A Novel Adenylyl Cyclase Detected in Rapidly Developing Mutants of Dictyostelium
| Autor: | Marcel Meima, Hyun Ji Kim, Pauline Schaap, Wen Tsan Chang, Julian D. Gross |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
IBMX
Protozoan Proteins Biology Biochemistry Adenylyl Cyclase Inhibitors ADCY10 Adenylyl cyclase chemistry.chemical_compound Osmotic Pressure 1-Methyl-3-isobutylxanthine Cyclic AMP Animals Dictyostelium Molecular Biology ADCY6 ADCY9 Phosphodiesterase Cell Biology ADCY3 Cyclic AMP-Dependent Protein Kinases Cell biology DNA-Binding Proteins Isoenzymes chemistry 3' 5'-Cyclic-AMP Phosphodiesterases Mutation Adenylyl Cyclases |
| Zdroj: | Journal of Biological Chemistry. 273:30859-30862 |
| ISSN: | 0021-9258 |
| Popis: | Disruption of either the RDEA or REGA genes leads to rapid development in Dictyostelium. The RDEA gene product displays homology to certain H2-type phosphotransferases, while REGA encodes a cAMP phosphodiesterase with an associated response regulator. It has been proposed that RDEA activates REGA in a multistep phosphorelay. To test this proposal, we examined cAMP accumulation in rdeA and regA null mutants and found that these mutants show a pronounced accumulation of cAMP at the vegetative stage that is not observed in wild-type cells. This accumulation was due to a novel adenylyl cyclase and not to the known Dictyostelium adenylyl cyclases, aggregation stage adenylyl cyclase (ACA) or germination stage adenylyl cyclase (ACG), since it occurred in an acaA/rdeA double mutant and, unlike ACG, was inhibited by high osmolarity. The novel adenylyl cyclase was not regulated by G-proteins and was relatively insensitive to stimulation by Mn2+ ions. Addition of the cAMP phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine (IBMX) permitted detection of the novel adenylyl cyclase activity in lysates of an acaA/acgA double mutant. The fact that disruption of the RDEA gene as well as inhibition of the REGA-phosphodiesterase by IBMX permitted detection of the novel AC activity supports the hypothesis that RDEA activates REGA. |
| Databáze: | OpenAIRE |
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