Abstract
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 α-subunits, G-α-1 and G-α-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-α-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.
Original language | English (US) |
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Pages (from-to) | 75-80 |
Number of pages | 6 |
Journal | Development |
Volume | 107 |
Issue number | SUPPL. |
State | Published - 1989 |
Keywords
- G-protein
- cAMP receptors
- dictyostelium
- phosphorylation
ASJC Scopus subject areas
- Molecular Biology
- Developmental Biology