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

总结 长期记忆（LTM）存储需要重塑预先存在的突触和形成新的突触。 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， 关于核和突触过程在LTM存储期间如何协调的了解相对较少。我们 先前已经表明，驱动蛋白，介导细胞核之间的通信的分子马达， 和突触通过微管依赖的基因产物的运输，在这一过程中具有关键作用。 虽然这些研究确立了顺行运输在学习和记忆储存过程中的作用， 逆行运输在学习过程中的贡献是未知的。了解逆行运输将有助于 阐明了从突触到细胞体的分子通讯，从而提供了更深层次的 了解LTM的形成和储存。基于我们的基因组学，蛋白质组学，基因表达和活 在初步结果部分描述的细胞成像实验中，我们的中心假设是， 的LTM需要调节组件的逆行运输机械在前和后， 突触神经元在这里，我们专注于调节两个蛋白质复合物，已知介导 逆行转运：动力蛋白运动复合体，其中包含动力蛋白重链（DHC）、中间链（DHC）、 (DIC)、轻中间链（DLIC）和轻链（DLC）;以及动力肌动蛋白复合物，其由23个 与动力蛋白1（p150胶合）一起作为动力蛋白功能的关键介质的蛋白质。探索优势 已识别的神经元和定义的突触连接的海蛞蝓，我们将测试我们的 通过评估（1）5 HT对动力蛋白-动力肌动蛋白机制组分表达的调节 （5-羟色胺），一种对学习很重要的调节性神经递质;（2）定量活细胞成像 货物和动力蛋白运输机械;（3）5 HT管制组件的必要性和充分性， 鳃回缩反射突触后神经元;（4）局部翻译在逆向转运调节中的作用 （5）阐明动力蛋白转运机制从突触转运的物质的分子本质。 我们预计这些研究将是开创性的，因为我们对动力蛋白的作用知之甚少。 动态肌动蛋白复合物。这些研究的顺利完成预计将产生重大的积极影响 对活动调节逆行运输和记忆生物学的潜在机制的影响。

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.