David Geffen School of Medicine, Department of Biological Chemistry, 615 Charles E. Young Drive, University of California, Los Angeles, CA 90095-1737, USA.
Proc Natl Acad Sci U S A. 2012 Feb 7;109(6):1931-6. doi: 10.1073/pnas.1109994109. Epub 2012 Jan 23.
ATPases and histone chaperones facilitate RNA polymerase II (pol II) elongation on chromatin. In vivo, the coordinated action of these enzymes is necessary to permit pol II passage through a nucleosome while restoring histone density afterward. We have developed a biochemical system recapitulating this basic process. Transcription through a nucleosome in vitro requires the ATPase remodels structure of chromatin (RSC) and the histone chaperone nucleosome assembly protein 1 (NAP1). In the presence of NAP1, RSC generates a hexasome. Despite the propensity of RSC to evict histones, NAP1 reprograms the reaction such that the hexasome is retained on the template during multiple rounds of transcription. This work has implications toward understanding the mechanism of pol II elongation on chromatin.
ATP 酶和组蛋白伴侣促进 RNA 聚合酶 II（pol II）在染色质上的延伸。在体内，这些酶的协调作用对于允许 pol II 通过核小体并在之后恢复组蛋白密度是必要的。我们已经开发了一种生化系统来重现这个基本过程。体外转录通过核小体需要 ATP 酶重塑染色质结构（RSC）和组蛋白伴侣核小体组装蛋白 1（NAP1）。在 NAP1 的存在下，RSC 生成六聚体。尽管 RSC 有驱逐组蛋白的倾向，但 NAP1 重新编程反应，使得六聚体在多个转录循环中保留在模板上。这项工作对于理解 pol II 在染色质上的延伸机制具有重要意义。
