Source:http://linkedlifedata.com/resource/pubmed/id/10493819
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
38
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| pubmed:dateCreated |
1999-10-28
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| pubmed:abstractText |
Binding of lutropin/choriogonadotropin (LH/CG) to its cognate receptor results in the activation of adenylyl cyclase and phospholipase C. This divergent signaling of the LH receptor is based on the independent activation of distinct G protein subfamilies, i.e. , Gs, Gi, and potentially also Gq. To examine the selectivity of LH receptor coupling to phospholipase C beta-activating G proteins, we used an in vivo reconstitution system based on the coexpression of the LH receptor and different G proteins in baculovirus-infected insect cells. In this paper, we describe a refined expression strategy for the LH receptor in insect cells. The receptor protein was inserted into the cell membrane at an expression level of 0.8 pmol/mg of membrane protein. Sf9 cells expressing the LH receptor responded to hCG challenge with a concentration-dependent accumulation of intracellular cAMP (EC50 = 630 nM) but not of inositol phosphates, whereas stimulation of the histamine H1 receptor in Sf9 cells led to increased phospholipase C (PLC) activity. Immunoblotting experiments using G protein-specific antisera revealed the absence of quantitative amounts of alpha i in Sf9 cells, whereas alpha s and alpha q/11 were detected. We therefore attempted to restore the hCG-dependent PLC activation by infection of Sf9 cells with viruses encoding the LH receptor and different G protein alpha subunits. HCG stimulation of cells coexpressing the LH receptor and exogenous alpha i2 resulted in stimulation of PLC activity. In cells coinfected with an alpha i3-baculovirus, hCG challenge led to a minor activation of PLC, whereas no hCG-dependent PLC stimulation was observed in cells coexpressing alpha i1. Most notably, coinfection with baculoviruses encoding alpha q or alpha 11 did not reproduce the PLC activation by the LH receptor. Thus, the murine LH receptor activates adenylyl cyclase via Gs and PLC via selective coupling to Gi2.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Chorionic Gonadotropin,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP,
http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Protein alpha Subunit...,
http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Protein alpha...,
http://linkedlifedata.com/resource/pubmed/chemical/Gnai2 protein, mouse,
http://linkedlifedata.com/resource/pubmed/chemical/Heterotrimeric GTP-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Inositol Phosphates,
http://linkedlifedata.com/resource/pubmed/chemical/Iodine Radioisotopes,
http://linkedlifedata.com/resource/pubmed/chemical/Proto-Oncogene Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, LH,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Type C Phospholipases
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| pubmed:status |
MEDLINE
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| pubmed:month |
Sep
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| pubmed:issn |
0006-2960
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:day |
21
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| pubmed:volume |
38
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
12490-8
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| pubmed:dateRevised |
2009-11-19
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| pubmed:meshHeading |
pubmed-meshheading:10493819-Animals,
pubmed-meshheading:10493819-Baculoviridae,
pubmed-meshheading:10493819-Cells, Cultured,
pubmed-meshheading:10493819-Chorionic Gonadotropin,
pubmed-meshheading:10493819-Cyclic AMP,
pubmed-meshheading:10493819-Enzyme Activation,
pubmed-meshheading:10493819-GTP-Binding Protein alpha Subunit, Gi2,
pubmed-meshheading:10493819-GTP-Binding Protein alpha Subunits, Gi-Go,
pubmed-meshheading:10493819-Genetic Vectors,
pubmed-meshheading:10493819-Guinea Pigs,
pubmed-meshheading:10493819-Heterotrimeric GTP-Binding Proteins,
pubmed-meshheading:10493819-Inositol Phosphates,
pubmed-meshheading:10493819-Iodine Radioisotopes,
pubmed-meshheading:10493819-Mice,
pubmed-meshheading:10493819-Protein Binding,
pubmed-meshheading:10493819-Proto-Oncogene Proteins,
pubmed-meshheading:10493819-Receptors, LH,
pubmed-meshheading:10493819-Recombinant Proteins,
pubmed-meshheading:10493819-Spodoptera,
pubmed-meshheading:10493819-Type C Phospholipases
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| pubmed:year |
1999
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| pubmed:articleTitle |
The luteinizing hormone receptor activates phospholipase C via preferential coupling to Gi2.
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| pubmed:affiliation |
Institut für Pharmakologie, Freie Universität Berlin, Germany.
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| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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