Browsing by Author "Black, B. E."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Assembly in G1 phase and long-term stability are unique intrinsic features of CENP-A nucleosomesPublication . Bodor, D. L.; Valente, L. P.; Mata, J. F.; Black, B. E.; Jansen, L. E. T.Centromeres are the site of kinetochore formation during mitosis. Centromere protein A (CENP-A), the centromere-specific histone H3 variant, is essential for the epigenetic maintenance of centromere position. Previously we showed that newly synthesized CENP-A is targeted to centromeres exclusively during early G1 phase and is subsequently maintained across mitotic divisions. Using SNAP-based fluorescent pulse labeling, we now demonstrate that cell cycle-restricted chromatin assembly at centromeres is unique to CENP-A nucleosomes and does not involve assembly of other H3 variants. Strikingly, stable retention is restricted to the CENP-A/H4 core of the nucleosome, which we find to outlast general chromatin across several cell divisions. We further show that cell cycle timing of CENP-A assembly is independent of centromeric DNA sequences and instead is mediated by the CENP-A targeting domain. Unexpectedly, this domain also induces stable transmission of centromeric nucleosomes, independent of the CENP-A deposition factor HJURP. This demonstrates that intrinsic properties of the CENP-A protein direct its cell cycle-restricted assembly and induces quantitative mitotic transmission of the CENP-A/H4 nucleosome core, ensuring long-term stability and epigenetic maintenance of centromere position.
- Chromosomes. CENP-C reshapes and stabilizes CENP-A nucleosomes at the centromerePublication . Falk, S. J.; Guo, L. Y.; Sekulic, N.; Smoak, E. M.; Mani, T.; Logsdon, G. A.; Gupta, K.; Jansen, L. E. T.; Van Duyne, G. D.; Vinogradov, S. A.; Lampson, M. A.; Black, B. E.Inheritance of each chromosome depends upon its centromere. A histone H3 variant, centromere protein A (CENP-A), is essential for epigenetically marking centromere location. We find that CENP-A is quantitatively retained at the centromere upon which it is initially assembled. CENP-C binds to CENP-A nucleosomes and is a prime candidate to stabilize centromeric chromatin. Using purified components, we find that CENP-C reshapes the octameric histone core of CENP-A nucleosomes, rigidifies both surface and internal nucleosome structure, and modulates terminal DNA to match the loose wrap that is found on native CENP-A nucleosomes at functional human centromeres. Thus, CENP-C affects nucleosome shape and dynamics in a manner analogous to allosteric regulation of enzymes. CENP-C depletion leads to rapid removal of CENP-A from centromeres, indicating their collaboration in maintaining centromere identity.
- Esperanto for histones: CENP-A, not CenH3, is the centromeric histone H3 variantPublication . Earnshaw, W. C.; Allshire, R. C.; Black, B. E.; Bloom, K.; Brinkley, B. R.; Brown, W.; Cheeseman, I. M.; Choo, K. H. A.; Copenhaver, G. P.; DeLuca, J. G.; Desai, A.; Diekmann, S.; Erhardt, S.; Fitzgerald-Hayes, M.; Foltz, D.; Fukagawa, T.; Gassmann, R.; Gerlich, D. W.; Glover, D. M.; Gorbsky, G. J.; Harrison, S. C.; Heun, P.; Hirota, T.; Jansen, L. E. T.; Karpen, G.; Kops, G. J. P. L.; Lampson, M. A.; Lens, S. M.; Losada, A.; Luger, K.; Maiato, H.; Maddox, P. S.; Margolis, R. L.; Masumoto, H.; McAinsh, A. D.; Mellone, B. G.; Meraldi, P.; Musacchio, A.; Oegema, K.; O’Neill, R. J.; Salmon, E. D.; Scott, K. C.; Straight, A. F.; Stukenberg, P. T.; Sullivan, B. A.; Sullivan, K. F.; Sunkel, C. E.; Swedlow, J. R.; Walczak, C. E.; Warburton, P. E.; Westermann, S.; Willard, H. F.; Wordeman, L.; Yanagida, M.; Yen, T. J.; Yoda, K.; Cleveland, D. W.The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres.