Polypeptide release factors and stop codon recognition in the apicoplast and mitochondrion ofPlasmodium falciparum

Translation termination requires codon-dependent polypeptide release factors. The mechanism of stop codon recognition by release factors is unknown and holds considerable interest since it entails protein–RNA recognition rather than the well-understood mRNA–tRNA interaction in codon–anticodon pairing. Bacteria have two codon-specific release factors and our picture of prokaryotic translation is changing because a third factor, which stimulates the other two, has now been found. Moreover, a highly conserved eukaryotic protein family possessing properties of polypeptide release factor has now been sought. This review summarizes our current understanding of the structural and functional organization of release factors as well as our recent findings of highly conserved structural motifs in bacterial and eukaryotic polypeptide release factors.Key words: translation termination, stop codon recognition, peptide chain release factors, seven-domain model.

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Structure of the mammalian ribosomal pre-termination complex associated with eRF1•eRF3•GDPNP

Nucleic Acids Research ◽

10.1093/nar/gkt1279 ◽

2013 ◽

Vol 42 (5) ◽

pp. 3409-3418 ◽

Cited By ~ 44

Author(s):

Amédée des Georges ◽

Yaser Hashem ◽

Anett Unbehaun ◽

Robert A. Grassucci ◽

Derek Taylor ◽

...

Keyword(s):

Electron Microscopy ◽

Stop Codon ◽

Translation Termination ◽

Gtpase Activity ◽

Gtp Hydrolysis ◽

Eukaryotic Translation ◽

Release Factors ◽

Codon Recognition ◽

Cryo Electron Microscopy ◽

Stop Codon Recognition

Abstract Eukaryotic translation termination results from the complex functional interplay between two release factors, eRF1 and eRF3, in which GTP hydrolysis by eRF3 couples codon recognition with peptidyl-tRNA hydrolysis by eRF1. Here, we present a cryo-electron microscopy structure of pre-termination complexes associated with eRF1•eRF3•GDPNP at 9.7 -Å resolution, which corresponds to the initial pre-GTP hydrolysis stage of factor attachment and stop codon recognition. It reveals the ribosomal positions of eRFs and provides insights into the mechanisms of stop codon recognition and triggering of eRF3’s GTPase activity.

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GGQ methylation enhances both speed and accuracy of stop codon recognition by bacterial class-I release factors

Journal of Biological Chemistry ◽

10.1016/j.jbc.2021.100681 ◽

2021 ◽

pp. 100681

Author(s):

Shreya Pundir ◽

Xueliang Ge ◽

Suparna Sanyal

Keyword(s):

Stop Codon ◽

Class I ◽

Release Factors ◽

Codon Recognition ◽

Stop Codon Recognition ◽

Speed And Accuracy

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Eukaryotic Release Factor 1 Phosphorylation by CK2 Protein Kinase Is Dynamic but Has Little Effect on the Efficiency of Translation Termination in Saccharomyces cerevisiae

Eukaryotic Cell ◽

10.1128/ec.00073-06 ◽

2006 ◽

Vol 5 (8) ◽

pp. 1378-1387 ◽

Cited By ~ 12

Author(s):

Adam K. Kallmeyer ◽

Kim M. Keeling ◽

David M. Bedwell

Keyword(s):

Saccharomyces Cerevisiae ◽

Protein Synthesis ◽

Protein Kinase ◽

Stop Codon ◽

Translation Termination ◽

Release Factor ◽

Codon Recognition ◽

Number Of Factors ◽

Stop Codon Recognition

ABSTRACT Protein synthesis requires a large commitment of cellular resources and is highly regulated. Previous studies have shown that a number of factors that mediate the initiation and elongation steps of translation are regulated by phosphorylation. In this report, we show that a factor involved in the termination step of protein synthesis is also subject to phosphorylation. Our results indicate that eukaryotic release factor 1 (eRF1) is phosphorylated in vivo at serine 421 and serine 432 by the CK2 protein kinase (previously casein kinase II) in the budding yeast Saccharomyces cerevisiae. Phosphorylation of eRF1 has little effect on the efficiency of stop codon recognition or nonsense-mediated mRNA decay. Also, phosphorylation is not required for eRF1 binding to the other translation termination factor, eRF3. In addition, we provide evidence that the putative phosphatase Sal6p does not dephosphorylate eRF1 and that the state of eRF1 phosphorylation does not influence the allosuppressor phenotype associated with a sal6Δ mutation. Finally, we show that phosphorylation of eRF1 is a dynamic process that is dependent upon carbon source availability. Since many other proteins involved in protein synthesis have a CK2 protein kinase motif near their extreme C termini, we propose that this represents a common regulatory mechanism that is shared by factors involved in all three stages of protein synthesis.

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