Differential expression and targeting of K+ channel genes in the lobster pyloric central pattern generator
Differential expression and targeting of K+ channel genes in the lobster pyloric central pattern generator
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DOI：
10.1111/j.1749-6632.1998.tb09056.x
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发表时间：
1998-01-01
期刊：
影响因子：
--
通讯作者：
Harris-Warrick, RM
中科院分区：
文献类型：
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作者：
Baro, DJ;Harris-Warrick, RM
运动模式生成的分子分析是电生理学和计算研究的重要补充。在节肢动物中，A-通道是后修饰的多聚体蛋白，其含有可与β-亚基、γ-亚基和其他辅助蛋白相互作用的Shaker家族α-亚基。A通道结构的一个结果是，几种机制可能是幽门I（A）的细胞特异性差异的基础，包括差异基因表达，可变剪接和翻译后修饰。卵母细胞表达研究，单细胞RT-PCR和免疫细胞化学表明，差异α亚基基因表达不是产生幽门I-A异质性的机制，同一个基因shal编码幽门网络中整个体细胞I（A）家族的α亚基。shal基因表达水平的变化改变了细胞之间的A通道密度，但不能解释六个幽门I（A）的生物物理特性的差异。初步数据表明，shal基因也编码粗和细神经元的A通道α亚基，但不编码大多数轴突的A通道α亚基。编码大多数轴突和神经肌肉接头处的A通道α亚单位。这两种类型的A通道的不同特性与I-A在不同部位的不同作用相一致。shaker和shal基因都是交替剪接的，目前正在进行研究以确定交替剪接是否是产生幽门I-A异质性的机制。
A molecular analysis of motor pattern generation is an essential complement to electrophysiological and computational investigations. In arthropods, A-channels are posttranslationally modified multimeric proteins containing Shaker family alpha-subunits that may interact with beta-subunits, gamma-subunits, and other auxiliary proteins. One consequence of A-channel structure is that several mechanisms could underlie the cell-specific differences in pyloric I(A)s including differential gene expression, alternate splicing, and posttranslational modifications. Oocyte expression studies, single-cell RT-PCR, and immunocytochemistry suggest that differential alpha-subunit gene expression is not a mechanism for creating pyloric I-A heterogeneity, and that the same gene, shal, encodes the alpha-subnuits for the entire family of somatic I(A)s in the pyloric network. Changes in the level of shal gene expression alter A-channel density between cells, but cannot account for the differences in the biophysical properties of the six pyloric I(A)s, Preliminary data suggest that the shal gene also encodes the A-channel alpha-subunits for the coarse and fine neuropil but not for most axons, A second gene, shaker, encodes the A-channel alpha-subunits in the majority of axons and at the neuromuscular junction. The distinct properties of the two types of A-channels are consistent with the different roles of I-A at the different locations. Both the shaker and shal genes are alternately spliced, and investigations are under way to determine whether alternate splicing is a mechanism for generating pyloric I-A heterogeneity.