State Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101 Beijing, P.R. China.
J Biol Chem. 2012 Dec 7;287(50):42053-63. doi: 10.1074/jbc.M112.415968. Epub 2012 Oct 16.
Ei24 is a DNA damage response gene involved in growth suppression and apoptosis. The physiological function of Ei24, however, is poorly understood. Here we generated conditional knock-out mice of Ei24 and demonstrated that EI24 is an essential component of the basal autophagy pathway. Mice with neural-specific Ei24 deficiency develop age-dependent neurological abnormalities caused by massive axon degeneration and extensive neuron loss in brain and spinal cord. Notably, ablation of Ei24 leads to vacuolated oligodendroglial cells and demyelination of axons. Liver-specific depletion of Ei24 causes severe hepatomegaly with hepatocyte hypertrophy. Ei24 deficiency impairs autophagic flux, leading to accumulation of LC3, p62 aggregates, and ubiquitin-positive inclusions. Our study indicates that Ei24 is an essential autophagy gene and plays an important role in clearance of aggregate-prone proteins in neurons and hepatocytes.
Ei24 是一个参与生长抑制和细胞凋亡的 DNA 损伤反应基因。然而,Ei24 的生理功能还知之甚少。在这里,我们生成了条件敲除 Ei24 的小鼠,并证实 Ei24 是基础自噬途径的必需组成部分。神经特异性 Ei24 缺失的小鼠表现出年龄依赖性的神经异常,表现为大脑和脊髓中大量轴突退化和广泛的神经元丢失。值得注意的是,Ei24 的缺失会导致少突胶质细胞空泡化和轴突脱髓鞘。肝特异性 Ei24 缺失会导致严重的肝肿大和肝细胞肥大。Ei24 缺失会损害自噬流,导致 LC3、p62 聚集体和泛素阳性包涵体的积累。我们的研究表明,Ei24 是一个必需的自噬基因,在清除神经元和肝细胞中易聚集的蛋白质方面发挥着重要作用。