Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. Plays a role in glial cell differentiation during embryogenesis; loco, Galphao and the G-protein coupled receptor, moody, are required in the surface glia to achieve effective insulation of the nerve cord. G proteins are composed of 3 units; alpha, beta and gamma. The alpha chain contains the guanine nucleotide binding site. Interacts (via GDP- or GTP-bound forms) with loco (via GoLoco and RGS domains). Interacts with raps/pins. Colocalizes with loco and raps/pins at the apical cortex throughout mitosis in neuroblasts. Expressed in the surface glial cells of the nerve cords at the larval stage (at protein level). Expressed primarily in embryos and pupae. Belongs to the G-alpha family. G(i/o/t/z) subfamily.