title: Influence of histone tails and H4 tail acetylations on nucleosome-nucleosome interactions.
abstract: Nucleosome-nucleosome interaction plays a fundamental role in chromatin folding and self-association. The cation-induced condensation of nucleosome core particles (NCPs) displays properties similar to those of chromatin fibers, with important contributions from the N-terminal histone tails. We study the self-association induced by addition of cations [Mg(2+), Ca(2+), cobalt(III)hexammine(3+), spermidine(3+) and spermine(4)(+)] for NCPs reconstituted with wild-type unmodified histones and with globular tailless histones and for NCPs with the H4 histone tail having lysine (K) acetylations or lysine-to-glutamine mutations at positions K5, K8, K12 and K16. In addition, the histone construct with the single H4K16 acetylation was investigated. Acetylated histones were prepared by a semisynthetic native chemical ligation method. The aggregation behavior of NCPs shows a general cation-dependent behavior similar to that of the self-association of nucleosome arrays. Unlike nucleosome array self-association, NCP aggregation is sensitive to position and nature of the H4 tail modification. The tetra-acetylation in the H4 tail significantly weakens the nucleosome-nucleosome interaction, while the H4 K→Q tetra-mutation displays a more modest effect. The single H4K16 acetylation also weakens the self-association of NCPs, which reflects the specific role of H4K16 in the nucleosome-nucleosome stacking. Tailless NCPs can aggregate in the presence of oligocations, which indicates that attraction also occurs by tail-independent nucleosome-nucleosome stacking and DNA-DNA attraction in the presence of cations. The experimental data were compared with the results of coarse-grained computer modeling for NCP solutions with explicit presence of mobile ions.
authors: School of Biological Sciences, Nanyang Technological University, 637551 Singapore, Singapore.
authors: Ying
authors: Y
authors: Liu
authors: Chenning
authors: C
authors: Lu
authors: Ye
authors: Y
authors: Yang
authors: Yanping
authors: Y
authors: Fan
authors: Renliang
authors: R
authors: Yang
authors: Chuan-Fa
authors: CF
authors: Liu
authors: Nikolay
authors: N
authors: Korolev
authors: Lars
authors: L
authors: Nordenskiöld
mesh_terms: D000107:Acetylation; D000818:Animals; D002118:Calcium / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D003198:Computer Simulation; D006657:Histones / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008274:Magnesium / Q000737:chemistry; D009154:Mutation; D009707:Nucleosomes / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D013095:Spermidine / Q000737:chemistry; D013096:Spermine / Q000737:chemistry; D029867:Xenopus Proteins; D014982:Xenopus laevis
chemical_list: D006657:Histones; D009707:Nucleosomes; D029867:Xenopus Proteins; C032300:hexaamminecobalt(II); D013096:Spermine; D003035:Cobalt; D008274:Magnesium; D002118:Calcium; D013095:Spermidine