Role of the second and third intracellular loops of metabotropic glutamate receptors in mediating dual signal transduction activation

Anna Francesconi, Robert Duvoisin

Research output: Contribution to journalArticle

128 Citations (Scopus)

Abstract

On the basis of sequence homology and structural similarities, metabotropic glutamate receptors (mGluRs), extracellular Ca2+-sensing receptor, γ-aminobutyric acid type B receptor, and pheromone receptors are enlisted in a distinct family within the larger G protein-coupled receptor superfamily. When expressed in heterologous systems, group I mGluRs can activate dual signal transduction pathways, phosphoinositides turnover and cAMP production. To investigate the structural basis of these coupling properties, we introduced single amino acid substitutions within the second and third intracellular loops (i2 and i3) of mGluR1α. Wild-type and mutant receptors were expressed in human embryonic kidney 293 cells and analyzed for their capacity to stimulate both signaling cascades. Each domain appeared to be critical for the coupling to phospholipase C and adenylyl cyclase. Within i2, Thr695, Lys697, and Ser702 were found to be selectively involved in the interaction with G(q) class α subunit(s), whereas mutation of Pro695 and the deletion Cys694-Thr695 affected only G(s) coupling. Furthermore, the mutation K690A profoundly altered mGluR1α signaling properties and imparted to the receptor the ability to couple to the inhibitory cAMP pathway. Within i3, we uncovered two residues, Arg775 and Phe781, that are crucial for coupling to both pathways, since their substitution leads to receptor inactivation.

Original languageEnglish (US)
Pages (from-to)5615-5624
Number of pages10
JournalJournal of Biological Chemistry
Volume273
Issue number10
DOIs
StatePublished - Mar 6 1998
Externally publishedYes

Fingerprint

Signal transduction
Metabotropic Glutamate Receptors
Signal Transduction
Substitution reactions
Pheromone Receptors
Chemical activation
Aminobutyrates
Calcium-Sensing Receptors
Sequence Deletion
Type C Phospholipases
Amino Acid Substitution
Sequence Homology
G-Protein-Coupled Receptors
Phosphatidylinositols
Adenylyl Cyclases
Kidney
Amino Acids
Mutation
metabotropic glutamate receptor type 1

ASJC Scopus subject areas

  • Biochemistry

Cite this

Role of the second and third intracellular loops of metabotropic glutamate receptors in mediating dual signal transduction activation. / Francesconi, Anna; Duvoisin, Robert.

In: Journal of Biological Chemistry, Vol. 273, No. 10, 06.03.1998, p. 5615-5624.

Research output: Contribution to journalArticle

@article{9328c99b55d9497da7f6dbdfdfd91e87,
title = "Role of the second and third intracellular loops of metabotropic glutamate receptors in mediating dual signal transduction activation",
abstract = "On the basis of sequence homology and structural similarities, metabotropic glutamate receptors (mGluRs), extracellular Ca2+-sensing receptor, γ-aminobutyric acid type B receptor, and pheromone receptors are enlisted in a distinct family within the larger G protein-coupled receptor superfamily. When expressed in heterologous systems, group I mGluRs can activate dual signal transduction pathways, phosphoinositides turnover and cAMP production. To investigate the structural basis of these coupling properties, we introduced single amino acid substitutions within the second and third intracellular loops (i2 and i3) of mGluR1α. Wild-type and mutant receptors were expressed in human embryonic kidney 293 cells and analyzed for their capacity to stimulate both signaling cascades. Each domain appeared to be critical for the coupling to phospholipase C and adenylyl cyclase. Within i2, Thr695, Lys697, and Ser702 were found to be selectively involved in the interaction with G(q) class α subunit(s), whereas mutation of Pro695 and the deletion Cys694-Thr695 affected only G(s) coupling. Furthermore, the mutation K690A profoundly altered mGluR1α signaling properties and imparted to the receptor the ability to couple to the inhibitory cAMP pathway. Within i3, we uncovered two residues, Arg775 and Phe781, that are crucial for coupling to both pathways, since their substitution leads to receptor inactivation.",
author = "Anna Francesconi and Robert Duvoisin",
year = "1998",
month = "3",
day = "6",
doi = "10.1074/jbc.273.10.5615",
language = "English (US)",
volume = "273",
pages = "5615--5624",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "10",

}

TY - JOUR

T1 - Role of the second and third intracellular loops of metabotropic glutamate receptors in mediating dual signal transduction activation

AU - Francesconi, Anna

AU - Duvoisin, Robert

PY - 1998/3/6

Y1 - 1998/3/6

N2 - On the basis of sequence homology and structural similarities, metabotropic glutamate receptors (mGluRs), extracellular Ca2+-sensing receptor, γ-aminobutyric acid type B receptor, and pheromone receptors are enlisted in a distinct family within the larger G protein-coupled receptor superfamily. When expressed in heterologous systems, group I mGluRs can activate dual signal transduction pathways, phosphoinositides turnover and cAMP production. To investigate the structural basis of these coupling properties, we introduced single amino acid substitutions within the second and third intracellular loops (i2 and i3) of mGluR1α. Wild-type and mutant receptors were expressed in human embryonic kidney 293 cells and analyzed for their capacity to stimulate both signaling cascades. Each domain appeared to be critical for the coupling to phospholipase C and adenylyl cyclase. Within i2, Thr695, Lys697, and Ser702 were found to be selectively involved in the interaction with G(q) class α subunit(s), whereas mutation of Pro695 and the deletion Cys694-Thr695 affected only G(s) coupling. Furthermore, the mutation K690A profoundly altered mGluR1α signaling properties and imparted to the receptor the ability to couple to the inhibitory cAMP pathway. Within i3, we uncovered two residues, Arg775 and Phe781, that are crucial for coupling to both pathways, since their substitution leads to receptor inactivation.

AB - On the basis of sequence homology and structural similarities, metabotropic glutamate receptors (mGluRs), extracellular Ca2+-sensing receptor, γ-aminobutyric acid type B receptor, and pheromone receptors are enlisted in a distinct family within the larger G protein-coupled receptor superfamily. When expressed in heterologous systems, group I mGluRs can activate dual signal transduction pathways, phosphoinositides turnover and cAMP production. To investigate the structural basis of these coupling properties, we introduced single amino acid substitutions within the second and third intracellular loops (i2 and i3) of mGluR1α. Wild-type and mutant receptors were expressed in human embryonic kidney 293 cells and analyzed for their capacity to stimulate both signaling cascades. Each domain appeared to be critical for the coupling to phospholipase C and adenylyl cyclase. Within i2, Thr695, Lys697, and Ser702 were found to be selectively involved in the interaction with G(q) class α subunit(s), whereas mutation of Pro695 and the deletion Cys694-Thr695 affected only G(s) coupling. Furthermore, the mutation K690A profoundly altered mGluR1α signaling properties and imparted to the receptor the ability to couple to the inhibitory cAMP pathway. Within i3, we uncovered two residues, Arg775 and Phe781, that are crucial for coupling to both pathways, since their substitution leads to receptor inactivation.

UR - http://www.scopus.com/inward/record.url?scp=0032489519&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032489519&partnerID=8YFLogxK

U2 - 10.1074/jbc.273.10.5615

DO - 10.1074/jbc.273.10.5615

M3 - Article

C2 - 9488690

AN - SCOPUS:0032489519

VL - 273

SP - 5615

EP - 5624

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 10

ER -