Ribosome Footprinting for uORF Translation Quantification
Solution Overview
Problem
Current methods for measuring translation, especially on a genome-wide scale, are technically challenging and cannot accurately quantify ribosome occupancy on upstream open reading frames (uORFs) or distinguish between ribosomes occupying uORFs and coding sequences, limiting our understanding of translational regulation.
Innovation Solution
The method involves capturing and characterizing ribosome footprints in vivo using enzymatic or chemical degradants to form protected RNA fragments, which are then amplified and sequenced, allowing for the determination of ribosome occupancy and translation activity with high reproducibility and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If polysome fractionation is used to measure translation, then genome-wide translation measurements can be obtained, but the method cannot distinguish ribosome occupancy on uORFs versus coding sequences
Solution Approach 1:
The patent segments the continuous polysome profile into discrete ribosome footprint positions through nuclease digestion and deep sequencing. Instead of analyzing bulk polysome fractions, the method divides the mRNA into individual nucleotide positions occupied by ribosomes, allowing precise determination of whether ribosomes are on uORFs or coding sequences.
Solution Approach 2:
The patent introduces nuclease digestion as an intermediary step between polysome formation and detection. By using nucleases to digest unprotected RNA and leaving only ribosome-protected footprints, the method creates an intermediate state that reveals precise ribosome positions while maintaining the genome-wide scope of polysome analysis.
2Ease of operation
If conventional translation measurement methods are used, then technical challenges are reduced, but quantitative resolution and reproducibility remain limited
Solution Approach 1:
The patent replaces the mechanical/physical separation approach of polysome fractionation with a chemical/enzymatic approach using nuclease digestion. This substitution allows for more precise quantitative measurements through deep sequencing while maintaining operational feasibility through standardized enzymatic protocols.
Solution Approach 2:
The patent changes the detection parameter from bulk RNA quantity in fractions to individual nucleotide position occupancy. By measuring translation at the level of single nucleotides rather than bulk RNA, the method achieves superior quantitative resolution and reproducibility while remaining experimentally tractable.
3Loss of information
If ribosome footprinting is performed without deep sequencing, then the position of ribosomes can be identified, but quantitative measurement of translation is not achieved
Solution Approach 1:
The patent creates multiple copies of ribosome footprint information through deep sequencing. Each ribosome position is sequenced multiple times, generating a quantitative signal that reflects the number of ribosomes at each position. This copying approach transforms qualitative position information into quantitative translation measurements.
Solution Approach 2:
The patent makes the ribosome footprinting method multi-functional by combining position identification and quantitative measurement into a single deep sequencing approach. The same sequencing data that reveals ribosome positions also provides quantitative translation levels, eliminating the need for separate measurement methods.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach provides quantitative and reproducible measurements of translation, enabling the identification of ribosome occupancy on uORFs and coding sequences, and reveals the full translational profile of the cell, thereby improving our understanding of translational regulation and its role in development and disease.
Implementation Method 1
contacting the plurality of RNA molecules with an enzymatic degradant or a chemical degradant thereby forming a plurality of RNA fragments, wherein each RNA fragment comprises an RNA portion protected from the enzymatic degradant or the chemical degradant by a ribosome
Implementation Method 2
contacting the plurality of RNA molecules with an enzymatic degradant or a chemical degradant thereby forming a plurality of RNA fragments
Implementation Method 3
each RNA fragment comprises an RNA portion protected from the enzymatic degradant or the chemical degradant by a ribosome to which the RNA portion is bound
Implementation Method 4
amplifying the RNA fragments to form a detectable number of amplified nucleic acid fragments
Data Source
AI summary
Methods are provided for, inter alia, detecting nucleic acid molecules resistant to degradation, such as a plurality of RNA molecules bound to a ribosome, using various technologies including deep sequencing.