Angiotensin II receptors: one type coupled to two signals or receptor subtypes?
1987; Elsevier BV; Volume: 8; Issue: 2 Linguagem: Inglês
10.1016/0165-6147(87)90005-8
ISSN1873-3735
Autores Tópico(s)Ion channel regulation and function
ResumoThe carboxyl terminus of the type 1 angiotensin II receptor (AT1) plays an important role in receptor phosphorylation, desensitization, and internalization. The yeast two-hybrid system was employed to isolate proteins associated with the carboxyl terminal region of the AT1A receptor. In the present study, we report the isolation of a novel protein, ARAP1, which promotes recycling of AT1A to the plasma membrane in HEK-293 cells. ARAP1 cDNA encodes a 493-amino-acid protein and its mRNA is ubiquitously expressed in rat tissues. A complex of ARAP1 and AT1A was observed by immunoprecipitation and Western blotting in HEK-293 cells. In the presence of ARAP1, recycled AT1A showed a significant Ca2+ release response to a second stimulation by Ang II 30 min after the first treatment. Immunocytochemical analysis revealed co-localization of recycled AT1A and ARAP1 in the plasma membrane 45 min after the initial exposure to Ang II. Taken together, these results indicate a role for ARAP1 in the recycling of the AT1 receptor to the plasma membrane with presumable concomitant recovery of receptor signal functions.
Referência(s)