Hefei National Laboratory for Physical Science at Microscale and School of Life Science, University of Science and Technology of China, Hefei, Anhui, People's Republic of China.
Anhui Province Key Laboratory of Medical Physics and Technology, Center of Medical Physics and Technology, Chinese Academy of Sciences, Hefei, Anhui, People's Republic of China.
Biochem J. 2018 Dec 6;475(23):3763-3778. doi: 10.1042/BCJ20180752.
Centrin is a conserved calcium-binding protein that plays an important role in diverse cellular biological processes such as ciliogenesis, gene expression, DNA repair and signal transduction. In , TbCentrin4 is mainly localized in basal bodies and bi-lobe structure, and is involved in the processes coordinating karyokinesis and cytokinesis. In the present study, we solved the solution structure of TbCentrin4 using NMR (nuclear magnetic resonance) spectroscopy. TbCentrin4 contains four EF-hand motifs consisting of eight α-helices. Isothermal titration calorimetry experiment showed that TbCentrin4 has a strong Ca binding ability. NMR chemical shift perturbation indicated that TbCentrin4 binds to Ca through its C-terminal domain composed of EF-hand 3 and 4. Meanwhile, we revealed that TbCentrin4 undergoes a conformational change and self-assembly induced by high concentration of Ca Intriguingly, localization of TbCentrin4 was dispersed or disappeared from basal bodies and the bi-lobe structure when the cells were treated with Ca, implying the influence of Ca on the cellular functions of TbCentrin4. Besides, we observed the interactions between TbCentrin4 and other Tbcentrins and revealed that the interactions are Ca dependent. Our findings provide a structural basis for better understanding the biological functions of TbCentrin4 in the relevant cellular processes.
中心体蛋白是一种保守的钙结合蛋白，在多种细胞生物学过程中发挥重要作用，如纤毛发生、基因表达、DNA 修复和信号转导。在本研究中，我们使用 NMR（核磁共振）光谱法解析了 TbCentrin4 的溶液结构。TbCentrin4 包含四个 EF 手模体，由八个 α-螺旋组成。等温滴定量热实验表明 TbCentrin4 具有很强的 Ca 结合能力。NMR 化学位移扰动实验表明，TbCentrin4 通过其由 EF 手 3 和 4 组成的 C 末端结构域与 Ca 结合。同时，我们揭示了 TbCentrin4 在高浓度 Ca 诱导下发生构象变化和自组装。有趣的是，当用 Ca 处理细胞时，TbCentrin4 的定位从基体和双叶结构中分散或消失，这表明 Ca 对 TbCentrin4 的细胞功能有影响。此外，我们观察到 TbCentrin4 与其他 Tbcentrins 之间的相互作用，揭示了这种相互作用依赖于 Ca。我们的研究结果为更好地理解 TbCentrin4 在相关细胞过程中的生物学功能提供了结构基础。
