TY  - JOUR
A1  - Gandin, Valentina
A1  - Masvidal, Laia
A1  - Hulea, Laura
A1  - Gravel, Simon-Pierre
A1  - Cargnello, Marie
A1  - McLaughlan, Shannon
A1  - Cai, Yutian
A1  - Balanathan, Preetika
A1  - Morita, Masahiro
A1  - Rajakumar, Arjuna
A1  - Furic, Luc
A1  - Pollak, Michael
A1  - Porco, John A.
A1  - St-Pierre, Julie
A1  - Pelletier, Jerry
A1  - Larsson, Ola
A1  - Topisirovic, Ivan
T1  - nanoCAGE reveals 5′ UTR features that define specific modes of translation of functionally related MTOR-sensitive mRNAs
Y1  - 2016/05/01 
JF  - Genome Research 
JO  - Genome Research 
SP  - 636 
EP  - 648 
DO  - 10.1101/gr.197566.115 
VL  - 26 
IS  - 5 
UR  - http://genome.cshlp.org/content/26/5/636.abstract 
N2  - The diversity of MTOR-regulated mRNA translation remains unresolved. Whereas ribosome-profiling suggested that MTOR almost exclusively stimulates translation of the TOP (terminal oligopyrimidine motif) and TOP-like mRNAs, polysome-profiling indicated that MTOR also modulates translation of mRNAs without the 5′ TOP motif (non-TOP mRNAs). We demonstrate that in ribosome-profiling studies, detection of MTOR-dependent changes in non-TOP mRNA translation was obscured by low sensitivity and methodology biases. Transcription start site profiling using nano-cap analysis of gene expression (nanoCAGE) revealed that not only do many MTOR-sensitive mRNAs lack the 5′ TOP motif but that 5′ UTR features distinguish two functionally and translationally distinct subsets of MTOR-sensitive mRNAs: (1) mRNAs with short 5′ UTRs enriched for mitochondrial functions, which require EIF4E but are less EIF4A1-sensitive; and (2) long 5′ UTR mRNAs encoding proliferation- and survival-promoting proteins, which are both EIF4E- and EIF4A1-sensitive. Selective inhibition of translation of mRNAs harboring long 5′ UTRs via EIF4A1 suppression leads to sustained expression of proteins involved in respiration but concomitant loss of those protecting mitochondrial structural integrity, resulting in apoptosis. Conversely, simultaneous suppression of translation of both long and short 5′ UTR mRNAs by MTOR inhibitors results in metabolic dormancy and a predominantly cytostatic effect. Thus, 5′ UTR features define different modes of MTOR-sensitive translation of functionally distinct subsets of mRNAs, which may explain the diverse impact of MTOR and EIF4A inhibitors on neoplastic cells. 
ER  -