Function
Guanine nucleotide exchange factor (GEF), which can activate some, but not all, G-alpha proteins independently of G-protein coupled receptors. Acts by exchanging bound GDP for free GTP. Able to facilitate synaptic transmission in the nervous system probably by activating G(q)-alpha (egl-30). Also able to activate the G(s)-alpha in synaptic signaling network. Plays a key role in asymmetric spindle positioning, a step for asymmetric cell division that generates cell diversity during development by activating G(i)-alpha protein goa-1 and gpa-16 independently of G-protein coupled receptors. While it acts as a GEF for goa-1, it has no GEF activity toward gpa-16. In addition to its GEF activity, it is required for cortical subcellular localization of G-alpha proteins such as gpa-16. Also required for the interaction of goa-1 and gpr-1/2, suggesting that it may act by generating G-alpha proteins free from G-beta-gamma subunits, enabling gpr-1/2 to mediate asymmetric cell division.
Sequence
MSEELHSDLIASIFGGKPAKIEEFFSKWNFANAAVSKFDMANSAKNELGDRICEVIENGELTHVLLETIKILSREKDGLEGLLNDPLCDKILAFAELSSNENNSKTVHTLMEAQKCLINTLFHSQRMRDRFYANPKTGENLQFFLGEFEENRRKTSSIDWIRLLNPVQAAEIWYFYHRIAFIATALGREFQKNWANDPKTIDSLLLAVEICTNRSENSTQDINRATEALKTFFNVFCHFHGDVKAIDHKNAAKTCQILRDAICSDVLTDDVVQSAIHCLSVPPLPMVLSVLCGKNSKNNGGENEEEKFFVEELSNMQLTEAILMHLDKQLTKVVALLLNDAPNQQQNPMLSAEASTLTDLVGPYFQVLARLCTDSKYVRRYCRIRVIPPLVSEEVQKRPEENNTLRGRIARIMMLPSSTKDVAAEFLFIICKRSVNRMIKYLGFGHSAGHLANLGLLGQINQPKHASDSEDSETEDYNQIKDSVNPVTGAIYPSDHGSALAGMSEEQKEYEAMKLVDAMNQMMETGIVKPGTIGDDGKIREVSHVLELLKNAPEPAPAENSDSDEE