Biophysical and functional characterization of hippocalcin mutants responsible for human dystonia.
Biophysical and functional characterization of hippocalcin mutants responsible for human dystonia.
复制标题
DOI：
10.1093/hmg/ddx133
复制
发表时间：
2017-07-01
影响因子：
3.5
通讯作者：
Burgoyne RD
中科院分区：
文献类型：
--
作者：
Helassa N;Antonyuk SV;Lian LY;Haynes LP;Burgoyne RD
肌张力障碍是一种神经运动障碍，它迫使身体扭曲，重复运动，有时甚至是痛苦的异常姿势。随着新一代测序技术的出现，神经元钙传感器（NCS）海马钙蛋白的纯合突变T71N和A190T被确定为原发性孤立性肌张力障碍（DYT2肌张力障碍）的遗传原因。然而，这些突变对希波calcin生理作用的影响尚未阐明。使用多学科方法，我们证明了海马体蛋白以钙依赖的方式寡聚，并结合电压门控钙通道。突变T71N和A190T不影响稳定性、钙结合亲和力或细胞膜易位（Ca2+/肉豆蔻酰基开关）。我们获得了hippocalcin的第一个晶体结构，与其他NCS蛋白的比对显示，分子c端部分的取向有显著的可变性，该区域对靶标结合很重要。我们证明了致病突变不影响蛋白质的结构，但两种突变都表现出寡聚化缺陷。此外，我们观察到表达突变希波钙蛋白的kcl去极化细胞中钙内流增加，主要由n型电压门控钙通道驱动。我们的数据表明，引起肌张力障碍的突变强烈影响海马钙蛋白的细胞功能，这表明在DYT2肌张力障碍中钙信号紊乱起着核心作用。
Dystonia is a neurological movement disorder that forces the body into twisting, repetitive movements or sometimes painful abnormal postures. With the advent of next-generation sequencing technologies, the homozygous mutations T71N and A190T in the neuronal calcium sensor (NCS) hippocalcin were identified as the genetic cause of primary isolated dystonia (DYT2 dystonia). However, the effect of these mutations on the physiological role of hippocalcin has not yet been elucidated. Using a multidisciplinary approach, we demonstrated that hippocalcin oligomerises in a calcium-dependent manner and binds to voltage-gated calcium channels. Mutations T71N and A190T in hippocalcin did not affect stability, calcium-binding affinity or translocation to cellular membranes (Ca2+/myristoyl switch). We obtained the first crystal structure of hippocalcin and alignment with other NCS proteins showed significant variability in the orientation of the C-terminal part of the molecule, the region expected to be important for target binding. We demonstrated that the disease-causing mutations did not affect the structure of the protein, however both mutants showed a defect in oligomerisation. In addition, we observed an increased calcium influx in KCl-depolarised cells expressing mutated hippocalcin, mostly driven by N-type voltage-gated calcium channels. Our data demonstrate that the dystonia-causing mutations strongly affect hippocalcin cellular functions which suggest a central role for perturbed calcium signalling in DYT2 dystonia.
登录
查看更多内容
DOI：
10.1107/s0907444905036693
发表时间：
2006-01-01
影响因子：
2.2
作者：
Evans, P
通讯作者：
Evans, P
DOI：
10.1016/j.bbamcr.2014.10.029
发表时间：
2015-09
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Burgoyne RD;Haynes LP
通讯作者：
Haynes LP
影响因子：
34.7
作者：
Burgoyne, Robert D.
通讯作者：
Burgoyne, Robert D.
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
16.2
作者：
Erickson, MG;Alseikhan, BA;Yue, DT
通讯作者：
Yue, DT