Interactions between beta subunits of the KCNMB family and Slo3: beta4 selectively modulates Slo3 expression and function.
Interactions between beta subunits of the KCNMB family and Slo3: beta4 selectively modulates Slo3 expression and function.
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DOI：
10.1371/journal.pone.0006135
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发表时间：
2009-07-03
期刊：
影响因子：
3.7
通讯作者：
Lingle CJ
中科院分区：
文献类型：
--
作者：
Yang CT;Zeng XH;Xia XM;Lingle CJ
pH和电压调节的Slo3 K+通道是Ca2+和电压调节的Slo1 K+通道的同源物，被认为主要在精子中表达，但在异种系统中研究的Slo3的特性与原生精子KSper pH调节电流有所不同。有可能调节Slo3功能的关键伴侣仍未被发现。Slo3和Slo1之间氨基酸的广泛一致性表明，调节Slo1通道的辅助β亚基可能与Slo3通道共同聚集并调节。已知组成KCNMB家族的四个不同的β亚基调节Slo1通道的功能和表达。为了研究KCNMB家族辅助β亚基调控Slo3功能的能力，我们在异源表达系统中共表达Slo3和每个β亚基，并通过电生理和生化分析研究其功能后果。与yfp标记的Slo3或生物素标记的Slo3相比，β4亚基在爪蟾卵母细胞中产生了8-10倍的Slo3电流表达增强，并且Slo3表面表达也有类似的增强。β1、β2和β3都没有模仿β4增加表面表达的能力，尽管生化测试表明所有四个β亚基都能与Slo3共同组装。在β4 KO小鼠的荧光显微镜下，eGFP标签取代了缺失的外显子，显示β4基因启动子在精母细胞中是活跃的。此外，定量RT-PCR显示β4和Slo3在睾丸和精子中表现出相当的mRNA丰度。这些结果表明，对于原生小鼠Slo3通道，β4亚基必须被视为潜在的相互作用伙伴，此外，KCNMB亚基可能具有与Slo1 α亚基调节无关的功能。
The pH and voltage-regulated Slo3 K+ channel, a homologue of the Ca2+- and voltage-regulated Slo1 K+ channel, is thought to be primarily expressed in sperm, but the properties of Slo3 studied in heterologous systems differ somewhat from the native sperm KSper pH-regulated current. There is the possibility that critical partners that regulate Slo3 function remain unidentified. The extensive amino acid identity between Slo3 and Slo1 suggests that auxiliary β subunits regulating Slo1 channels might coassemble with and modulate Slo3 channels. Four distinct β subunits composing the KCNMB family are known to regulate the function and expression of Slo1 Channels. To examine the ability of the KCNMB family of auxiliary β subunits to regulate Slo3 function, we co-expressed Slo3 and each β subunit in heterologous expression systems and investigated the functional consequences by electrophysiological and biochemical analyses. The β4 subunit produced an 8–10 fold enhancement of Slo3 current expression in Xenopus oocytes and a similar enhancement of Slo3 surface expression as monitored by YFP-tagged Slo3 or biotin labeled Slo3. Neither β1, β2, nor β3 mimicked the ability of β4 to increase surface expression, although biochemical tests suggested that all four β subunits are competent to coassemble with Slo3. Fluorescence microscopy from β4 KO mice, in which an eGFP tag replaced the deleted exon, revealed that β4 gene promoter is active in spermatocytes. Furthermore, quantitative RT-PCR demonstrated that β4 and Slo3 exhibit comparable mRNA abundance in both testes and sperm. These results argue that, for native mouse Slo3 channels, the β4 subunit must be considered as a potential interaction partner and, furthermore, that KCNMB subunits may have functions unrelated to regulation of the Slo1 α subunit.
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DOI：
10.1152/nips.01387.2002
发表时间：
2002-08-01
期刊：
NEWS IN PHYSIOLOGICAL SCIENCES
影响因子：
--
作者：
Orio, P;Rojas, P;Latorre, R
通讯作者：
Latorre, R
影响因子：
5.6
作者：
Li, Wei;Gao, Shang-Bang;Xu, Tao
通讯作者：
Xu, Tao
影响因子：
3.5
作者：
Behrens, R;Nolting, A;Pongs, O
通讯作者：
Pongs, O
影响因子：
3
作者：
Lingle, Christopher J.
通讯作者：
Lingle, Christopher J.
影响因子：
14.8
作者：
Nolan, Tania;Hands, Rebecca E.;Bustin, Stephen A.
通讯作者：
Bustin, Stephen A.