The GoLoco Motif: Heralding a New Tango Between G Protein Signaling and Cell Division

Hypothetical mechanism of G protein activation during asymmetric cell division. Inscuteable uses its N-terminal “asymmetry domain” to bind to the tetratrico-peptide repeat (TPR) protein Pins. This interaction facilitates the polarized localization of both Pins and Gα_i. Heterotrimeric Gα_iβγ binds one or more of the GoLoco motifs present in Pins, causing subunit dissociation and the formation of Inscuteable–Pins–Gα_i•GDP and free Gβγ complexes. Dissociated Gβγ and GoLoco-complexed Gα_i could possibly regulate independent, as yet uncharacterized, effector pathways to mediate asymmetric cell division.