Université de Lorraine, CNRS, IMoPA, Nancy, France.
Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA.
Nat Commun. 2021 Mar 25;12(1):1859. doi: 10.1038/s41467-021-22077-4.
Biogenesis of eukaryotic box C/D small nucleolar ribonucleoproteins initiates co-transcriptionally and requires the action of the assembly machinery including the Hsp90/R2TP complex, the Rsa1p:Hit1p heterodimer and the Bcd1 protein. We present genetic interactions between the Rsa1p-encoding gene and genes involved in chromatin organization including RTT106 that codes for the H3-H4 histone chaperone Rtt106p controlling H3K56ac deposition. We show that Bcd1p binds Rtt106p and controls its transcription-dependent recruitment by reducing its association with RNA polymerase II, modulating H3K56ac levels at gene body. We reveal the 3D structures of the free and Rtt106p-bound forms of Bcd1p using nuclear magnetic resonance and X-ray crystallography. The interaction is also studied by a combination of biophysical and proteomic techniques. Bcd1p interacts with a region that is distinct from the interaction interface between the histone chaperone and histone H3. Our results are evidence for a protein interaction interface for Rtt106p that controls its transcription-associated activity.
真核生物 box C/D 小核仁核糖核蛋白的生物发生是在转录过程中起始的，需要组装机制的作用，包括 Hsp90/R2TP 复合物、Rsa1p:Hit1p 异二聚体和 Bcd1 蛋白。我们展示了 Rsa1p 编码基因与参与染色质组织的基因之间的遗传相互作用，包括编码 H3-H4 组蛋白伴侣 Rtt106p 的 RTT106 基因，该蛋白控制 H3K56ac 的沉积。我们表明 Bcd1p 与 Rtt106p 结合，并通过降低其与 RNA 聚合酶 II 的关联来控制其转录依赖性募集，从而调节基因体中的 H3K56ac 水平。我们使用核磁共振和 X 射线晶体学揭示了游离和与 Rtt106p 结合的 Bcd1p 的三维结构。通过结合生物物理和蛋白质组学技术研究了相互作用。Bcd1p 与一个不同于组蛋白伴侣和组蛋白 H3 之间相互作用界面的区域相互作用。我们的结果为控制其转录相关活性的 Rtt106p 的蛋白质相互作用界面提供了证据。
