The eIF4E-binding proteins (4E-BPs) represent a diverse class of translation inhibitors that are often deregulated in cancer cells. 4E-BPs inhibit translation by competing with eIF4G for binding to eIF4E through an interface that consists of canonical and non-canonical eIF4E-binding motifs connected by a linker ...
The eIF4E-binding proteins (4E-BPs) represent a diverse class of translation inhibitors that are often deregulated in cancer cells. 4E-BPs inhibit translation by competing with eIF4G for binding to eIF4E through an interface that consists of canonical and non-canonical eIF4E-binding motifs connected by a linker. The lack of high-resolution structures including the linkers, which contain phosphorylation sites, limits our understanding of how phosphorylation inhibits complex formation. Furthermore, the binding mechanism of the non-canonical motifs is poorly understood. Here, we present structures of human eIF4E bound to 4E-BP1 and fly eIF4E bound to Thor, 4E-T, and eIF4G. These structures reveal architectural elements that are unique to 4E-BPs and provide insight into the consequences of phosphorylation. Guided by these structures, we designed and crystallized a 4E-BP mimic that shows increased repressive activity. Our studies pave the way for the rational design of 4E-BP mimics as therapeutic tools to decrease translation during oncogenic transformation.
Organizational Affiliation: 
Department of Biochemistry, Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tübingen, Germany. Electronic address: elisa.izaurralde@tuebingen.mpg.de.