SMARCB1 C-Terminal Domain Nucleosome Binding Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The mechanisms by which mutations in the mSWI/SNF complex, particularly in the SMARCB1 subunit, alter chromatin structure and function, leading to intellectual disability and cancer, remain unclear, and high-resolution structures of these complexes have not been achieved due to their heterogeneous composition and reconstitution challenges.
Innovation Solution
The elucidation of the architecture and function of the SMARCB1 C-terminal domain's interaction with the nucleosome acidic patch, demonstrating how mutations affect nucleosome binding and remodeling activity, and the development of modified protein complexes and methods for screening agents that modulate these interactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-resolution structures of mSWI/SNF complexes are pursued, then structural understanding is improved, but the heterogeneous composition and reconstitution challenges worsen the difficulty of obtaining such structures
Solution Approach 1:
The patent segments the mSWI/SNF complex into distinct subcomplexes (cBAF, PBAF, ncBAF) based on their specific subunit compositions. By studying these segmented subcomplexes rather than the entire heterogeneous mixture, the patent achieves high-resolution structural understanding while managing the complexity through systematic classification and separate reconstitution of each subcomplex type.
2Loss of information
If mutant mSWI/SNF complexes are studied to understand disease mechanisms, then insight into intellectual disability and cancer is improved, but the dominant negative effects and functional disruption worsen the interpretation complexity
Solution Approach 1:
The patent uses modified SMARCB1 subunits with specific mutations (e.g., K364del, R377H) as intermediaries to study disease mechanisms. These defined mutations serve as controlled models that recapitulate dominant negative effects while allowing systematic investigation of how specific amino acid changes disrupt nucleosome binding and complex assembly, thereby managing interpretation complexity through precise molecular definitions.
3Loss of information
If the SMARCB1 C-terminal domain interactions with nucleosome acidic patch are elucidated, then nucleosome remodeling mechanism is improved, but the binding specificity and interaction complexity worsen the structural determination difficulty
Solution Approach 1:
The patent focuses on the local C-terminal domain of SMARCB1 (specifically residues involved in nucleosome acidic patch binding) rather than attempting to resolve the entire complex structure. By concentrating structural and functional analysis on this specific local region, the patent achieves detailed understanding of nucleosome remodeling mechanisms while avoiding the overwhelming complexity of full complex characterization.
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 decouples genome-wide binding of mutant mSWI/SNF complexes from their nucleosome remodeling activity, revealing the dominant negative effects of SMARCB1 mutations on gene expression and phenotypic effects, and provides a basis for understanding and addressing related disorders.
Implementation Method 1
the SMARCB1 C-terminal domain's interaction with the nucleosome acidic patch
Data Source
AI summary
The present invention is directed to compositions comprising modified SMARCB1 and uses thereof.