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

Abstract

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 alpha-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 alpha-subunit genes. The predicted amino acid sequences of these PCR fragments are very similar to other Dictyostelium G-protein alpha-subunits in the conserved regions and share little homology outside of those regions. Northern blot analysis indicate that each of these genes has very distinct pattern of expression during development. The possible roles of these G-protein alpha-subunits are discussed.