Investigating mechanisms of neuronal growth and synapse formation

神经细胞(神经元)之间神经元连接(突触)的形成是神经系统的一个基本标志。突触对大脑功能至关重要，因为它们调节认知过程。突触是通过信号分子的协调作用形成的，这些信号分子进行结构和功能的变化，以促进生长和成熟。我们的长期目标是发现调控哺乳动物突触形成的新信号机制，以更好地了解神经系统是如何发育的。通常，在一条信号通路中，只研究给定蛋白质的单一异构体。然而，蛋白质可以有多种不同的亚型，在神经元中具有非常不同的活动。因此，我们对同一蛋白质家族的不同异构体是否有不同或相似的信号网络的理解还很不发达。这些知识将加强我们对神经系统发育的基本理解。因此，在短期内，我们正在研究具有多种异构体的STE蛋白家族中的一个成员，这些成员在突触发育过程中研究得很少，以确定异构体特异性的信号机制。我们先前对STE家族成员一千零一个氨基酸2(TAOK2)的研究表明，缺乏TAOK2的小鼠在皮质兴奋性突触中存在结构和功能缺陷。然而，TAOK2有两种主要的蛋白质亚型(α和β)，但这些亚型何时以及如何调控突触发育、成熟和可塑性的细节尚不清楚。我们已经开发了蛋白质组学试剂来研究这个问题，并使用BioID(一种筛选蛋白质-蛋白质相互作用的方法)确定每个TAOK2亚型的结合伙伴。我们将使用蛋白质组数据结合我们的TAOK2小鼠模型进行功能研究，以了解新的TAOK2异构体特异性信号通路如何调控突触发育。我们的功能研究包括使用最先进的方法，包括对单个神经元进行电生理学，以及使用新的多电极阵列技术对神经元群体进行电生理学。我们的计划将解决以前的限制，并提供新的机制洞察如何蛋白激酶调节突触发育。新的和无偏见的蛋白质组技术将揭示一个具有多种异构体的激酶如何控制突触形成和成熟的不同方面的未知细节。如果我们成功，我们未来的计划将对其他突触蛋白进行特定形式的蛋白质组学和功能验证实验，包括新的TAOK2相互作用蛋白，这将显著促进我们对神经元信号转导的基本理解。最后，我们的计划将利用新兴和最先进的实验方法，包括分子和细胞生物学、蛋白质组学、生物化学、基因编辑和电生理学，为HQP提供一个尖端和动态的培训环境。

The formation of neuronal connections (synapses) between nerve cells (neurons) is a fundamental hallmark in the nervous system. Synapses are critical for brain function as they mediate cognitive processes. Synapses form by the coordinated actions of signaling molecules that carryout structural and functional changes to promote growth and maturation. Our long-term goal is to uncover novel signaling mechanisms regulating mammalian synapse formation, to better understand how the nervous system develops. Typically, only a single isoform of a given protein is studied within a signaling pathway. However, proteins can have multiple isoforms that have very different activities in neurons. Therefore, our understanding of whether different isoforms of the same protein family have distinct or similar signaling networks is significantly under developed. This knowledge would strenghthen our basic understanding of nervous system development . Therefore in the short term, we are studying a member of the Ste family of kinases with multiple isoforms that have been poorly studied during synapse development, to identify isoform-specific signaling mechanisms. Our previously work on the Ste family member, thousand and one amino acid 2 (TAOK2) revealed that mice lacking TAOK2 have structural and functional defects in cortical excitatory synapses. However, TAOK2 has two predominant protein isoforms (alpha and beta), but the details of when and how these isoforms regulate synapse development, maturation and plasticity are unknown. We have generated proteomics reagents to study this problem and identify binding partners of each TAOK2 isoform using BioID, a method for screening protein-protein interactions. We will use proteomic data in combination with our TAOK2 mouse model to perform functional studies to understand how the novel TAOK2 isoform-specific signaling pathways regulate synapse development. Our functional studies include the use of state-of-the-art approaches including electrophysiology on individual neurons, and electrophysiology on populations of neurons with new multielectrode array technology. Our program will address previous limitations and provide novel mechanistic insight into how kinases regulate synapse development. The novel and unbiased proteomic techniques will reveal unappreciated details into how a kinase with multiple isoforms controls different aspects of synapse formation and maturation. If we are successful, our future program will perform isoform-specific proteomics and functional validation experiments on other synaptic proteins, including the novel TAOK2-interacting proteins, which will significantly advance our fundamental understanding of neuronal signaling. Lastly, our program will make use of emerging and state-of-the-art experimental approaches including molecular and cellular biology, proteomics, biochemistry, gene editing and electrophysiology, providing HQP a cutting-edge and dynamic training environment.