Guanine nucleotide-binding protein subunit alpha-13is aproteinthat in humans is encoded by theGNA13gene. Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. G proteins are composed of 3 units, alpha, beta and gamma. The alpha chain contains the guanine nucleotide binding site. Interacts with UBXD5. Interacts with HAX1. Interacts (when active) with PPP5C (via TPR repeats), activates PPP5C phosphatase activity and translocates PPP5C to the cell membrane.