| Structural highlights
Function
[IF4E_HUMAN] Its translation stimulation activity is repressed by binding to the complex CYFIP1-FMR1 (By similarity). Recognizes and binds the 7-methylguanosine-containing mRNA cap during an early step in the initiation of protein synthesis and facilitates ribosome binding by inducing the unwinding of the mRNAs secondary structures. Component of the CYFIP1-EIF4E-FMR1 complex which binds to the mRNA cap and mediates translational repression. In the CYFIP1-EIF4E-FMR1 complex this subunit mediates the binding to the mRNA cap.[1] [4EBP1_HUMAN] Regulates eIF4E activity by preventing its assembly into the eIF4F complex. Mediates the regulation of protein translation by hormones, growth factors and other stimuli that signal through the MAP kinase and mTORC1 pathways.[2]
Publication Abstract from PubMed
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.
Molecular Architecture of 4E-BP Translational Inhibitors Bound to eIF4E.,Peter D, Igreja C, Weber R, Wohlbold L, Weiler C, Ebertsch L, Weichenrieder O, Izaurralde E Mol Cell. 2015 Feb 18. pii: S1097-2765(15)00018-0. doi:, 10.1016/j.molcel.2015.01.017. PMID:25702871[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Tomoo K, Matsushita Y, Fujisaki H, Abiko F, Shen X, Taniguchi T, Miyagawa H, Kitamura K, Miura K, Ishida T. Structural basis for mRNA Cap-Binding regulation of eukaryotic initiation factor 4E by 4E-binding protein, studied by spectroscopic, X-ray crystal structural, and molecular dynamics simulation methods. Biochim Biophys Acta. 2005 Dec 1;1753(2):191-208. Epub 2005 Aug 24. PMID:16271312 doi:10.1016/j.bbapap.2005.07.023
- ↑ Pause A, Belsham GJ, Gingras AC, Donze O, Lin TA, Lawrence JC Jr, Sonenberg N. Insulin-dependent stimulation of protein synthesis by phosphorylation of a regulator of 5'-cap function. Nature. 1994 Oct 27;371(6500):762-7. PMID:7935836 doi:http://dx.doi.org/10.1038/371762a0
- ↑ Peter D, Igreja C, Weber R, Wohlbold L, Weiler C, Ebertsch L, Weichenrieder O, Izaurralde E. Molecular Architecture of 4E-BP Translational Inhibitors Bound to eIF4E. Mol Cell. 2015 Feb 18. pii: S1097-2765(15)00018-0. doi:, 10.1016/j.molcel.2015.01.017. PMID:25702871 doi:http://dx.doi.org/10.1016/j.molcel.2015.01.017
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