Dictyostelium transiently expresses eight distinct G-protein α-subunits during its developmental program

Guanine nucleotide-binding proteins (G-proteins) play important roles in signal transduction and in controlling the developmental program of Dictyostelium discoideum. While five G-protein α-subunits have been identified in this organism, several lines of evidence suggest that additional G-proteins exist. Using the polymerase chain reaction technique, we have isolated three novel G-protein α-subunit genes. The predicted amino acid sequences of these PCR fragments are very similar to other Dictyostelium G-protein α-subunits in the conserved regions and share little homology outside of those regions. Northern blot analyses indicate that each of these genes has very distinct pattern of expression during development. The possible roles of these G-protein α-subunits are discussed.