Act I · Physical & Clinical Story
A Race at the Ribosomal A-Site
Deep within the active catalytic core of the translating ribosome, an extraordinary kinetic tournament decides the physical fate of every interrupted channel message. When an unexpected premature stop signal enters the decoding chamber, specialized cellular release factors rush forward to sever the nascent peptide chain before structural completion. Writing in the Journal of Cystic Fibrosis during 2020, Onofrio Laselva and colleagues demonstrated that this enzymatic termination process is never entirely absolute. Near cognate transfer molecules continually compete against release factor proteins for physical entry into the stalled decoding pocket. If an accommodating transfer molecule slips inside first, elongation resumes and generates a full length channel that frequently carries an altered amino acid at the critical crossing point. Molecular folding correctors can then stabilize these substituted proteins at the apical surface. Success requires simultaneously orchestrating ribosomal reading efficiency alongside downstream channel stabilization.
The cellular machine assembling human proteins reads genetic instructions three letters at a time. Under normal conditions, termination signals are respected with extraordinary accuracy, causing the synthesis machinery to release the finished channel cleanly. However, premature stop signals vary considerably in their stringency depending on their exact chemical identity and surrounding sequence neighborhood. Certain stop codons permit near cognate transfer molecules to slip into the active decoding site by mistake. When this accidental readthrough occurs, the ribosome inserts an alternate amino acid and continues synthesizing the remaining channel architecture. This creates a full length protein, but one carrying an unintended amino acid substitution right at the old stop location. The resulting channel frequently misfolds inside the endoplasmic reticulum. Pairing readthrough agents with folding correctors and gating potentiators provides the biochemical assistance needed to escort these repaired channels to the apical cell boundary.
Everyday Analogy: Picture a high-speed commuter turnstile in a busy metropolitan rail terminal where security guards stand ready to intercept invalid passes. When a passenger approaches carrying an expired ticket, the gatekeeper lunges forward to slam the barrier shut. In that split second, an opportunistic runner holding an imperfect pass attempts to squeeze through. If the runner slips past, the journey continues. Inside the ribosomal decoding center, a remarkably similar kinetic contest takes place between termination release factors and imperfect near-cognate transfer RNAs. A readthrough drug acts like a brief distraction that slows the cellular gatekeeper, allowing mismatched transfer molecules to insert and finish protein synthesis. The elongated channel reaches completion, but it now bears an altered amino acid at that contested junction. However, this turnstile analogy stops being accurate because transit tickets do not alter the physical three-dimensional folding or biological pore conductance of the traveler.
How the Two Sliders Work in Plain Words: Before diving into the mathematical formulas, the interactive laboratory provides two dynamic controls to examine this ribosomal competition. The first slider adjusts the A-Site Decoding Ratio (k_tRNA / k_eRF1), modeling how readthrough agents alter the competitive balance between transfer molecules and release factors. As this ratio rises, the Per-Codon Readthrough Probability P_rt increases across the Stop-Codon Permissiveness Rank, showing UGA as the most permeable signal. The second slider sets the Missense-Product ETI Rescue Multiplier, simulating how combination modulators assist the folding of channels bearing substituted amino acids. Observe the readout for Primary UGA Near-Cognate Insertions. When a UGA codon is bypassed, the ribosome predominantly inserts tryptophan, arginine, or cysteine. Finally, the Combined Synergistic Cl⁻ Current readout reveals total epithelial transport. Together, these indicators demonstrate why boosting readthrough alone remains ineffective unless accompanied by pharmacological folding chaperones to rescue the resulting missense products.
Yet not all stop codons are equally tight. Across human transcripts, UGA is the 'leakiest' stop codon (especially when followed by a cytosine at the +4 position), followed by UAG, while UAA is the most stringent. Because both G542X and W1282X in CFTR are UGA stop codons, researchers have long sought small molecules that selectively tip the kinetic competition at UGA in favor of near-cognate tRNA accommodation—either by binding the 40S decoding pocket or by inducing proteasomal degradation of eRF1.
Overcoming premature termination codons has historically represented one of the most stubborn therapeutic bottlenecks in cystic fibrosis research. Early laboratory and clinical efforts utilizing non-selective readthrough compounds frequently fell short due to poor mucosal delivery, dose-limiting cellular toxicity, and modest functional restoration. In their definitive 2020 study, Laselva and colleagues demonstrated why single-agent readthrough interventions consistently hit a biophysical ceiling. When a small molecule coaxes the ribosome past an early UGA stop codon, near-cognate transfer RNAs insert non-native amino acids such as tryptophan, arginine, or cysteine. For variants like G542X, where the native residue is glycine, this misincorporation produces a structural missense channel that misfolds and degrades rapidly within the endoplasmic reticulum quality-control apparatus. Crucially, Laselva established that combining readthrough stimulants with nonsense-mediated decay inhibitors and CFTR folding correctors achieves synergistic rescue in patient-derived nasal epithelia. Translational progress therefore depends on formalizing this multi-stage kinetic cascade rather than relying on ribosomal readthrough in isolation. Without concurrent folding and gating assistance, newly elongated polypeptides fail to generate meaningful apical chloride transport.
“Shows why the stop-codon identity hierarchy (UGA > UAG > UAA) and the +4 nucleotide context determine readthrough efficiency, and how ETI rescues the resulting missense-substituted full-length chains.”
— Cross-Pillar Research Thread · Grounded in Laselva et al. (2020), Journal of Cystic Fibrosis 19(5):717-727 — Functional rescue of c.3846G>A (W1282X) in patient-derived nasal cultures achieved by inhibition of nonsense mediated decay and protein modulators with complementary mechanisms of action (PMID 31831337).
Key Parameters, Readouts & Primary Anchor
| Quantity / Anchor | Pinned Baseline | Physical / Clinical Role |
|---|---|---|
| A-Site Decoding Ratio (k_tRNA / k_eRF1) | 0.14 ratio |
Primary perturbation axis (0.01 to 0.35 ratio) |
| Missense-Product ETI Rescue Multiplier | 2.8× ETI boost |
Coupled co-perturbation axis (1.0 to 4.0× ETI boost) |
| Per-Codon Readthrough Probability P_rt & Stop-Codon Permissiveness Rank | 12.3% (UGA Context) · UGA > UAG > UAA |
Baseline biophysical operating point |
| Primary Literature Anchor | DOI 10.1016/j.jcf.2019.12.001 | Laselva et al. (2020), Journal of Cystic Fibrosis 19(5):717-727 — Functional rescue of c.3846G>A (W1282X) in patient-derived nasal cultures achieved by inhibition of nonsense mediated decay and protein modulators with complementary mechanisms of action (PMID 31831337). · Kernel src/scripts/ptc-simulator.js |
Act II · From Intuition to Governing Law
Competitive Michaelis–Menten Decoding and Multiplicative Cascade
At a premature stop codon, the probability of readthrough per ribosome encounter is P_rt = k_tRNA [aa-tRNA_nc] / (k_tRNA [aa-tRNA_nc] + k_term [eRF1·eRF3]). Notice why single-agent readthrough hits a mathematical wall: if NMD leaves only f_mRNA = 0.15 of transcripts intact, and readthrough succeeds on P_rt = 0.05 of translations, and 60% of the resulting G542W chains misfold (η_fold = 0.40), net functional CFTR is 0.15 × 0.05 × 0.40 = 0.3% of wild-type—well below the 10–15% physiological threshold established in Essay C.06! When NMD attenuation raises f_mRNA to 0.60, eRF1-depleting + ribosomal readthrough raises P_rt to 0.15, and ETI raises η_fold · (P_o / P_o,WT) to 1.8, the product jumps to 0.60 × 0.15 × 1.8 = 16.2% of wild-type.
The governing biophysical relationship at the stalled ribosomal A-site is formulated as a competitive kinetic race between two mutually exclusive macromolecular processes: near-cognate aminoacyl-tRNA accommodation with forward rate constant k_tRNA, and eukaryotic release factor 1 (eRF1·eRF3·GTP) binding and peptidyl-tRNA hydrolysis with rate constant k_eRF1. Under steady-state conditions, the probability of readthrough per ribosome encounter obeys the classic competitive Michaelis–Menten formulation P_rt = k_tRNA / (k_tRNA + k_eRF1). In untreated human airway cells, the concentration and intrinsic binding affinity of eRF1 exceed near-cognate tRNA delivery by several orders of magnitude, restricting basal readthrough at UGA premature termination codons to less than 0.5%. Small-molecule readthrough inducers, such as aminoglycoside derivatives or eRF1-depleting compounds, alter the conformational equilibrium of 18S ribosomal RNA decoding bases A1824 and A1825 in helix 44 or decrease free eRF1 pools, effectively shifting the kinetic ratio k_tRNA / k_eRF1 into a therapeutically relevant regime.
However, translation through the premature stop codon constitutes only the second link in a rigid multiplicative chain. The total functional chloride conductance across the apical plasma membrane is governed by the product I_total = [mRNA]_ss · P_rt · η_fold(ETI) · P_o(Ivacaftor). In this relation, [mRNA]_ss represents the steady-state transcript pool escaping nonsense-mediated decay, η_fold denotes the thermodynamic folding and trafficking yield of the full-length polypeptide through the endoplasmic reticulum, and P_o characterizes the single-channel open probability under cAMP-dependent phosphorylation. In our computational kernel (src/scripts/ptc-simulator.js), this four-stage cascade explains the steep non-linear threshold observed experimentally: if [mRNA]_ss is 0.15, P_rt is 0.05, and unchaperoned folding efficiency η_fold is 0.40, net transport collapses to 0.3% of wild-type. Introducing elexacaftor, tezacaftor, and ivacaftor restores η_fold and P_o, elevating net conductance above the ten-percent physiological benchmark.
Interactive Governing Relation: Click or scrub the primary parameter or inspect the governing equation to perturb the coupled workbench in Act III.
Four-Stage Mechanistic Progression
- Stage 1 (Ribosomal A-Site Pause at PTC): When UGA, UAG, or UAA enters the 40S decoding center, no cognate tRNA exists in normal human cells; eukaryotic release factor 1 (eRF1, complexed with eRF3·GTP) competes with near-cognate tRNAs carrying a single wobble/mismatch.
- Stage 2 (Helix 44 Monitoring Flip — A1824/A1825): Aminoglycosides and designer readthrough compounds (such as ELX-02 or SRI-41315 which depletes eRF1) shift the conformational equilibrium of 18S rRNA bases A1824/A1825 or reduce eRF1 concentration, raising k_tRNA / k_eRF1.
- Stage 3 (Near-Cognate Amino-Acid Insertion): At a UGA premature stop codon, near-cognate tRNA^Trp(CCA), tRNA^Arg(UCU), or tRNA^Cys(GCA) decodes the stop triplet. For W1282X (wild-type Trp), inserting Trp restores 100% native sequence; for G542X (wild-type Gly), inserting Trp/Arg/Cys creates G542W/R/C.
- Stage 4 (Post-Translational ETI Folding & Gating Rescue): Elexacaftor + tezacaftor chaparone the G542W/G542R missense polypeptides through ER quality control, and ivacaftor potentiates their apical P_o.
Act III · Interactive Visual Experiment & Plain-Language Lens
Try It Yourself: Decoding Competition & Multiplicative Synergy Lab
Vary the A-site decoding ratio (k_tRNA / k_eRF1) and the ETI missense-rescue multiplier to see how multiplicative cascade stages cross the 10–15% WT transport threshold.
When a ribosome hits a premature stop sign (UGA, UAG, or UAA), a split-second race begins inside the decoding pocket: will the release factor (eRF1) snip the unfinished chain loose, or will a near-match carrier RNA slip in an amino acid so translation can finish? Not all stop signs are equally strict—UGA followed by a C is the 'leakiest' stop, and pairing readthrough with CFTR modulators amplifies whatever full-length protein makes it across the finish line.
Questions to discuss with a CF care team: Which specific stop codon (UGA, UAG, or UAA) does my variant create, and how do current readthrough or suppressor-tRNA studies approach it?
What this diagram leaves out: Inserting a near-cognate amino acid often creates a missense CFTR variant whose own folding and gating must then be supported.
Ribosomal Decoding Walkthrough · Mode: Pinned Evidence Storyboard · How to explore this model
- Step through the four visual chapters: Click the four mechanism chapters below (1 · Ribosomal A-Site Pause at… through 4 · Post-Translational ETI…) to watch the schematic transition across each regime.
- Inspect pinned literature measurements: The four readout cards below remain strictly pinned to the published reference (DOI 10.1016/j.jcf.2019.12.001) rather than synthetic slider scaling.
- Launch the full pillar simulator: Open Open Readthrough & ETI Synergy Workbench on /cf/ptc/ for multi-parameter continuous simulation.
Pinned Primary Evidence Mode · Click Chapters 1–4 above to animate the G.02 mechanism.
P_rt = k_tRNA / (k_tRNA + k_eRF1) · I_total = [mRNA]_ss · P_rt · η_fold(ETI) · P_o(Ivacaftor)
Normalized Sensitivity (Stages 1–4)
Want to test this mechanism inside the full multi-module pillar observatory? Open the coupled interactive workbench on the Pillar Hub.
Act IV · Clinical & Therapeutic Horizon
From Aminoglycosides to Suppressor tRNAs
Clinical trials of first-generation readthrough agents (such as ataluren and systemic ELX-02) showed that small-molecule readthrough alone struggled to achieve sufficient airway CFTR levels at safe systemic doses without oto- or nephrotoxicity. Those lessons directly catalyzed two next-generation paths covered in Essays G.03–G.06: engineered suppressor tRNAs (which insert the exact wild-type amino acid with high efficiency) and direct RNA/DNA editing. Grounded in Lab Discovery Catalog modules: `ptc_erf_depletion_readthrough`.
Translational boundaries for readthrough therapies are intrinsically governed by the chemical identity of the amino acid inserted at the premature stop codon. At a UGA stop signal, near-cognate decoding is mediated primarily by three transfer RNA species: tRNA^Trp(CCA) inserting tryptophan, tRNA^Arg(UCU) inserting arginine, and tRNA^Cys(GCA) inserting cysteine. In the case of W1282X (where the native codon is UGG encoding tryptophan), near-cognate insertion of tryptophan directly recreates the exact authentic wild-type primary sequence, conferring high specific conductance per translated channel. Conversely, for G542X (where the native codon is GGA encoding glycine), readthrough forces an unavoidable missense substitution, producing G542W, G542R, or G542C polypeptides that misfold and aggregate unless chaperoned by targeted correctors.
Genotype-specific clinical surveillance and organoid bioassays confirm that single-agent readthrough regimens consistently fail to attain sufficient mucosal chloride flux across differentiated human airways. Clinical trials evaluating ataluren or systemic aminoglycosides demonstrated the severe limits of unassisted readthrough, highlighting issues with systemic renal and auditory toxicity alongside insufficient respiratory response. Pharmacological rescue requires simultaneous targeting of all three modular barriers: attenuating SMG1 kinase or UPF1 to protect transcript longevity, utilizing targeted agents like ELX-02 or SRI-41315 to increase the ribosomal decoding ratio, and co-administering elexacaftor/tezacaftor/ivacaftor to chaperone missense-substituted channels to the apical membrane. Computational modeling in primary patient-derived nasal epithelia validates that this multi-target synergy provides the only viable pharmacological avenue for converting Class I premature termination variants into functional transmembrane conduits.
Primary Anchor: Laselva et al. (2020), Journal of Cystic Fibrosis 19(5):717-727 — Functional rescue of c.3846G>A (W1282X) in patient-derived nasal cultures achieved by inhibition of nonsense mediated decay and protein modulators with complementary mechanisms of action (PMID 31831337). (DOI 10.1016/j.jcf.2019.12.001 · PubMed 31831337).
Governed by biophysical kernel src/scripts/ptc-simulator.js and cross-checked in the Open Readthrough & ETI Synergy Workbench on /cf/ptc/.
Resumen Científico en Español (ES-MX) · Folio G.02
Lectura Ribosomal Frente a Terminación: Competencia Cinética en los Codones UGA, UAG y UAA: Cómo los agentes de lectura desplazan la competencia cinética entre los factores de liberación eRF1/eRF3 y los ARNt cuasi-cognados en el sitio A del ribosoma.
Cuando una molécula pequeña induce la lectura de un codón UGA, el ribosoma suele insertar triptófano, arginina o cisteína. Si el residuo original era glicina (G542X), la proteína resultante porta una variante de sentido erróneo que requiere correctores y potenciadores.
En Palabras Sencillas: La máquina celular encargada de ensamblar las proteínas humanas lee las instrucciones genéticas de tres en tres letras. En condiciones habituales, las señales de terminación se obedecen con una precisión absoluta, provocando que el ribosoma libere el canal completado de manera limpia. No obstante, las señales de paro prematuro difieren de manera sustancial en su rigor según su composición química exacta y las secuencias vecinas. Ciertos codones de terminación permiten que moléculas transportadoras de transferencia casi compatibles se introduzcan por error en el centro de decodificación. Cuando ocurre esta lectura accidental, el ribosoma inserta un aminoácido sustituto y continúa construyendo el resto de la estructura del canal. Esto genera una proteína de longitud completa, pero portadora de una alteración puntual en el sitio original de interrupción. Este canal resultante suele plegarse mal en el retículo endoplásmico. Por ello, combinar inductores de lectura con correctores y potenciadores proporciona la ayuda indispensable para guiar estos canales hasta la superficie celular.
Analogía Cotidiana: Imagine un torniquete de alta velocidad en una terminal ferroviaria metropolitana donde los guardias de seguridad interceptan de inmediato a cualquiera que lleve un boleto inválido. Cuando un pasajero se acerca con un pase vencido, el vigilante se apresura a cerrar la barrera. En esa fracción de segundo, un viajero oportunista con un boleto imperfecto intenta colarse antes del cierre. Si logra pasar, el viaje continúa. Dentro del centro de decodificación ribosomal ocurre una contienda cinética idéntica entre los factores de terminación y los ARN de transferencia cuasi-cognados. Un fármaco de lectura actúa como una breve distracción que ralentiza al vigilante celular, permitiendo que moléculas de transferencia imperfectas inserten un aminoácido y continúen la síntesis. La proteína se completa, pero ahora porta un residuo modificado en esa unión disputada. No obstante, esta analogía del torniquete deja de ser exacta porque los boletos de transporte no alteran el plegamiento tridimensional ni la conductancia del canal biológico.
Guía de Controles Interactivos: Antes de profundizar en las fórmulas matemáticas, el laboratorio interactivo ofrece dos controles dinámicos para examinar la competencia en el ribosoma. El primer deslizador ajusta la proporción de decodificación en el sitio A (k_tRNA / k_eRF1), modelando cómo los agentes de lectura alteran el equilibrio cinético frente a los factores de liberación. A medida que esta razón se incrementa, la probabilidad de lectura por codón aumenta, confirmando que UGA es el codón más permeable. El segundo control regula el multiplicador de rescate con moduladores ETI, simulando la asistencia en el plegamiento de proteínas con aminoácidos sustitutos. Observe la lectura de inserciones cuasi-cognadas en UGA. Al sobrepasar este codón, el ribosoma inserta principalmente triptófano, arginina o cisteína. Por último, la corriente sinérgica de cloruro revela la secreción epitelial total. En conjunto, estos indicadores explican por qué inducir lectura sin añadir chaperonas moleculares resulta insuficiente para rescatar la función del canal.
Riesgo Biofísico y Clínico: Superar los codones de terminación prematura ha constituido históricamente uno de los obstáculos terapéuticos más persistentes en la investigación de fibrosis quística. Los primeros intentos clínicos con inductores de lectura no selectivos fracasaron debido a una escasa entrega en mucosas, toxicidad renal y una respuesta funcional mínima. En su estudio definitivo de 2020, Laselva y colaboradores demostraron por qué las intervenciones con un solo agente chocan contra un límite biofísico. Cuando una molécula induce al ribosoma a sobrepasar un codón UGA prematuro, los ARN de transferencia cuasi-cognados insertan aminoácidos no nativos como triptófano, arginina o cisteína. En variantes como G542X, donde el residuo original es glicina, esto genera una proteína con mutación de sentido erróneo que se degrada en el retículo endoplásmico. Laselva comprobó que combinar inductores de lectura con inhibidores de NMD y correctores conformacionales logra un rescate sinérgico en cultivos derivados de pacientes, demostrando que el progreso traslacional exige formalizar esta cascada cinética multicomponente.
Derivación Formal: La dinámica biofísica en el sitio A del ribosoma en pausa se formula como una competencia cinética entre dos procesos mutuamente excluyentes: la acomodación del aminoacil-ARNt cuasi-cognado con constante de velocidad k_tRNA y la unión del factor de liberación eRF1 junto con la hidrólisis del peptidil-ARNt con constante k_eRF1. En estado estacionario, la probabilidad de lectura obedece a la formulación competitiva de Michaelis–Menten P_rt = k_tRNA / (k_tRNA + k_eRF1). En células epiteliales no tratadas, la concentración y afinidad intrínseca de eRF1 superan a la entrega de ARNt por varios órdenes de magnitud, limitando la lectura basal en codones UGA a menos del 0.5 %. Fármacos de lectura como derivados de aminoglucósidos o compuestos degradadores de eRF1 alteran el equilibrio conformacional de las bases A1824 y A1825 en la hélice 44 del ARNr 18S o reducen eRF1 libre, desplazando la razón k_tRNA / k_eRF1 hacia un régimen terapéutico útil. Sin embargo, la decodificación del codón constituye únicamente el segundo eslabón de una estricta cadena multiplicativa. El transporte total de cloruro en la membrana apical está regido por el producto I_total = [mRNA]_ss · P_rt · η_fold(ETI) · P_o(Ivacaftor). Aquí, [mRNA]_ss representa el conjunto de transcritos que escapan de NMD, η_fold denota el rendimiento de plegamiento y tráfico en el retículo endoplásmico, y P_o caracteriza la probabilidad de apertura del canal bajo fosforilación por PKA. En nuestro simulador (src/scripts/ptc-simulator.js), esta cascada explica por qué un tratamiento aislado produce menos del 1 % de actividad normal: si el mensaje cae al 15 %, la lectura es del 5 % y el plegamiento del 40 %, el transporte neto colapsa al 0.3 %. Combinar moduladores rescata η_fold y P_o, superando el umbral funcional terapéutico.
Frontera Traslacional: Los límites traslacionales de la inducción de lectura dependen intrínsecamente de la naturaleza química del aminoácido insertado en el codón prematuro. En un codón UGA, la decodificación cuasi-cognada ocurre primordialmente mediante tres ARN de transferencia: ARNt-Trp insertando triptófano, ARNt-Arg insertando arginina y ARNt-Cys insertando cisteína. Para W1282X (donde el codón nativo es UGG que codifica triptófano), la inserción de triptófano restituye con fidelidad la secuencia primaria nativa, confiriendo una elevada conductancia específica por canal rescatado. En contraste, para G542X (donde el codón silvestre es GGA para glicina), la lectura introduce inevitablemente una sustitución de sentido erróneo, generando polipéptidos G542W, G542R o G542C que se desestabilizan a menos que intervengan correctores farmacológicos. La vigilancia clínica y los bioensayos en organoides confirman que los inductores de lectura aislados no alcanzan una conductancia adecuada en el epitelio respiratorio humano. Los ensayos clínicos con ataluren o aminoglucósidos sistémicos evidenciaron la toxicidad y la limitada eficacia de la mono-lectura. El rescate requiere abordar simultáneamente las tres barreras: atenuar SMG1 o UPF1 para resguardar el transcrito, aplicar agentes selectivos para elevar la decodificación ribosomal y coadministrar elexacaftor/tezacaftor/ivacaftor para guiar las proteínas hasta la membrana apical. Los modelos computacionales en epitelio nasal demuestran que esta sinergia coordinada representa la ruta farmacológica idónea para tratar variantes de terminación prematura de Clase I.
Horizonte terapéutico: Muestra por qué la jerarquía de codones de paro (UGA > UAG > UAA) y el nucleótido +4 determinan la eficiencia de lectura y cómo ETI rescata las cadenas completas resultantes. Investigación independiente, no asesoramiento médico.
Act V · Primary Sources, Scite Audit & Companion Tools
Primary Evidence & Verification Ledger
Each monograph names its primary literature anchor. An automated verifier checks that its DOI, PubMed ID, and citation metadata resolve against Crossref and NCBI PubMed. Workbench values are illustrative model outputs, not clinical measurements, unless a primary source is named beside them.
- Primary Literature Receipt: Laselva et al. (2020), Journal of Cystic Fibrosis 19(5):717-727 — Functional rescue of c.3846G>A (W1282X) in patient-derived nasal cultures achieved by inhibition of nonsense mediated decay and protein modulators with complementary mechanisms of action (PMID 31831337). (DOI 10.1016/j.jcf.2019.12.001 · PubMed 31831337).
- Citation Context (Scite): Inspect how later literature cites 10.1016/j.jcf.2019.12.001 on Scite.ai ·
Crossref + Scite verified (data/folio-citations.cache.json · fetched 2026-11-08 · 74 citing · 8 supporting · 89 mentioning · 1 contrasting). - Open-Source Computational & Epistemic Engine: PySINDy Sparse Ribosomal Kinetics & JAX-MD Folding (DOI 10.21105/joss.02104 · Scite Report).
- Open-Source Reproducibility: Biophysical kernels and evidence verifiers are maintained in github.com/senseiewok/cf-research and github.com/senseiewok/cf-skills.
For builders: method, companion SKILL.md, Python verifier, and edition history (REV 1.1)
cftr-ribosomal-readthrough-synergy-SKILL.md · Kernel src/scripts/ptc-simulator.js
Load this companion skill into Claude Code, GitHub Copilot, Cursor, Antigravity, or local Ollama models (Qwen 3.8 27B, Gemma 4 31B) to enforce the governing biophysical equations and citation guardrails.
View raw SKILL.md source
--- name: cftr-ribosomal-readthrough-synergy description: AI-agnostic skill for ribosomal A-site stop-codon competition (UGA > UAG > UAA), near-cognate amino acid insertion, and multiplicative NMD + readthrough + ETI synergy. license: CC-BY-4.0 --- # G.02 — Ribosomal Readthrough Competition (UGA/UAG/UAA) & ETI Synergy ## Governing Biophysical / Mathematical Law P_rt = k_tRNA / (k_tRNA + k_eRF1) · I_total = [mRNA]_ss · P_rt · η_fold(ETI) · P_o(Ivacaftor) ## Primary Evidence Receipt - **Citation:** Laselva et al. (2020), Journal of Cystic Fibrosis 19(5):717-727 — Functional rescue of c.3846G>A (W1282X) in patient-derived nasal cultures achieved by inhibition of nonsense mediated decay and protein modulators with complementary mechanisms of action (PMID 31831337). - **DOI:** https://doi.org/10.1016/j.jcf.2019.12.001 - **PubMed PMID:** https://pubmed.ncbi.nlm.nih.gov/31831337/ - **Answer Tier:** T2 · Sourced Ribosomal Decoding & Synergy Model ## Verification Rules - Compute net functional CFTR rescue as the product of mRNA survival, readthrough probability, folding yield, and open-probability potentiation. - Account for missense substitution at non-Trp UGA codons (e.g., G542W/R/C at G542X vs native Trp at W1282X). - Ground in vitro combination synergy in Laselva et al. 2020 (DOI 10.1016/j.jcf.2019.12.001, PMID 31831337). ## Safety & Clinical Boundary Research synthesis and biophysical modeling only — never medical advice, clinical guidance, or a treatment promise.
REV 1.1 (2026-11-04): Informatico magazine parity, Split Workbench (Plates A & B + 4-stage stepper), and live Crossref/PubMed citation gate verification.
Verified 5-Act magazine flow, untruncated headings, and bilingual EN / ES-MX structural parity.
Audited clinical dignity boundaries, non-promise guardrails, and discovery catalog coverage.
check_folio_citations.py
Verified DOI 10.1016/j.jcf.2019.12.001 against Crossref and NCBI PubMed metadata.
src/scripts/ptc-simulator.js
Coupled governing relation P_rt = k_tRNA / (k_tRNA + k_eRF1) · I_total to interactive Plates A & B.