Gamma-1-Syntrophin Mediates Trafficking of Gamma-Enolase towards the Plasma Membrane and Enhances Its Neurotrophic Activity
Gamma-1-Syntrophin Mediates Trafficking of Gamma-Enolase towards the Plasma Membrane and Enhances Its Neurotrophic Activity
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DOI：
10.1159/000324292
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发表时间：
2010-01-01
期刊：
影响因子：
--
通讯作者：
Kos, Janko
中科院分区：
文献类型：
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作者：
Hafner, Anja;Obermajer, Natasa;Kos, Janko
促共营养蛋白是一种支架蛋白，可以结合几种信号分子并将其定位于质膜。我们在这里证明，在神经母细胞瘤SH-SY 5 Y细胞中，脑特异性γ（1）-syntrophin通过其PDZ结构域结合神经营养因子γ-烯醇化酶，并将其转位到质膜，如免疫沉淀，表面等离子体共振，荧光共定位和流式细胞术所示。在分化的SH-SY 5 Y细胞的轴突生长锥中观察到广泛的γ（1）-syntrophin和γ-烯醇化酶的共定位。通过RNA干扰沉默γ（1）-syntrophin基因显著降低了γ-烯醇化酶向质膜的再分布，并削弱了其神经营养作用。我们证明，一个完整的γ-烯醇化酶的C-末端是必不可少的γ-syntrophin辅助贩运。羧肽酶组织蛋白酶X在γ-烯醇化酶的C-末端切割两个氨基酸阻止与γ（1）-促突触蛋白PDZ结构域结合。总的来说，这些数据表明，γ（1）-syntrophin参与γ-烯醇化酶易位向质膜，其神经营养活性的先决条件。通过破坏这种γ（1）-突触营养蛋白引导的亚细胞分布，组织蛋白酶X减少γ-烯醇化酶诱导的神经营养信号。版权所有（C）2011 S. Karger AG，巴塞尔
Syntrophins are scaffold proteins that can bind several signaling molecules and localize them to the plasma membrane. We demonstrate here that in neuroblastoma SH-SY5Y cells, brain-specific gamma(1)-syntrophin binds the neurotrophic factor gamma-enolase through its PDZ domain, and translocates it to the plasma membrane, as shown by immunoprecipitation, surface plasmon resonance, fluorescence colocalization and flow cytometry. Extensive colocalization of gamma(1)-syntrophin and gamma-enolase was observed in neurite growth cones in differentiated SH-SY5Y cells. Silencing of the gamma(1)-syntrophin gene by RNA interference significantly reduced the re-distribution of gamma-enolase to the plasma membrane and impaired its neurotrophic effects. We demonstrated that an intact C-terminal end of gamma-enolase is essential for its gamma-syntrophin-assisted trafficking. The cleavage of two amino acids at the C-terminal end of gamma-enolase by the carboxypeptidase cathepsin X prevents binding with the gamma(1)-syntrophin PDZ domain. Collectively, these data demonstrate that gamma(1)-syntrophin participates in gamma-enolase translocation towards the plasma membrane, a pre-requisite for its neurotrophic activity. By disrupting this gamma(1)-syntrophin-guided subcellular distribution, cathepsin X reduces gamma-enolase-induced neurotrophic signaling. Copyright (C) 2011 S. Karger AG, Basel