E. Mansson et al., ISOLATION OF A HUMAN KAPPA-OPIOID RECEPTOR CDNA FROM PLACENTA, Biochemical and biophysical research communications, 202(3), 1994, pp. 1431-1437
By using a mouse delta opioid receptor cDNA as a probe, a kappa opioid
receptor gene was isolated from a human genomic library. Reverse tran
scriptase/PCR was subsequently used to isolate the corresponding cDNA
from human placenta mRNA. Characterization of the cloned receptor with
a kappa agonist in transfected COS-7 cells, revealed a Kd Of 0.67nM,
which is similar to rodent kappa 1 receptors. In competition binding e
xperiments, non-kappa agonists had k(i)s > 1000nM. Furthermore, when e
xpressed in COS-7 cells, the kappa receptor is negatively linked to cA
MP. A Northern blot showed the presence of two transcripts, 6 and 7 kB
in size, in both placenta and brain mRNA, which hybridized to the kap
pa cDNA. (C) 1994 Academic Press, Inc.