Extracellular cAMP induces excitation of adenylate and guanylate cyclase in Dictyostelium discoideum. Continuous stimulation with cAMP leads to adaptation, while cells deadapt upon removal of the cAMP stimulus. Excitation of guanylate cyclase by cAMP has a lag time of ~oI s; excitation of adenylate cyclase is much slower with a lag time of 30 s. Excitation of both enzyme activities is less than...

Basal as well as GTP-dependent adenylate cyclase activity was partially resistant to porcine pancreatic phospholipase A2, although more activity was degraded at 16 than at 2 degrees C. In contrast, isoproterenol-dependent activity was completely destroyed regardless of the temperature. Snake venom phospholipase A2 destroyed approximately 90% of basal and GTP-dependent adenylate cyclase activity...

Globin and adenylate cyclase play individually numerous crucial roles in eukaryotic organisms. Comparison of the amino acid sequences of globins and adenylate cyclase from prokaryotic to eukaryotic organisms suggests that they share an early common ancestor, even though these proteins execute different functions in these two kingdoms. The latest studies of biological signaling molecules in both...

INTRODUCTION........................................... 60 ADENYLATE CYCLASE FROM B. PERTUSSIS ........................................... 60 CALMODULIN REGULATION ........................................... 61 PATHOGENICITY AND CELL INVASION ........................................... 61 PURIFICATION AND CHARACTERIZATION ........................................... 62 ADENYLATE CYCLASE FROM BAC...

An important eukaryotic signal transduction pathway involves the regulation of the effector enzyme adenylate cyclase, which produces the second messenger, cAMP. Previous genetic analyses demonstrated that glucose repression of transcription of the Schizosaccharomyces pombe fbp1 gene requires the function of adenylate cyclase, encoded by the git2 gene. As mutations in git2 and in six additional ...

Prostaglandins (PGE1, PGE2, PGA1) and histamine have opposing effects on gastric HCl secretion, but we found that both stimulate adenylate cyclase activity in cell-free membrane preparations of guinea pig gastric fundic mucosa. The stimulatory effect of prostaglandins was found in this study to be specific and dose-dependent over a concentration range from 10(-7) to 10(-4) M. In similar prepara...

Desensitization of adenylate cyclase-coupled beta-adrenergic receptors in avian erythrocytes results in a 40-65% decrease in agonist-stimulated adenylate cyclase activity and correlates with increased phosphorylation of beta-adrenergic receptors. To assess the role of phosphorylation in desensitization, membranes from isoprenaline- and dibutyryl cyclic AMP-desensitized turkey erythrocytes were ...

Extracellular cAMP induces excitation of adenylate and guanylate cyclase in Dictyostelium discoideum. Continuous stimulation with cAMP leads to adaptation, while cells deadapt upon removal of the cAMP stimulus. Excitation of guanylate cyclase by cAMP has a lag time of ~oI s; excitation of adenylate cyclase is much slower with a lag time of 30 s. Excitation of both enzyme activities is less than...

The core of adenylate and guanylate cyclases is formed by an intramolecular or intermolecular dimer of two cyclase domains arranged in an antiparallel fashion. Metazoan membrane-bound adenylate cyclases are composed of 12 transmembrane spanning regions, and two cyclase domains which function as a heterodimer and are activated by G-proteins. In contrast, membrane-bound guanylate cyclases have on...

1. Adenylate cyclase (EC 4.6.1.1) activity was characterized in human liver, and its subcellular distribution compared with that of three other potential enzyme markers of the pericellular membrane: leucine aminopeptidase (EC 3.4.11.1), gamma-glutamyltransferase (EC 2.3.2.2) and 5'-nucleotidase (EC 3.1.3.5). Although these three enzyme activities were detected in each of the subcellular fractio...