of agonist binding on the function of the reciprocal receptor within the D1R-AT1R complex in renal proximal tubule cells. Exposure of rat renal proximal tubule cells to a D1 agonist was found to result in a rapid partial internalization of AT1R and complete abolishment of AT1R signaling. Similarly, exposure of rat proximal tubule cells and renal tissue to angiotensin II resulted in a rapid partial internalization of D1R and abolishment of D1R signaling. D1R and AT1R were, by use of coimmunoprecipitation studies and glutathione-S-transferase pull-down assays, shown to be partners in a multiprotein complex. Na+-K+-ATPase, the target for both receptors, was included in this complex, and a region in the COOH-terminal tail of D1R (residues 397-416) was found to interact with both AT1R and Na+-K+-ATPase. Results indicate that AT1R and D1R function as a unit of opposites, which should provide a highly versatile and sensitive system for short-term regulation of sodium excretion.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Sódio
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Receptores de Dopamina D1
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Sinalização do Cálcio
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Receptor Tipo 1 de Angiotensina
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Túbulos Renais Proximais
Limite:
Animals
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article