Source 1primary paper2018Proceedings of the National Academy of Sciences
Toolkit/upstream ORFs
upstream ORFs
Also known as: uORFs
Taxonomy: Mechanism Branch / Component. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
Upstream open reading frames (uORFs) are endogenous 5′-leader RNA elements that can take precedence over translation of the main ORF and reduce protein output. In Arabidopsis, blue light can increase use of downstream transcription start sites that bypass uORFs, enabling higher expression of light-responsive genes.
Usefulness & Problems
Why this is useful
uORFs provide a native RNA-level mechanism for suppressing main-ORF expression through the 5′ leader, and they can be functionally bypassed by alternative transcription start site selection. This makes them useful for studying or engineering coupling between transcript architecture, translation efficiency, and light-responsive gene regulation in Arabidopsis.
Problem solved
This regulatory architecture helps explain and potentially exploit how genes with inhibitory 5′-leader uORFs can still achieve increased expression under specific conditions. The cited work specifically addresses how blue light-responsive genes evade uORF-mediated repression by initiating transcription downstream of the uORFs.
Problem links
Need precise spatiotemporal control with light input
DerivedUpstream open reading frames (uORFs) are endogenous 5′-leader RNA elements that can take precedence over translation of the main ORF and reduce protein output. In Arabidopsis, blue light can increase use of downstream transcription start sites that bypass uORFs, enabling higher expression of light-responsive genes.
Need tighter control over gene expression timing or amplitude
DerivedUpstream open reading frames (uORFs) are endogenous 5′-leader RNA elements that can take precedence over translation of the main ORF and reduce protein output. In Arabidopsis, blue light can increase use of downstream transcription start sites that bypass uORFs, enabling higher expression of light-responsive genes.
Need tighter control over protein production
DerivedUpstream open reading frames (uORFs) are endogenous 5′-leader RNA elements that can take precedence over translation of the main ORF and reduce protein output. In Arabidopsis, blue light can increase use of downstream transcription start sites that bypass uORFs, enabling higher expression of light-responsive genes.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Component: A low-level RNA part used inside a larger architecture that realizes a mechanism.
Mechanisms
alternative transcription start site selection that bypasses uorfslight-regulated transcription start site selectionnonsense-mediated mrna decaytranslational inhibition of the main orf by upstream open reading framestranslational inhibition of the main orf by upstream orfsTranslation ControlTechniques
No technique tags yet.
Target processes
transcriptiontranslationInput: Light
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: spectral hardware requirementoperating role: regulator
uORFs reside in the 5′ leader upstream of the main ORF, so implementation depends on transcript architecture and transcription start site placement relative to the uORF. The cited evidence supports use in Arabidopsis and links regulation to blue light-dependent downstream TSS selection, but it does not provide construct design parameters, delivery methods, or expression-system requirements.
The evidence is drawn from a single Arabidopsis study and does not establish general performance across organisms or synthetic construct contexts. Quantitative effects on protein output, sequence design rules, and portability as an engineered regulatory part are not provided in the supplied evidence.
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Observations
successBacteriaapplication demoArabidopsis
Inferred from claim c3 during normalization. Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes. Derived from claim c3. Quoted text: Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
Source:
genes with enhanced downstream TSS usage220
successBacteriaapplication demoArabidopsis
Inferred from claim c3 during normalization. Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes. Derived from claim c3. Quoted text: Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
Source:
genes with enhanced downstream TSS usage220
successBacteriaapplication demoArabidopsis
Inferred from claim c3 during normalization. Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes. Derived from claim c3. Quoted text: Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
Source:
genes with enhanced downstream TSS usage220
successBacteriaapplication demoArabidopsis
Inferred from claim c3 during normalization. Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes. Derived from claim c3. Quoted text: Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
Source:
genes with enhanced downstream TSS usage220
successBacteriaapplication demoArabidopsis
Inferred from claim c3 during normalization. Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes. Derived from claim c3. Quoted text: Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
Source:
genes with enhanced downstream TSS usage220
successBacteriaapplication demoArabidopsis
Inferred from claim c3 during normalization. Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes. Derived from claim c3. Quoted text: Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
Source:
genes with enhanced downstream TSS usage220
successBacteriaapplication demoArabidopsis
Inferred from claim c3 during normalization. Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes. Derived from claim c3. Quoted text: Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
Source:
genes with enhanced downstream TSS usage220
Supporting Sources
Ranked Claims
uORFs often inhibit translation of the main ORF or trigger nonsense-mediated mRNA decay.
The uORFs often function as translation inhibitors of the mORF or as triggers of nonsense-mediated mRNA decay (NMD).
uORFs often inhibit translation of the main ORF or trigger nonsense-mediated mRNA decay.
The uORFs often function as translation inhibitors of the mORF or as triggers of nonsense-mediated mRNA decay (NMD).
uORFs often inhibit translation of the main ORF or trigger nonsense-mediated mRNA decay.
The uORFs often function as translation inhibitors of the mORF or as triggers of nonsense-mediated mRNA decay (NMD).
uORFs often inhibit translation of the main ORF or trigger nonsense-mediated mRNA decay.
The uORFs often function as translation inhibitors of the mORF or as triggers of nonsense-mediated mRNA decay (NMD).
uORFs often inhibit translation of the main ORF or trigger nonsense-mediated mRNA decay.
The uORFs often function as translation inhibitors of the mORF or as triggers of nonsense-mediated mRNA decay (NMD).
uORFs often inhibit translation of the main ORF or trigger nonsense-mediated mRNA decay.
The uORFs often function as translation inhibitors of the mORF or as triggers of nonsense-mediated mRNA decay (NMD).
uORFs often inhibit translation of the main ORF or trigger nonsense-mediated mRNA decay.
The uORFs often function as translation inhibitors of the mORF or as triggers of nonsense-mediated mRNA decay (NMD).
Transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of the 220 genes, including HY5.
We also show that transcripts from TSSs upstream of uORFs in 45 of the 220 genes, including HY5, accumulated in a mutant of NMD.
genes with upstream TSS transcript accumulation in NMD mutant 45total genes with enhanced downstream TSS usage 220
Transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of the 220 genes, including HY5.
We also show that transcripts from TSSs upstream of uORFs in 45 of the 220 genes, including HY5, accumulated in a mutant of NMD.
genes with upstream TSS transcript accumulation in NMD mutant 45total genes with enhanced downstream TSS usage 220
Transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of the 220 genes, including HY5.
We also show that transcripts from TSSs upstream of uORFs in 45 of the 220 genes, including HY5, accumulated in a mutant of NMD.
genes with upstream TSS transcript accumulation in NMD mutant 45total genes with enhanced downstream TSS usage 220
Transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of the 220 genes, including HY5.
We also show that transcripts from TSSs upstream of uORFs in 45 of the 220 genes, including HY5, accumulated in a mutant of NMD.
genes with upstream TSS transcript accumulation in NMD mutant 45total genes with enhanced downstream TSS usage 220
Transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of the 220 genes, including HY5.
We also show that transcripts from TSSs upstream of uORFs in 45 of the 220 genes, including HY5, accumulated in a mutant of NMD.
genes with upstream TSS transcript accumulation in NMD mutant 45total genes with enhanced downstream TSS usage 220
Transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of the 220 genes, including HY5.
We also show that transcripts from TSSs upstream of uORFs in 45 of the 220 genes, including HY5, accumulated in a mutant of NMD.
genes with upstream TSS transcript accumulation in NMD mutant 45total genes with enhanced downstream TSS usage 220
Transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of the 220 genes, including HY5.
We also show that transcripts from TSSs upstream of uORFs in 45 of the 220 genes, including HY5, accumulated in a mutant of NMD.
genes with upstream TSS transcript accumulation in NMD mutant 45total genes with enhanced downstream TSS usage 220
Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes.
Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
genes with enhanced downstream TSS usage 220
Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes.
Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
genes with enhanced downstream TSS usage 220
Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes.
Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
genes with enhanced downstream TSS usage 220
Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes.
Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
genes with enhanced downstream TSS usage 220
Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes.
Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
genes with enhanced downstream TSS usage 220
Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes.
Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
genes with enhanced downstream TSS usage 220
Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes.
Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
genes with enhanced downstream TSS usage 220
Blue light controls gene expression not only by enhancing transcription but also by choosing transcription start sites, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
These results suggest that BL controls gene expression not only by enhancing transcriptions but also by choosing the TSS, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
Blue light controls gene expression not only by enhancing transcription but also by choosing transcription start sites, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
These results suggest that BL controls gene expression not only by enhancing transcriptions but also by choosing the TSS, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
Blue light controls gene expression not only by enhancing transcription but also by choosing transcription start sites, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
These results suggest that BL controls gene expression not only by enhancing transcriptions but also by choosing the TSS, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
Blue light controls gene expression not only by enhancing transcription but also by choosing transcription start sites, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
These results suggest that BL controls gene expression not only by enhancing transcriptions but also by choosing the TSS, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
Blue light controls gene expression not only by enhancing transcription but also by choosing transcription start sites, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
These results suggest that BL controls gene expression not only by enhancing transcriptions but also by choosing the TSS, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
Blue light controls gene expression not only by enhancing transcription but also by choosing transcription start sites, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
These results suggest that BL controls gene expression not only by enhancing transcriptions but also by choosing the TSS, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
Blue light controls gene expression not only by enhancing transcription but also by choosing transcription start sites, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
These results suggest that BL controls gene expression not only by enhancing transcriptions but also by choosing the TSS, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
Approval Evidence
1 source4 linked approval claimsfirst-pass slug upstream-orfs
some transcripts have upstream ORFs (uORFs) that take precedence over the main ORF (mORF) encoding proteins
Source:
mechanistic claimsupports
uORFs often inhibit translation of the main ORF or trigger nonsense-mediated mRNA decay.
The uORFs often function as translation inhibitors of the mORF or as triggers of nonsense-mediated mRNA decay (NMD).
Source:
mutant accumulation observationsupports
Transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of the 220 genes, including HY5.
We also show that transcripts from TSSs upstream of uORFs in 45 of the 220 genes, including HY5, accumulated in a mutant of NMD.
Source:
regulatory responsesupports
Blue light enhances transcription from transcription start sites located downstream of uORFs in 220 genes.
Transcription from TSSs located downstream of the uORFs in 220 genes is enhanced by BL exposure.
Source:
summary conclusionsupports
Blue light controls gene expression not only by enhancing transcription but also by choosing transcription start sites, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
These results suggest that BL controls gene expression not only by enhancing transcriptions but also by choosing the TSS, and transcripts from downstream TSSs evade uORF-mediated inhibition to ensure high expression of light-regulated genes.
Source:
Comparisons
Source-backed strengths
The mechanism is supported by transcriptome-scale evidence in Arabidopsis showing that blue light enhances transcription from downstream transcription start sites in 220 genes. Additional support for uORF-linked repression comes from the observation that transcripts from TSSs upstream of uORFs accumulated in an NMD mutant for 45 of those genes, including HY5.
Compared with 4pLRE-cPAOX1
upstream ORFs and 4pLRE-cPAOX1 address a similar problem space because they share transcription, translation.
Shared frame: shared target processes: transcription, translation; shared mechanisms: translation_control; same primary input modality: light
Compared with blue-light-activated DNA template ON switch
upstream ORFs and blue-light-activated DNA template ON switch address a similar problem space because they share transcription, translation.
Shared frame: shared target processes: transcription, translation; shared mechanisms: translation_control; same primary input modality: light
Compared with microRNA
upstream ORFs and microRNA address a similar problem space because they share transcription, translation.
Shared frame: same top-level item type; shared target processes: transcription, translation; shared mechanisms: translation_control; same primary input modality: light
Ranked Citations
- 1.