How is the H2A.Z
#histone variant targeted to specific sites in the genome by the SWR
#chromatin remodeler? This study shows that DNA sequences contribute to SWR specificity and that SWR’s H2A.Z insertion activity is stimulated by polyA tracts in
#nucleosomes @PLOSBiology https://plos.io/4kggWyD
H2A.Z deposition by the SWR complex is stimulated by polyadenine DNA sequences in nucleosomes
The variant histone H2A.Z is deposited into nucleosomes immediately downstream of promoters, where it plays a critical role in transcription. The site-specific deposition of H2A.Z is catalyzed by the SWR complex, a conserved chromatin remodeler with affinity for promoter-proximal nucleosome-depleted regions (NDRs) and histone acetylation. By comparing the genomic distribution of H2A.Z in wild-type and SWR-deficient cells, we found that SWR is also responsible for depositing H2A.Z at thousands of non-canonical sites not directly linked to NDRs or histone acetylation. To understand the targeting mechanism of H2A.Z, we presented SWR to a library of canonical nucleosomes isolated from yeast and analyzed the preferred substrates. Our results revealed that SWR preferentially deposited H2A.Z into a subset of endogenous H2A.Z sites, which are overrepresented by polyadenine tracts on the top strands of the DNA duplex at the nucleosomal entry-exit sites. Insertion of polyadenine sequences into recombinant nucleosomes near the outgoing H2A-H2B dimer enhanced SWR’s affinity for the nucleosomal substrate and increased its H2A.Z insertion activity. These findings suggest that the genome encodes sequence-based information that facilitates remodeler-mediated targeting of H2A.Z.
Single nucleosomes tracked in live cells during cell division using super-resolution microscopy
Individual cells divide through a process called mitosis, during which the cell's copied DNA is separated between two resulting daughter cells. Despite recent advances in cell biology, the mechanism by which DNA condenses during mitosis is still poorly understood. Researchers recently tracked small stretches of DNA wound around histone proteins, called nucleosomes, to better characterize nucleosome behavior during cell division.
Organization Of DNA In Cell
#ArchaeaDNA, #DNA, #Histone, #Nucleosomes, #Supercoil #Genetics All living cells contain DNA in the form of double helix, its organization differs among cells in the three domains…. Medical Microbiology & Recombinant DNA Technology (RDT) Labs | Read More -
https://micrordt.wordpress.com/2024/04/27/organization-of-dna-in-cell/
Organization Of DNA In Cell
#ArchaeaDNA, #DNA, #Histone, #Nucleosomes, #Supercoil #Genetics All living cells contain DNA in the form of double helix, its organization differs among cells in the three domains…. Medical Microbi…
To find
#nucleosomes, chromatin remodelers slide and hop along
#DNA, and their direction of approach affects the direction that nucleosomes slide in.
https://elifesciences.org/articles/96836?utm_source=mastodon&utm_medium=social&utm_campaign=organic_insights
Chromatin Remodeling: The voyage is as important as the harbor
To find nucleosomes, chromatin remodelers slide and hop along DNA, and their direction of approach affects the direction that nucleosomes slide in.
Biologists discover the secrets of how gene traits are passed on
A research team has recently made a significant breakthrough in understanding how the DNA copying machine helps pass on epigenetic information to maintain gene traits at each cell division.
"Is X-ray crystallography dead?" some asked when #cryoEM got momentum, then when #AlphaFold arrived. Depends on what you work on. For #nucleosomes it certainly looks like it is dead: all structures with nucleosomes released in 2023 were cryoEM structures!
https://guillawme.github.io/insights-from-the-pdb/nucleosome-structures.html#Nucleosome_structures_by_year_and_experimental_method
On this #ThrowbackThursday we go back to our Episode #58 where we talked with Efrat Shema from the Weizmann Institute of Science about her work on Single Molecule Imaging of #chromatin, and the analysis of #nucleosomes circulating in plasma. #epigenetics
Listen here: https://www.activemotif.com/podcasts-efrat-shema
Single molecule analysis of CENP-A chromatin by high-speed atomic force microscopy
A novel analytical workflow to quantitatively track motions of thousands of nucleosomes within chromatin fibers by high-speed atomic force microscopy.
Changes in adenoviral
#chromatin organization precede early gene activation upon infection
Harald Wodrich, Gernot Laengst and colleagues show that host
#nucleosomes replace
#adenoviral genome packaging before viral genes are transcribed.
https://www.embopress.org/doi/full/10.15252/embj.2023114162New microscopy assay by Sue Biggins and collaborators
#fredhutch enables direct observation of coordinated de novo assembly of native
#CENPA #nucleosomes driven by several protein cofactors and the AT run content of
#centromeric DNA
#RefereedPreprint c/o
@ReviewCommons https://www.embopress.org/doi/10.15252/embj.2023114534
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