Human 5-HT1A receptor expressed in insect cells activates endogenous G(o)-like G protein(s)
Insect cell expression systems are used to characterize signaling components such as G protein-coupled receptors. As such, one must know whether endogenous G proteins couple to non-native receptors. We examined G protein linkages after infection of Sporodoptera frugiperda (Sf9) cells with a baculovi...
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Published in | The Journal of biological chemistry Vol. 269; no. 17; pp. 12954 - 12962 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Biochemistry and Molecular Biology
29.04.1994
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Subjects | |
Online Access | Get full text |
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Summary: | Insect cell expression systems are used to characterize signaling components such as G protein-coupled receptors. As such,
one must know whether endogenous G proteins couple to non-native receptors. We examined G protein linkages after infection
of Sporodoptera frugiperda (Sf9) cells with a baculovirus encoding the 5-HT1A receptor. Receptor expression was confirmed
by immunoblot. Some of the receptors were functional, showing guanine nucleotide-sensitive binding to the specific agonist
ligand [3H]8-hydroxy-2-(di-n-propylamino)-1,2,3,4-tetranaphthalene). Peak expression (approximately 150 fmol/mg of membrane
protein) was attained approximately 72-96 h post-infection. 5-HT-increased covalent binding of [32P]GTP-azidoanilide to a
40 kDa band, which was identified as a G protein by nucleotide blocking, Mg2+ dependence, and immunoblot and immunoprecipitation
studies. The band comigrated with 1) pertussis toxin substrate(s), and 2) a band recognized by two G(o) alpha antisera and
one common to heterotrimeric G protein alpha-subunits, but not by sera specific for Gs alpha or G(i) alpha. Labeled species
could be precipitated with a G(o) alpha antiserum. 5-HT-increased labeling of the band was prevented by preincubation with
pertussis toxin. These studies suggest that the 5-HT1A receptor couples effectively to native insect cell G(o)-like proteins. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/s0021-9258(18)99968-0 |