Dynein light chain LC8 promotes assembly of the coiled-coil domain of swallow protein.
Dynein light chain LC8 promotes assembly of the coiled-coil domain of swallow protein.
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DOI：
10.1021/bi036328x
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发表时间：
2004-04
期刊：
影响因子：
2.9
通讯作者：
Lei Wang;M. Hare;T. Hays;E. Barbar
中科院分区：
文献类型：
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作者：
Lei Wang;M. Hare;T. Hays;E. Barbar
LC8是细胞质动力蛋白的一个高度保守的轻链亚基，被认为在运动复合物的组装和货物的招募中起着重要作用。LC8和果蝇蛋白燕子之间的相互作用已经被表征，并支持动力蛋白在卵发生过程中母体形态形成的定位中的作用。燕子是bicoid mRNA正确定位所必需的，bicoid mRNA在果蝇胚胎轴的建立中起着关键作用。在这项工作中，我们准备了燕子的结构，每个结构包含一个预测的线圈结构域和位于被提议与LC8相互作用的区域内的可变周围片段。LC8和swallow结构域之间的相互作用通过谷胱甘肽s -转移酶（GST）下拉分析、质谱分析和圆二色光谱分析进行了表征。流体动力学测量、共价交联和圆二向色光谱表明，这是一个不稳定的二聚体线圈。然而，在LC8结合后，卷曲的线圈变得更加稳定。讨论了LC8在大分子组装中可能的一般作用。
LC8 is a highly conserved light-chain subunit of cytoplasmic dynein that is thought to play a fundamental role in both the assembly of the motor complex and the recruitment of cargo. An interaction between LC8 and the Drosophila protein swallow has been previously characterized and supports a role for dynein in the localization of maternal morphogens during oogenesis. Swallow is required for the proper localization of bicoid mRNA, the anterior determinant that plays a critical role in establishment of the Drosophila embryonic axis. In this work, we prepared constructs of swallow, each containing a predicted coiled-coil domain and variable surrounding segments that lie within the domain proposed to interact with LC8. The interaction between LC8 and swallow domains was characterized by glutathione S-transferase (GST) pull-down assays, limited proteolysis followed by mass spectrometry, and circular dichroic spectroscopy. Hydrodynamic measurements, covalent cross-linking, and circular dichroic spectroscopy show that this domain of swallow is an unstable dimeric coiled-coil. Upon LC8 binding, however, the coiled-coil becomes significantly more stable. A possible general role for LC8 in macromolecular assembly is discussed.