mShal, a subfamily of A-type K+ channel cloned from mammalian brain.
mShal, a subfamily of A-type K+ channel cloned from mammalian brain.
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DOI：
10.1073/pnas.88.10.4386
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发表时间：
1991-05
影响因子：
11.1
通讯作者：
M. Pak;K. Baker;M. Covarrubias;A. Butler;Ann Ratcliffe;L. Salkoff
中科院分区：
文献类型：
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作者：
M. Pak;K. Baker;M. Covarrubias;A. Butler;Ann Ratcliffe;L. Salkoff
我们已经克隆并表达了小鼠脑cDNA，mShal，编码一个瞬时的，A型K+电流。mShal是果蝇Shal基因的脊椎动物同源物，定义了电压门控K+通道的独特亚家族。Shal推导的蛋白质在小鼠和果蝇之间比目前已知的其他K+通道更高度保守。mShal携带具有超极化稳态失活中点的“低阈值”A型电流。在激活的电压敏感性、宏观失活、稳态失活和4-氨基吡啶敏感性方面，观察到mShal及其果蝇同系物fShal之间的显著相似性。Shal蛋白的序列保守性在氨基末端异常高，这是一个被认为对失活很重要的区域。从mShal中去除保守的氨基末端残基改变了宏观失活，但保留了电流的瞬时性质。mShal和fShal的高度保守性的基础可能是在神经系统中的作用，该作用在广泛不同的物种中是保守的。
We have cloned and expressed a mouse brain cDNA, mShal, that encodes a transient, A-type K+ current. mShal, the vertebrate homolog of the Drosophila Shal gene, defines a distinct subfamily of voltage-gated K+ channels. The Shal deduced proteins are more highly conserved between mouse and Drosophila than other presently known K+ channels. mShal carries a "low-threshold" A-type current with a hyperpolarized steady-state inactivation midpoint. Marked similarity was observed between mShal and its Drosophila homolog, fShal, with regard to voltage sensitivity of activation, macroscopic inactivation, steady-state inactivation, and 4-aminopyridine sensitivity. Sequence conservation for Shal proteins is unusually high at the amino terminus, an area considered important for inactivation. Removal of conserved amino-terminal residues from mShal modifies macroscopic inactivation but the transient nature of the current is preserved. Underlying the very high conservation of mShal and fShal may be a role in the nervous system that is conserved in widely divergent species.