Regulation of eukaryotic translation initiation is a process that requ
ires collaboration between multiple proteins. The cap-binding factor e
ukaryotic initiation factor (eIF)4E, its binding protein 4E-BP1, and t
he guanine-nucleotide-exchange factor eIF2B play important roles in th
e regulation of the rate of protein synthesis. This review describes t
he regulation of the activity of these three proteins and the signal-t
ransduction pathways involved therein.