Summary
ATP-dependent complexes slide or evict nucleosomes to control access to DNA.
In depth
Complexes such as SWI/SNF use ATP to slide, eject or restructure nucleosomes, exposing promoters. Mutations in subunits occur in about 20 percent of cancers.
Remodellers work with histone modifiers and transcription factors.
There are four main families: SWI/SNF, ISWI, CHD and INO80. They slide nucleosomes along DNA, evict them, exchange histone variants or change their spacing. ISWI complexes space nucleosomes evenly, while SWI/SNF opens promoters. Their ATPase subunits are related to helicases.
SWI/SNF mutations, such as ARID1A and SMARCA4, are found in ovarian, lung and kidney tumours, and some cancers depend on remaining subunits, offering drug targets. Mutations in CHD7 cause CHARGE syndrome, a developmental disorder.
Remember: remodelers need ATP and work with histone modifiers, so the two systems act together to give access to DNA.
Frequently asked questions
What is Chromatin Remodelling?
ATP-dependent complexes slide or evict nucleosomes to control access to DNA.
Which area of biology covers Chromatin Remodelling, and how advanced is it?
Chromatin Remodelling is one of the 52 topics in Molecular Biology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include DNA Methylation, Transcription Factors, Histone Modification.
Can you give an example of Chromatin Remodelling?
Nucleosome remodelling is needed to open the promoter of the interferon-beta gene on viral infection.
What should I learn before Chromatin Remodelling?
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Chromatin Remodelling. Advanced topics assume the Intermediate vocabulary.
What topics are related to Chromatin Remodelling?
The closest topics to Chromatin Remodelling are DNA Methylation, Transcription Factors, Histone Modification, Enhancers and Silencers. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Chromatin Remodelling?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Chromatin Remodelling. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
How is Chromatin Remodelling different from DNA Methylation?
Chromatin Remodelling: ATP-dependent complexes slide or evict nucleosomes to control access to DNA. DNA Methylation: Addition of methyl groups to cytosine, usually silencing gene expression. Read both side by side and note what each one explains.
How should I study Chromatin Remodelling step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with DNA Methylation and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.