| Autor: |
Rachel Leicher, Adewola Osunsade, Gabriella N. L. Chua, Sarah C. Faulkner, Andrew P. Latham, John W. Watters, Tuan Nguyen, Emily C. Beckwitt, Sophia Christodoulou-Rubalcava, Paul G. Young, Bin Zhang, Yael David, Shixin Liu |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
Nat Struct Mol Biol |
| Popis: |
The H1 linker histone family is the most abundant group of eukaryotic chromatin-binding proteins. However, their contribution to chromosome structure and function remains incompletely understood. Here we use single-molecule fluorescence and force microscopy to directly visualize the behavior of H1 on various nucleic acid and nucleosome substrates. We observe that H1 coalesces around single-stranded DNA generated from tension-induced DNA duplex melting. Using a droplet fusion assay controlled by optical tweezers, we find that single-stranded nucleic acids mediate the formation of gel-like H1 droplets, whereas H1-double-stranded DNA and H1-nucleosome droplets are more liquid-like. Molecular dynamics simulations reveal that multivalent and transient engagement of H1 with unpaired DNA strands drives their enhanced phase separation. Using eGFP-tagged H1, we demonstrate that inducing single-stranded DNA accumulation in cells causes an increase in H1 puncta that are able to fuse. We further show that H1 and Replication Protein A occupy separate nuclear regions, but that H1 colocalizes with the replication factor Proliferating Cell Nuclear Antigen, particularly after DNA damage. Overall, our results provide a refined perspective on the diverse roles of H1 in genome organization and maintenance, and indicate its involvement at stalled replication forks. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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