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Agonist‐dependent AT 4 receptor internalization in bovine aortic endothelial cells
Author(s) -
Briand Sandie I.,
Neugebauer Witold,
Guillemette Gaétan
Publication year - 1999
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/(sici)1097-4644(19991215)75:4<587::aid-jcb5>3.0.co;2-q
Subject(s) - internalization , agonist , chemistry , receptor , microbiology and biotechnology , pharmacology , medicine , biology , biochemistry
Recent studies have characterized a specific binding site for the C‐terminal 3‐8 fragment of angiotensin II (Ang IV). In the present study we looked at the internalization process of this receptor on bovine aortic endothelial cells (BAEC). Under normal culture conditions, BAEC efficiently internalized 125 I‐Ang IV as assessed by acid‐resistant binding. Internalization of 125 I‐Ang IV was considerably decreased after pretreatment of cells with hyperosmolar sucrose or after pretreatment of BAEC with inhibitors of endosomal acidification such as monensin or NH 4 Cl. About 50% of internalized 125 I‐Ang IV recycled back to the extracellular medium during a 2 h incubation at 37°C. 125 I‐Ang IV remained mostly intact during the whole process of internalization and recycling as assessed by thin layer chromatography. As expected, internalization of 125 I‐Ang IV was completely abolished by divalinal‐Ang IV, a known AT 4 receptor antagonist. Interestingly, 125 I‐divalinal‐Ang IV did not internalize into BAEC. These results suggest that AT 4 receptor undergoes an agonist‐dependent internalization and recycling process commonly observed upon activation of functional receptors. J. Cell. Biochem. 75:587–597, 1999. © 1999 Wiley‐Liss, Inc.