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.
Department of Animal Biology, University of Pennsylvania, Philadelphia 19104, USA.
D K
DK
Yee
J N
JN
Heerding
M Z
MZ
Krichavsky
S J
SJ
Fluharty
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