MacMARCKS interacts with the metabotropic glutamate receptor type 7 and modulates G protein-mediated constitutive inhibition of calcium channels.
We have previously shown that the interaction of Ca2+/calmodulin with the metabotropic glutamate receptor type 7 (mGluR7) promotes the G-protein-mediated inhibition of voltage-sensitive Ca2+ channels (VSCCs) seen upon agonist activation. Here, we performed a yeast two-hybrid screen of a new-born rat brain cDNA library using the cytoplasmic C-terminal tail of mGluR7 as bait and identified macrophage myristoylated alanine-rich c-kinase substrate (MacMARCKS) as a binding protein. The interaction was confirmed in vitro and in vivo by pull-down assays, immunoprecipitation, and colocalization of mGluR7 and MacMARCKS in transfected HEK293 cells and cultured cerebellar granule cells. Binding of MacMARCKS to mGluR7 was antagonized by Ca2+/calmodulin. In neurons, cotransfection of MacMARCKS with mGluR7, but not mGluR7 mutants unable to bind MacMARCKS, reduced the G-protein-mediated tonic inhibition of VSCCs in the absence of mGluR7 agonist. These results suggest that competitive interactions of Ca2+/calmodulin and MacMARCKS with mGluR7 control the tonic inhibition of VSCCs by G-proteins.
Bertaso
Federica
F
CNRS, UMR5203, Montpellier; INSERM, U661, Montpellier, University Montpellier I & II, Montpellier, France.
Lill
Yoriko
Y
Airas
José M
JM
Espeut
Julien
J
Blahos
Jaroslav
J
Bockaert
Joël
J
Fagni
Laurent
L
Betz
Heinrich
H
El-Far
Oussama
O
D000595:Amino Acid Sequence; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000502:physiology; D002121:Calcium Channel Blockers; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D019204:GTP-Binding Proteins / Q000502:physiology*; D015723:Gene Library; D005982:Glutathione Transferase / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D010446:Peptide Fragments / Q000737:chemistry; D051381:Rats; D018094:Receptors, Metabotropic Glutamate / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D002121:Calcium Channel Blockers; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D010446:Peptide Fragments; D018094:Receptors, Metabotropic Glutamate; D011993:Recombinant Fusion Proteins; C102719:metabotropic glutamate receptor 7; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D005982:Glutathione Transferase; D019204:GTP-Binding Proteins