磷酸化和乙酰化修饰对微管结构特性和胞内运输功能的调节

微管蛋白的翻译后修饰（修饰密码）与微管的结构特征密切相关，对微管参与的多种细胞活动发挥着关键作用。然而，已有研究中对微管蛋白修饰密码鉴定的覆盖面、深度和准确性都较有限，并且对不同种微管蛋白修饰密码的功能性研究也有待拓展和深入。前期研究中我们建立了微管纯化和质谱分析技术用以解析以往表征不足的微管蛋白修饰密码，并初步探索了特定位点的修饰如何调节微管的结构特性和细胞功能。在此基础上，本课题锁定磷酸化和乙酰化这两种广泛调节蛋白质活性与功能的翻译后修饰类型，全面解析它们在微管蛋白上的定位，并模拟空间分布；而后构建特定的磷酸化或乙酰化位点的模拟修饰和缺失修饰的微管蛋白突变体，通过研究突变体在特定胞内功能实验中的表型，系统地考察位点特异的磷酸化或乙酰化修饰对微管的稳定性、再生效率以及微管介导的胞内运输过程的调控作用。

The post-translational modifications (PTMs) of tubulin, or tubulin PTM codes, are highly related to structural properties of microtubules and essential roles in the cellular functions of microtubules. The proteomic landscape of tubuiln PTM codes, however, is far from complete and accurate, with deficient knowledge about their spacial and temporal distribution as well as functional roles. In our preliminary study, we established a proteomic workflow to identify tubulin PTM codes that have been less characterized before. In addition, we explored the roles of site-specific modifications in mediating microtubuledynamics and cellular function. The current project is aimed at systematic identification of phosphorylation and acetylation of tubulin and study of their roles in mediating the structural properties and cellular transport function of microtubules. Following the in-depth proteomic analysis, we will construct a panel of modification-mimic or modification-deficient mutants of tubulin at specific sites. These mutants will be subjected to in vitro and in vivo functional assays to determine the roles of certain PTM codes in regulating microtubule stability, dynamics and microtubule-dependent intracellular transport.