RRC ID |
29001
|
著者 |
Thomason PA, Traynor D, Cavet G, Chang WT, Harwood AJ, Kay RR.
|
タイトル |
An intersection of the cAMP/PKA and two-component signal transduction systems in Dictyostelium.
|
ジャーナル |
EMBO J
|
Abstract |
Terminal differentiation of both stalk and spore cells in Dictyostelium can be triggered by activation of cAMP-dependent protein kinase (PKA). A screen for mutants where stalk and spore cells mature in isolation produced three genes which may act as negative regulators of PKA: rdeC (encoding the PKA regulatory subunit), regA and rdeA. The biochemical properties of RegA were studied in detail. One domain is a cAMP phosphodiesterase (Km approximately 5 microM); the other is homologous to response regulators (RRs) of two-component signal transduction systems. It can accept phosphate from acetyl phosphate in a reaction typical of RRs, with transfer dependent on Asp212, the predicted phosphoacceptor. RegA phosphodiesterase activity is stimulated up to 8-fold by the phosphodonor phosphoramidate, with stimulation again dependent on Asp212. This indicates that phosphorylation of the RR domain activates the phosphodiesterase domain. Overexpression of the RR domain in wild-type cells phenocopies a regA null. We interpret this dominant-negative effect as due to a diversion of the normal flow of phosphates from RegA, thus preventing its activation. Mutation of rdeA is known to produce elevated cAMP levels. We propose that cAMP breakdown is controlled by a phosphorelay system which activates RegA, and may include RdeA. Cell maturation should be triggered when this system is inhibited.
|
巻・号 |
17(10)
|
ページ |
2838-45
|
公開日 |
1998-5-15
|
DOI |
10.1093/emboj/17.10.2838
|
PMID |
9582277
|
PMC |
PMC1170624
|
MeSH |
3',5'-Cyclic-AMP Phosphodiesterases / genetics
3',5'-Cyclic-AMP Phosphodiesterases / metabolism*
Animals
Base Sequence
Binding Sites
Cyclic AMP-Dependent Protein Kinases / genetics
Cyclic AMP-Dependent Protein Kinases / metabolism*
DNA, Fungal
Dictyostelium / enzymology*
Dictyostelium / genetics
Enzyme Activation
Molecular Sequence Data
Mutation
Phosphates / metabolism
Phosphorylation
Protozoan Proteins*
Signal Transduction*
Spores, Fungal
|
IF |
9.889
|
引用数 |
110
|
WOS 分野
|
BIOCHEMISTRY & MOLECULAR BIOLOGY
CELL BIOLOGY
|
リソース情報 |
細胞性粘菌 |
S00141
S00482 |