JNK-dependent phosphorylation of c-Jun on serine 63 mediates nitric oxide-induced apoptosis of neuroblastoma cells
JNK-dependent phosphorylation of c-Jun on serine 63 mediates nitric oxide-induced apoptosis of neuroblastoma cells
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DOI：
10.1074/jbc.m310415200
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发表时间：
2004-02-06
影响因子：
4.8
通讯作者：
Porter, AG
中科院分区：
文献类型：
--
作者：
Li, L;Feng, ZW;Porter, AG
C-jun氨基末端激酶(JNKs)通过磷酸化丝氨酸63和73来增强c-jun的转录活性。此外，JNK和c-Jun还可以调节细胞凋亡。然而，一氧化氮(NO)诱导的c-jun在Ser-63和Ser-73上的磷酸化在细胞凋亡中的作用尚未被探讨。我们报道，在SH-SY5Y神经母细胞瘤细胞中，NO在JNK活化和c-Jun磷酸化后诱导细胞凋亡，几乎完全是在Ser-63上。重要的是，在稳定转化显性负性c-jun的细胞中，Ser-63突变为丙氨酸(S63A)的细胞中，NO诱导的细胞凋亡和caspase-3活性受到抑制，而在显性负性c-jun(S73A)转化的细胞中，NO诱导的细胞凋亡和caspase-3活性没有受到抑制。C-Jun的Ser-63(但不是Ser-73)是NO诱导的c-Jun依赖的转录活动所必需的。在显性阴性JNK转化的SH-SY5Y细胞中，NO诱导的细胞凋亡、c-Jun的Ser-63磷酸化和caspase-3活性均受到抑制。Caspase-3抑制剂可阻止细胞凋亡，但不能阻止c-jun的磷酸化。在不同的神经母细胞瘤细胞系中，NO诱导的c-Jun的Ser-63磷酸化和细胞凋亡可被JNK特异性抑制剂阻断。我们认为，神经母细胞瘤细胞中NO诱导的细胞凋亡是由caspase-3激活上游的JNK依赖的丝氨酸蛋白-63磷酸化所介导的。
c-Jun NH2-terminal kinases (JNKs) potentiate transcriptional activity of c-Jun by phosphorylating serines 63 and 73. Moreover, JNK and c-Jun can modulate apoptosis. However, an involvement of nitric oxide (NO)induced phosphorylation of c-Jun on Ser-63 and Ser-73 in apoptosis has not been explored. We report that in SH-Sy5y neuroblastoma cells, NO induced apoptosis following JNK activation and phosphorylation of c-Jun almost exclusively on Ser-63. Importantly, NO-induced apoptosis and caspase-3 activity were inhibited in cells stably transformed with dominant-negative c-Jun in which Ser-63 is mutated to alanine (S63A), but not in cells transformed with dominant-negative c-Jun (S73A). Ser-63 of c-Jun (but not Ser-73) was required for NO-induced, c-Jun-dependent transcriptional activity. NO-induced apoptosis, Ser-63 phosphorylation of c-Jun, and caspase-3 activity were all inhibited in SH-Sy5y cells transformed with dominant-negative jnk. A caspase-3 inhibitor prevented apoptosis but not c-Jun phosphorylation. In a different neuroblastoma cell line, NO-induced Ser-63 phosphorylation of c-Jun and apoptosis were blocked by a specific JNK inhibitor. We conclude that NO-inducible apoptosis is mediated by JNK-dependent Ser-63 phosphorylation of c-Jun upstream of caspase-3 activation in neuroblastoma cells.