Regulation of cardiac volume-sensitive chloride channel by focal adhesion kinase and Src kinase.
Regulation of cardiac volume-sensitive chloride channel by focal adhesion kinase and Src kinase.
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DOI：
10.1152/ajpheart.00292.2005
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发表时间：
2005-12
期刊：
影响因子：
--
通讯作者：
K. Walsh;Jining Zhang
中科院分区：
文献类型：
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作者：
K. Walsh;Jining Zhang
体积敏感氯电流 (ICl,swell) 存在于哺乳动物心肌中，并由渗透性膨胀激活。本研究的目的是检查酪氨酸激酶粘着斑激酶 (FAK) 和 Src 激酶在心脏 ICl、肿胀调节中的重要性。新生大鼠心室肌细胞在胶原膜上培养，并用表达 β-半乳糖苷酶 (AdLacZ)、FAK 或 FAK 相关非激酶的腺病毒感染。 FAK 相关非激酶 (FRNK) 是一种内源性心脏蛋白，可作为 FAK 的抑制剂。全细胞膜片钳记录表明，渗透膨胀与未感染和 AdLacZ 感染细胞中外向整流电流的激活有关。与 ICl,swell 的特性一致，该电流显示出接近 Cl- 平衡电位的反转电位；被 Cl-通道阻滞剂 4,4'-二硝基芪-2,2'-二磺酸、5-硝基-2-(3-苯基丙氨基)-苯甲酸和他莫昔芬抑制；并在高渗溶液中被消除。除了激活 ICl,swell 之外，低渗肿胀还增强了多种心脏蛋白的酪氨酸磷酸化，包括 68-70 和 120-130 kDa 范围内的蛋白。用药物 4-氨基-5-(4-氯苯基)-7-(叔丁基)吡唑并[3,4-d]嘧啶（FAK 和 Src 的抑制剂）预处理细胞，减少了这些蛋白质的肿胀诱导的磷酸化，但反而增加了 ICl,swell。此外，FRNK 而非 FAK 的过度表达会导致 I(Cl,swell) 增加两倍，并增加电流激活率。因此，酪氨酸激酶FAK和Src有助于ICl,swell的调节。
The volume-sensitive chloride current (ICl,swell) is found in the mammalian myocardium and is activated by osmotic swelling. The goal of this study was to examine the importance of the tyrosine kinases focal adhesion kinase (FAK) and Src kinase in cardiac ICl,swell regulation. Neonatal rat ventricular myocytes were cultured on collagen membranes and infected with adenovirus expressing beta-galactosidase (AdLacZ), FAK, or FAK-related nonkinase. FAK-related nonkinase (FRNK) is an endogenous cardiac protein, which functions as an inhibitor of FAK. Whole cell patch-clamp recordings demonstrated that osmotic swelling was associated with the activation of an outward rectifying current in uninfected and AdLacZ-infected cells. Consistent with the properties of ICl,swell, this current displayed a reversal potential close to the equilibrium potential for Cl-; was inhibited by the Cl- channel blockers 4,4'-dinitrostilbene-2,2'-disulfonic acid, 5-nitro-2-(3-phenylpropylamino)-benzoic acid, and tamoxifen; and was eliminated in hypertonic solution. In addition to activating ICl,swell, hypotonic swelling enhanced the tyrosine phosphorylation of multiple cardiac proteins including those in the range of 68-70 and 120-130 kDa. Pretreatment of the cells with the drug 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine, an inhibitor of FAK and Src, diminished swelling-induced phosphorylation of these proteins but paradoxically increased ICl,swell. Furthermore, overexpression of FRNK but not FAK caused a twofold augmentation in I(Cl,swell) and increased the rate of current activation. Thus the tyrosine kinases FAK and Src contribute to the regulation of ICl,swell.