Bu Weiwen, Di Jie, Zhao Junkui, Liu Ruming, Wu Yue, Ran Jie, Li Te
Department of Genetics and Cell Biology, Haihe Laboratory of Cell Ecosystem, State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China.
Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University, Jinan, China.
J Clin Lab Anal. 2024 Apr;38(7):e25030. doi: 10.1002/jcla.25030. Epub 2024 Mar 25.
The motor protein dynein is integral to retrograde transport along microtubules and interacts with numerous cargoes through the recruitment of cargo-specific adaptor proteins. This interaction is mediated by dynein light intermediate chain subunits LIC1 (DYNC1LI1) and LIC2 (DYNC1LI2), which govern the adaptor binding and are present in distinct dynein complexes with overlapping and unique functions.
Using bioinformatics, we analyzed the C-terminal domains (CTDs) of LIC1 and LIC2, revealing similar structural features but diverse post-translational modifications (PTMs). The methylation status of LIC2 and the proteins involved in this modification were examined through immunoprecipitation and immunoblotting analyses. The specific methylation sites on LIC2 were identified through a site-directed mutagenesis analysis, contributing to a deeper understanding of the regulatory mechanisms of the dynein complex.
We found that LIC2 is specifically methylated at the arginine 397 residue, a reaction that is catalyzed by protein arginine methyltransferase 1 (PRMT1).
The distinct PTMs of the LIC subunits offer a versatile mechanism for dynein to transport diverse cargoes efficiently. Understanding how these PTMs influence the functions of LIC2, and how they differ from LIC1, is crucial for elucidating the role of dynein-related transport pathways in a range of diseases. The discovery of the arginine 397 methylation site on LIC2 enhances our insight into the regulatory PTMs of dynein functions.
动力蛋白是沿微管逆行运输所必需的，它通过招募特定货物的衔接蛋白与众多货物相互作用。这种相互作用由动力蛋白轻中间链亚基LIC1（DYNC1LI1）和LIC2（DYNC1LI2）介导，它们控制衔接蛋白的结合，并存在于具有重叠和独特功能的不同动力蛋白复合物中。
我们利用生物信息学分析了LIC1和LIC2的C末端结构域（CTD），发现它们具有相似的结构特征，但翻译后修饰（PTM）不同。通过免疫沉淀和免疫印迹分析检测了LIC2的甲基化状态以及参与这种修饰的蛋白质。通过定点诱变分析确定了LIC2上的特定甲基化位点，有助于更深入地了解动力蛋白复合物的调控机制。
我们发现LIC2在精氨酸397残基处发生特异性甲基化，该反应由蛋白质精氨酸甲基转移酶1（PRMT1）催化。
LIC亚基独特的PTM为动力蛋白高效运输多种货物提供了一种通用机制。了解这些PTM如何影响LIC2的功能以及它们与LIC1有何不同，对于阐明动力蛋白相关运输途径在一系列疾病中的作用至关重要。LIC2上精氨酸397甲基化位点的发现增强了我们对动力蛋白功能调控PTM的认识。
