MAP2-mediated in vitro interactions of brain microtubules and their modulation by cAMP.
MAP2-mediated in vitro interactions of brain microtubules and their modulation by cAMP.
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MAP2 介导的脑微管体外相互作用及其 cAMP 的调节。
DOI：
10.1007/s00249-008-0381-1
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Janmey,PA
中科院分区：
文献类型：
--
作者：
Leterrier,JF;Kurachi,M;Tashiro,T;Janmey,PA
微管相关蛋白（MAPs）参与微管（MT）的结合以及MT与其他细胞器之间的桥接。以往的研究将map的MT捆绑功能定位于它们的MT结合域，并通过投影域对其进行调制。在本工作中，我们分析了在cAMP存在或不存在的情况下MT悬浮液的粘弹性特性。实验数据揭示了包含MAP2和cAMP调控的MT聚合物之间相互作用的发生。cAMP的两种不同的作用机制被确定，其中一方面涉及与MAP2 n端投射末端结合的cAMP依赖性蛋白激酶A （PKA）对MT蛋白的磷酸化，另一方面cAMP与PKA的RII亚基的结合以磷酸化不依赖的方式影响MT之间的相互作用。这些发现暗示了PKA与MAP2投射域复合物在MT - MT相互作用中的作用，并表明cAMP可能直接影响神经元树突中MT阵列的密度和捆绑。
Microtubule-associated proteins (MAPs) are involved in microtubule (MT) bundling and in crossbridges between MTs and other organelles. Previous studies have assigned the MT bundling function of MAPs to their MT-binding domain and its modulation by the projection domain. In the present work, we analyse the viscoelastic properties of MT suspensions in the presence or the absence of cAMP. The experimental data reveal the occurrence of interactions between MT polymers involving MAP2 and modulated by cAMP. Two distinct mechanisms of action of cAMP are identified, which involve on one hand the phosphorylation of MT proteins by the cAMP-dependent protein kinase A (PKA) bound to the end of the N-terminal projection of MAP2, and on the other hand the binding of cAMP to the RII subunit of the PKA affecting interactions between MTs in a phosphorylation-independent manner. These findings imply a role for the complex of PKA with the projection domain of MAP2 in MT–MT interactions and suggest that cAMP may influence directly the density and bundling of MT arrays in dendrites of neurons.