Nanodiamonds as sensitive sensors to study tetherin structure and dynamics

人Tetherin可阻断病毒释放，也可作为模式识别受体在HIV-1感染细胞中诱导依赖于NF-kB的抗病毒基因表达。限制病毒粒子释放的能力在不同物种的Tetherin同源基因中是保守的，并在数亿年前进化出来。然而，与生俱来的病毒感知似乎是Tetherin的一种进化新近的活动，只有人类和(在较小程度上)更大的类人猿tetherin同源基因被报道作为先天性免疫传感器，而来自猴子和其他物种的tetherin缺乏这一功能。病毒感知涉及到保守的酪氨酸残基在Tetherin二聚体的细胞质尾巴中的磷酸化，但Tetherin感知病毒的确切机制和结构要求仍有待确定。基于纳米钻石中氮空位缺陷(N-V)的量子传感器具有很大的潜力，可以在环境条件下通过原子分辨配体结合位置来实现对自然环境中蛋白质的单分子检测。我们的合作项目集中在N-V磁测量的应用上，以原子精度解析膜受体Tetherin的病毒粒子捕获位置，并在病毒粒子结合时监测膜内的Tetherin动力学。因此，使用ND传感器的分析可以提供关于HIV-1结合的动力学和这种重要的先天抗病毒因子的信号转导的基本信息。总体而言，预计量子传感在生物学中的实施将为具有挑战性的生物分子(如膜系留在其自然环境中)的结构和动力学提供全新的见解，从而提供第一种方法，允许在生理条件下以非侵入性的方式收集具有原子分辨率的结构信息。

Human tetherin blocks virus release and also acts as a pattern recognition receptor to induce NF-kB-dependent antiviral gene expression in HIV-1 infected cells. The ability to restrict virion release is conserved among tetherin orthologues from different species and evolved hundreds of millions of years ago. However, innate viral sensing seems to be an evolutionarily recent activity of tetherin and only human and (to a lesser extent) greater apes tetherin orthologues were reported to act as innate immune sensors, whereas tetherins from monkeys and other species lack this function. Viral sensing involves the phosphorylation of conserved tyrosine residues in the cytoplasmic tails of tetherin dimers but the exact mechanism and the structural requirements for viral sensing by tetherin remain to be determined. Quantum sensors based on nitrogen-vacancy defects (N-V) in nanodiamonds offer great potential to achieve single molecule detection of proteins in their native environment with atomic resolution of ligand binding sites under ambient conditions. Our collaborative project focuses on the application of N-V magnetometry for resolving the virion capturing site of the membrane receptor tetherin with atomic precision and for monitoring tetherin dynamics inside the membrane upon virion binding. Thus, analyses with ND sensors could yield fundamental information regarding the dynamics of HIV-1 binding and signal transduction of this important innate antiviral factor. Overall, it is expected that the implementation of quantum sensing in biology provides radically new insights into the structure and dynamics of challenging biomolecules such as the membrane tetherin in its native environement thus providing the first method that would allow collecting structural information with atomic resolution in a non-invasive fashion under physiological conditions.