[Cross-talk between signal transduction pathways in the cell-- the role of G proteins in these processes].

Family of heterotrimeric G proteins plays an essential role in transducing signals across the plasma membrane in animal cells. Members of G protein family have been grouped into four subtypes: Gs, Gi, Gq and G12. A cross-talk between Gi- and Gq-; Gs- and Gi-; and Gs- and Gi-coupled receptors are presented. Interactions between G protein coupled receptors and receptor tyrosine kinases and between G12 protein and the small molecular weight guanosine trisphosphate protein Rho are also described.