Guanine nucleotides, protein phosphorylation and the control of translation

Initiation Factor-2 (eIF-2) mediates the early steps of the initiation of protein synthesis in eukaryotic cells. Over the last 15 years evidence has accumulated linking the phosphorylation of eIF-2 with the control of translation, but the mechanism by which phosphorylation of this protein affects its biological activity has only recently been established. It involves the exchange of guanine nucleotides bound to eIF-2 and resembles mechanisms involved in regulating other, quite diverse, biological processes.