Stabilization of eukaryotic initiation factor 4E binding to the mRNA 5'-Cap by domains of eIF4G

von der Haar, Tobias and Ball, Philip D. and McCarthy, John E. G. (2000) Stabilization of eukaryotic initiation factor 4E binding to the mRNA 5'-Cap by domains of eIF4G. Journal of Biological Chemistry, 275 (39). pp. 30551-30555. ISSN 0021-9258. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1074/jbc.M004565200

Abstract

The eukaryotic cap-binding complex eIF4F is an essential component of the translational machinery. Recognition of the mRNA cap structure through its subunit eIF4E is a requirement for the recruitment of other translation initiation factors to the mRNA 5'-end and thereby for the attachment of the 40 S ribosomal subunit. In this study, we have investigated the mechanistic basis of the observation that eIF4E binding to the cap is enhanced in the presence of the large eIF4F subunit, eIF4G. We show that eIF4E requires access to both the mRNA 5'-cap and eIF4G to form stable complexes with short RNAs. This stabilization can be achieved using fragments of eIF4G that contain the eIF4E binding site but not the RNA recognition motifs. Full-length eIF4G is shown to induce increased eIF4E binding to cap analogues that do not contain an RNA body. Both results show that interaction of eIF4G with the mRNA is not necessary to enhance cap binding by eIF4E. Moreover, we show that the effect of binding of full-length eIF4G on the cap affinity of eIF4E can be further modulated through binding of Pab1 to eIF4G. These data are consistent with a model in which heterotropic cooperativity underlies eIF4F function.

Item Type: Article
Subjects: Q Science
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences > Protein Science Group
Depositing User: Tobias von der Haar
Date Deposited: 27 May 2009 07:03
Last Modified: 11 Jun 2014 10:43
Resource URI: http://kar.kent.ac.uk/id/eprint/5341 (The current URI for this page, for reference purposes)
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