Positive and negative phosphorylation regulates RIP1- and RIP3-induced programmed necrosis.
Positive and negative phosphorylation regulates RIP1- and RIP3-induced programmed necrosis.
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DOI：
10.1042/bj20130860
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发表时间：
2013-12-15
期刊：
影响因子：
--
通讯作者：
Chan FK
中科院分区：
文献类型：
--
作者：
McQuade T;Cho Y;Chan FK
程序性坏死或坏死性凋亡由两种丝氨酸/苏氨酸激酶，受体相互作用蛋白激酶1（RIP 1）和RIP 3的作用控制。RIP 1和RIP 3的磷酸化对于坏死体的组装至关重要，坏死体是一种淀粉样复合物，其启动促坏死信号的传递。在这里，我们使用定点突变系统地研究了假定的磷受体位点对RIP 1和RIP 3对TNF诱导的程序性坏死的影响。我们发现RIP 1激酶结构域中单个丝氨酸残基的突变对RIP 1激酶活性和TNF诱导的程序性坏死几乎没有影响。令人惊讶的是，Ser 89的丙氨酸取代增强了RIP 1激酶活性和TNF诱导的程序性坏死，而不影响RIP 1-RIP 3坏死体的形成。这表明Ser 89是一个抑制性磷酸受体位点，可以抑制RIP 1的促坏死功能。此外，我们还发现RIP 3的一个磷酸模拟突变体S204 D导致了程序性坏死，而RIP 1 siRNA对程序性坏死不敏感，对necrostatin-1抑制不敏感。我们的研究结果表明，程序性坏死是由积极和抑制磷酸化事件。
Programmed necrosis or necroptosis is controlled by the action of two serine/threonine kinases, receptor interacting protein kinase 1 (RIP1) and RIP3. The phosphorylation of RIP1 and RIP3 is critical for assembly of the necrosome, an amyloid-like complex that initiates transmission of the pro-necrotic signal. Here, we used site-directed mutagenesis to systematically examine the effects of putative phosphor acceptor sites on RIP1 and RIP3 on TNF-induced programmed necrosis. We found that mutation of individual serine residues in the kinase domain of RIP1 had little effects on RIP1 kinase activity and TNF-induced programmed necrosis. Surprisingly, alanine substitution of Ser89 enhanced RIP1 kinase activity and TNF-induced programmed necrosis without affecting RIP1-RIP3 necrosome formation. This indicates that Ser89 is an inhibitory phospho-acceptor site that can dampen the pro-necrotic function of RIP1. In addition, we show that a phosphor-mimetic mutant of RIP3, S204D, led to programmed necrosis that was refractory to RIP1 siRNA and insensitive to necrostatin-1 inhibition. Our results show that programmed necrosis is regulated by positive and inhibitory phosphorylation events.