SEARCH Articles Figures Tables Activation of Heterotrimeric G Proteins Classification of the Heterotrimeric G-Proteins Heterotrimeric proteins Signal transduction pathways through heterotrimeric G proteins transmission of hormonal and sensory signals The Functional Cycle of Heterotrimeric G-Proteins The Heterotrimeric G-Proteins Toxins as Tools in Characterization of Heterotrimeric G-proteins Toxins as Tools in the Characterization of Heterotrimeric G Proteins