title: Switching heterotrimeric G protein subunits with a chemical dimerizer.
abstract: The selective manipulation of single intracellular-signaling events remains one of the key tasks when studying signaling networks. Here, we demonstrate for the first time the stimulation of FKBP fusions of various subunits of heterotrimeric G proteins by the simple addition of the chemical dimerizer rapamycin. Activation of constitutively active Gα(q), but not its GDP-bound form, leads to sustained oscillations of intracellular calcium and myo-inositol 1,4,5-trisphosphate (InsP(3)) levels in HEK cells, independent of the activation of endogenous Gα(q), in full agreement with the InsP(3)-Ca(2+) cross-coupling model of calcium oscillations. Rapamycin-induced translocation of wild-type Gα(s) to the plasma membrane results in elevated cAMP levels. Activation of rapamycin-inducible Gα(s) or Gβ(1)γ(2) evokes extensive modulation of ATP-induced calcium transients. The results demonstrate that inducible heterotrimeric G protein subunits will provide ways for dissecting G protein-coupled receptor signaling.
authors.affiliation: Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Putyrski
authors.forename: Carsten
authors.initials: C
authors.lastname: Schultz
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D019281:Dimerization; D004789:Enzyme Activation / Q000187:drug effects; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000378:metabolism; D044387:GTP-Binding Protein beta Subunits / Q000378:metabolism; D020962:Heterotrimeric GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D020123:Sirolimus / Q000494:pharmacology; D022021:Tacrolimus Binding Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D044387:GTP-Binding Protein beta Subunits; D011993:Recombinant Fusion Proteins; D015544:Inositol 1,4,5-Trisphosphate; D000242:Cyclic AMP; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D019205:GTP-Binding Protein alpha Subunits, Gs; D020962:Heterotrimeric GTP-Binding Proteins; D022021:Tacrolimus Binding Proteins; D002118:Calcium; D020123:Sirolimus