Evidence of Presynaptic Localization and Function of the c-Jun N-Terminal Kinase
Evidence of Presynaptic Localization and Function of the c-Jun N-Terminal Kinase
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DOI：
10.1155/2017/6468356
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发表时间：
2017-01-01
影响因子：
3.1
通讯作者：
Borsello, Tiziana
中科院分区：
文献类型：
--
作者：
Biggi, Silvia;Buccarello, Lucia;Borsello, Tiziana
C-Jun氨基末端激酶(JNK)是受NMDA刺激强烈激活的应激信号通路的一部分，参与突触的可塑性。许多研究都集中在JNK的突触后作用机制上，而对JNK突触前定位及其在该部位的生理作用知之甚少。在这里，我们研究了JNK是否存在于突触前部位，以及它在突触前NMDA受体刺激后的活动。通过N-SIM结构的超分辨显微镜和生化方法，我们证明了突触前部分含有大量的JNK蛋白及其激活形式。通过模型设计，我们发现JNK通过JBD结构域对T-SNARE蛋白起到生理效应；然后用生化方法证明了Synaxin-1-JNK、Synaxin-2-JNK和Snap25-JNK之间的相互作用。此外，利用JNK的特异性抑制肽D-JNKI1，我们确定了JNK在SNARE复合体形成中的作用。最后，电生理记录证实了JNK在突触前调节囊泡释放中的作用。这些数据表明，JNK依赖的T-SNARE蛋白的磷酸化可能在突触可塑性中发挥重要的功能作用。
The c-Jun N-terminal kinase (JNK) is part of a stress signalling pathway strongly activated by NMDA-stimulation and involved in synaptic plasticity. Many studies have been focused on the post-synaptic mechanism of JNK action, and less is known about JNK presynaptic localization and its physiological role at this site. Here we examined whether JNK is present at the presynaptic site and its activity after presynaptic NMDA receptors stimulation. By using N-SIM Structured Super Resolution Microscopy as well as biochemical approaches, we demonstrated that presynaptic fractions contained significant amount of JNK protein and its activated form. By means of modelling design, we found that JNK, via the JBD domain, acts as a physiological effector on T-SNARE proteins; then using biochemical approaches we demonstrated the interaction between Syntaxin-1-JNK, Syntaxin-2-JNK, and Snap25-JNK. In addition, taking advance of the specific JNK inhibitor peptide, D-JNKI1, we defined JNK action on the SNARE complex formation. Finally, electrophysiological recordings confirmed the role of JNK in the presynaptic modulation of vesicle release. These data suggest that JNK-dependent phosphorylation of T-SNARE proteins may have an important functional role in synaptic plasticity.