Structural and Biophysical Studies of Kinase-Ion Channel Interactions

激酶-离子通道相互作用的结构和生物物理研究

• 批准号: RGPIN-2022-03036
• 负责人: HajiGhassemi, Omid
• 金额: $ 2.7万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=744751
• 关键词: Structural; Biophysical; Studies; Kinase; Ion

The transformation of electrical signals to biochemical ones requires the movement of ions from one compartment to another in excitable cells. Thus, having the right amount of these ions at the right time is critical for proper muscle and neuronal function. These ions must pass through special channel proteins that can open and close, thus determining the amount and timing of their release. Protein kinases are a group of regulatory proteins that modify ion channels by adding a little 'tag' to it, which in turn can alter the activity of the channel. This tagging, which is known as 'phosphorylation', is normally required for the activity of ion channels however, when the tagging is excessive, it can lead to disorders. Surprisingly, kinase involvement in ion channel regulation is poorly understood. Only a few studies show which protein kinase target which site, and fewer still have measured phosphorylation rates. Understanding the rate of phosphorylation toward each target site is physiologically important because this modification alters conditions of excitation, such as the "fight-or-flight" response, where timing of an ion channel opening is critical. My research program focuses on how protein kinases target mammalian ion channels and their associated proteins using biochemical and biophysical approaches. My long-term goal is to use an interdisciplinary approach to unravel how certain protein kinases regulate ion channels. While this ultimately this requires us to elucidate the cascade of signaling events involving numerous kinases and proteins, my short-term goal is to focus on two protein kinases PKA and CaMKII, and their regulation of the voltage gated sodium channels (NaVs). To this end, my lab seek to determine how their catalytic subunits bind and regulate proteins and ion channels involved in the formation of signaling junctions starting with peptide substrates derived from NaVs, and eventually including other ion channels, their different isoforms and ancillary subunits. There are only a handful of experimentally derived kinase-substrate complexes. Long-term, this program aims to study the affects of phosphorylation in context of fully folded channels as opposed to peptides and explore how kinases such as CaMKII and PKA are recruited to ion channels. This will bring concomitant insights into their inhibition and a better mechanistic understanding of these kinases. Finally, we seek to uncover how other regulatory proteins are affected by the activity and action of kinases, as these are known to regulate ion channels in a phosphorylation dependent manner. This work not only advance our knowledge of human physiology, but may eventually aid in design of drugs that alter specific kinase-ion channel interactions. Importantly, the proposed studies utilize cutting-edge biochemical and biophysical methods which provides a rich training environment for the next generation of scientific personnel and future research innovation in Canada.

电信号转化为生化信号需要离子在可兴奋细胞中从一个隔室移动到另一个隔室。因此，在正确的时间拥有适量的这些离子对于适当的肌肉和神经元功能至关重要。这些离子必须通过可以打开和关闭的特殊通道蛋白，从而决定它们释放的量和时间。蛋白激酶是一组调节蛋白，通过向其添加一点“标签”来修饰离子通道，这反过来可以改变通道的活性。这种被称为“磷酸化”的标记通常是离子通道活性所需的，然而，当标记过量时，它可能导致疾病。 令人惊讶的是，激酶参与离子通道调节知之甚少。只有少数研究表明哪种蛋白激酶靶向哪一个位点，更少的是测量磷酸化速率。了解每个靶位点的磷酸化速率在生理学上是重要的，因为这种修饰改变了兴奋的条件，例如“战斗或逃跑”反应，其中离子通道开放的时机是至关重要的。我的研究项目主要集中在蛋白激酶如何利用生物化学和生物物理方法靶向哺乳动物离子通道及其相关蛋白。我的长期目标是使用跨学科的方法来解开某些蛋白激酶如何调节离子通道。虽然这最终需要我们阐明涉及许多激酶和蛋白质的信号事件级联，但我的短期目标是关注两种蛋白激酶PKA和CaMKII，以及它们对电压门控钠通道（NaVs）的调节。为此，我的实验室试图确定它们的催化亚基如何结合和调节参与信号连接形成的蛋白质和离子通道，从NaV衍生的肽底物开始，最终包括其他离子通道，它们的不同亚型和辅助亚基。 只有少数实验衍生的激酶-底物复合物。长期而言，该计划旨在研究磷酸化在完全折叠通道背景下的影响，而不是肽，并探索激酶如CaMKII和PKA如何被招募到离子通道。这将带来对它们的抑制的伴随的见解和对这些激酶的更好的机械理解。最后，我们试图揭示其他调节蛋白如何受到激酶活性和作用的影响，因为已知这些激酶以磷酸化依赖的方式调节离子通道。 这项工作不仅推进了我们对人类生理学的了解，而且最终可能有助于设计改变特定激酶-离子通道相互作用的药物。重要的是，拟议的研究利用尖端的生物化学和生物物理方法，为加拿大下一代科学人员和未来的研究创新提供了丰富的培训环境。