Recycling of 40S ribosomal subunits following translation termination, entailing release of deacylated tRNA and dissociation of the empty 40S from mRNA, involves yeast Tma20/Tma22 heterodimer and Tma64, counterparts of mammalian MCTS1/DENR and eIF2D. MCTS1/DENR enhance reinitiation (REI) at short upstream open reading frames (uORFs) harboring penultimate codons that confer heightened dependence on these factors in bulk 40S recycling. Tma factors, by contrast, inhibited REI at particular uORFs in extracts; however, their roles at regulatory uORFs in vivo were unknown. We examined effects of eliminating Tma proteins on REI at regulatory uORFs mediating translational control of GCN4 optimized for either promoting (uORF1) or preventing (uORF4) REI. We found that the Tma proteins generally impede REI at native uORF4 and its variants equipped with various penultimate codons regardless of their Tma-dependence in bulk recycling. The Tma factors have no effect on REI at native uORF1 and equipping it with Tma-hyperdependent penultimate codons generally did not confer Tma-dependent REI; nor did converting the uORFs to AUG-stop elements. Thus, effects of the Tma proteins vary depending on the REI potential of the uORF and penultimate codon, but unlike in mammals, are not principally dictated by the Tma-dependence of the codon in bulk 40S recycling.

Division of Molecular and Cellular Biology Eunice Kennedy Shriver National Institute of Child Health and Human Development National Institutes of Health Bethesda MD 20892 USA

Faculty of Science Charles University Albertov 6 128 00 Prague Czech Republic

Laboratory of Regulation of Gene Expression Institute of Microbiology of the Czech Academy of Sciences Videnska 1083 142 20 Prague Czech Republic

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Valášek, L. S. ‘Ribozoomin’—translation initiation from the perspective of the ribosome-bound eukaryotic initiation factors (eIFs). PubMed DOI PMC

Hinnebusch, A. G. The scanning mechanism of eukaryotic translation initiation. PubMed DOI

Jackson, R. J., Hellen, C. U. & Pestova, T. V. Termination and post-termination events in eukaryotic translation. PubMed DOI

Hellen, C. U. T. Translation termination and ribosome recycling in eukaryotes. PubMed PMC

Gunisova, S., Hronova, V., Mohammad, M. P., Hinnebusch, A. G. & Valasek, L. S. Please do not recycle! Translation reinitiation in microbes and higher eukaryotes. PubMed DOI PMC

Young, D. J. & Guydosh, N. R. Rebirth of the translational machinery: the importance of recycling ribosomes. PubMed DOI PMC

Shoemaker, C. J. & Green, R. Kinetic analysis reveals the ordered coupling of translation termination and ribosome recycling in yeast. PubMed DOI PMC

Pisarev, A. V. et al. The role of ABCE1 in eukaryotic posttermination ribosomal recycling. PubMed DOI PMC

Young, D. J., Guydosh, N. R., Zhang, F., Hinnebusch, A. G. & Green, R. Rli1/ABCE1 recycles terminating ribosomes and controls translation reinitiation in 3’UTRs in vivo. PubMed DOI PMC

Young, D. J. & Guydosh, N. R. Hcr1/eIF3j is a 60S ribosomal subunit recycling accessory factor in vivo. PubMed DOI PMC

Kratzat, H. et al. A structural inventory of native ribosomal ABCE1-43S pre-initiation complexes. PubMed DOI PMC

Skabkin, M. A. et al. Activities of ligatin and MCT-1/DENR in eukaryotic translation initiation and ribosomal recycling. PubMed DOI PMC

Bohlen, J. et al. DENR promotes translation reinitiation via ribosome recycling to drive expression of oncogenes including ATF4. PubMed DOI PMC

Fleischer, T. C., Weaver, C. M., McAfee, K. J., Jennings, J. L. & Link, A. J. Systematic identification and functional screens of uncharacterized proteins associated with eukaryotic ribosomal complexes. PubMed DOI PMC

Young, D. J. et al. Tma64/eIF2D, Tma20/MCT-1, and Tma22/DENR recycle post-termination 40S subunits in vivo. PubMed DOI PMC

Young, D. J., Meydan, S. & Guydosh, N. R. 40S ribosome profiling reveals distinct roles for Tma20/Tma22 (MCT-1/DENR) and Tma64 (eIF2D) in 40S subunit recycling. PubMed DOI PMC

Schleich, S. et al. DENR-MCT-1 promotes translation re-initiation downstream of uORFs to control tissue growth. PubMed DOI PMC

Schleich, S., Acevedo, J. M., Clemm von Hohenberg, K. & Teleman, A. A. Identification of transcripts with short stuORFs as targets for DENR*MCTS1-dependent translation in human cells. PubMed DOI PMC

Skabkin, M. A., Skabkina, O. V., Hellen, C. U. & Pestova, T. V. Reinitiation and other unconventional posttermination events during eukaryotic translation. PubMed DOI PMC

Vasudevan, D. et al. Translational induction of ATF4 during integrated stress response requires noncanonical initiation factors eIF2D and DENR. PubMed DOI PMC

Bohlen, J., Fenzl, K., Kramer, G., Bukau, B. & Teleman, A. A. Selective 40S footprinting reveals cap-tethered ribosome scanning in human cells. PubMed DOI

Lin, Y. et al. eIF3 associates with 80S ribosomes to promote translation elongation, mitochondrial homeostasis, and muscle health. PubMed DOI

Wagner, S. et al. Selective translation complex profiling reveals staged initiation and co-translational assembly of initiation factor complexes. PubMed DOI PMC

Szamecz, B. et al. eIF3a cooperates with sequences 5’ of uORF1 to promote resumption of scanning by post-termination ribosomes for reinitiation on GCN4 mRNA. PubMed DOI PMC

Munzarová, V. et al. Translation reinitiation relies on the interaction between eIF3a/TIF32 and progressively folded cis-acting mRNA elements preceding short uORFs. PubMed DOI PMC

Mohammad, M. P., Munzarova Pondelickova, V., Zeman, J., Gunisova, S. & Valasek, L. S. In vivo evidence that eIF3 stays bound to ribosomes elongating and terminating on short upstream ORFs to promote reinitiation. PubMed PMC

Mohammad, M. P., Smirnova, A., Gunisova, S. & Valasek, L. S. eIF4G is retained on ribosomes elongating and terminating on short upstream ORFs to control reinitiation in yeast. PubMed DOI PMC

Dever, T. E., Ivanov, I. P. & Hinnebusch, A. G. Translational regulation by uORFs and start codon selection stringency. PubMed DOI PMC

Gaikwad, S. et al. Reprogramming of translation in yeast cells impaired for ribosome recycling favors short, efficiently translated mRNAs. PubMed PMC

Mueller, P. P. & Hinnebusch, A. G. Multiple upstream AUG codons mediate translational control of PubMed DOI

Miller, P. F. & Hinnebusch, A. G. Sequences that surround the stop codons of upstream open reading frames in PubMed DOI

Gunisova, S. & Valasek, L. S. Fail-safe mechanism of GCN4 translational control-uORF2 promotes reinitiation by analogous mechanism to uORF1 and thus secures its key role in GCN4 expression. PubMed DOI PMC

Gunisova, S., Beznoskova, P., Mohammad, M. P., Vlckova, V. & Valasek, L. S. In-depth analysis of cis-determinants that either promote or inhibit reinitiation on GCN4 mRNA after translation of its four short uORFs. PubMed DOI PMC

Abastado, J. P., Miller, P. F., Jackson, B. M. & Hinnebusch, A. G. Suppression of ribosomal reinitiation at upstream open reading frames in amino acid-starved cells forms the basis for PubMed PMC

Grant, C. M. & Hinnebusch, A. G. Effect of sequence context at stop codons on efficiency of reinitiation in PubMed PMC

Grant, C. M., Miller, P. F. & Hinnebusch, A. G. Requirements for intercistronic distance and level of eIF-2 activity in reinitiation on GCN4 mRNA varies with the downstream cistron. PubMed PMC

Beznosková, P., Gunišová, S. & Valášek, L. S. Rules of UGA-N decoding by near-cognate tRNAs and analysis of readthrough on short uORFs in yeast. PubMed DOI PMC

Hronova, V. et al. Does eIF3 promote reinitiation after translation of short upstream ORFs also in mammalian cells? PubMed PMC

Lomakin, I. B. et al. Crystal structure of the human ribosome in complex with DENR-MCT-1. PubMed DOI PMC

Longtine, M. S. et al. Additonal modules for versatile and economical PCR-based gene deletion and modification in PubMed DOI

Carter, Z. & Delneri, D. New generation of loxP-mutated deletion cassettes for the genetic manipulation of yeast natural isolates. PubMed DOI

Looke, M., Kristjuhan, K. & Kristjuhan, A. Extraction of genomic DNA from yeasts for PCR-based applications. PubMed DOI PMC

Mueller, P. P., Harashima, S. & Hinnebusch, A. G. A segment of PubMed DOI PMC

Hinnebusch, A. G. A hierarchy of PubMed PMC

Moehle, C. M. & Hinnebusch, A. G. Association of RAP1 binding sites with stringent control of ribosomal protein gene transcription in PubMed PMC

Sievers, F. et al. Fast, scalable generation of high-quality protein multiple sequence alignments using Clustal Omega. PubMed DOI PMC

Madeira, F. et al. Search and sequence analysis tools services from EMBL-EBI in 2022. PubMed DOI PMC

Abramson, J. et al. Accurate structure prediction of biomolecular interactions with AlphaFold 3. PubMed PMC