Fig. 1: Small G protein activation cycle

In this post, I invite you to discover some state-of-the art methods to measure the activation of the most prominent small G proteins. In future posts, we’ll then be looking at methods to measure the activity of Guanine nucleotide exchange factors (GEFs) which stimulate the release of GDP to allow the binding of GTP (which activates the small G protein) and of GTPase-activating proteins (GAPs) which stimulate the GTPase activity of small G proteins to inactive them (see Fig. 1).