G-protein-linked signal transduction systems control development in Dictyostelium.
G-protein-linked cAMP receptors play an essential role in Dictyostelium development. The cAMP receptors are proposed to have seven transmembrane domains and a cytoplasmic C-terminal region. Overexpression of the receptor in cells, when the endogenous receptor is not present, results in a 10- to 50-fold increase in cAMP-binding sites. Antisense cell lines, which lack cAMP receptors, do not enter the developmental program. Ligand-induced phosphorylation is proposed to occur on serine and threonine residues in the receptor C-terminus. The kinetics of receptor phosphorylation and dephosphorylation correlate closely with the shift of receptor mobility and the adaptation of several cAMP-induced responses. Two alpha-subunits, G-alpha-1 and G-alpha-2, have been cloned and specific antisera developed against each. Both subunits are expressed as multiple RNAs with different developmental time courses. The mutant Frigid A has a functional defect in G-alpha-2 which prevents it from entering development. We propose that G-protein-linked receptor systems will be a major component in the development of many organisms.
Duke Scholars
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Related Subject Headings
- Signal Transduction
- Receptors, Cyclic AMP
- Molecular Sequence Data
- GTP-Binding Proteins
- Dictyostelium
- Amino Acid Sequence
- 42 Health sciences
- 32 Biomedical and clinical sciences
- 31 Biological sciences
- 11 Medical and Health Sciences
Citation
Published In
DOI
ISSN
Publication Date
Volume
Start / End Page
Location
Related Subject Headings
- Signal Transduction
- Receptors, Cyclic AMP
- Molecular Sequence Data
- GTP-Binding Proteins
- Dictyostelium
- Amino Acid Sequence
- 42 Health sciences
- 32 Biomedical and clinical sciences
- 31 Biological sciences
- 11 Medical and Health Sciences