Solution structure of TbCentrin4 from Trypanosoma brucei and its interactions with Ca2+ and other centrins
Solution structure of TbCentrin4 from Trypanosoma brucei and its interactions with Ca2+ and other centrins
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布氏锥虫 TbCentrin4 的溶液结构及其与 Ca2 和其他中心蛋白的相互作用
DOI：
10.1042/bcj20180752
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发表时间：
2018
影响因子：
4.1
通讯作者：
Xiaoming Tu
中科院分区：
文献类型：
--
作者：
Fangzhen Shan;Kaiqin Ye;Jiahai Zhang;Shanhui Liao;Xuecheng Zhang;Chao Xu;Xiaoming Tu
中心蛋白是一种保守的钙离子结合蛋白，在纤毛发生、基因表达、DNA修复和信号转导等多种细胞生物学过程中发挥重要作用。在布氏锥虫中，TbCentrin 4主要定位于基底体和双叶结构中，并参与协调核分裂和胞质分裂的过程。在本研究中，我们解决了溶液结构的TbCentrin 4使用NMR（核磁共振）光谱。TbCentrin 4含有4个EF-手形基序，由8个α-螺旋组成。等温滴定量热实验表明TbCentrin 4具有较强的钙离子结合能力。NMR化学位移扰动表明TbCentrin 4通过其由EF-手3和4组成的C-末端结构域与Ca 2+结合。同时，我们发现TbCentrin 4在高浓度Ca ~（2+）的诱导下发生了构象变化和自组装。有趣的是，TbCentrin 4的定位分散或消失，从基体和双叶结构时，细胞与Ca 2+在体内处理，这意味着Ca 2+对TbCentrin 4的细胞功能的影响。此外，我们还观察了TbCentrin 4与其他Tbcentrins之间的相互作用，发现这种相互作用是依赖于Ca ~（2+）的。我们的研究结果为更好地理解TbCentrin 4在相关细胞过程中的生物学功能提供了结构基础。
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. InTrypanosoma brucei, 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 Ca2+binding ability. NMR chemical shift perturbation indicated that TbCentrin4 binds to Ca2+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 Ca2+. Intriguingly, localization of TbCentrin4 was dispersed or disappeared from basal bodies and the bi-lobe structure when the cells were treated with Ca2+in vivo, implying the influence of Ca2+on the cellular functions of TbCentrin4. Besides, we observed the interactions between TbCentrin4 and other Tbcentrins and revealed that the interactions are Ca2+dependent. Our findings provide a structural basis for better understanding the biological functions of TbCentrin4 in the relevant cellular processes.