The Many Faces of G Protein Signaling

Progress in areas of research that once might have seemed distant from the field of G protein signaling now shows that G proteins are involved in a broad range of cellular regulatory activities. The understanding of how the proteins interact (receptors, G proteins, and effectors, as well as other regulatory proteins) thus has enormous implications for physiology. The rapid progress in determining three-dimensional structures of G proteins, and more recently their regulators and effectors, has illuminated the search for mechanisms of activation and regulation and has allowed structure-based mutagenesis to test these ideas. The structural and mechanistic studies will in the future also hopefully provide opportunities to alter those interactions in pathological situations.