Tissue-specific regulation of translational readthrough tunes functions of the traffic jam transcription factor

Prajwal Karki, Travis D Carney, Cristina Maracci, Andriy S Yatsenko, Halyna R Shcherbata, and Marina V Rodnina

Nucleic Acids Research, gkab1189, doi: 10.1093/nar/gkab1189

Stop-codon readthrough is believed to be infrequent however, recent studies suggest that translational readthrough in eukaryotes may be more prevalent than expected. Many translational readthrough candidates are transcription factors (TF) or regulators. A longer isoform of such a factor would attain a C-terminal extension that could alter the specificity of the TF for its ligands, localization, or transitions in the nucleus. In this study, the authors tested several candidate readthrough genes in D. melanogaster and selected the TF Traffic jam (Tj) to study the functional significance of readthrough in the whole organism. They show that the expression of the longer isoform is tissue-specific and tightly controlled. Relatively efficient readthrough is necessary in the brain but is harmful in the gonads. They show that the difference in the readthrough efficiency is likely due to the differential expression of several tissue-specific isoforms of translation termination factors.

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