title: Novel interaction between the M4 muscarinic acetylcholine receptor and elongation factor 1A2.
abstract: The activation of the muscarinic acetylcholine receptor (mAChR) family, consisting of five subtypes (M1-M5), produces a variety of physiological effects throughout the central nervous system. However, the role of each individual subtype remains poorly understood. To further elucidate signal transduction pathways for specific subtypes, we used the most divergent portion of the subtypes, the intracellular third (i3) loop, as bait to identify interacting proteins. Using a brain pull-down assay, we identify elongation factor 1A2 (eEF1A2) as a specific binding partner to the i3 loop of M4, and not to M1 or M2. In addition, we demonstrate a direct interaction between these proteins. In the rat striatum, the M4 mAChR colocalizes with eEF1A2 in the soma and neuropil. In PC12 cells, endogenous eEF1A2 co-immunoprecipitates with the endogenous M4 mAChR, but not with the endogenous M1 mAChR. In our in vitro model, M4 dramatically accelerates nucleotide exchange of eEF1A2, a GTP-binding protein. This indicates the M4 mAChR is a guanine exchange factor for eEF1A2. eEF1A2 is an essential GTP-binding protein for protein synthesis. Thus, our data suggest a novel role for M4 in the regulation of protein synthesis through its interaction with eEF1A2.
authors.affiliation: Center for Neurodegenerative Diseases, Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: McClatchy
authors.forename: Charlotte R
authors.initials: CR
authors.lastname: Knudsen
authors.forename: Brian F
authors.initials: BF
authors.lastname: Clark
authors.forename: Richard A
authors.initials: RA
authors.lastname: Kahn
authors.forename: Randy A
authors.initials: RA
authors.lastname: Hall
authors.forename: Allan I
authors.initials: AI
authors.lastname: Levey
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005982:Glutathione Transferase / Q000378:metabolism; D006153:Guanosine Diphosphate / Q000378:metabolism; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D016716:PC12 Cells; D020648:Peptide Elongation Factor 1 / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D014176:Protein Biosynthesis; D051381:Rats; D043588:Receptor, Muscarinic M4; D011976:Receptors, Muscarinic / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: C503236:Eef1a2 protein, rat; D020648:Peptide Elongation Factor 1; D043588:Receptor, Muscarinic M4; D011976:Receptors, Muscarinic; D011993:Recombinant Fusion Proteins; D006153:Guanosine Diphosphate; D005982:Glutathione Transferase