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Post‐Termination Events in Eukaryotic Translation
Author(s) -
Pestova Tatyana,
Skabkin Maxim,
Skabkina Olga,
Hellen Christopher
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.461.2
Subject(s) - stop codon , transfer rna , release factor , p site , translation (biology) , ribosomal rna , chemistry , peptidyl transferase , biochemistry , biology , messenger rna , ribosome , genetics , rna , gene
Termination occurs when a stop codon enters the ribosomal A‐site. It consists of stop codon recognition followed by hydrolysis of the P‐site peptidyl‐tRNA. The hydrolysis step involves nucleophilic attack of water on peptidyl‐tRNA in the peptidyl transferase center of the large ribosomal subunit. In eukaryotes, termination results from the complex functional interplay between release factors eRF1 and eRF3, in which GTP hydrolysis by eRF3 couples stop codon recognition and peptidyl‐tRNA hydrolysis by eRF1. Recycling of post‐termination complexes (post‐TCs) is promoted by the concerted action of ABCE1, an essential member of ATP‐binding cassette family of proteins, and eRF1, which remains associated with post‐TCs after peptide release. ABCE1 and eRF1 dissociate post‐TCs into free 60S and tRNA/mRNA‐bound 40S subunits. Subsequent tRNA/mRNA release from 40S subunits can be promoted either by initiation factors 1/1A/3, or by Ligatin. In some cases post‐TCs do not undergo complete recycling, and termination is instead followed by reinitiation on the same mRNA, usually downstream of the stop codon. This mostly occurs after translation of short open reading frames. To investigate the molecular mechanisms underlying reinitiation, we investigated different fates of ribosomal post‐termination complexes depending on the presence of initiation, as well as elongation, factors, and initiator or elongator tRNAs.