NH2-terminal heterogeneity in the KCC3 K+-Cl- cotransporter.
NH2-terminal heterogeneity in the KCC3 K+-Cl- cotransporter.
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KCC3 K -Cl- 协同转运蛋白中的 NH2 末端异质性。
DOI：
10.1152/ajprenal.00464.2004
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Mount,DavidB
中科院分区：
文献类型：
--
作者：
Mercado,Adriana;Vazquez,Norma;Song,Luyan;Cortes,Rosa;Enck,AlissaH;Welch,Rick;Delpire,Eric;Gamba,Gerardo;Mount,DavidB
编码K+-Cl−协同转运蛋白KCC 3的SLC 12 A6基因在多种组织中表达，包括肾脏。在这里，我们报告的几个NH 2-末端亚型的人和小鼠KCC 3的分子特征，沿着肾内的定位和功能的特点在非洲爪蟾laevisoocytes。两种主要的同种型KCC 3a和KCC 3b由两个不同的第一编码外显子的5′转录起始产生。小鼠组织的北方印迹分析表明，KCC 3b表达在肾脏中特别稳健，肾脏也表达KCC 3a。使用外显子3特异性抗体的小鼠组织的蛋白质印迹法揭示，肾脏也是独特的表达免疫反应性蛋白质的较低的质量，提示证据表明，较短的KCC 3b蛋白占主导地位的肾脏。免疫荧光显示，在小鼠和大鼠中，KCC 3蛋白沿着整个近端小管的基底外侧表达。通过选择性剪接去除15个残基的外显子2产生KCC 3a-x2 M和KCC 3b-x2 M亚型;外显子1a内的选择性受体位点处的其他剪接事件产生KCC 3a-S亚型，其比KCC 3a短60个残基。这种变化的NH 2-末端胞质结构域的序列发生接近一段高度保守的残基，并影响推定的磷酸化位点的内容。KCC 3a在X.左心室细胞显示Rb+和Cl−的表观Km值分别为10.7 ± 2.5和7.3 ± 1.2 mM，阴离子选择性为Br−> Cl−> PO 4 = I−= SCN−= glucose。所有五种NH 2-末端同种型均通过细胞溶胀（低渗条件）活化，在等渗条件下无活性。尽管同种型在溶胀活化的渗透设定点方面没有差异，但KCC 3a-x2 M和KCC 3a-S蛋白的这种活化更快。总之，KCC 3存在显著的NH 2-末端异质性，KCC 3b在肾脏中的表达特别强烈。由KCC 3介导的基底外侧肿胀激活的K+-Cl−共转运可能在近端小管跨上皮转运盐和溶质期间的细胞体积调节中起作用。
TheSLC12A6gene encoding the K+-Cl−cotransporter KCC3 is expressed in multiple tissues, including kidney. Here, we report the molecular characterization of several NH2-terminal isoforms of human and mouse KCC3, along with intrarenal localization and functional characterization inXenopus laevisoocytes. Two major isoforms, KCC3a and KCC3b, are generated by transcriptional initiation 5′ of two distinct first coding exons. Northern blot analysis of mouse tissues indicates that KCC3b expression is particularly robust in the kidney, which also expresses KCC3a. Western blotting of mouse tissue using an exon 3-specific antibody reveals that the kidney is also unique in expressing immunoreactive protein of a lower mass, suggestive evidence that the shorter KCC3b protein predominates in kidney. Immunofluorescence reveals basolateral expression of KCC3 protein along the entire length of the proximal tubule, in both the mouse and rat. Removal of the 15-residue exon 2 by alternative splicing generates the KCC3a-x2M and KCC3b-x2M isoforms; other splicing events at an alternative acceptor site within exon 1a generate the KCC3a-S isoform, which is 60 residues shorter than KCC3a. This variation in sequence of NH2-terminal cytoplasmic domains occurs proximal to a stretch of highly conserved residues and affects the content of putative phosphorylation sites. Kinetic characterization of KCC3a inX. laevisoocytes reveals apparentKms for Rb+and Cl−of 10.7 ± 2.5 and 7.3 ± 1.2 mM, respectively, with an anion selectivity of Br−> Cl−> PO4= I−= SCN−= gluconate. All five NH2-terminal isoforms are activated by cell swelling (hypotonic conditions), with no activity under isotonic conditions. Although the isoforms do not differ in the osmotic set point of swelling activation, this activation is more rapid for the KCC3a-x2M and KCC3a-S proteins. In summary, there is significant NH2-terminal heterogeneity of KCC3, with particularly robust expression of KCC3b in the kidney. Basolateral swelling-activated K+-Cl−cotransport mediated by KCC3 likely functions in cell volume regulation during the transepithelial transport of both salt and solutes by the proximal tubule.
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血管内皮细胞中肿胀激活的 K 通量：通过 K-Cl 共转运和 K 通道进行体积调节。
影响因子：
--
作者：
P. Perry;W. O'Neill
通讯作者：
W. O'Neill
NO 信号通路差异调节 KCC3a 和 KCC3b mRNA 表达。
DOI：
--
发表时间：
2003
期刊：
Nitric oxide
影响因子：
--
作者：
M. Di Fulvio;P. Lauf;N. Adragna
通讯作者：
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影响因子：
2.9
作者：
Moore-Hoon, ML;Turner, RJ
通讯作者：
Turner, RJ
影响因子：
5.8
作者：
ENAN, E;MATSUMURA, F
通讯作者：
MATSUMURA, F
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DOI：
--
发表时间：
1999
期刊：
Pflügers Archiv
影响因子：
--
作者：
K. Taouil;P. Hannaert
通讯作者：
P. Hannaert