Isozyme-dependent sensitivity of adenylyl cyclases to P-site-mediated inhibition by adenine nucleosides and nucleoside 3'-polyphosphates.
Recombinant adenylyl cyclase isozyme Types I, II, VI, VII, and three splice variants of Type VIII were compared for their sensitivity to P-site-mediated inhibition by several adenine nucleoside derivatives and by the family of recently synthesized adenine nucleoside 3'-polyphosphates (Désaubry, L., Shoshani, I., and Johnson, R. A. (1996) J. Biol. Chem. 271, 14028-14034). Inhibitory potencies were dependent on isozyme type, the mode of activation of the respective isozymes, and on P-site ligand. For the nucleoside derivatives potency typically followed the order 2',5'-dideoxyadenosine (2',5'-ddAdo) > beta-adenosine > 9-(cyclopentyl)-adenine (9-CP-Ade) >/= 9-(tetrahydrofuryl)-adenine (9-THF-Ade; SQ 22,536), with the exception of Type II adenylyl cyclase, which was essentially insensitive to inhibition by 9-CP-Ade. For the adenine nucleoside 3'-polyphosphates inhibitory potency followed the order Ado < 2'-dAdo < 2',5'-ddAdo and 3'-mono- < 3'-di- < 3'-triphosphate. Differences in potency of these ligands were noted between isozymes. The most potent ligand was 2',5'-dd-3'-ATP with IC50 values of 40-300 nM. The data demonstrate isozyme selectivity for some ligands, suggesting the possibility of isozyme-selective inhibitors to take advantage of differences in P-site domains among adenylyl cyclase isozymes. Differential expression of adenylyl cyclase isozymes may dictate the physiological sensitivity and hence importance of this regulatory mechanism in different cells or tissues.
Johnson
R A
RA
Department of Physiology and Biophysics, State University of New York, Health Sciences Center, Stony Brook, New York 11794-8661, USA. rjohnson@ccmail.sunysb.edu
Désaubry
L
L
Bianchi
G
G
Shoshani
I
I
Lyons
E
E
Taussig
R
R
Watson
P A
PA
Cali
J J
JJ
Krupinski
J
J
Pieroni
J P
JP
Iyengar
R
R
D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism; D002417:Cattle; D016048:Dideoxyadenosine / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000378:metabolism; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D015513:Oncogene Proteins / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship
D000067956:Adenylyl Cyclase Inhibitors; D002147:Calmodulin; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D015513:Oncogene Proteins; D011994:Recombinant Proteins; D016048:Dideoxyadenosine; C021008:2',5'-dideoxyadenosine; D019205:GTP-Binding Protein alpha Subunits, Gs; D000262:Adenylyl Cyclases; C106670:adenylyl cyclase 1; C100622:adenylyl cyclase 2; D000241:Adenosine; D002118:Calcium