Dynein-Dynactin Complex Mediated Retrograde Transport during Long-term Memory Storage

摘要 长时记忆(LTM)的存储需要对先前存在的突触进行重塑，并形成新的 一个。虽然转录和突触蛋白合成在这些过程中的作用得到了很好的描述， 对于核和突触过程在LTM存储过程中是如何协调的，人们知之甚少。我们 之前已经证明了激动素，一种调节细胞核之间通讯的分子马达 而突触通过微管依赖的基因产物的运输，在这一过程中起着关键作用。 虽然这些研究确定了顺行运输在学习和记忆存储中的作用，但 学习过程中逆行运输的作用尚不清楚。了解逆行运输将有所帮助 阐明从突触到细胞体的分子通讯，从而提供更深层次的 了解LTM的形成和储存。基于我们的基因组学、蛋白质组学、基因表达和生命 细胞成像实验在初步结果部分描述，我们的中心假设是存储 LTM要求对逆行运输机械的部件进行管理，包括在 突触神经元。在这里，我们集中在两个已知的蛋白质复合体的调节。 逆行转运：动力蛋白运动复合体，包含动力蛋白重链(DHC)、中间链 (DIC)、轻中间链(DLIC)和轻链(DLC)；以及动力蛋白复合体，由23 具有dynactin 1(p150胶合)的蛋白质作为dynactin功能的关键介质。探索优势 对于已识别的神经元和确定的突触连接，我们将测试我们的 评估假说：(1)5-羟色胺对动力蛋白-动力蛋白机械各组成部分表达的调节 (5-羟色胺)，一种对海兔学习很重要的调节性神经递质；(2)定量活细胞成像 货物和动力运输机械；(3)前和后5HT调节部件的必要性和充分性 鳃收缩反射的突触后神经元；(4)局部翻译在调节逆行运输中的作用 以及(5)阐明由动力蛋白运输机械从突触运输货物的分子性质。 我们预计这些研究将是开创性的，因为人们对动力蛋白的作用知之甚少。 LTM中的动力蛋白复合体。这些研究的成功完成预计将产生重大的积极影响 对潜在活动机制的影响，调节了记忆的逆行运输和生物学。

SUMMARY Long-term memory (LTM) storage requires remodeling of pre-existing synapses and formation of new ones. While the roles of transcription and synaptic protein synthesis in these processes are well described, relatively little is known about how nuclear and synaptic processes are coordinated during LTM storage. We have previously shown that kinesin, the molecular motor that mediates communication between the nucleus and synapses through the microtubule-dependent transport of gene products, has a key role in this process. While these studies established the role of anterograde transport during learning and memory storage, the contribution of retrograde transport during learning is unknown. Understanding retrograde transport will help elucidate the molecular communication from the synapse to the cell body and thus provide a deeper understanding of LTM formation and storage. Based on our genomics, proteomics, gene expression and live cell-imaging experiments described in the preliminary results section, our central hypothesis is that storage of LTM requires regulation of components of the retrograde transport machinery in both pre- and post- synaptic neurons. Here, we focus on the regulation of two protein complexes that are known to mediate retrograde transport: the dynein motor complex, which contains dynein heavy chain (DHC), intermediate chain (DIC), light intermediate chain (DLIC), and light chain (DLC); and the dynactin complex which consists of 23 proteins with dynactin 1 (p150glued) acting as a critical mediator of dynactin function. Exploring the advantages of identified neurons and defined synaptic connections of the sea slug Aplysia californica, we will test our hypothesis by assessing (1) regulation of expression of components of dynein-dynactin machinery by 5HT (serotonin), a modulatory neurotransmitter important for learning in Aplysia; (2) quantitative live cell imaging of cargo and dynein transport machinery; (3) necessity and sufficiency of 5HT regulated components in pre- and post-synaptic neurons of gill withdrawal reflex; (4) role of local translation in modulating retrograde transport and (5) elucidate the molecular nature of cargos transported from the synapses by dynein transport machinery. We anticipate that these studies will be ground breaking because little is known about the role of dynein- dynactin complexes in LTM. Successful completion of these studies is expected to have a major positive impact on mechanisms underlying activity regulated retrograde transport and biology of memory.