Mycobacterium tuberculosis CarD, an essential global transcriptional regulator forms amyloid-like fibrils.
Mycobacterium tuberculosis CarD, an essential global transcriptional regulator forms amyloid-like fibrils.
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DOI：
10.1038/s41598-018-28290-4
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发表时间：
2018-07-04
影响因子：
4.6
通讯作者：
Thakur KG
中科院分区：
文献类型：
--
作者：
Kaur G;Kaundal S;Kapoor S;Grimes JM;Huiskonen JT;Thakur KG
CARD是结核分枝杆菌(Mtb)的一种重要的全球转录调节因子，它结合RNA聚合酶并通过稳定转录起始复合体来激活转录。现有的晶体结构已经捕获了CARD的两种截然不同的单体和结构域交换的同源二聚体和寡聚态。然而，CARD在溶液中的实际低聚状态及其生物学相关性仍不清楚。在这里，我们用基于同步加速器的小角X射线散射证实了CARD在溶液中的同质二聚态的存在。此外，通过生化和生物物理实验，除了质谱学、透射电子显微镜和共聚焦成像外，我们还发现CARD是Mtb中第一个可溶的胞浆蛋白，在体外和体内都有形成淀粉样纤维的趋势。我们证明了参与结构域交换的14个N末端残基的缺失阻碍了淀粉样蛋白的形成，因此，表明结构域交换在淀粉样蛋白的发生中是至关重要的。在致病细菌中发现了一种重要的胞浆全局转录调节因子CARD的淀粉样蛋白致病特性，这将进一步开辟研究的新领域。
CarD is an essential global transcription regulator from Mycobacterium tuberculosis (Mtb) that binds RNA polymerase and activates transcription by stabilizing the transcription initiation complex. Available crystal structures have captured two distinct, monomeric and domain-swapped homodimeric, oligomeric states of CarD. However, the actual oligomeric state of CarD in solution and its biological relevance has remained unclear. Here, we confirm the presence of the homodimeric state of CarD in solution by using synchrotron-based small-angle X-ray scattering. Furthermore, by using biochemical and biophysical experiments, in addition to mass-spectrometry, transmission electron microscopy, and confocal imaging, we show that CarD is the first soluble cytosolic protein in Mtb which displays the tendency to form amyloid-like fibrils both in vitro as well as in vivo. We demonstrate that the deletion of the fourteen N-terminal residues involved in domain-swapping hampers amyloid formation, thus, suggesting that domain-swapping is crucial in amyloidogenesis. The discovery of the amyloidogenic property of an essential cytosolic global transcription regulator, CarD, in a pathogenic bacteria will further open up new frontiers in research.
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影响因子：
14.9
作者：
Davis E;Chen J;Leon K;Darst SA;Campbell EA
通讯作者：
Campbell EA
对RNA聚合酶识别的结构洞察力和粘膜CDNL的基本功能。
影响因子：
3.7
作者：
Gallego-García A;Mirassou Y;García-Moreno D;Elías-Arnanz M;Jiménez MA;Padmanabhan S
通讯作者：
Padmanabhan S
DOI：
10.1073/pnas.0706522104
发表时间：
2007-11-27
影响因子：
11.1
作者：
Cobb, Nathan J.;Soennichsen, Frank D.;Surewicz, Witold K.
通讯作者：
Surewicz, Witold K.
影响因子：
64.8
作者：
BURGESS, RR;TRAVERS, AA;BAUTZ, EKF
通讯作者：
BAUTZ, EKF
影响因子：
6.1
作者：
Kozin, MB;Svergun, DI
通讯作者：
Svergun, DI