mTOR Signaling and the Tumor Microenvironment

4EBP1 and skeletal muscle protein synthesis

Eukaryotic translation initiation factor 4E binding protein 1, or 4EBP1, is an mRNA translational repressor protein that negatively regulates eukaryotic translation initiation factor 4E, or EIF4E.  EIF4E is a protein that forms a complex necessary to block the 5’ ends of mRNA with a 7-methyl-guanosine five-prime cap structure, which is important for normal translation of mRNA.  Specifically, the EIF4E complex recruits 40s ribosome subunits to scan mRNA in order to regulate protein synthesis.  When EIF4E is bound to 4EBP1, it is held in an