Regulation of angiotensin II type 1 (AT(1)) receptor function

The type 1 angiotensin receptor (AT(1)) mediates the important biological a ctions of the peptide hormone, angiotensin II (AngII), by activating an arr ay of intracellular signaling pathways. The unique temporal arrangement and duration of AngII-stimulated signals suggests a hierarchy of post-AT(1) re ceptor binding events that permits activation of selective effector pathway s. Moreover, it predicts that the coupling of AT(1) receptors is tightly re gulated, allowing cells to differentiate acute responses from those requiri ng longer periods of stimulation. Recent studies have concentrated on delin eating the molecular processes involved in modulating AT(1) receptor activi ty. In addition to AT(1) receptor modification (phosphorylation), trafficki ng (internalization and degradation) and interaction with regulatory intrac ellular proteins, other processes may include receptor dimerization, cross- regulation by other receptor systems, and receptor isomerization between ac tivated and non-activated forms. This review focuses on recent advances in this area of research, highlighting directions for future investigation. (C ) 1999 Elsevier Science B.V. All rights reserved.