Structural, biochemical and computational studies of KIBRA protein-protein and protein-phospholipid interactions that are important for memory

Kibra和记忆的分子机制我们的记忆决定了我们是谁。因此，了解记忆获取、存储和回忆背后的机制是神经科学的圣杯。记忆依赖于不同类型的蛋白质(如受体、通道、酶、支架蛋白)的相互作用。我们将研究Kibra，一种对记忆很重要的支架蛋白，它与阿尔茨海默病有关。由于Kibra在神经元(脑细胞)中的功能缺乏许多细节，我们将使用实验和计算方法来研究Kibra与伙伴蛋白和膜(细胞不同部分或细胞之间的可渗透生物边界)的相互作用。PKMzeta是长时记忆储存的关键，短时记忆和长时记忆的机制不同。在长期记忆存储中起关键作用的是一种名为PKMzeta的蛋白质，它通过修改其他蛋白质来发挥作用。例如，PKMzeta对神经元表面的受体蛋白，特别是AMPA受体的修饰，会导致受体移动到突触后膜，在那里它们在神经元之间提供电或化学信号，以维持记忆。PKMzeta就像一条传送带，将AMPA受体运送到突触。PKMzeta活性的调节可以扰乱或增强记忆。KIBRA-PKMzeta相互作用对PKMzeta功能至关重要我们的合作者已经证明Kibra与PKMzeta的相互作用对PKMzeta的传送带作用至关重要。我们将定义Kibra-PKMzeta相互作用的细节，例如蛋白质之间界面的性质，蛋白质运动的作用，以及哪些蛋白质成分对相互作用最重要。对记忆很重要的其他Kibra相互作用我们将研究另外两个Kibra相互作用：与关键神经元蛋白质Dendrin和Synaptopodin的相互作用，它们是赋予神经元特征形状的分子骨架的组织者；Kibra与膜的相互作用，使Kibra保持在神经元内的正确位置。Kibra的不同部位参与了与PKMzeta、Dendrin和Synaptopodin以及膜的相互作用。核磁共振利用原子核的磁性来提供有关蛋白质的形状、形状变化和相互作用的信息，这些信息在整个蛋白质中的许多位置和跨广泛的时间尺度(皮秒到分钟)。X射线结晶学提供了更高分辨率的形状信息，但对动态行为的洞察较少。其他方法告诉我们蛋白质与其他分子相互作用的强度和动力学。蛋白质行为的计算机模拟提供了仅从实验中无法获得的见解，有助于解释实验数据，并为新实验的设计提供信息。结合我们对分子的研究和我们的合作者Joachim Kremerskoten对细胞和动物的平行实验，应该会导致对Kibra功能的深入了解。长期目标：治疗成瘾、恐惧症、压力和焦虑症以及记忆力下降我们将利用我们的结果来指导Kibra的改变，这些改变扰乱/增强了Kibra的互动。Kremerskoten博士将研究这些Kibra变化如何影响动物的神经元功能和记忆过程。这可能有助于开发影响记忆的新分子。例如，一种名为ZIP的现有分子可以抑制PKMzeta，它可以消除所有的长期记忆，但允许形成新的记忆。提高对记忆相关分子相互作用的了解，如Kibra的分子相互作用，可能有助于开发专门破坏个人长期记忆而不是所有长期记忆的分子，例如用于治疗成瘾、恐惧症、压力和焦虑症，或开发提高老年人、阿尔茨海默氏症患者或身体创伤受害者记忆性能的分子。

KIBRA and the molecular mechanism of memoryOur memories define who we are. Understanding the mechanisms behind the acquisition, storage and recall of memories is consequently a neuroscience holy grail. Memory depends on the interplay of different types of proteins (e.g. receptors, channels, enzymes, scaffold proteins). We will study KIBRA, a scaffold protein that is important for memory and that is linked to Alzheimer's disease. Since many details of how KIBRA functions in neurons (brain cells) are lacking, we will use experimental and computational methods to study KIBRA interactions with partner proteins and membranes (permeable biological boundaries between different parts of a cell or between cells). PKMzeta is crucial for long term memory storageThe mechanisms of short and long term memory differ. The pivotal player in long term memory storage is a protein called PKMzeta which works by modifying other proteins. Modification by PKMzeta of receptor proteins, especially AMPA receptors, at the surface of neurons, for example, causes the receptors to move to the postsynaptic membrane where they contribute to electrical or chemical signalling between neurons to maintain memories. PKMzeta acts like a conveyor belt to carry AMPA receptors to the synapse. Modulation of PKMzeta activity can disrupt or enhance memory.KIBRA-PKMzeta interaction is vital for PKMzeta functionOur collaborators have shown that KIBRA interaction with PKMzeta is crucial for PKMzeta's conveyor belt action. We will define details of KIBRA-PKMzeta interaction, e.g. the nature of the interface between the proteins, role of protein movement, and which protein components are most important for the interaction. Other KIBRA interactions that are important for memoryWe will study two other KIBRA interactions: with the key neuronal proteins Dendrin and Synaptopodin that are organisers of the molecular skeleton that gives neurons their characteristic shape; and KIBRA's interaction with membranes that maintains KIBRA in the correct location within neurons. Different parts of KIBRA are involved in its interactions with PKMzeta, Dendrin and Synaptopodin, and membranes.MethodsWe will use the complementary characteristics of multiple methods. NMR exploits the magnetic properties of nuclei to provide information about the shapes, shape changes and interactions of proteins at many locations throughout proteins and across a wide range of timescales (picoseconds to minutes). X-ray crystallography provides higher resolution shape information but less insight into dynamic behaviour. Other methods tell us about the strength and dynamics of protein interactions with other molecules. Computer simulations of protein behaviour provide insights that are not available from experiment alone, aid interpretation of experimental data and inform design of new experiments. Combining our study of molecules with our collaborator Joachim Kremerskothen's parallel experiments on cells and animals should lead to deep insight into KIBRA function. Long term goal: treatments for addictions, phobias, stress and anxiety disorders, and memory declineWe will use our results to guide alterations in KIBRA that disrupt/enhance its interactions. Dr Kremerskothen will study how these KIBRA alterations affect neuron functions and memory processes in animals. This could help in the development of new molecules that affect memory. One existing molecule called ZIP that inhibits PKMzeta, for example, erases all long term memories yet permits formation of new memories. Improved understanding of memory-related molecular interactions such as those of KIBRA could help to develop molecules that specifically disrupt individual long term memories rather than all long term memories, for example to treat addiction, phobias, stress and anxiety disorders, or develop molecules that enhance memory performance in the elderly, Alzheimer's patients, or physical trauma victims.