G-proteins and second messengers in mitogenesis.

Growth factors stimulate mitogenesis via the generation of signal molecules or events. Transduction of these messages into the cell proceeds by the binding of the mitogen to a specific cell surface receptor which then stimulates the effector system (enzyme, ion channel, etc.) via a guanine nucleotide binding regulatory protein (G-protein). The specificity of a particular G-protein is a function of its unique alpha-subunit. This article reviews the effects of different growth factors upon second messenger generation and discusses the involvement of the different G-proteins in these signal transduction pathways.