MECHANISMS OF THE VOLTAGE-DEPENDENT SODIUM CHANNEL

电压依赖性钠通道的机制

• 批准号: 6186974
• 负责人: Simon R LEVINSON
• 金额: $ 26.21万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-07-01 至 2001-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6186974
• 关键词: developmental neurobiology; exo alpha sialidase; glycoprotein biosynthesis; glycoprotein structure; glycosylation; laboratory mouse; laboratory rabbit; laboratory rat; membrane biogenesis; membrane structure; molecular cloning; neurons; posttranslational modifications; protein isoforms; protein structure function; sialate; sodium channel; striated muscles; tissue /cell culture; voltage gated channel

DESCRIPTION: Progress in the previous award period provides strong evidence that channel sialylation plays a role in the gating behavior of sodium channels. Specifically, it has been shown that the removal of sialic acids from channels results in a reduction in the voltage and calcium sensitivity of sodium channel gating. The manner of these effects suggest that sialic acids influence sodium channel gating through an electrostatic mechanism. In this renewal application, this basic hypothesis and its biological significance will be addressed by exploring two questions: 1) What is the actual magnitude of the effect of sialylation on sodium channel gating in vivo? 2) Is variable channel sialylation a potential means of controlling sodium channel gating behavior in vivo? The specific aims proposed are as follows: 1) To determine the effects of increased sialylation on the gating of sodium channels expressed in transfected cell lines. These studies are intended as a further test of the hypothetical electrostatic role of sialic acid in channel gating by complementing previous experiments that removed sialic acid. In these experiments, channel sialylation will be increased through the chimeric addition of glycosylation sites to channels, sialylation of both wild-type and chimeric channels will be increased through expression in cell lines transfected with cloned sialytransferases. 2) To characterize the gating of glycosylation-deficient rSkM1 mutants expressed in skeletal muscle fibers. The gating of mutants of rSkM1 will be determined when these glycosylation-site deletion mutants are transfected into rat skeletal muscle fibers. These studies will provide a direct assessment of the actual contribution of channel sialylation to channel gating in vivo. 3) To investigate whether correlative variations in channel sialylation and gating occur for a given channel isoform in the nervous system and during development. Through the use of isoform-specific antibodies, the sialylation levels of channels will be determined in different parts of the adult and developing nervous system. Variations of such sialylation levels will be correlated with the gating properties of brain sodium channels using the CHO cell expression system developed in Aim #1. Further, the molecular basis for such variations will be addressed through study of the expression of endogenous sialyltransferases. Thus these experiments will determine whether variable sialylation is a potential channel modulation mechanism in the nervous system. These studies are relevant to the understanding of neuromuscular dysfunction that is present in disorders of calcium and glycoprotein metabolism, particularly those involving genetic defects of glycosylation. Furthermore, the project may provide insight into changes in electrical excitability that occur in aging brain, Alzheimer s disease, and epilepsy.

描述：上一个授标期的进展提供了强有力的证据 通道唾液酸化在钠离子的门控行为中起作用， 渠道 具体地，已经表明，唾液酸的去除 导致电压和钙敏感性降低 钠通道门控 这些影响的方式表明，唾液酸 酸通过静电机制影响钠通道门控。 在这个更新的应用程序中，这个基本假设及其生物学 通过探讨两个问题来解决重要性：1）什么是 唾液酸化对钠通道门控作用的实际幅度 体内？ 2)可变通道唾液酸化是一种潜在的控制 体内钠通道门控行为？ 提出的具体目标如下：1）确定 增加唾液酸化对钠通道门控的表达， 转染细胞系。 这些研究旨在进一步测试 唾液酸在通道门控中假设静电作用 补充了之前去除唾液酸的实验。 在这些 在实验中，通道唾液酸化将通过嵌合的 将糖基化位点添加到通道中， 并且嵌合通道将通过在细胞系中的表达而增加 用克隆的唾液酸转移酶转染。 2)为了表征门控， 在骨骼肌纤维中表达的糖基化缺陷型rSkM1突变体。 rSkM1突变体的门控将在以下情况下确定： 将糖基化位点缺失突变体转染到大鼠骨骼肌中， 纤维 这些研究将提供一个直接的评估， 通道唾液酸化对体内通道门控的贡献。 3)到 研究通道唾液酸化和门控的相关变化是否 发生在神经系统中给定的通道亚型， 发展 通过使用同种型特异性抗体， 通道的唾液酸化水平将在细胞的不同部分中测定。 成人和发育中的神经系统。 这种唾液酸化水平的变化 将与脑钠通道的门控特性相关， 目标#1中开发的CHO细胞表达系统。 此外，分子 这种变化的基础将通过研究表达 内源性唾液酸转移酶。 因此这些实验将决定 可变唾液酸化是否是一种潜在的通道调节机制， 神经系统 这些研究与神经肌肉功能障碍的理解有关 存在于钙和糖蛋白代谢紊乱中， 特别是涉及糖基化遗传缺陷的那些。 此外，委员会认为， 该项目可以提供对电兴奋性变化的洞察， 发生在老化的大脑，阿尔茨海默氏症，和癫痫。

项目成果

Na+ channel aggregation in remyelinating mouse sciatic axons following transection.

横断后髓鞘再生小鼠坐骨轴突中Na通道聚集。

• DOI: 10.1002/glia.440150211
• 发表时间: 1995
• 期刊: Glia.
• 作者: Tzoumaka,EE;Novakovic,SD;Levinson,SR;Shrager,P
• 通讯作者: Shrager,P

Contribution of the Na(+)-K+ pump to membrane potential in familial periodic paralysis.

Na( )-K 泵对家族性周期性麻痹中膜电位的贡献。

• DOI: 10.1002/mus.880080503
• 发表时间: 1985
• 期刊: Muscle & nerve
• 影响因子: 3.4
• 作者: Martin,AR;Levinson,SR
• 通讯作者: Levinson,SR

Distribution of sodium and potassium channels as well as myelin associated glycoprotein (MAG) during the early stages of Wallerian degeneration.

沃勒变性早期阶段钠和钾通道以及髓磷脂相关糖蛋白 (MAG) 的分布。

• 发表时间: 1999
• 期刊: Journal of submicroscopic cytology and pathology.
• 作者: Martinez,AM

Clustering of Na+ channels and node of Ranvier formation in remyelinating axons.

髓鞘再生轴突中 Na 通道和 Ranvier 形成节点的聚集。

• DOI: 10.1523/jneurosci.15-01-00492.1995
• 发表时间: 1995
• 期刊: The Journal of neuroscience : the official journal of the Society for Neuroscience.
• 作者: Dugandzija-Novakovic,S;Koszowski,AG;Levinson,SR;Shrager,P
• 通讯作者: Shrager,P

The clustering of axonal sodium channels during development of the peripheral nervous system.

周围神经系统发育过程中轴突钠通道的聚集。

• DOI: 10.1523/jneurosci.16-16-04914.1996
• 发表时间: 1996
• 期刊: The Journal of neuroscience : the official journal of the Society for Neuroscience.
• 作者: Vabnick,I;Novakovic,SD;Levinson,SR;Schachner,M;Shrager,P
• 通讯作者: Shrager,P