Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.

The efficiency of start codon selection during ribosomal scanning in eukaryotic translation initiation is influenced by the context or flanking nucleotides surrounding the AUG codon. The levels of eukaryotic translation initiation factors 1 (eIF1) and 5 (eIF5) play critical roles in controlling the...

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Main Authors: Gary Loughran, Andrew E Firth, John F Atkins, Ivaylo P Ivanov
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2018-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC5823381?pdf=render
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author Gary Loughran
Andrew E Firth
John F Atkins
Ivaylo P Ivanov
author_facet Gary Loughran
Andrew E Firth
John F Atkins
Ivaylo P Ivanov
author_sort Gary Loughran
collection DOAJ
description The efficiency of start codon selection during ribosomal scanning in eukaryotic translation initiation is influenced by the context or flanking nucleotides surrounding the AUG codon. The levels of eukaryotic translation initiation factors 1 (eIF1) and 5 (eIF5) play critical roles in controlling the stringency of translation start site selection. The basic leucine zipper and W2 domain-containing proteins 1 and 2 (BZW1 and BZW2), also known as eIF5-mimic proteins, are paralogous human proteins containing C-terminal HEAT domains that resemble the HEAT domain of eIF5. We show that translation of mRNAs encoding BZW1 and BZW2 homologs in fungi, plants and metazoans is initiated by AUG codons in conserved unfavorable initiation contexts. This conservation is reminiscent of the conserved unfavorable initiation context that enables autoregulation of EIF1. We show that overexpression of BZW1 and BZW2 proteins enhances the stringency of start site selection, and that their poor initiation codons confer autoregulation on BZW1 and BZW2 mRNA translation. We also show that overexpression of these two proteins significantly diminishes the effect of overexpressing eIF5 on stringency of start codon selection, suggesting they antagonize this function of eIF5. These results reveal a surprising role for BZW1 and BZW2 in maintaining homeostatic stringency of start codon selection, and taking into account recent biochemical, genetic and structural insights into eukaryotic initiation, suggest a model for BZW1 and BZW2 function.
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spelling doaj.art-ec785573cb3b4b33b8aea214646794ba2022-12-22T01:58:11ZengPublic Library of Science (PLoS)PLoS ONE1932-62032018-01-01132e019264810.1371/journal.pone.0192648Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.Gary LoughranAndrew E FirthJohn F AtkinsIvaylo P IvanovThe efficiency of start codon selection during ribosomal scanning in eukaryotic translation initiation is influenced by the context or flanking nucleotides surrounding the AUG codon. The levels of eukaryotic translation initiation factors 1 (eIF1) and 5 (eIF5) play critical roles in controlling the stringency of translation start site selection. The basic leucine zipper and W2 domain-containing proteins 1 and 2 (BZW1 and BZW2), also known as eIF5-mimic proteins, are paralogous human proteins containing C-terminal HEAT domains that resemble the HEAT domain of eIF5. We show that translation of mRNAs encoding BZW1 and BZW2 homologs in fungi, plants and metazoans is initiated by AUG codons in conserved unfavorable initiation contexts. This conservation is reminiscent of the conserved unfavorable initiation context that enables autoregulation of EIF1. We show that overexpression of BZW1 and BZW2 proteins enhances the stringency of start site selection, and that their poor initiation codons confer autoregulation on BZW1 and BZW2 mRNA translation. We also show that overexpression of these two proteins significantly diminishes the effect of overexpressing eIF5 on stringency of start codon selection, suggesting they antagonize this function of eIF5. These results reveal a surprising role for BZW1 and BZW2 in maintaining homeostatic stringency of start codon selection, and taking into account recent biochemical, genetic and structural insights into eukaryotic initiation, suggest a model for BZW1 and BZW2 function.http://europepmc.org/articles/PMC5823381?pdf=render
spellingShingle Gary Loughran
Andrew E Firth
John F Atkins
Ivaylo P Ivanov
Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.
PLoS ONE
title Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.
title_full Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.
title_fullStr Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.
title_full_unstemmed Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.
title_short Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection.
title_sort translational autoregulation of bzw1 and bzw2 expression by modulating the stringency of start codon selection
url http://europepmc.org/articles/PMC5823381?pdf=render
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AT johnfatkins translationalautoregulationofbzw1andbzw2expressionbymodulatingthestringencyofstartcodonselection
AT ivaylopivanov translationalautoregulationofbzw1andbzw2expressionbymodulatingthestringencyofstartcodonselection