Purification and functional analysis of Ric-8A: a guanine nucleotide exchange factor for G-protein alpha subunits

Abstract

Ric-8A (synembryn) has been shown to accelerate the in vitro guanine nucleotide exchange activities of most G-protein alpha subunits (with the exception of Galphas). Methods are presented in this article for the purification of Ric-8A and functional analysis of the effects Ric-8A has on G-protein alpha subunit guanine nucleotide-binding activities. The use of Ric-8A to prepare GTPgammaS-Galpha and nucleotide-free Galpha (in complex with Ric-8A) is described.