Role of the amino terminus in ligand binding for the angiotensin II type 2 receptor.
Key amino terminal residues in type 1 (AT1) angiotensin II (AngII) receptors are not conserved within type 2 (AT2) receptors. We therefore characterized amino terminal mutants that are transiently expressed in COS-3 membranes. AT2 amino terminal deletion drastically reduced affinity for AngII, suggesting its importance for this subtype. AT1-AT2 amino terminal exchanges retained wild type AngII affinities (Kd ranging from 3-5 nM), indicating compensation despite substantial sequence dissimilarities. Finally, binding of AT2 selective ligands (CGP42112A and PD123319) was not dependent on the amino terminus.
Yee
D K
DK
Department of Animal Biology, University of Pennsylvania, Philadelphia 19104, USA.
Heerding
J N
JN
Krichavsky
M Z
MZ
Fluharty
S J
SJ
D000595:Amino Acid Sequence; D001667:Binding, Competitive; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D011869:Radioligand Assay; D011945:Receptors, Angiotensin / Q000235:genetics / Q000378:metabolism*
D011945:Receptors, Angiotensin