Role of poly(ADP-ribose) polymerase (PARP) cleavage in apoptosis - Caspase 3-resistant PARP mutant increases rates of apoptosis in transfected cells
Role of poly(ADP-ribose) polymerase (PARP) cleavage in apoptosis - Caspase 3-resistant PARP mutant increases rates of apoptosis in transfected cells
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DOI：
10.1074/jbc.274.33.22932
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发表时间：
1999-08-13
影响因子：
4.8
通讯作者：
Smulson, M
中科院分区：
文献类型：
--
作者：
Boulares, AH;Yakovlev, AG;Smulson, M
最近显示核蛋白的聚（ADP-核糖基）化的早期瞬时爆发是在各种细胞系中进行细胞凋亡所必需的（Simbulan-Rosenthal，C.，Rosenthal，D.，伊耶，S.，Boulares，H.，和Smulson，M，（1998）J.Biol.Chem.273，13703-13712），然后裂解聚（ADP-核糖）聚合酶（PARP），由半胱天冬酶-3催化。（PARP底物）和ATP，这被认为是细胞凋亡后期事件所必需的，现在已经在用编码半胱天冬酶-3抗性PARP突变体的载体稳定转染的人骨肉瘤细胞和PARP -/-成纤维细胞中研究了PARP切割在细胞凋亡中的作用。这种突变体PARP的表达增加了星形孢菌素和肿瘤坏死因子-α诱导的细胞凋亡的速率，至少部分是通过减少半胱天冬酶-3活化和核小体间DNA片段化的开始所需的时间间隔，以及产生被认为与早期染色质展开相关的50-β-D-半胱天冬酶对DNA断裂。在骨肉瘤细胞中过表达野生型PARP也加速了凋亡过程，尽管与表达突变型PARP的细胞中明显的程度不同。突变型和野生型酶的这些作用可能是由于响应于DNA断裂的早期和瞬时的聚（ADP-核糖）合成，以及在转染细胞中明显的伴随的NAD耗尽。这些结果表明，PARP激活和随后的切割在凋亡中具有积极和复杂的作用。
An early transient burst of poly(ADP-ribosyl)ation of nuclear proteins was recently shown to be required for apoptosis to proceed in various cell lines (Simbulan-Rosenthal, C., Rosenthal, D., Iyer, S., Boulares, H., and Smulson, M, (1998) J. Biol. Chem. 273, 13703-13712) followed by cleavage of poly(ADP-ribose) polymerase (PARP), catalyzed by caspase-3, This inactivation of PARP has been proposed to prevent depletion of NAD (a PARP substrate) and ATP, which are thought to be required for later events in apoptosis, The role of PARP cleavage in apoptosis has now been investigated in human osteosarcoma cells and PARP -/- fibroblasts stably transfected with a vector encoding a caspase-3-resistant PARP mutant. Expression of this mutant PARP increased the rate of staurosporine and tumor necrosis factor-alpha-induced apoptosis, at least in part by reducing the time interval required for the onset of caspase-3 activation and internucleosomal DNA fragmentation, as well as the generation of 50-kilobase pair DNA breaks, thought to be associated with early chromatin unfolding. Overexpression of wild-type PARP in osteosarcoma cells also accelerated the apoptotic process, although not to the same extent as that apparent in cells expressing the mutant PARP, These effects of the mutant and wild-type enzymes might be due to the early and transient poly(ADP-ribose) synthesis in response to DNA breaks, and the accompanying depletion of NAD apparent in the transfected cells. The accelerated NAD depletion did not seem to interfere with the later stages of apoptosis, These results indicate that PARP activation and subsequent cleavage have active and complex roles in apoptosis.