title: Type 1 angiotensin II receptor-associated protein ARAP1 binds and recycles the receptor to the plasma membrane.
abstract: The carboxyl terminus of the type 1 angiotensin II receptor (AT(1)) 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 AT(1A) receptor. In the present study, we report the isolation of a novel protein, ARAP1, which promotes recycling of AT(1A) 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 AT(1A) was observed by immunoprecipitation and Western blotting in HEK-293 cells. In the presence of ARAP1, recycled AT(1A) showed a significant Ca(2+) release response to a second stimulation by Ang II 30 min after the first treatment. Immunocytochemical analysis revealed co-localization of recycled AT(1A) 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 AT(1) receptor to the plasma membrane with presumable concomitant recovery of receptor signal functions.
authors.affiliation: Research Centre, Hôtel-Dieu du CHUM, Department of Medicine, Université de Montréal, Montréal, Québec, Canada H2W 1T8. guod@magellan.umontreal.ca
authors.forename: Deng-Fu
authors.initials: DF
authors.lastname: Guo
authors.forename: Isabelle
authors.initials: I
authors.lastname: Chenier
authors.forename: Valerie
authors.initials: V
authors.lastname: Tardif
authors.forename: Sergei N
authors.initials: SN
authors.lastname: Orlov
authors.forename: Tadashi
authors.initials: T
authors.lastname: Inagami
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000091302:Angiopoietin-Like Protein 2; D000075802:Angiopoietin-like Proteins; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D018076:DNA, Complementary; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D011485:Protein Binding; D051381:Rats; D011945:Receptors, Angiotensin / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000091302:Angiopoietin-Like Protein 2; D000075802:Angiopoietin-like Proteins; C479625:Angptl2 protein, rat; D002352:Carrier Proteins; D018076:DNA, Complementary; D011945:Receptors, Angiotensin; D000804:Angiotensin II