title: Activation of protein tyrosine kinase PYK2 by the m1 muscarinic acetylcholine receptor.
abstract: Several G protein-coupled receptors are known to direct the tyrosine phosphorylation, and in some cases the activation, of diverse tyrosine kinases. Using a stable cell line approach, we characterize the activation of PYK2, a tyrosine kinase structurally related to focal adhesion kinase, by the G protein-coupled m1 muscarinic acetylcholine receptor. We find that PYK2 tyrosine kinase activity is critical for the m1 receptor-stimulated tyrosine phosphorylation of PYK2. Furthermore, we identify two tyrosine residues that are subject to phosphorylation in response to muscarinic signaling and show that this phosphorylation induces two cytosolic proteins, c-Src and Grb2, to bind to PYK2. This is the first demonstration of the significance played by distinct PYK2 tyrosine residues in G protein-coupled signaling to this kinase. By comparison, though m1 receptors induce the tyrosine phosphorylation of the cytoskeletal protein paxillin, the association of paxillin with PYK2 is unaffected by muscarinic signaling. We also provide evidence that PYK2 specifically phosphorylates the carboxyl-terminal cytosolic portion of the potassium channel Kv1.2 in a manner regulated by the m1 receptor. These results delineate molecular events attending the m1 muscarinic receptor stimulation of this tyrosine kinase and establish PYK2 as an effector of the m1 muscarinic receptor in the regulation of multiple cell functions.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Felsch
authors.forename: T G
authors.initials: TG
authors.lastname: Cachero
authors.forename: E G
authors.initials: EG
authors.lastname: Peralta
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D003593:Cytoplasm / Q000378:metabolism; D004789:Enzyme Activation; D051418:Focal Adhesion Kinase 2; D051380:GRB2 Adaptor Protein; D006801:Humans; D051663:Kv1.2 Potassium Channel; D019000:Phosphotyrosine / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism; D024642:Potassium Channels, Voltage-Gated; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000378:metabolism; D043643:Receptor, Muscarinic M1; D011976:Receptors, Muscarinic / Q000378:metabolism*; D015398:Signal Transduction; D013329:Structure-Activity Relationship
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; C496969:KCNA2 protein, human; D051663:Kv1.2 Potassium Channel; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D011506:Proteins; D043643:Receptor, Muscarinic M1; D011976:Receptors, Muscarinic; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; D016392:Proto-Oncogene Proteins pp60(c-src)