Overview:

4EBP1 is a member of a family of translation repressor proteins that directly interact with eukaryotic translation initiation factor 4E (EIF4E). Interaction of 4EBP1 with EIF4E inhibits the multisubunit complex that recruits 40S ribosomal subunits to the 5' end of mRNAs thereby leading to repression of translation. Insulin treatment of adipose cells increases the phosphorylation of 4EBP1 and leads to reduced interaction of 4EBP1 with EIF4E (1). 4EBP1 is expressed in most tissues, with highest levels seen in adipose tissue, pancreas, and skeletal muscle (2).

References:

1. Pause, A. et al: Insulin-dependent stimulation of protein synthesis by phosphorylation of a regulator of 5-prime-cap function. Nature 371: 762-767, 1994.

2. Tsukiyama-Kohara, K. et al: Tissue distribution, genomic structure, and chromosome mapping of mouse and human eukaryotic initiation factor 4E-binding proteins 1 and 2. Genomics 38: 353-363, 1996.