3′:5′-Cyclic AMP-dependent 3′:5′-cyclic GMP accumulation in Dictyostelium discoideum

• DOI: 10.1073/pnas.74.6.2348
• Publication Date: 2006-05-31T07:30:39Z
• Authors: José M. Mato; Frans A. Krens; Peter J. M. Van H...; Theo M. Konijn
• Keywords: Cyclic adenosine monophosphate

Suspensions of 3':5'-cyclic AMP (cAMP)-sensitive cells Dictyostelium discoideum responded to a cAMP pulse with increased GMP (cGMP) levels. Under the assay conditions used (2 x 10(8) per ml in 10 mM phosphate buffer, pH 6.0) (5 10(-8) M final concentration) cGMP levels from 1 pmol 10(7) 7 sec and basal were recovered 20-25 sec. accumulation did not occur when cAMP-insensitive stage. cAMP-sensitive triggered by 5 5'-CH(2)-cAMP or 10(-5) adenosine-5'-methylmonophosphate (5'-AMPMe) but after addition IMP (cIMP) 5'-AMP. As agonists cAMP, 5'-AMPMe have, respectively, more than 10% 1% chemotactic activity while cIMP has 0.01% 5'-AMP is inactive up concentration 10(-3) M. cAMP-mediated formation was dependent upon concentration, half-maximal about This agrees closely that necessary for receptor occupation. independent presence extracellular Ca(2+); cell aggregation chemotaxis also external Ca(2+). Therefore, action does depend on stimulation Ca(2+) influx. found mediate desensitization cAMP-dependent formation. Addition sensitive induced period lasted 1-5 min. Desensitization concentration. Finally, we propose translation signal surface pseudopod involves changes cGMP.