MARK1 in dendritic spine neoteny

树突棘幼态持续中的 MARK1

• 批准号: 10753728
• 负责人: Huaye Zhang
• 金额: $ 40.12万
• 依托单位: RUTGERS BIOMEDICAL AND HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-15 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10753728
• 关键词: AMPA Receptors; Acceleration; Adult; Affect; Affinity; Antibodies; Biochemical; Biological Assay; Biosensor; Biotinylation; Bipolar Disorder; Brain; C-terminal; Complement; DLG4 gene; Data; Dendritic Spines; Development; Evolution; Fluorescence Resonance Energy Transfer; Genes; GluR2 subunit AMPA receptor; Glutamates; Hippocampus; Human; Image; Impairment; Knowledge; Learning; Length; Link; Mediating; Memory; Microtubules; Molecular; Molecular Conformation; Morphology; Mus; Neurodevelopmental Disorder; Neurons; PHluorin; Phosphorylation; Phosphotransferases; Prosencephalon; Reporting; Rodent; Role; Scaffolding Protein; Single Nucleotide Polymorphism; Site; Stimulus; Surface; Synapses; Testing; Time; Vertebral column; autism spectrum disorder; cognitive capacity; cognitive function; cognitive performance; density; experimental study; hippocampal pyramidal neuron; imaging approach; nano; nanocluster; optogenetics; premature; pressure; scaffold; spatiotemporal; superresolution imaging; tau Proteins; trafficking; two-photon; uptake

Project Summary A key cellular substrate underlying learning and memory is the plasticity of dendritic spines, which are sites of excitatory synaptic inputs in the mammalian brain. Dendritic spines show protracted synaptic maturation during human brain development, leading to longer spines with higher density in adulthood as compared with rodents. This extraordinary neoteny of spines is believed to underlie the high cognitive performance in humans. However, there remains a dearth of knowledge regarding the molecular mechanisms that contribute to dendritic spine neoteny unique to humans. One way to approach this issue is to examine genes that show adaptive evolution along the human lineage. These genes are under positive selection pressure and are likely to play a role in human speciation. In particular, genes that show adaptive evolution and genetically linked to neurodevelopmental disorders are strong candidates that may contribute to the high cognitive capacity of the human brain. To date, there are only a handful of genes reported to fit both criteria. One of the genes encodes the Microtubule Affinity Regulating Kinase 1 (MARK1), a Ser/Thr kinase highly expressed in the brain. MARK1 displays strong evidence of adaptive evolution in the lineage leading to humans, and single nucleotide polymorphisms (SNPs) of MARK1 are associated with autism spectrum disorders (ASD) and bipolar disorder. We previously found MARK-mediated phosphorylation of the synaptic scaffolding protein PSD-95 is important for bidirectional dendritic spine plasticity. Moreover, our preliminary studies show loss of MARK1 in forebrain pyramidal neurons leads to reduced spine formation and delayed spatial learning. In addition, we observed a significant increase in the synaptic levels of the AMPA receptor subunit GluR2 in the MARK1 conditional KO (cKO) hippocampus. By contrast, in neurons where rodent MARK1 was replaced with human MARK1, we observed increased spine density and immature morphology reminiscent of human neurons. These exciting data led us to hypothesize that loss of MARK1 leads to premature dendritic spine stabilization, which limits spine density and impairs learning. Conversely, human MARK1 shows enhanced kinase activity leading to dendritic spine neoteny and increased spine density, which contributes to high cognitive functions in humans. Aim 1 will test the hypothesis that human MARK1 contributes to spine neoteny through regulating the PSD scaffold and GluR2 trafficking. Aim 2 will test the hypothesis that altered spatiotemporal dynamics of human MARK1 activity is responsible for its effects on spine neoteny. We will utilize FRET, FRAP, super resolution imaging, and two- photon glutamate uncaging. We will complement these imaging approaches with biochemical analyses and optogenetic manipulation of MARK1 activity. Completion of the proposed experiments will establish a role for MARK1 in dendritic spine neoteny observed in human neurons. The results can shed light on the molecular mechanisms underlying high level cognitive functions of the human brain.

项目摘要 基础学习和记忆的关键细胞底物是树突状棘的可塑性，它是 哺乳动物大脑中兴奋性突触输入的部位。树突状棘显示长期突触 人脑发育期间的成熟，导致较长的棘突在成年中的密度较高 与啮齿动物相比。据信这种非凡的刺刺是高认知的基础 在人类中的表现。但是，关于分子仍然缺乏知识 有助于人类独有的树突状脊柱新型机制。一种方法 问题是检查显示出沿着人类谱系的适应性进化的基因。这些基因不在 积极的选择压力，可能在人类物种形成中发挥作用。特别是显示的基因 自适应进化和与神经发育障碍的遗传有关的是强大的候选者 有助于人脑的高认知能力。迄今为止，只有少数基因 据报道符合这两个标准。其中一个基因编码了调节激酶1（MARK1）的微管亲和力，A Ser/Thr激酶在大脑中高度表达。 Mark1显示了有力的自适应演变的证据 导致人类的谱系和Mark1的单核苷酸多态性（SNP）与自闭症有关 频谱障碍（ASD）和躁郁症。我们先前发现了标记介导的磷酸化 突触支架蛋白PSD-95对于双向树突状脊柱可塑性很重要。而且，我们的 初步研究表明，前脑锥体神经元中MARK1的丧失导致脊柱形成减少和 延迟的空间学习。此外，我们观察到AMPA的突触水平显着增加 Mark1条件KO（CKO）海马中的受体亚基Glur2。相比之下，在神经元中 啮齿动物Mark1被人类Mark1取代，我们观察到脊柱密度增加和未成熟 形态学让人联想到人类神经元。这些令人兴奋的数据导致我们假设Mark1的丢失 导致过早的树突状脊柱稳定，从而限制脊柱密度并损害学习。 相反，人Mark1显示出增强的激酶活性，导致树突状脊柱新味和 脊柱密度增加，这有助于人类的高认知功能。 AIM 1将测试 假设人Mark1通过调节PSD支架和Glur2有助于脊柱新的脊柱 贩运。 AIM 2将检验以下假设：人类Mark1活性改变时空动力学的假设是 负责其对脊柱Neoteny的影响。我们将利用FRET，FRAP，超级分辨率成像和两种 光子谷氨酸渗透。我们将通过生化分析和 MARK1活性的光学遗传操纵。拟议实验的完成将确定 在人类神经元中观察到的树突状脊柱新肾上腺中的Mark1。结果可以散发出分子 人脑高水平认知功能的机制。