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| Status |
Public on Oct 03, 2023 |
| Title |
Transcriptome-wide analysis of the function of Ded1 in translation preinitiation complex assembly in a reconstituted in vitro system |
| Organism |
Saccharomyces cerevisiae |
| Experiment type |
Other
|
| Summary |
We have developed a deep sequencing-based approach, Rec-Seq, that allows simultaneous monitoring of ribosomal 48S pre-initiation complex (PIC) formation on every mRNA in the translatome in an in vitro reconstituted system. Rec-Seq isolates key early steps in translation initiation in the absence of all other cellular components and processes. Using this approach we show that the DEAD-box ATPase Ded1 promotes 48S PIC formation on the start codons of >1000 native mRNAs, most of which have long, structured 5’-untranslated regions (5’UTRs). Remarkably, initiation measured in Rec-Seq was enhanced by Ded1 for most mRNAs previously shown to be highly Ded1-dependent by ribosome profiling of ded1 mutants in vivo, demonstrating that the core translation functions of the factor are recapitulated in the purified system. Our data do not support a model in which Ded1acts by reducing initiation at start codons in 5’UTRs and instead indicate it functions by directly promoting mRNA recruitment to the 43S PIC and scanning to locate the start codon. We also provide evidence that eIF4A, another essential DEAD-box initiation factor, is required for efficient PIC assembly on almost all mRNAs, regardless of their structural complexity, in contrast to the preferential stimulation by Ded1 of initiation on mRNAs with long, structured 5’UTRs.
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| Overall design |
We tested yeast Ded1 and eIF4A in promoting mRNA recruitments using Rec-Seq experiment. For Ded1 protein, we tested conditions with 0, 100 or 500 nM Ded1, for eIF4A protein, we tested 500 or 5000 nM eIF4A.
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| Contributor(s) |
Zhou F, Bocetti JM, Hou M, Qin D, Hinnebusch AG, Lorsch JR |
| Citation(s) |
38573742 |
| |
| Submission date |
Sep 26, 2023 |
| Last update date |
Apr 11, 2024 |
| Contact name |
Jon R. Lorsch |
| E-mail(s) |
jon.lorsch@nih.gov
|
| Phone |
301-594-2172
|
| Organization name |
National Institutes of Health
|
| Department |
Eunice Kennedy Shriver National Institute of Child Health and Human Development,
|
| Lab |
Section on the Mechanism and Regulation of Protein Synthesis
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| Street address |
BG 49 RM 2C08, 49 Convent Dr.
|
| City |
Bethesda |
| State/province |
MD |
| ZIP/Postal code |
20892 |
| Country |
USA |
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| Platforms (1) |
| GPL27812 |
Illumina NovaSeq 6000 (Saccharomyces cerevisiae) |
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| Samples (14)
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| Relations |
| BioProject |
PRJNA1021217 |
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