Anti-4EBP2 Antibody, clone 16D9.1 clone 16D9.1, from mouse

Eukaryotic translation initiation factor 4E-binding protein 2 (UniProt: Q13542; also known as 4E-BP2, eIF4E-binding protein 2) is encoded by the EIF4EBP2 gene (Gene ID; 1979) in human. 4E-BP2 acts as a repressor of translation initiation involved in synaptic plasticity, learning and memory formation. However, insulin and other growth factors can release this inhibition via a phosphorylation-dependent disruption of their binding to eIF4E. 4E-BP2 regulates EIF4E activity by preventing its assembly into the eIF4F complex. 4E-BP2 undergoes phosphorylation at Threonine 37, 46, and 70 and Serine 65 and 83 by mTOR. 4E-BP2 contains a TOR signaling (TOS) motif (aa 116-120) that mediates interaction with RPTOR, leading to promote phosphorylation by mTORC1 complex. Its hypophosphorylated form competes with EIF4G1/EIF4G3 and strongly binds to EIF4E, leading to repression of translation. On the other hand, hyperphosphorylated form of 4E-BP2 dissociates from EIF4E, which allows interaction between EIF4G1/EIF4G3 and EIF4E and leads to initiation of translation. 4E-BP2 is first phosphorylated at Threonine 37 and 46 by mTOR that induces folding of region from Proline 18 to Arginine 62 into a four-stranded beta-domain, which sequesters the helical YXXXXLPhi motif into a partly buried beta-strand that blocks accessibility to EIF4E. Protein phosphorylated at Threonine 37 and 46 is, however, unstable. Hence, subsequent phosphorylation at Serine 65 and 83 and Threonine 70 is required to stabilize the fold, which significantly reduces affinity for EIF4E. 4E-BP2 is enriched in brain where it acts as a regulator of synapse activity and neuronal stem cell renewal via its ability to repress translation initiation.