title: Heterodimers of adenylyl cyclases 2 and 5 show enhanced functional responses in the presence of Galpha s.
abstract: Recent studies have demonstrated that adenylyl cyclase isoforms can form both homo- and heterodimers and that this may be the basic functional unit of these enzymes (see Cooper, D.M.F. and Crossthwaite, A.J. (2006) Trends. Pharmacol. Sci. 8:426-431). Here, we show that adenylyl cyclases 2 and 5 can form a functional heterodimeric complex in HEK293 cells using a combination of BRET, confocal imaging, co-immunoprecipitation and assays of adenylyl cyclase activity. The AC2/5 complex is formed constitutively and is stable in the presence of receptor or forskolin stimulation. The complex formed by AC2/5 is also much more sensitive to the presence of Galpha(s) and forskolin than either of the parent AC isoforms themselves. Finally, we also show that this complex can be detected in native tissues as AC2 and AC5 were localized to the same structures in adult mouse ventricular myocytes and neonatal mouse cardiac fibroblasts and could be co-immunoprecipitated from lysates of mouse heart.
authors.affiliation: Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Baragli
authors.forename: Maria-Laura
authors.initials: ML
authors.lastname: Grieco
authors.forename: Phan
authors.initials: P
authors.lastname: Trieu
authors.forename: Louis R
authors.initials: LR
authors.lastname: Villeneuve
authors.forename: Terence E
authors.initials: TE
authors.lastname: Hébert
mesh_terms: D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D002460:Cell Line; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D020536:Enzyme Activators / Q000494:pharmacology; D031541:Fluorescence Resonance Energy Transfer; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism*; D049410:Luciferases, Renilla / Q000378:metabolism; D051379:Mice; D018613:Microscopy, Confocal; D009638:Norepinephrine / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000235:genetics / Q000378:metabolism; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
chemical_list: D020536:Enzyme Activators; D007527:Isoenzymes; D011943:Receptors, Adrenergic, beta; D018342:Receptors, Adrenergic, beta-1; D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D005576:Colforsin; D000242:Cyclic AMP; D049410:Luciferases, Renilla; D019205:GTP-Binding Protein alpha Subunits, Gs; D000262:Adenylyl Cyclases; C100622:adenylyl cyclase 2; C419510:adenylyl cyclase type V; D009638:Norepinephrine