Molecular ordering of the caspase activation cascade initiated by the cytotoxic T lymphocyte/natural killer (CTL/NK) protease granzyme B
Molecular ordering of the caspase activation cascade initiated by the cytotoxic T lymphocyte/natural killer (CTL/NK) protease granzyme B
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DOI：
10.1074/jbc.m410915200
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发表时间：
2005-02-11
影响因子：
4.8
通讯作者：
Martin, SJ
中科院分区：
文献类型：
--
作者：
Adrain, C;Murphy, BM;Martin, SJ
颗粒酶B是一种主要的细胞毒性T淋巴细胞/自然杀伤（CTL/NK）颗粒蛋白酶，其可以通过加工半胱氨酸蛋白酶酶原来激活半胱氨酸蛋白酶的半胱氨酸蛋白酶家族的成员。然而，颗粒酶B引发的细胞凋亡期间靶细胞中发生的半胱天冬酶激活事件的分子顺序和相对重要性尚未确定。在这里，我们已经研究了层次的颗粒酶B启动的半胱天冬酶激活事件使用无细胞系统，其中所有的半胱天冬酶都存在于生理水平。我们发现，颗粒酶B启动一个两层的caspase激活级联反应，涉及7个caspase，其中caspase-3是所需的第二层caspase激活事件。使用二维凝胶为基础的蛋白质组学方法，我们还研究了颗粒酶B启动的改变的蛋白质组中存在或不存在的效应caspase-3或-7的规模。这些研究表明，颗粒酶B的目标是一个高度有限的范围内的基板和协调细胞拆除主要是通过激活半胱天冬酶-3。
Granzyme B is a major cytotoxic T lymphocyte/natural killer (CTL/NK) granule protease that can activate members of the caspase family of cysteine proteases through processing of caspase zymogens. However, the molecular order and relative importance of caspase activation events that occur in target cells during granzyme B-initiated apoptosis has not been established. Here, we have examined the hierarchy of granzyme B-initiated caspase activation events using a cell-free system where all caspases are present at physiological levels. We show that granzyme B initiates a two-tiered caspase activation cascade involving seven caspases, where caspase-3 is required for the second tier of caspase activation events. Using a two-dimensional gel-based proteomics approach we have also examined the scale of granzyme B-initiated alterations to the proteome in the presence or absence of effector caspase-3 or -7. These studies indicate that granzyme B targets a highly restricted range of substrates and orchestrates cellular demolition largely through activation of caspase-3.