Caspase-mediated cleavage of the ubiquitin-protein ligase Nedd4 during apoptosis
Caspase-mediated cleavage of the ubiquitin-protein ligase Nedd4 during apoptosis
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DOI：
10.1074/jbc.273.22.13524
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发表时间：
1998-05-29
影响因子：
4.8
通讯作者：
Kumar, S
中科院分区：
文献类型：
--
作者：
Harvey, KF;Harvey, NL;Kumar, S
细胞凋亡的发生与半胱氨酸蛋白酶家族的蛋白水解激活有关，这些蛋白酶在天冬氨酸残基后切割其靶蛋白。在细胞凋亡期间半胱天冬酶激活后，许多特定的蛋白质已被切割。在这里，我们表明，Nedd 4，一种泛素蛋白连接酶，含有多个WW结构域和钙/脂质结合结构域，也被切割在凋亡诱导的各种刺激，包括Fas连接，γ-辐射，肿瘤坏死因子-α，C-8神经酰胺，和依托泊苷治疗。凋亡细胞的提取物也产生了类似于体内所见的裂解模式，并且这种裂解被半胱天冬酶-3样蛋白酶抑制剂抑制。在体外，Nedd 4被许多半胱天冬酶裂解，包括半胱天冬酶-1、-3、-6和-7。通过定点诱变，小鼠Nedd 4中的一个体外半胱天冬酶切割位点被定位到DQPD（237向下箭头）序列，该序列在小鼠、大鼠和人蛋白质之间是保守的。这是第一份报告表明，泛素途径的酶被半胱天冬酶在细胞凋亡过程中切割。
The onset of apoptosis is coupled to the proteolytic activation of a family of cysteine proteases, termed caspases, These proteases cleave their target proteins after an aspartate residue. Following caspase activation during apoptosis, a number of specific proteins have been shown to be cleaved. Here we show that Nedd4, a ubiquitin-protein ligase containing multiple WW domains and a calcium/lipid-binding domain, is also cleaved during apoptosis induced by a variety of stimuli including Fas-ligation, gamma-radiation, tumor necrosis factor-alpha, C-8 ceramide, and etoposide treatment. Extracts from apoptotic cells also generated cleavage patterns similar to that seen in vivo, and this cleavage was inhibited by an inhibitor of caspase-3-like proteases, In vitro, Nedd4 was cleaved by a number of caspases, including caspase-1, -3, -6, and -7. By site-directed mutagenesis, one of the in vitro caspase cleavage sites in mouse Nedd4 was mapped to a DQPD(237 down arrow) sequence, which is conserved between mouse, rat, and human proteins. This is the first report demonstrating that an enzyme of the ubiquitin pathway is cleaved by caspases during apoptosis.