pVHL interacts with Ceramide kinase like (CERKL) protein and ubiquitinates it for oxygen dependent proteasomal degradation
pVHL interacts with Ceramide kinase like (CERKL) protein and ubiquitinates it for oxygen dependent proteasomal degradation
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pVHL 与神经酰胺激酶样 (CERKL) 蛋白相互作用，并将其泛素化以进行氧依赖性蛋白酶体降解
DOI：
10.1016/j.cellsig.2015.08.011
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发表时间：
2015-11-01
影响因子：
4.8
通讯作者：
Liu, Mugen
中科院分区：
文献类型：
--
作者：
Chen, Jiaxiang;Liu, Fei;Liu, Mugen
神经酰胺激酶样蛋白(CERKL)基因突变与遗传性退行性眼病视网膜色素变性(RP)相关。CERKL编码一种对光感受器存活至关重要的抗氧化蛋白，它的缺失会导致视网膜氧化损伤而退化。然而，CERKL对氧化应激的调控及其对光感受器存活的贡献仍不清楚。PVHL是环指型SCF的底物受体，类似于ECV泛素连接酶，结合和泛素化许多羟化蛋白以降解蛋白酶体。由于PhD1-3修饰的羟化蛋白质，依赖pVHL的泛素-蛋白酶体降解途径被PhD1-3抑制剂(如缺氧或氧化应激)阻断。在本研究中，我们发现pVHL是CERKL的重要调节因子。Western印迹和体内泛素化实验表明，低氧通过下调CERKL的多泛素化，在蛋白水平上调CERKL的表达。通过共IP和结构域作图研究，我们发现CERKL通过pVHL与ECV连接酶形成复合体。通过过表达和小RNA干扰分析，我们证明了pVHL泛素化CERKL对蛋白酶体的降解作用。此外，我们的工作表明氧传感器PhD1和PHD3参与了CERKL的降解。综上所述，我们的结果表明pVHL与CERKL相互作用，并使其泛素化以进行氧依赖的蛋白酶体降解。(C)2015 Elsevier Inc.保留所有权利。
Mutations of Ceramide kinase-like (CERKL) gene are associated with retinitis pigmentosa (RP), an inherited degenerative eye disease. CERKL encodes an antioxidant protein which is critical to photoreceptor survival, its deficiency causes retinal degeneration as a result of oxidative damage. However, the regulation of CERKL in response to oxidative stress, and its contribution to photoreceptor survival remain unclear. pVHL, the substrate receptor of RING finger-type SCF like ECV ubiquitin ligase, binds and ubiquitinates a number of hydroxylated proteins for proteasomal degradation. Due to hydroxylated proteins which are modified by PHD1-3, pVHL dependent ubiquitin-proteasomal degradation pathway is blocked by PHD1-3 inhibitors (e.g. hypoxia or oxidative stress). In this study, we identified pVHL as an important regulator of CERKL. Western blot and in vivo ubiquitination assays showed hypoxia up-regulates CERKL at protein level by down-regulating its polyubiquitination. By Co-IP and domain mapping studies, we found CERKL complexes with ECV ligase via pVHL. Through overexpression and small RNA interference analysis, we demonstrated pVHL ubiquitinates CERKL for proteasomal degradation. Additionally, our work showed that the oxygen sensors PHD1 and PHD3 are involved in CERKL degradation. Collectively, our results indicated that pVHL interacts with CERKL and ubiquitinates it for oxygen dependent proteasomal degradation. (C) 2015 Elsevier Inc. All rights reserved.