Phosphorylation of zipcode binding protein 1 is required for brain-derived neurotrophic factor signaling of local beta-actin synthesis and growth cone turning.
Phosphorylation of zipcode binding protein 1 is required for brain-derived neurotrophic factor signaling of local beta-actin synthesis and growth cone turning.
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DOI：
10.1523/jneurosci.0499-10.2010
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发表时间：
2010-07-14
期刊：
影响因子：
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通讯作者：
Bassell GJ
中科院分区：
文献类型：
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作者：
Sasaki Y;Welshhans K;Wen Z;Yao J;Xu M;Goshima Y;Zheng JQ;Bassell GJ
特定mrna的定位及其在发育中的轴突生长锥中的局部翻译已被证明在调节生长锥对吸引或排斥信号的反应中起重要作用。然而，局部翻译和生长锥转向可能由特定mrna结合蛋白控制的机制尚不清楚。在这里，我们证明脑源性神经营养因子（BDNF）指示src依赖的β-肌动蛋白mRNA zipcode结合蛋白1 （ZBP1）的磷酸化，这是β-肌动蛋白合成和生长锥转向所必需的。我们针对Src磷酸化位点Tyr396构建了磷酸化特异性ZBP1抗体，该抗体显示BDNF诱导生长锥内ZBP1磷酸化。bdnf诱导的具有β-actin 3'UTR的GFP翻译报告蛋白荧光信号的增加被Src家族激酶特异性抑制剂PP2减弱。此外，一个不可磷酸化的突变体ZBP1 Y396F抑制了bdnf诱导的和蛋白质合成依赖的生长锥中β-肌动蛋白定位的增加。最后，ZBP1 Y396F突变体阻断了bdnf诱导的有吸引力的生长锥转向。这些结果表明，生长锥内ZBP1 Tyr396位点的磷酸化在调节局部蛋白合成和生长锥转向中起着关键作用。我们的发现为mrna结合蛋白的磷酸化调控如何影响生长锥运动和轴突引导的局部翻译提供了新的见解。
The localization of specific mRNAs and their local translation in growth cones of developing axons has been shown to play an important mechanism to regulate growth cone turning responses to attractive or repulsive cues. However, the mechanism whereby local translation and growth cone turning may be controlled by specific mRNA-binding proteins is unknown. Here we demonstrate that brain-derived neurotrophic factor (BDNF) signals the Src-dependent phosphorylation of the β-actin mRNA zipcode binding protein 1 (ZBP1), which is necessary for β-actin synthesis and growth cone turning. We raised a phospho-specific ZBP1 antibody to Tyr396, which is a Src phosphorylation site, and this antibody revealed BDNF induced phosphorylation of ZBP1 within growth cones. The BDNF-induced increase in fluorescent signal of a GFP translation reporter with the 3’UTR of β-actin was attenuated with the Src family kinase-specific inhibitor, PP2. Furthermore, a non-phosphorylatable mutant, ZBP1 Y396F, suppressed the BDNF-induced and protein synthesis-dependent increase in β-actin localization in growth cones. Lastly, the ZBP1 Y396F mutant blocked BDNF-induced attractive growth cone turning. These results indicate that phosphorylation of ZBP1 at Tyr396 within growth cones has a critical role to regulate local protein synthesis and growth cone turning. Our findings provide new insight into how the regulated phosphorylation of mRNA-binding proteins influences local translation underlying growth cone motility and axon guidance.