scholarly journals Guanylate cyclase in Dictyostelium discoideum with the topology of mammalian adenylate cyclase

2001 ◽  
Vol 354 (3) ◽  
pp. 697-706 ◽  
Author(s):  
Jeroen ROELOFS ◽  
Helena SNIPPE ◽  
Reinhard G. KLEINEIDAM ◽  
Peter J.M. Van HAASTERT
Keyword(s):  
Adenylate Cyclase ◽  
G Proteins ◽  
Guanylate Cyclase ◽  
Cyclase Activity ◽  
Knock Out ◽  
Guanylate Cyclase Activity ◽  
Cyclase Domain ◽  
Cellular Slime ◽  
Membrane Bound ◽  
Camp Receptor

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 only one transmembrane spanning region and one cyclase domain, and are activated by extracellular ligands to form a homodimer. In the cellular slime mould, Dictyosteliumdiscoideum, membrane-bound guanylate cyclase activity is induced after cAMP stimulation; a G-protein-coupled cAMP receptor and G-proteins are essential for this activation. We have cloned a Dictyostelium gene, DdGCA, encoding a protein with 12 transmembrane spanning regions and two cyclase domains. Sequence alignment demonstrates that the two cyclase domains are transposed, relative to these domains in adenylate cyclases. DdGCA expressed in Dictyostelium exhibits high guanylate cyclase activity and no detectable adenylate cyclase activity. Deletion of the gene indicates that DdGCA is not essential for chemotaxis or osmo-regulation. The knock-out strain still exhibits substantial guanylate cyclase activity, demonstrating that Dictyostelium contains at least one other guanylate cyclase.

scholarly journals The metabolism of cyclic nucleotides in the guinea-pig pancreas. Adenylate cyclase and guanylate cyclase

1980 ◽  
Vol 186 (2) ◽  
pp. 499-505 ◽  
Author(s):  
M Lemon ◽  
P Methven ◽  
K Bhoola
Keyword(s):  
Adenylate Cyclase ◽  
Guinea Pig ◽  
Guanylate Cyclase ◽  
Cyclic Nucleotides ◽  
Cyclase Activity ◽  
Dependent Manner ◽  
Guanylate Cyclase Activity ◽  
Triton X ◽  
Dose Dependent ◽  
Significant Activation

Adenylate cyclase from the guinea-pig pancreas was activated in a dose-dependent manner by both secretin and cholecystokinin-pancreozymin, but in contrast with results in other species the hormones were approximately equipotent. All other hormones and transmitter substances tested were without any effect on adenylate cyclase activity. Guanylate cyclase activity was shown to have both particulate and supernatant components in the guinea-pig pancreas. The particulate enzyme, but not the supernatant enzyme, was markedly activated by Triton X-100, and most of the induced activity was released into the supernatant. The supernatant enzyme was specifically Mn2+-dependent, but, even though Mn2+ was maximally effective at a concentration of 3 mM, activity could be raised further by increasing Ca2+ concentration. The particulate enzyme, by contrast, was relatively Mn2+-independent. Activity of the particulate guanylate cyclase was enhanced by phosphatidylserine. The supernatant enzyme displayed classical Michaelis-Menten kinetics, but the particulate enzyme deviated markedly from such kinetics. Under none of the conditions used was any significant activation of guanylate cyclase observed with any of the secretogen hormones or transmitter substances.

scholarly journals Guanylate cyclase activity in Escherichia coli mutants defective in adenylate cyclase.

1981 ◽  
Vol 147 (3) ◽  
pp. 931-934 ◽  
Author(s):  
V Macchia ◽  
G Caputo ◽  
E Mandato ◽  
A Rocino ◽  
S Adhya ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Adenylate Cyclase ◽  
Guanylate Cyclase ◽  
Cyclase Activity ◽  
Guanylate Cyclase Activity

scholarly journals Guanylate cyclase activity and cyclic nucleotide concentrations during liver regeneration after experimental injury

1977 ◽  
Vol 164 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Christo Goridis ◽  
Jean Zwiller ◽  
Werner Reutter
Keyword(s):  
Dna Synthesis ◽  
Guanylate Cyclase ◽  
Cyclic Gmp ◽  
Cyclic Nucleotide ◽  
Cyclase Activity ◽  
Tissue Concentrations ◽  
Guanylate Cyclase Activity ◽  
Time Period ◽  
Membrane Bound ◽  
Experimental Injury

Cyclic nucleotide concentrations and guanylate cyclase activity were measured in regenerating rat liver. Previous work has shown that in livers of partially hepatectomized rats the activity of a membrane-bound guanylate cyclase increases considerably during the early replicative phase [Kimura & Murad (1975) Proc. Natl. Acad. Sci. U.S.A.72, 1965–1969; Goridis & Reutter (1975) Nature (London) 257, 698–700]. Over the same time period after partial hepatectomy, increased tissue concentrations of cyclic GMP were found when the rats were killed under pentobarbital anaesthesia, but not when anaesthesia was omitted. The results obtained on hepatectomized livers were compared with the changes in guanylate cyclase activity and cyclic nucleotide concentrations during the response to galactosamine treatment. Here, a peak of guanylate cyclase activity and of cyclic GMP concentrations occurred at 8h, that is before the beginning of the proliferative response. Both parameters were normal at the time of increased DNA synthesis. There does not, therefore, seem to be a consistent correlation between changes in guanylate cyclase activity or concentrations of cyclic GMP and an increase in liver DNA synthesis. A modest rise in cyclic AMP concentrations was found, however, in livers of galactosamine-treated rats, which was coincident with the time of DNA synthesis.

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