Purinergic agonists stimulate lens Na-K-ATPase-mediated transport via a Src tyrosine kinase-dependent pathway
Purinergic agonists stimulate lens Na-K-ATPase-mediated transport via a Src tyrosine kinase-dependent pathway
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DOI：
10.1152/ajpcell.00579.2006
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发表时间：
2007-08-01
影响因子：
5.5
通讯作者：
Delamere, Nicholas A.
中科院分区：
文献类型：
--
作者：
Tamiya, Shigeo;Okafor, Mansim C.;Delamere, Nicholas A.
嘌呤能激动剂通过Src酪氨酸激酶依赖性途径刺激透镜Na-K-ATP酶介导的转运。美国生理学杂志细胞生理学293：C790-C796，2007年。首次发表于2007年5月23日; doi：10.1152/ajpcell.00579.2006。P4 a-K-ATP酶对维持透镜的透明度至关重要。过去使用完整透镜的研究表明，酪氨酸激酶参与了Na-K-ATP酶的短期调节。此外，在体外磷酸化的透镜上皮细胞膜制备Src家族激酶（SFKs），一个家庭的非受体酪氨酸激酶，导致修改的Na-K-ATP酶活性。在这里，嘌呤能激动剂，ATP和UTP，对Na-K-ATP酶功能和SFK激活的影响，在兔透镜中进行了检查。采用两种不同的方法检测Na-K-ATP酶功能，测量完整透镜对哇巴因敏感的钾（（86 R）B）摄取，以及透镜上皮匀浆中Na-K-ATP酶活性。ATP和UTP引起哇巴因敏感的钾（Rb-86）摄取显着增加。ATP预处理晶状体上皮细胞Na-K-ATP酶活性增加。用ATP或UTP处理的晶状体显示出SFK的活化，如通过活性SFK（在活性环Y 416处磷酸化）的蛋白质印迹带密度增加和非活性SFK（在COOH末端处磷酸化）的带密度降低所证明的。观察到类似于60 kDa的单一PY 416-Src免疫反应性条带，表明并非所有Src家族成员都被激活。免疫沉淀研究表明，带密度的活性Src，并在较小程度上活性Fyn，显着增加，而积极的是没有改变。用SFK抑制剂PP 2预孵育晶状体可消除ATP诱导的哇巴因敏感性钾（Rb-86）摄取增加。结果表明Src和/或Fyn的选择性激活是嘌呤能激动剂引发的信号传导机制的一部分，该机制增加了器官培养的透镜中Na-K-ATP酶介导的转运。
Purinergic agonists stimulate lens Na-K-ATPase-mediated transport via a Src tyrosine kinase-dependent pathway. Am J Physiol Cell Physiol 293: C790-C796, 2007. First published May 23, 2007; doi:10.1152/ajpcell.00579.2006.-The P4a-K-ATPase is vital for maintenance of lens transparency. Past studies using intact lens suggested the involvement of tyrosine kinases short-term regulation of Na-K-ATPase. Furthermore, in vitro phosphorylation of a lens epithelial membrane preparation by Src family kinases (SFKs), a family of nonreceptor tyrosine kinases, resulted in modification of Na-K-ATPase activity. Here, the effect of purinergic agonists, ATP and UTP, on Na-K-ATPase function and SFK activation was examined in the rabbit lens. Na-K-ATPase function was examined using two different approaches, measurement of ouabain-sensitive potassium ((86R)b) uptake by the intact lens, and Na-K-ATPase activity in lens epithelial homogenates. ATP and UTP caused a significant increase in ouabain-sensitive potassium (Rb-86) uptake. Na-K-ATPase activity was increased in the epithelium of lenses pretreated with ATP. Lenses treated with ATP or UTP displayed activation of SFKs as evidenced by increased Western blot band density of active SFK (phosphorylated at the active loop Y416) and decreased band density of inactive SFKs (phosphorylated at the COOH terminal). A single PY416-Src immunoreactive band at similar to 60 kDa was observed, suggesting not all Src family members are activated. Immunoprecipitation studies showed that band density of active Src, and to a lesser extent active Fyn, was significantly increased, while active Yes did not change. Preincubation of the lenses with SFK inhibitor PP2 abolished the ATP-induced increase in ouabain-sensitive potassium (Rb-86) uptake. The results suggest selective activation of Src and/or Fyn is part of a signaling mechanism initiated by purinergic agonists that increases Na-K-ATPase-mediated transport in the organ-cultured lens.