Targeted mutation of serine 697 in the Ret tyrosine kinase causes migration defect of enteric neural crest cells
Targeted mutation of serine 697 in the Ret tyrosine kinase causes migration defect of enteric neural crest cells
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DOI：
10.1242/dev.02616
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发表时间：
2006-11-15
期刊：
影响因子：
4.6
通讯作者：
Costantini, Frank
中科院分区：
文献类型：
--
作者：
Asai, Naoya;Fukuda, Toshifumi;Costantini, Frank
RET 受体酪氨酸激酶在肠神经系统 (ENS) 和肾脏的发育中发挥着关键作用。在胶质细胞源性神经营养因子 (GDNF) 刺激下，RET 可以激活多种细胞内信号，包括 Ras/丝裂原激活蛋白激酶、磷脂酰肌醇 3-激酶 (PI3K)/AKT 和 RAC1/JUN NH2 末端激酶 (JNK) 通路。我们最近证明，RAC1/JNK 通路受 RET 近膜区丝氨酸磷酸化的调节，且以 cAMP 依赖性方式进行。确定 cAMP 依赖性 modi 的重要性。为了体内 RET 信号的阳离子，我们产生了突变小鼠，其中丝氨酸残基 697（推定的蛋白激酶 A (PKA) 磷酸化位点）被丙氨酸取代（指定为 S697A 小鼠）。纯合子 S697A 突变小鼠在远端结肠中缺乏 ENS，这是由于肠神经嵴细胞 (ENCC) 的迁移缺陷造成的。体外器官培养显示突变型 ENCC 对 GDNF 的趋化反应受损。在来自突变小鼠的神经元中，GDNF 激活的 JNK 显着减少，而 ERK、AKT 和 SRC 激活则不然。 JNK 抑制剂 SP600125 和 PKA 抑制剂 KT5720 对野生型小鼠培养肠道中 ENCC 的迁移抑制程度相当。因此，这些发现表明 cAMP 依赖性 modi。 RET 功能的阳离子调节 JNK 信号传导，负责 ENCC 在发育中肠道的正确迁移。
The RET receptor tyrosine kinase plays a critical role in the development of the enteric nervous system (ENS) and the kidney. Upon glial-cell-line-derived neurotrophic factor (GDNF) stimulation, RET can activate a variety of intracellular signals, including the Ras/mitogen-activated protein kinase, phosphatidylinositol 3-kinase (PI3K)/AKT, and RAC1/JUN NH2-terminal kinase (JNK) pathways. We recently demonstrated that the RAC1/JNK pathway is regulated by serine phosphorylation at the juxtamembrane region of RET in a cAMP-dependent manner. To determine the importance of cAMP-dependent modi. cation of the RET signal in vivo, we generated mutant mice in which serine residue 697, a putative protein kinase A (PKA) phosphorylation site, was replaced with alanine (designated S697A mice). Homozygous S697A mutant mice lacked the ENS in the distal colon, resulting from a migration defect of enteric neural crest cells (ENCCs). In vitro organ culture showed an impaired chemoattractant response of the mutant ENCCs to GDNF. JNK activation by GDNF but not ERK, AKT and SRC activation was markedly reduced in neurons derived from the mutant mice. The JNK inhibitor SP600125 and the PKA inhibitor KT5720 suppressed migration of the ENCCs in cultured guts from wild-type mice to comparable degrees. Thus, these findings indicated that cAMP-dependent modi. cation of RET function regulates the JNK signaling responsible for proper migration of the ENCCs in the developing gut.