利用 Nuc-MS 对完整核小体的蛋白质组成进行解码。

Department of Chemistry, Northwestern University, Evanston, IL, USA.

The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA.

Nat Methods. 2021 Mar;18(3):303-308. doi: 10.1038/s41592-020-01052-9. Epub 2021 Feb 15.

Current proteomic approaches disassemble and digest nucleosome particles, blurring readouts of the 'histone code'. To preserve nucleosome-level information, we developed Nuc-MS, which displays the landscape of histone variants and their post-translational modifications (PTMs) in a single mass spectrum. Combined with immunoprecipitation, Nuc-MS quantified nucleosome co-occupancy of histone H3.3 with variant H2A.Z (sixfold over bulk) and the co-occurrence of oncogenic H3.3K27M with euchromatic marks (for example, a >15-fold enrichment of dimethylated H3K79me2). Nuc-MS is highly concordant with chromatin immunoprecipitation-sequencing (ChIP-seq) and offers a new readout of nucleosome-level biology.

目前的蛋白质组学方法会将核小体颗粒进行分解和消化，从而模糊了“组蛋白密码”的读取结果。为了保留核小体水平的信息，我们开发了 Nuc-MS，它可以在单个质谱中显示组蛋白变体及其翻译后修饰（PTM）的全景图。结合免疫沉淀，Nuc-MS 定量了核小体中组蛋白 H3.3 与变体 H2A.Z 的共占据（是整体的六倍），以及致癌性 H3.3K27M 与常染色质标记的共出现（例如，二甲基化 H3K79me2 的丰度增加了 15 倍以上）。Nuc-MS 与染色质免疫沉淀测序（ChIP-seq）高度一致，并提供了核小体水平生物学的新读取结果。