1. Translation termination depends on the sequential ribosomal entry of eRF1 and eRF3.
- Author
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Beißel C, Neumann B, Uhse S, Hampe I, Karki P, and Krebber H
- Subjects
- Codon, Terminator genetics, Guanosine Triphosphate genetics, Protein Binding genetics, Protein Biosynthesis genetics, RNA, Transfer genetics, Ribosomes genetics, Saccharomyces cerevisiae genetics, DEAD-box RNA Helicases genetics, Nucleocytoplasmic Transport Proteins genetics, Peptide Chain Termination, Translational, Peptide Termination Factors genetics, Saccharomyces cerevisiae Proteins genetics
- Abstract
Translation termination requires eRF1 and eRF3 for polypeptide- and tRNA-release on stop codons. Additionally, Dbp5/DDX19 and Rli1/ABCE1 are required; however, their function in this process is currently unknown. Using a combination of in vivo and in vitro experiments, we show that they regulate a stepwise assembly of the termination complex. Rli1 and eRF3-GDP associate with the ribosome first. Subsequently, Dbp5-ATP delivers eRF1 to the stop codon and in this way prevents a premature access of eRF3. Dbp5 dissociates upon placing eRF1 through ATP-hydrolysis. This in turn enables eRF1 to contact eRF3, as the binding of Dbp5 and eRF3 to eRF1 is mutually exclusive. Defects in the Dbp5-guided eRF1 delivery lead to premature contact and premature dissociation of eRF1 and eRF3 from the ribosome and to subsequent stop codon readthrough. Thus, the stepwise Dbp5-controlled termination complex assembly is essential for regular translation termination events. Our data furthermore suggest a possible role of Dbp5/DDX19 in alternative translation termination events, such as during stress response or in developmental processes, which classifies the helicase as a potential drug target for nonsense suppression therapy to treat cancer and neurodegenerative diseases., (© The Author(s) 2019. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Published
- 2019
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