Richter B W, Duckett C S
Division of Clinical Sciences, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
Sci STKE. 2000 Aug 8;2000(44):pe1. doi: 10.1126/stke.2000.44.pe1.
Apoptosis, or programmed cell death, occurs as an outcome of signals that direct cells to perish. Whether initiated by specifically activated receptors or induced through viral infection, apoptosis is an important means by which organisms maintain health and homeostasis. The apoptotic pathway uses several regulatory proteins that prevent uncontrolled cell death, which would be detrimental to the organism. Richter and Duckett review the recently discovered and characterized inhibitors of apoptosis proteins (IAPs). Not surprisingly, IAPs were first identified in viruses that were able to subvert apoptosis in infected cells. Evidence exists suggesting that, in addition to inhibiting apoptosis, IAPs are involved in signal transduction and cell cycle regulation. Richter and Duckett also review other recent observations indicating that some IAPs may have roles in protein ubiquitination. Although the various roles of the IAPs are beginning to be uncovered, new questions arise about the breadth of their functions and the proteins to which IAPs bind.
细胞凋亡，即程序性细胞死亡，是由引导细胞死亡的信号所导致的结果。无论是由特异性激活的受体引发，还是通过病毒感染诱导，细胞凋亡都是生物体维持健康和体内平衡的重要方式。细胞凋亡途径利用多种调节蛋白来防止细胞不受控制地死亡，这种不受控制的死亡对生物体是有害的。里希特和达克特综述了最近发现并鉴定的凋亡抑制蛋白（IAPs）。不出所料，IAPs最初是在能够在受感染细胞中破坏细胞凋亡的病毒中被发现的。有证据表明，除了抑制细胞凋亡外，IAPs还参与信号转导和细胞周期调控。里希特和达克特还综述了其他最近的观察结果，表明一些IAPs可能在蛋白质泛素化中发挥作用。尽管IAPs的各种作用开始被揭示，但关于其功能的广度以及IAPs所结合的蛋白质又出现了新的问题。
