Dk. Yee et al., CLONING AND EXPRESSION OF ANGIOTENSIN-II TYPE-2 (AT(2)) RECEPTORS FROM MURINE NEUROBLASTOMA N1E-115 CELLS - EVIDENCE FOR AT(2) RECEPTOR HETEROGENEITY, Molecular brain research, 45(1), 1997, pp. 108-116
Homology-based PCR was used to isolate an angiotensin II type 2 (AT(2)
) receptor cDNA from murine neuroblastoma N1E-115 cells. Despite subtl
e differences in the nucleotide sequence (the N1E-115 clone coded for
Phe(133) as TTC and Gln(326) as GAG; base substitutions are in bold-it
alics), the AT(2) receptor protein was identical to other reported mur
ine AT(2) clones. When transfected into COS-1 cells, the expressed AT(
2) receptor displayed high affinity for AngII and for AT(2)-selective
compounds, GTP gamma S-insensitive agonist binding and enhanced agonis
t binding by dithiothreitol. Previously, we have demonstrated that N1E
-115 cells possess two distinct subpopulations of AT, receptors, defin
ed as peak I and peak LU receptors, that can be separated by heparin-s
epharose chromatography. The two subpopulations differ pharmacological
ly, biochemically and immunologically. The binding properties of the c
loned AT(2) receptor closely resembled that of peak III receptors. Mor
eover, antisera raised against peak I AT(2) receptor failed to immunor
eact to either peak III receptors or cloned AT(2) receptors expressed
in COS-1 cells. Collectively, these data suggest that the cloned AT(2)
receptor is identical to peak III receptors from N1E-115 cells and th
at a novel AT(2) receptor (peak I) remains to be cloned.