Synergistic activation of insect cAMP-dependent protein kinase A (type II) by cyclicAMP and cyclicGMP.
The high cGMP sensitivity of cAMP-dependent protein kinase A (type II) (PKAII) from invertebrates led to the hypothesis that cGMP directly activates PKAII under physiological conditions. We tested this idea using PKAII holoenzyme purified from the honeybee brain in an assay with short stimulation times. In the presence of very low cAMP concentrations, we found a synergistic increase in PKAII activation by physiological cGMP concentrations. Cloning honeybee regulatory subunit RII and phylogenetic comparison of the two cyclic nucleotide-binding sites of RII reveal a high relation of domain A of insect RII with cGMP-binding domains of cGMP-dependent protein kinases.
Institut für Biologie, Freie Universität Berlin, Neurobiologie Königin-Luise-Strasse 28/30, D-14195 Berlin, Germany. gerleb@zedat.fu-berlin.de
Gérard
G
Leboulle
Uli
U
Müller
D000818:Animals; D001516:Bees / Q000378:metabolism*; D001665:Binding Sites; D019295:Computational Biology; D000242:Cyclic AMP / Q000378:metabolism*; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism*; D004789:Enzyme Activation; D010802:Phylogeny
D000242:Cyclic AMP; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D006152:Cyclic GMP