Human μ Opioid
Receptor Expressed in Sf9 Insect Cells was
Functionally Coupled to Endogenous G Protein
WEI Qiang, WANG Tie-Lin, CHEN Jie, ZHOU De-He*
and CHI Zhi-Qiang
( Shanghai Institute of Materia Medica, the Chinese Academy of Sciences,
Shanghai 200031, China )
SHEN Qing-Xiang
( Shanghai Institute of Planted Parenthood, Shanghai 200032, China
)
Abstract Human μ opioid receptor(HμOR)
with a tag of six consecutive histidines at its carboxyl terminus overexpressed
in recombinant baculovirus infected Sf9 insect cells was demonstrated to be
functionally coupled to endogenous G proteins. Na+ and GTP could
reduce the affinity binding of etorphine and Ohmefentanyl(Ohm) to HμOR
overexpressed in Sf9. The binding of ［35S］GTPγS to Sf9 cell membranes
containing HμOR was stimulated by DAGO and Ohm. This stimulation could be
blocked by naloxone or the pretreatment of PTX. Also, DAGO and Ohm could
inhibit the increasing of intracellular cAMP stimulated by forskolin. The
results showed HμOR expressed in Sf9 insect cells were functionally coupled to
endogenous PTX sensitive Gi/o proteins.
Key Words human μ opioid receptor(HμOR)； endogenous G proteins； insect cells Sf9
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