受体相互作用丝氨酸/苏氨酸蛋白激酶 1 (RIPK1) 是一种胞质蛋白激酶,可调节多种炎症和细胞死亡途径。已知 RIPK1 的丝氨酸/苏氨酸磷酸化在炎症、感染和胚胎发生的背景下抑制 RIPK1 激酶介导的细胞死亡,但是,酪氨酸磷酸化的调节尚未见报道。在这里,我们表明非受体酪氨酸激酶 Janus 激酶 1 (JAK1) 和 SRC 能够在 Y384(小鼠 RIPK1 中的 Y383)磷酸化 RIPK1,从而抑制 TNF 诱导的细胞死亡。携带纯合 Ripk1 突变的小鼠会阻止 RIPK1 (Ripk1Y383F/Y383F) 的酪氨酸磷酸化,从而发展为全身炎症和紧急造血功能。从机械上讲,Ripk1Y383F/Y383F 突变促进 RIPK1 激酶激活并增强 TNF 诱导的细胞凋亡和坏死性凋亡,这部分是由于 MAP 激酶活化蛋白激酶 2 (MK2) 的募集和激活受损。Ripk1Y383F/Y383F 小鼠的全身炎症和紧急造血功能在很大程度上通过 RIPK1 激酶抑制得到缓解,并通过针对上游通路(同时针对肿瘤坏死因子受体 1 或 RIPK3 和半胱天冬酶 8)的基因组缺失来预防。总之,我们的结果表明 RIPK1 的酪氨酸磷酸化对于调节 RIPK1 活性以限制细胞死亡和炎症至关重要。Ripk1Y383F/Y383F 小鼠的全身炎症和紧急造血功能在很大程度上通过 RIPK1 激酶抑制得到缓解,并通过针对上游通路(同时针对肿瘤坏死因子受体 1 或 RIPK3 和半胱天冬酶 8)的基因组缺失来预防。总之,我们的结果表明 RIPK1 的酪氨酸磷酸化对于调节 RIPK1 活性以限制细胞死亡和炎症至关重要。Ripk1Y383F/Y383F 小鼠的全身炎症和紧急造血功能在很大程度上通过 RIPK1 激酶抑制得到缓解,并通过针对上游通路(同时针对肿瘤坏死因子受体 1 或 RIPK3 和半胱天冬酶 8)的基因组缺失来预防。总之,我们的结果表明 RIPK1 的酪氨酸磷酸化对于调节 RIPK1 活性以限制细胞死亡和炎症至关重要。
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Tyrosine phosphorylation regulates RIPK1 activity to limit cell death and inflammation
Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a cytosolic protein kinase that regulates multiple inflammatory and cell death pathways. Serine/Threonine phosphorylation of RIPK1 is known to suppress RIPK1 kinase-mediated cell death in the contexts of inflammation, infection and embryogenesis, however, regulation by tyrosine phosphorylation has not been reported. Here, we show that non-receptor tyrosine kinases Janus kinase 1 (JAK1) and SRC are able to phosphorylate RIPK1 at Y384 (Y383 in murine RIPK1), leading to suppression of TNF-induced cell death. Mice bearing a homozygous Ripk1 mutation that prevents tyrosine phosphorylation of RIPK1 (Ripk1Y383F/Y383F), develop systemic inflammation and emergency haematopoiesis. Mechanistically, Ripk1Y383F/Y383F mutation promotes RIPK1 kinase activation and enhances TNF-induced apoptosis and necroptosis, which is partially due to impaired recruitment and activation of MAP kinase-activated protein kinase 2 (MK2). The systemic inflammation and emergency haematopoiesis in Ripk1Y383F/Y383F mice are largely alleviated by RIPK1 kinase inhibition, and prevented by genomic deletions targeted to the upstream pathway (either to Tumor necrosis factor receptor 1 or RIPK3 and Caspase8 simultaneously). In summary, our results demonstrate that tyrosine phosphorylation of RIPK1 is critical for regulating RIPK1 activity to limit cell death and inflammation.