Knowra Chromatin remodeling Chromatin remodeling Chromatin remodeling is the repositioning or restructuring of DNA-associated proteins, especially nucleosomes, that changes access to genomic regions without changing the DNA sequence.
Nucleosome : A segment of DNA wrapped around a histone protein core, forming the basic repeating unit of chromatin. Remodeling complexes alter nucleosome positions and structures to change DNA accessibility.
Histone : A basic protein around which eukaryotic DNA is wrapped to form nucleosomes. Histones provide the protein core whose DNA contacts remodelers rearrange.
Transcriptional regulation : Control of RNA synthesis through mechanisms that influence when, where, and how strongly genes are transcribed. Remodeling can expose promoters and enhancers or restrict transcription-factor binding.
DNA methylation : The addition of methyl groups to DNA, commonly at cytosine bases, with effects on gene regulation. It changes regulatory state through a DNA chemical mark rather than directly moving nucleosomes.
ATP-dependent chromatin remodeling : Chromatin remodeling driven by ATP-hydrolyzing enzymes that reposition, restructure, or remove nucleosomes. ATP hydrolysis supplies the energy for many remodeling reactions.
Chromatin : The DNA, proteins, and associated molecules that package eukaryotic genomes in the nucleus. Chromatin is the material whose structure remodeling changes.
Enhancer : A DNA regulatory element that can increase transcription of a target gene, often from a distant genomic position. Remodeling helps transcription factors access enhancer sequences.
Histone acetylation : The addition of acetyl groups to histone proteins, often associated with more accessible chromatin. Acetylation changes histone chemistry, while remodeling changes nucleosome arrangement.
SWI/SNF : A family of ATP-dependent chromatin-remodeling complexes that can slide or evict nucleosomes. SWI/SNF complexes often expose regulatory DNA by moving or removing nucleosomes.
Histone variant : A noncanonical histone protein that replaces a standard histone in some nucleosomes and can alter their properties. Variant-containing nucleosomes can have distinct stability and remodeler interactions.
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