Inhibitor specificity of recombinant and endogenous caspase-9.
Inhibitor specificity of recombinant and endogenous caspase-9.
复制标题
重组和内源 caspase-9 的抑制剂特异性。
DOI：
10.1042/bj20020863
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
Salvesen,GuyS
中科院分区：
文献类型：
--
作者：
Ryan,CiaraA;Stennicke,HenningR;Nava,VictorE;Burch,JenniferB;Hardwick,JMarie;Salvesen,GuyS
辐射和抗肿瘤药物通过内在途径引发的细胞凋亡是由caspase-9的激活引发的。为了阐明这一途径的控制机制，我们使用了一系列合成和天然试剂。acetyl- asp - glul - val - asp -aldehyde (Ac-DEVD-CHO)， benzyloxycarbonyl- val - ala - asp - fluorom甲基酮（Z-VAD-FMK）和endogenous caspase inhibitor - x - chromolinked inhibitor of apoptosis protein （XIAP）对重组caspase-9的抑制效力预测了这些化合物在无细胞系统中的作用。然而，病毒蛋白CrmA和p35虽然是重组caspase-9的有效抑制剂，但在该系统中几乎没有阻断caspase-9的能力。这些发现也反映在细胞表达研究中。我们假设病毒抑制剂CrmA和p35不能在体内与天然形式的活性caspase-9产生有效反应，这使得抑制剂的效力高度依赖于环境。由表达p35或caspase-9催化突变体的Sindbis病毒驱动的小鼠凋亡模型的存活数据支持了这一点。这些结果巩固了先前的研究结果，即CrmA在体外是caspase-9的有效抑制剂，但不能阻断caspase-9介导的细胞死亡。
Apoptosis triggered through the intrinsic pathway by radiation and anti-neoplastic drugs is initiated by the activation of caspase-9. To elucidate control mechanisms in this pathway we used a range of synthetic and natural reagents. The inhibitory potency of acetyl-Asp-Glu-Val-Asp-aldehyde ('Ac-DEVD-CHO'), benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone ('Z-VAD-FMK') and the endogenous caspase inhibitor X-chromosome-linked inhibitor of apoptosis protein ('XIAP') against recombinant caspase-9 were predictive of the efficacy of these compounds in a cell-free system. However, the viral proteins CrmA and p35, although potent inhibitors of recombinant caspase-9, had almost no ability to block caspase-9 in this system. These findings were also mirrored in cell expression studies. We hypothesize that the viral inhibitors CrmA and p35 are excluded from reacting productively with the natural form of active caspase-9in vivo, making the potency of inhibitors highly context-dependent. This is supported by survival data from a mouse model of apoptosis driven by Sindbis virus expressing either p35 or a catalytic mutant of caspase-9. These results consolidate previous findings that CrmA is a potent inhibitor of caspase-9in vitro, yet fails to block caspase-9-mediated cell death.