Analysis of Gα4, a G-protein subunit required for multicellular development in Dictyostelium

Abstract

The Dictyostelium Gα4 gene encodes a G-protein α subunit that is primarily expressed during the multicellular stages of development. gα4 null mutants, created by gene disruption, show aberrant morphological differentiation, reduced levels of prespore gene expression, and a loss of the ability to produce spores. These developmental phenotypes can be rescued by complementation with the wild-type gene. Cells that overexpress the Gα4 gene [Gα4HC] also show reduced spore production but display an aberrant morphological phenotype distinct from that of gα4 cells. The gα4 phenotype can be partially rescued by the presence of wild-type or Gα4HC cells in chimeric organisms, suggesting that Gα4-expressing cells produce an intercellular signal that is essential for multicellular development.