title: Isoform selectivity of adenylyl cyclase inhibitors: characterization of known and novel compounds.
abstract: Nine membrane-bound adenylyl cyclase (AC) isoforms catalyze the production of the second messenger cyclic AMP (cAMP) in response to various stimuli. Reduction of AC activity has well documented benefits, including benefits for heart disease and pain. These roles have inspired development of isoform-selective AC inhibitors, a lack of which currently limits exploration of functions and/or treatment of dysfunctions involving AC/cAMP signaling. However, inhibitors described as AC5- or AC1-selective have not been screened against the full panel of AC isoforms. We have measured pharmacological inhibitor profiles for all transmembrane AC isoforms. We found that 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ22,536), 2-amino-7-(furanyl)-7,8-dihydro-5(6H)-quinazolinone (NKY80), and adenine 9-β-d-arabinofuranoside (Ara-A), described as supposedly AC5-selective, do not discriminate between AC5 and AC6, whereas the putative AC1-selective inhibitor 5-[[2-(6-amino-9H-purin-9-yl)ethyl]amino]-1-pentanol (NB001) does not directly target AC1 to reduce cAMP levels. A structure-based virtual screen targeting the ATP binding site of AC was used to identify novel chemical structures that show some preference for AC1 or AC2. Mutation of the AC2 forskolin binding pocket does not interfere with inhibition by SQ22,536 or the novel AC2 inhibitor, suggesting binding to the catalytic site. Thus, we show that compounds lacking the adenine chemical signature and targeting the ATP binding site can potentially be used to develop AC isoform-specific inhibitors, and discuss the need to reinterpret literature using AC5/6-selective molecules SQ22,536, NKY80, and Ara-A.
authors.affiliation: Department of Integrative Biology and Pharmacology (C.S.B., H.J.H., A.A.G., C.W.D.), and School of Biomedical Informatics (C.N.C.), University of Texas Health Science Center, Houston, Texas; and Instituto de Investigación en Biomedicina de Buenos Aires-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina (C.N.C.).
authors.forename: Cameron S
authors.initials: CS
authors.lastname: Brand
authors.forename: Harrison J
authors.initials: HJ
authors.lastname: Hocker
authors.forename: Alemayehu A
authors.initials: AA
authors.lastname: Gorfe
authors.forename: Claudio N
authors.initials: CN
authors.lastname: Cavasotto
authors.forename: Carmen W
authors.initials: CW
authors.lastname: Dessauer
mesh_terms: D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000737:chemistry / Q000235:genetics; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D002522:Chlorocebus aethiops; D000242:Cyclic AMP / Q000378:metabolism; D055808:Drug Discovery; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D007527:Isoenzymes; D062105:Molecular Docking Simulation; D010957:Plasmids; D051381:Rats; D061987:Sf9 Cells; D054852:Small Molecule Libraries / Q000737:chemistry / Q000494:pharmacology*; D018411:Spodoptera; D013329:Structure-Activity Relationship; D014162:Transfection
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D054852:Small Molecule Libraries; D000242:Cyclic AMP; D000262:Adenylyl Cyclases