Modes of interaction among yeast Nej1, Lif1 and Dnl4 proteins and comparison to human XLF, XRCC4 and Lig4
Modes of interaction among yeast Nej1, Lif1 and Dnl4 proteins and comparison to human XLF, XRCC4 and Lig4
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DOI：
10.1016/j.dnarep.2007.04.014
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发表时间：
2007-10-01
期刊：
影响因子：
3.8
通讯作者：
Wilson, Thomas E.
中科院分区：
文献类型：
--
作者：
Deshpande, Rajashree A.;Wilson, Thomas E.
双链断裂修复的非同源末端连接（NHEJ）途径依赖于DNA连接酶IV及其相互作用伴侣蛋白XRCC 4（酵母中的Lif 1）。第三种酵母蛋白Nej 1与Lif 1相互作用并支持NHEJ，类似于远亲哺乳动物Nej 1直系同源物XLF（也称为Cernunnos）。XRCC 4/Lif 1和XLF/Nej 1本身是相关的，并且可能折叠成类似的卷曲螺旋结构，这表明这些蛋白质之间存在许多可能的相互作用模式。使用酵母双杂交和共沉淀方法，我们研究了这些相互作用和支持它们所需的蛋白质结构域。结果表明，稳定的卷曲螺旋同源二聚体是XLF/Nej 1的主要形式，就像XRCC 4/Lif 1一样，但类似的异源二聚体不是。相反，XLF-XRCC 4和Nej 1-Lif 1相互作用独立于卷曲螺旋介导，并由XLF和Nej 1的不同区域介导。具体而言，XRCC 4/Lif 1的球状头部分别与XLF和Nej 1的N-和C-末端结构域相互作用。XLF/Nej 1和DNA连接酶IV之间的直接相互作用也被观察到，但再次出现定性不同的稳定的卷曲螺旋介导的XRCC 4/Lif 1和DNA连接酶IV之间的相互作用的影响，这些发现的DNA连接酶IV功能被认为是在光的XLF/XRCC 4和XLF/Nej 1家族的进化模式。(C)2007 Elsevier B. V.保留所有权利。
The nonhomologous end joining (NHEJ) pathway of double-strand break repair depends on DNA ligase IV and its interacting partner protein XRCC4 (Lif1 in yeast). A third yeast protein, Nej1, interacts with Lif1 and supports NHEJ, similar to the distantly related mammalian Nej1 orthologue XLF (also known as Cernunnos). XRCC4/Lif1 and XLF/Nej1 are themselves related and likely fold into similar coiled-coil structures, which suggests many possible modes of interaction between these proteins. Using yeast two-hybrid and co-precipitation methods we examined these interactions and the protein domains required to support them. Results suggest that stable coiled-coil homodimers are a predominant form of XLF/Nej1, just as for XRCC4/Lif1, but that similar heterodimers are not. XLF-XRCC4 and Nej1-Lif1 interactions were instead mediated independently of the coiled coil, and by different regions of XLF and Nej1. Specifically, the globular head of XRCC4/Lif1 interacted with N- and C-terminal domains of XLF and Nej1, respectively. Direct interactions between XLF/Nej1 and DNA ligase IV were also observed, but again appeared qualitatively different than the stable coiled-coil-mediated interaction between XRCC4/Lif1 and DNA ligase IV The implications of these findings for DNA ligase IV function are considered in light of the evolutionary pattern in the XLF/XRCC4 and XLF/Nej1 family. (C) 2007 Elsevier B.V. All rights reserved.