Adenylyl cyclase G, an osmosensor controlling germination of Dictyostelium spores.
Dictyostelium cells express a G-protein-coupled adenylyl cyclase, ACA, during aggregation and an atypical adenylyl cyclase, ACG, in mature spores. The ACG gene was disrupted by homologous recombination. acg- cells developed into normal fruiting bodies with viable spores, but spore germination was no longer inhibited by high osmolarity, a fairly universal constraint for spore and seed germination. ACG activity, measured in aca-/ACG cells, was strongly stimulated by high osmolarity with optimal stimulation occurring at 200 milliosmolar. RdeC mutants, which display unrestrained protein kinase A (PKA) activity and a cell line, which overexpresses PKA under a prespore specific promoter, germinate very poorly, both at high and low osmolarity. These data indicate that ACG is an osmosensor controlling spore germination through activation of protein kinase A.
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Related Subject Headings
- Water-Electrolyte Balance
- Spores, Fungal
- Signal Transduction
- Protozoan Proteins
- Mutagenesis, Insertional
- Fungal Proteins
- Dictyostelium
- Cyclic AMP-Dependent Protein Kinases
- Biochemistry & Molecular Biology
- Animals
Citation
Published In
DOI
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Water-Electrolyte Balance
- Spores, Fungal
- Signal Transduction
- Protozoan Proteins
- Mutagenesis, Insertional
- Fungal Proteins
- Dictyostelium
- Cyclic AMP-Dependent Protein Kinases
- Biochemistry & Molecular Biology
- Animals