ACF consists of two subunits, Acf1 and ISWI, that function cooperatively in the ATP-dependent catalysis of chromatin assembly
ACF consists of two subunits, Acf1 and ISWI, that function cooperatively in the ATP-dependent catalysis of chromatin assembly
复制标题
DOI：
10.1101/gad.13.12.1529
复制
发表时间：
1999-06-15
影响因子：
10.5
通讯作者：
Kadonaga, JT
中科院分区：
文献类型：
--
作者：
Ito, T;Levenstein, ME;Kadonaga, JT
核心组蛋白和 DNA 组装成周期性核小体阵列是由 ACF（一种包含 ISWI 的因子）和 NAP-1（一种核心组蛋白伴侣）在 ATP 依赖性过程中介导的。我们描述了果蝇 acf1 cDNA 的分离，该 cDNA 编码 ACF 中 Acf1 蛋白的 p170 和 p185 形式。 Acf1 是一种新型蛋白质，包含两个 PHD 指、一个溴结构域和两个新的保守区域。人类 WSTF 由威廉姆斯综合征个体中删除的多个基因之一编码，是目前已知的唯一具有 Acf1 中每个保守基序的哺乳动物蛋白。纯化 Acf1 的天然形式导致分离出包含 Acf1（p170 和 p185 形式）和 ISWI 的 ACF。天然 Acf1 不与 NURF 或 CHRAC 的成分共纯化，而 NURF 或 CHRAC 是果蝇中其他含有 ISWI 的复合物。纯化的重组 ACF 由 Acf1（单独的 p185 或 p170 和 p185）和 ISWI 组成，催化组蛋白沉积到扩展的周期性核小体阵列中。值得注意的是，Acf1 和 ISWI 亚基在染色质组装中协同发挥作用。 ISWI 单独表现出弱活性，与 ACF 的 3% 相似。这些结果表明 Acf1 和 ISWI 都参与染色质组装过程，并进一步表明 Acf1 亚基为 ISWI 的一般“运动”活动赋予了额外的功能。
The assembly of core histones and DNA into periodic nucleosome arrays is mediated by ACF, an ISWI-containing factor, and NAP-1, a core histone chaperone, in an ATP-dependent process. We describe the isolation of Drosophila acf1 cDNA, which encodes the p170 and p185 forms of the Acf1 protein in ACF. Acf1 is a novel protein that contains two PHD fingers, one bromodomain, and two new conserved regions. Human WSTF, which is encoded by one of multiple genes that is deleted in Williams syndrome individuals, is the only currently known mammalian protein with each of the conserved motifs in Acf1. Purification of the native form of Acf1 led to the isolation of ACF comprising Acf1 (both p170 and p185 forms) and ISWI. Native Acf1 did not copurify with components of NURF or CHRAC, which are other ISWI-containing complexes in Drosophila. Purified recombinant ACF, consisting of Acf1 (either p185 alone or both p170 and p185) and ISWI, catalyzes the deposition of histones into extended periodic nucleosome arrays. Notably, the Acf1 and ISWI subunits function synergistically in the assembly of chromatin. ISWI alone exhibits a weak activity that is similar to 3% that of ACF. These results indicate that both Acf1 and ISWI participate in the chromatin assembly process and suggest further that the Acf1 subunit confers additional functionality to the general 'motor' activity of ISWI.