Caspase-3 is required for DNA fragmentation and morphological changes associated with apoptosis
Caspase-3 is required for DNA fragmentation and morphological changes associated with apoptosis
复制标题
DOI：
10.1074/jbc.273.16.9357
复制
发表时间：
1998-04-17
影响因子：
4.8
通讯作者：
Porter, AG
中科院分区：
文献类型：
--
作者：
Jänicke, RU;Sprengart, ML;Porter, AG
白细胞介素1 β转换酶样蛋白酶（半胱天冬酶）是细胞死亡途径的重要组成部分。在已确定的caspase中，caspase-3非常突出，因为它通常被许多死亡信号激活，并切割多种重要的细胞蛋白。对caspase-3敲除小鼠的研究表明，这种蛋白酶对大脑发育至关重要。为了研究凋亡对caspase-3的需求，我们利用MCF-7乳腺癌细胞系，我们在这里显示，由于caspase-3基因外显子3内47个碱基对缺失，caspase-3丢失。这种缺失导致前mRNA剪接期间外显子3的跳跃，从而取消了CASP-3 mRNA的翻译。尽管MCF-7细胞仍然。对肿瘤坏死因子（TNF）或staurosporine诱导的细胞凋亡敏感，未观察到DNA断裂。此外，经历细胞死亡的MCF-7细胞没有表现出凋亡细胞的一些明显的形态学特征，如收缩和起泡。将CASP-3基因导入MCF-7细胞导致TNF处理后的DNA断裂和细胞起泡。这些结果表明，尽管caspase-3对于TNF-或staurosporine诱导的细胞凋亡不是必需的，但它是发生细胞凋亡的DNA断裂和一些典型形态学变化所必需的。
Interleukin 1 beta-converting enzyme-like proteases (caspases) are crucial components of cell death pathways. Among the caspases identified, caspase-3 stands out because it is commonly activated by numerous death signals and cleaves a variety of important cellular proteins. Studies in caspase-3 knock-out mice have shown that this protease is essential for brain development. To investigate the requirement for caspase-3 in apoptosis, we took advantage of the MCF-7 breast carcinoma cell line, which we show here has lost caspase-3 owing to a 47-base pair deletion within exon 3 of the CASP-3 gene. This deletion results in the skipping of exon 3 during pre-mRNA splicing, thereby abrogating translation of the CASP-3 mRNA. Although MCF-7 cells were still. sensitive to tumor necrosis factor (TNF)- or staurosporine-induced apoptosis, no DNA fragmentation was observed. In addition, MCF-7 cells undergoing cell death did not display some of the distinct morphological features typical of apoptotic cells such as shrinkage and blebbing. Introduction of the CASP-3 gene into MCF-7 cells resulted in DNA fragmentation and cellular blebbing following TNF treatment. These results indicate that although caspase-3 is not essential for TNF- or staurosporine-induced apoptosis, it is required for DNA fragmentation and some of the typical morphological changes of cells undergoing apoptosis.