In the INO80 chromatin remodeling complex, all of the accessory subunits are assembled on the following three domains of INO80: N-terminal domain (NTD), HSA domain, and ATPase domain. Although the ATPase and HSA domains and their interacting accessory subunits are known to be responsible for chromatin remodeling, it is largely unknown how the accessory subunits that interact with the INO80 NTD regulate chromatin status. Here, we identify both conserved and nonconserved accessory subunits that interact with the three domains in the INO80 complex in Arabidopsis thaliana. While the accessory subunits that interact with all the three INO80 domains can mediate transcriptional repression, the INO80 NTD and the accessory subunits interact with it can contribute to transcriptional activation even when the ATPase domain is absent, suggesting that INO80 has an ATPase-independent role. A subclass of the COMPASS histone H3K4 methyltransferase complexes interact with the INO80 NTD in the INO80 complex and function together with the other accessory subunits that interact with the INO80 NTD, thereby facilitating H3K4 trimethylation and transcriptional activation. This study suggests that the opposite effects of the INO80 complex on transcription are required for the balance between vegetative growth and flowering under diverse environmental conditions.

中文翻译：

---

COMPASS 作为 INO80 染色质重塑复合物的一个模块，在拟南芥中介导组蛋白 H3K4 甲基化

在 INO80 染色质重塑复合物中，所有附属亚基都组装在 INO80 的以下三个结构域上：N 末端结构域 (NTD)、HSA 结构域和 ATPase 结构域。虽然已知 ATPase 和 HSA 结构域及其相互作用的辅助亚基负责染色质重塑，但与 INO80 NTD 相互作用的辅助亚基如何调节染色质状态在很大程度上是未知的。在这里，我们确定了与拟南芥 INO80 复合体中的三个结构域相互作用的保守和非保守附属亚基。虽然与所有三个 INO80 结构域相互作用的辅助亚基可以介导转录抑制，但 INO80 NTD 和辅助亚基与其相互作用可以促进转录激活，即使 ATPase 结构域不存在，表明 INO80 具有独立于 ATPase 的作用。COMPASS 组蛋白 H3K4 甲基转移酶复合物的一个子类与 INO80 复合物中的 INO80 NTD 相互作用，并与其他与 INO80 NTD 相互作用的附属亚基一起发挥作用，从而促进 H3K4 三甲基化和转录激活。这项研究表明，INO80 复合物对转录的相反影响是在不同环境条件下营养生长和开花之间的平衡所必需的。