The CENP-A nucleosome

Bui, Minh; Walkiewicz, Marcin P.; Dimitriadis, Emilios K.; Dalal, Yamini

doi:10.4161/nucl.23588

Cited by 19 publications

(18 citation statements)

References 45 publications

(66 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This led us to suggest that K124ac might contribute to centromere priming for replication [20, 30]. Indeed, prior work has demonstrated that a single modification within histone H3 sets the stage for accurate origin firing during replication [14, 31].…”

Section: Resultsmentioning

confidence: 99%

Internal modifications in the CENP-A nucleosome modulate centromeric dynamics

Bui

Pitman

Nuccio³

et al. 2017

Epigenetics & Chromatin

Self Cite

View full text Add to dashboard Cite

BackgroundPosttranslational modifications of core histones are correlated with changes in transcriptional status, chromatin fiber folding, and nucleosome dynamics. However, within the centromere-specific histone H3 variant CENP-A, few modifications have been reported, and their functions remain largely unexplored. In this multidisciplinary report, we utilize in silico computational and in vivo approaches to dissect lysine 124 of human CENP-A, which was previously reported to be acetylated in advance of replication.ResultsComputational modeling demonstrates that acetylation of K124 causes tightening of the histone core and hinders accessibility to its C-terminus, which in turn diminishes CENP-C binding. Additionally, CENP-A K124ac/H4 K79ac containing nucleosomes are prone to DNA sliding. In vivo experiments using a CENP-A acetyl or unacetylatable mimic (K124Q and K124A, respectively) reveal alterations in CENP-C levels and a modest increase in mitotic errors. Furthermore, mutation of K124 results in alterations in centromeric replication timing. Purification of native CENP-A proteins followed by mass spectrometry analysis reveals that while CENP-A K124 is acetylated at G1/S, it switches to monomethylation during early S and mid-S phases. Finally, we provide evidence implicating the histone acetyltransferase (HAT) p300 in this cycle.ConclusionsTaken together, our data suggest that cyclical modifications within the CENP-A nucleosome contribute to the binding of key kinetochore proteins, the integrity of mitosis, and centromeric replication. These data support the paradigm that modifications in histone variants can influence key biological processes.Electronic supplementary materialThe online version of this article (doi:10.1186/s13072-017-0124-6) contains supplementary material, which is available to authorized users.

show abstract

Section: Resultsmentioning

confidence: 99%

Internal modifications in the CENP-A nucleosome modulate centromeric dynamics

Bui

Pitman

Nuccio³

et al. 2017

Epigenetics & Chromatin

Self Cite

View full text Add to dashboard Cite

show abstract

“…Current understanding of the organization of Cse4 itself within chromatin is equivocal (16). In organisms from yeast to mammal, more Cse4 resides in the centromere than lies at the plus-end of the kinetochore microtubule (62, 92).…”

Section: Introductionmentioning

confidence: 99%

“…Unlike in histone H3 and canonical nucleosomes, attempts to ascribe a single structure to Cse4-containing nucleosomes has been difficult, with both hemisome and nucleosomal states being identified. A parsimonious view is that the Cse4 nucleosome is dynamic (16). Because molecules closest to the plus-end of the microtubule experience more force than canonical nucleosomes, there may be value for the nucleosome to be adept at switching between hemisome and nucleosomal states.…”

Section: Introductionmentioning

confidence: 99%

Centromeric Heterochromatin: The Primordial Segregation Machine

Bloom

2014

Annu. Rev. Genet.

View full text Add to dashboard Cite

Centromeres are specialized domains of heterochromatin that provide the foundation for the kinetochore. Centromeric heterochromatin is characterized by specific histone modifications, a centromere-specific histone H3 variant (CENP-A), and the enrichment of cohesin, condensin, and topo-isomerase II. Centromere DNA varies orders of magnitude in size from 125 bp (budding yeast) to several megabases (human). In metaphase, sister kinetochores on the surface of replicated chromosomes face away from each other, where they establish microtubule attachment and bi-orientation. Despite the disparity in centromere size, the distance between separated sister kinetochores is remarkably conserved (approximately 1 μm) throughout phylogeny. The centromere functions as a molecular spring that resists microtubule-based extensional forces in mitosis. This review explores the physical properties of DNA in order to understand how the molecular spring is built and how it contributes to the fidelity of chromosome segregation.

show abstract

“…Over the last 30 years, AFM has been used for a broad variety of physical and electronic applications, but it has proven particularly useful for observation and analysis of biological molecules, including chromatin. The main advantage of AFM is that it allows for sample imaging with resolution akin to electron microscopy but with minimal processing, making it both an excellent analytical (high precision measurements of nucleosome dimensions) and preparative (quick determination of chromatin quality) technique [5, 14, 15]. …”

Section: Introductionmentioning

confidence: 99%

Tracking Histone Variant Nucleosomes Across the Human Cell Cycle Using Biophysical, Biochemical, and Cytological Analyses

Walkiewicz

Bui

Quénet

et al. 2014

Methods in Molecular Biology

Self Cite

View full text Add to dashboard Cite

Histone variants such as H3.3, macroH2A, H2A.Z, and CENP-A are important epigenetic modifiers of the chromatin state in eukaryotic genomes. The centromeric histone H3 variant CENP-A/CENH3 epigenetically marks centromeres and is required for assembly of the kinetochore complex, a region of the chromosome that is responsible for proper genome segregation during mitosis. Several diverse techniques using biochemical, cell biology, and biophysical approaches have been utilized to study the nature of the CENP-A nucleosome across the cell cycle. In this chapter, we describe methods for CENP-A nucleosome purification and separation of CENP-A from other core histones using traditional SDS-PAGE and more resolving techniques such as Triton acid urea (TAU) and two-dimensional gels. We also discuss methods for observation of CENP-A on chromatin fibers using immunofluorescence. Finally, we provide a detailed description of analysis of chromatin structures using atomic force microscopy.

show abstract

The CENP-A nucleosome

Cited by 19 publications

References 45 publications

Internal modifications in the CENP-A nucleosome modulate centromeric dynamics

Internal modifications in the CENP-A nucleosome modulate centromeric dynamics

Centromeric Heterochromatin: The Primordial Segregation Machine

Tracking Histone Variant Nucleosomes Across the Human Cell Cycle Using Biophysical, Biochemical, and Cytological Analyses

Contact Info

Product

Resources

About