The mammalian RACK1 protein binds activated protein kinase C, acting as an intracellular receptor to anchor the activated PKC to the cytoskeleton. Genes encoding RACK1-like proteins have been isolated from a wide range of eucaryotic organisms; we report the isolation of a Drosophila member of this family. This Drosophila RACK1-like protein shows 76% identity to the mammalian RACK1 proteins, but only about 60% identity to related proteins from plants and fungi. The Drosophila rack1 gene has a dynamic pattern of expression during early embryogenesis with the highest expression in the mesodermal and endodermal lineages.