Engineered histones reshape chromatin in human cells.

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Histone proteins and variants are critical for chromatin organization and gene regulation.
• The precise link between histone sequence and chromatin structure is not well understood.
• This knowledge gap hinders the design of synthetic histones and understanding of evolutionary sequence variations.

Purpose of the Study:

• To engineer histone variants that can modulate chromatin organization.
• To investigate the mechanisms by which histone sequence variations affect chromatin structure and gene expression.
• To develop a framework for rationally designing synthetic histones to achieve specific cellular states.

Main Methods:

• Expression of core histone sequence variant libraries in human cells.
• Utilized imaging, proteomics, and genomics for variant interrogation.
• Employed transcription factor libraries for functional screening.
• Combined double mutation screens with protein language models for sequence-to-function analysis.

Main Results:

• Identified histone variants that significantly alter chromatin structure.
• Elucidated both cis- and trans-acting mechanisms influencing chromatin organization.
• Discovered transcriptional programs facilitated by engineered histone expression.
• Developed predictive models for designing synthetic histones based on sequence-function relationships.

Conclusions:

• Established a foundation for high-throughput evaluation and engineering of chromatin-associated proteins.
• Demonstrated histones as tunable components for modulating mesoscale chromatin organization.
• Paved the way for rationally designing synthetic histones to engineer specific cell states.