PRRT2 controls neuronal excitability by negatively modulating Na+ channel 1.2/1.6 activity.
PRRT2 controls neuronal excitability by negatively modulating Na+ channel 1.2/1.6 activity.
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DOI：
10.1093/brain/awy051
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发表时间：
2018-04-01
期刊：
影响因子：
--
通讯作者：
Benfenati F
中科院分区：
文献类型：
--
作者：
Fruscione F;Valente P;Sterlini B;Romei A;Baldassari S;Fadda M;Prestigio C;Giansante G;Sartorelli J;Rossi P;Rubio A;Gambardella A;Nieus T;Broccoli V;Fassio A;Baldelli P;Corradi A;Zara F;Benfenati F
参见Lerche（doi：）对这篇文章的科学评论。 PRRT 2突变导致异质性阵发性神经系统疾病。Fruscione等人使用来自无义PRRT 2突变纯合子患者的iPSC衍生神经元和来自PRRT 2敲除小鼠的皮质神经元，表明PRRT 2是电压依赖性NaV 1.2/1.6通道的负调节剂。增加的神经元兴奋性可能有助于PRRT 2相关疾病的阵发性。参见Lerche（doi：）对这篇文章的科学评论。富脯氨酸跨膜蛋白2（PRRT 2）是一组异质性家族性阵发性神经系统疾病的致病基因，包括在出生后第一年内发作的癫痫发作（良性家族性婴儿癫痫发作）、阵发性运动诱发性运动障碍或两者的组合。大多数PRRT 2突变是导致单倍不足的功能丧失，80%的患者携带相同的移码突变（c.649dupC; p.Arg217Profs*8），导致提前终止密码子。为了模拟疾病和解剖PRRT 2的生理作用，我们研究了从先前描述的携带c.649dupC突变的杂合和纯合兄弟姐妹的诱导多能干细胞分化的神经元的表型。对纯合子患者的诱导多能干细胞衍生的神经元进行的单细胞膜片钳实验显示，野生型PRRT 2的表达完全挽救了Na+电流的增加。在从最近表征的PRRT 2敲除小鼠获得的原代神经元中观察到非常相似的电生理特征。这种表型与轴突起始段的长度增加相关，并与在网络水平上通过多电极阵列电生理学评估的自发和诱发放电和爆发活动显著增强相关。使用稳定表达Nav通道亚型的HEK-293细胞，我们证明了PRRT 2的表达降低了Nav1.2/Nav1.6通道的膜暴露和Na+电流，而不是Nav1.1通道。此外，PRRT 2直接与Nav1.2/Nav1.6通道相互作用，并诱导失活的电压依赖性负移和失活恢复的减慢。此外，通过免疫共沉淀测定，我们表明PRRT 2-Nav相互作用也发生在脑组织中。该研究表明，PRRT 2的缺乏导致纯合PRRT 2敲除的人和小鼠神经元中电压依赖性Na+通道的过度活跃，并且除了报道的突触功能之外，PRRT 2是Nav1.2和Nav1.6通道的重要负调节剂。鉴于PRRT 2相关疾病的主要阵发性特征，由于缺乏Na+通道的负调节而引起的细胞兴奋性紊乱似乎是关键的发病机制。
See Lerche (doi:) for a scientific commentary on this article. PRRT2 mutations cause heterogeneous paroxysmal neurological disorders. Using iPSC-derived neurons from patients homozygous for a nonsense PRRT2 mutation and cortical neurons from PRRT2-knockout mice, Fruscione et al. show that PRRT2 is a negative modulator of voltage-dependent NaV1.2/1.6 channels. Increased neuronal excitability may contribute to the paroxysmal nature of PRRT2-linked diseases. See Lerche (doi:) for a scientific commentary on this article. Proline-rich transmembrane protein 2 (PRRT2) is the causative gene for a heterogeneous group of familial paroxysmal neurological disorders that include seizures with onset in the first year of life (benign familial infantile seizures), paroxysmal kinesigenic dyskinesia or a combination of both. Most of the PRRT2 mutations are loss-of-function leading to haploinsufficiency and 80% of the patients carry the same frameshift mutation (c.649dupC; p.Arg217Profs*8), which leads to a premature stop codon. To model the disease and dissect the physiological role of PRRT2, we studied the phenotype of neurons differentiated from induced pluripotent stem cells from previously described heterozygous and homozygous siblings carrying the c.649dupC mutation. Single-cell patch-clamp experiments on induced pluripotent stem cell-derived neurons from homozygous patients showed increased Na+ currents that were fully rescued by expression of wild-type PRRT2. Closely similar electrophysiological features were observed in primary neurons obtained from the recently characterized PRRT2 knockout mouse. This phenotype was associated with an increased length of the axon initial segment and with markedly augmented spontaneous and evoked firing and bursting activities evaluated, at the network level, by multi-electrode array electrophysiology. Using HEK-293 cells stably expressing Nav channel subtypes, we demonstrated that the expression of PRRT2 decreases the membrane exposure and Na+ current of Nav1.2/Nav1.6, but not Nav1.1, channels. Moreover, PRRT2 directly interacted with Nav1.2/Nav1.6 channels and induced a negative shift in the voltage-dependence of inactivation and a slow-down in the recovery from inactivation. In addition, by co-immunoprecipitation assays, we showed that the PRRT2-Nav interaction also occurs in brain tissue. The study demonstrates that the lack of PRRT2 leads to a hyperactivity of voltage-dependent Na+ channels in homozygous PRRT2 knockout human and mouse neurons and that, in addition to the reported synaptic functions, PRRT2 is an important negative modulator of Nav1.2 and Nav1.6 channels. Given the predominant paroxysmal character of PRRT2-linked diseases, the disturbance in cellular excitability by lack of negative modulation of Na+ channels appears as the key pathogenetic mechanism.
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DOI：
10.1073/pnas.0810599106
发表时间：
2009-04-21
影响因子：
11.1
作者：
Becker, Esther B. E.;Olivera, Peter L.;Davies, Kay E.
通讯作者：
Davies, Kay E.
影响因子：
--
作者：
Liu YT;Nian FS;Chou WJ;Tai CY;Kwan SY;Chen C;Kuo PW;Lin PH;Chen CY;Huang CW;Lee YC;Soong BW;Tsai JW
通讯作者：
Tsai JW
影响因子：
5.6
作者：
Labate, Angelo;Tarantino, Patrizia;Gambardella, Antonio
通讯作者：
Gambardella, Antonio
DOI：
10.1523/jneurosci.4064-11.2011
发表时间：
2011-11-09
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Grubb MS;Shu Y;Kuba H;Rasband MN;Wimmer VC;Bender KJ
通讯作者：
Bender KJ
影响因子：
25
作者：
Kole, Maarten H. P.;Stuart, Greg J.
通讯作者：
Stuart, Greg J.