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Updated: Jun 15, 2026

Determining the Likelihood of Variant Pathogenicity Using Amino Acid-level Signal-to-Noise Analysis of Genetic Variation
Published on: January 16, 2019
Maximal entropy inference of oncogenicity from phosphorylation signaling
T G Graeber1, J R Heath, B J Skaggs
1Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging, University of California, Los Angeles, CA 90095, USA.
Abstract:
Point mutations in the phosphorylation domain of the Bcr-Abl fusion oncogene give rise to drug resistance in chronic myelogenous leukemia patients. These mutations alter kinase-mediated signaling function and phenotypic outcome. An information theoretic analysis of the correlation of phosphoproteomic profiling and transformation potency of the oncogene in different mutants is presented. The theory seeks to predict the leukemic transformation potency from the observed signaling by constructing a distribution of maximal entropy of site-specific phosphorylation events. The theory is developed with special reference to systems biology where high throughput measurements are typical. We seek sets of phosphorylation events most contributory to predicting the phenotype by determining the constraints on the signaling system. The relevance of a constraint is measured by how much it reduces the value of the entropy from its global maximum, where all events are equally likely. Application to experimental phospho-proteomics data for kinase inhibitor-resistant mutants shows that there is one dominant constraint and that other constraints are not relevant to a similar extent. This single constraint accounts for much of the correlation of phosphorylation events with the oncogenic potency and thereby usefully predicts the trends in the phenotypic output. An additional constraint possibly accounts for biological fine structure.
Insights
Point mutations in Bcr-Abl oncogenes cause drug resistance in chronic myelogenous leukemia. Information theory predicts leukemic transformation potency by analyzing phosphorylation events and identifying key signaling constraints.
Area of Science:
- Biochemistry
- Systems Biology
- Oncology
Background:
- Point mutations in the Bcr-Abl fusion oncogene's phosphorylation domain are linked to drug resistance in chronic myelogenous leukemia (CML).
- These mutations impact kinase-mediated signaling pathways and cellular transformation.
- Understanding these signaling alterations is crucial for developing effective CML therapies.
Purpose of the Study:
- To apply information theory to correlate phosphoproteomic profiles with the transformation potency of Bcr-Abl mutants.
- To develop a predictive model for leukemic transformation based on observed signaling patterns.
- To identify critical phosphorylation events and signaling constraints that drive oncogenic phenotypes.
Main Methods:
- Utilized an information theoretic approach to analyze phosphoproteomic data.
- Constructed a maximal entropy distribution of site-specific phosphorylation events.
- Quantified the relevance of signaling constraints by measuring entropy reduction.
- Applied the developed theory to experimental phospho-proteomics data from kinase inhibitor-resistant Bcr-Abl mutants.
Main Results:
- Identified a single dominant constraint significantly correlating phosphorylation events with oncogenic potency.
- Demonstrated that this constraint effectively predicts trends in phenotypic output.
- Found that other identified constraints were less relevant to the overall oncogenic potency.
- Observed an additional constraint that may explain biological fine structure in signaling.
Conclusions:
- A dominant signaling constraint in Bcr-Abl mutants largely predicts their leukemic transformation potency.
- This information theoretic framework provides a powerful tool for systems biology analysis of high-throughput omics data.
- The findings offer insights into drug resistance mechanisms and potential therapeutic targets in CML.
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