Probing the closed-loop model of mRNA translation in living cells

Date

2015-03-31

Authors

Archer, Stuart K.
Shirokikh, Nikolay E.
Hallwirth, Claus V.
Beilharz, Traude H.
Preiss, Thomas

Journal Title

Journal ISSN

Volume Title

Publisher

Taylor & Francis

Abstract

The mRNA closed-loop, formed through interactions between the cap structure, poly(A) tail, eIF4E, eIF4G and PAB, features centrally in models of eukaryotic translation initiation, although direct support for its existence in vivo is not well established. Here, we investigated the closed-loop using a combination of mRNP isolation from rapidly cross-linked cells and high-throughput qPCR. Using the interaction between these factors and the opposing ends of mRNAs as a proxy for the closed-loop, we provide evidence that it is prevalent for eIF4E/4G-bound but unexpectedly sparse for PAB1-bound mRNAs, suggesting it primarily occurs during a distinct phase of polysome assembly. We observed mRNA-specific variation in the extent of closed-loop formation, consistent with a role for polysome topology in the control of gene expression.

Description

Keywords

cap-poly(a) synergy, eukaryotic translation, mrna closed-loop, polysomes, ribosomal recycling

Citation

Source

RNA Biology

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

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