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
Collections
Source
RNA Biology
Type
Journal article
Book Title
Entity type
Access Statement
Open Access