Phosphatidylinositol-dependent actin filament binding by the SWI/SNF-like BAF chromatin remodeling complex
Phosphatidylinositol-dependent actin filament binding by the SWI/SNF-like BAF chromatin remodeling complex
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DOI：
10.1073/pnas.032662899
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发表时间：
2002-03-05
影响因子：
11.1
通讯作者：
Crabtree, GR
中科院分区：
文献类型：
--
作者：
Rando, OJ;Zhao, KJ;Crabtree, GR
最近，在酵母、果蝇和哺乳动物中的几种染色质重塑复合物已被证明含有肌动蛋白和肌动蛋白相关蛋白（arps）。然而，肌动蛋白在这些复合物中的功能尚不清楚。在这里，我们表明，哺乳动物SWI/SNF样BAF复合物结合磷脂酰肌醇4，5-二磷酸（PIP 2）胶束和PIP 2含有混合脂质囊泡，PIP 2的结合允许复合物与肌动蛋白的尖端和分支点。肌动蛋白在Brg 1蛋白的C末端结合至少两个不同的结构域，并且仅与其中一个结构域的相互作用对PIP 2敏感。基于这些发现，我们提出了一个模型PIP 2激活肌动蛋白结合的救济分子内帽肌动蛋白Brg 1。
Recently, several chromatin remodeling complexes in yeast, Drosophila, and mammals have been shown to contain actin and actin-related proteins (arps). However, the function of actin in these complexes is unclear. Here, we show that the mammalian SWI/SNF-like BAF complex binds to phosphatidylinositol 4,5-bisphosphate (PIP2) micelles and PIP2-containing mixed lipid vesicles, and that PIP2 binding allows the complex to associate with actin pointed ends and branch points. Actin binds to at least two distinct domains in the C terminus of the Brg1 protein, and interaction with only one of these domains is sensitive to PIP2. Based on these findings, we propose a model for PIP2 activation of actin binding by relief of intramolecular capping of actin by Brg1.