Regulation of inhibitory synapse function by Neuroligin 2 membrane dynamics, trafficking and phosphorylation

Neuroligin 2 膜动力学、运输和磷酸化对抑制性突触功能的调节

• 批准号: BB/S017496/1
• 负责人: Josef Kittler
• 金额: $ 70.12万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FS017496%2F1
• 关键词: Regulation; inhibitory; synapse; function; Neuroligin

Nerve cells communicate with each other via specialised cell-cell contact sites called synapses. On the presynaptic side the input neuron releases neurotransmitters that activate specialised neurotransmitter receptors located on the receiving neuron at the postsynaptic side. Synapses can have either an excitatory (activating) or an inhibitory (inactivating) role in brain signalling. For the brain to function well, it is important that synapses are formed correctly, i.e. the pre- and postsynaptic side are precisely apposed to each other, and that brain activity is properly regulated. If synapses do not wire correctly during development or go wrong later in life this can lead to devastating neuropsychiatric and neurodegenerative brain disorders like Schizophrenia, autism and Alzheimer's disease, respectively. The protein family of Neuroligins play a key role in synapse formation and maintenance. They are positioned in the membrane of the postsynaptic side and, by binding the protein Neurexin at the presynaptic side, bridge the synaptic cleft. Neuroligin-2 (NL2) is specifically located at the inhibitory synapse, where it induces clustering of the protein gephyrin to form a scaffold. The main inhibitory neurotransmitter receptor of our central nervous system, the GABA-A receptor, is then stabilised at the synapse by gephyrin and LHFPL4. Synapses can change their strength in response to changes in neural activity, an important property for key brain functions such as learning and memory, and for maintaining the balance between excitation and inhibition. The strength of the response at a synapse can be regulated by altering the size of the scaffold and the number of attached neurotransmitter receptors. Through its role in stabilising the synapse, NL2 is likely to be a key regulator of the number of GABA-A receptors in the postsynaptic membrane, and thus of inhibitory synapse strength and information processing in the brain. Little is known, however, about the molecular mechanisms that control NL2 number at the synapse, or its dynamic movement into and out of the synapse.We have initial data suggesting that brain activity causes a change in the amount of NL2 on the cell surface, through its release from the synapse and uptake into the cell (a process called endocytosis). We have also identified a number of novel proteins that interact with NL2 and may be involved with either its stabilisation at the synapse, or regulating whether NL2 taken into the cell is recycled to the synapse or sent for destruction. It is, however, still unknown how brain activity affects these processes, and reciprocally how alterations of NL2 number at the synapse affects its strength. Our research is therefore aimed at answering the following related questions:- Under what physiologically relevant conditions is the stability of NL2 at the synapse altered?- How do the various binding partners of NL2 regulate its stability at the synapse, as well as its endocytosis, recycling and degradation?- How do changes in the amount of NL2 at the synapse affect the strength of the inhibitory synapse?Ultimately, by gaining molecular insight into how inhibitory synapses are formed and regulated, we will better understand how wiring in the brain is controlled. In addition, since synaptic dysfunction is implicated in many neurodegenerative and neuropsychiatric diseases, our proposed work may also lead to an improved understanding of diseases such as epilepsy, stroke, Alzheimer's disease, Huntington's disease and schizophrenia, and may suggest targets for therapeutic intervention. A detailed understanding of the processes that we study for NL2, will also have implications for other Neuroligins, synaptic membrane proteins, and membrane proteins in non-neuronal cells. Thus, our research may contribute to understanding basic cell biological principles as well as specifically how connections in the brain are formed and maintained.

神经细胞通过被称为突触的特殊的细胞间接触点相互交流。在突触前一侧，输入神经元释放神经递质，激活位于突触后一侧接收神经元上的特殊神经递质受体。突触在大脑信号传导中可以起到兴奋（激活）或抑制（灭活）的作用。要使大脑正常工作，重要的是突触的正确形成，即突触前和突触后的两侧精确地相互相对，并且大脑活动得到适当的调节。如果突触在发育过程中连接不正确，或者在以后的生活中出现问题，这可能会导致毁灭性的神经精神疾病和神经退行性大脑疾病，如精神分裂症、自闭症和阿尔茨海默病。神经脂素蛋白家族在突触的形成和维持中起着关键作用。它们位于突触后侧的膜上，通过与突触前侧的Neurexin蛋白结合，在突触间隙上架起桥梁。神经胶质素-2 （NL2）特别位于抑制性突触，在那里它诱导蛋白卟啉聚集形成一个支架。我们中枢神经系统的主要抑制性神经递质受体，GABA-A受体，然后在突触上被葛菲林和LHFPL4稳定。突触可以根据神经活动的变化改变其强度，神经活动是学习和记忆等关键大脑功能的重要特性，也是维持兴奋和抑制之间平衡的重要特性。突触反应的强度可以通过改变支架的大小和附着的神经递质受体的数量来调节。通过其稳定突触的作用，NL2可能是突触后膜中GABA-A受体数量的关键调节因子，从而调节大脑中抑制性突触强度和信息处理。然而，关于控制突触中NL2数量的分子机制，或其进出突触的动态运动，我们知之甚少。我们有初步的数据表明，大脑活动导致细胞表面NL2的数量发生变化，这是通过突触释放NL2并将其摄取到细胞中（这一过程称为内吞作用）。我们还发现了一些与NL2相互作用的新蛋白质，这些蛋白质可能与NL2在突触中的稳定有关，或者调节进入细胞的NL2是被循环到突触还是被送去破坏。然而，大脑活动如何影响这些过程，以及突触中NL2数量的变化如何影响其强度，目前尚不清楚。因此，我们的研究旨在回答以下相关问题：-在什么生理相关条件下突触中NL2的稳定性被改变？- NL2的各种结合伙伴如何调节其在突触中的稳定性，以及其内吞、再循环和降解？-突触中NL2数量的变化如何影响抑制性突触的强度？最终，通过深入了解抑制性突触是如何形成和调节的，我们将更好地了解大脑中的线路是如何被控制的。此外，由于突触功能障碍与许多神经退行性疾病和神经精神疾病有关，我们提出的工作也可能导致对癫痫、中风、阿尔茨海默病、亨廷顿病和精神分裂症等疾病的更好理解，并可能为治疗干预提供目标。我们对NL2的研究过程的详细了解，也将对其他神经素、突触膜蛋白和非神经元细胞中的膜蛋白产生影响。因此，我们的研究可能有助于理解基本的细胞生物学原理，特别是大脑中的连接是如何形成和维持的。

项目成果

PKA-mediated phosphorylation of Neuroligin-2 regulates its cell surface expression and synaptic stabilisation

PKA 介导的 Neuroligin-2 磷酸化调节其细胞表面表达和突触稳定

• DOI: 10.1101/2020.07.23.218008
• 发表时间: 2020
• 作者: Halff E

Physics-based Deep Learning for Imaging Neuronal Activity via Two-photon and Light Field Microscopy

基于物理的深度学习通过双光子和光场显微镜对神经元活动进行成像

• DOI: 10.1101/2022.10.11.511633
• 发表时间: 2022
• 作者: Verinaz-Jadan H

SARS-CoV-2 triggers pericyte-mediated cerebral capillary constriction.

• DOI: 10.1093/brain/awac272
• 发表时间: 2023-02-13
• 期刊: Brain : a journal of neurology

Phosphorylation of neuroligin-2 by PKA regulates its cell surface abundance and synaptic stabilization.

PKA 磷酸化 Neuroligin-2 可调节其细胞表面丰度和突触稳定性。

• DOI: 10.1126/scisignal.abg2505
• 发表时间: 2022
• 期刊: Science signaling
• 影响因子: 7.3
• 作者: Halff EF