Calcium-Dependent Protein Regulation

钙依赖性蛋白质调节

• 批准号: 7493384
• 负责人: JOHN Anthony PUTKEY
• 金额: $ 25.95万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7493384
• 关键词: Acceleration; Accounting; Affect; Affinity; Amino Acid Motifs; Binding; Biochemical; Calcineurin; Calcium; Calmodulin; Calmodulin-Binding Proteins; Cells; Complex; Computer Simulation; Cyclic AMP; Data; Defect; Dimensions; Disease; Enzymes; Exhibits; Family; Growth Associated Protein 43; Guanosine Triphosphate Phosphohydrolases; Kinetics; Knockout Mice; Lead; Learning; Mediating; Memory; Modeling; Nervous system structure; Neurons; Outcome; Phosphotransferases; Play; Property; Proteins; RGS Proteins; Range; Rate; Reagent; Regulation; Relative (related person); Research Personnel; Role; Sampling; Signal Pathway; Signal Transduction; Solutions; Structure; Testing; Time; Work; base; calmodulin-dependent protein kinase II; concept; design; experience; in vivo; mutant; neurogranin; novel; phosphoric diester hydrolase; protein function; research study; response

PEP-19, neurogranin and neuromodulin are Small Neuronal IQ motif (SNIQs) calmodulin (CaM) binding proteins found in high abundance throughout the nervous system. Neurogranin knockout mice exhibit altered learning and memory, and have diverse defects in neuronal Ca2+ dynamics and multiple neuronal signaling pathways. This suggests that SNIQs play a fundamental role in CaM-dependent cell regulation, but there is a lack of experimental evidence to support a unifying mechanism that could explain these diverse effects. The only known activity of SNIQs is there ability to bind calmodulin in the presence or absence of Ca2+. We present the novel finding that SNIQs greatly accelerate the intrinsically slow kinetics of Ca2+ binding to the C-domain of CaM to achieve greatly enhanced rate of Ca2+ exchange by PEP-19, or a large decrease in Ca2+ affinity by neurogranin. We also show that SNIQs can affect Ca2+ binding to CaM even in the presence of another Ca2+-dependent CaM-binding protein. These observations demonstrate the potential for SNIQs to modulate the response of CaM to diverse Ca2+ signals it experiences in neurons, and they have broad implications for signal transduction in neuronal compartments that are rich in CaM and CaM-binding proteins. The experiments in this proposal will define the biochemical and structural basis for modulation of Ca2+ binding to CaM by SNIQs. The Aims are: Identify Ca2+ modulatory domains in SNIQs and determine if they function when paired with other CaM binding motifs. Quantify binding and rate constants for dynamic interactions between Ca2+, CaM and SNIQs that define the ability of SNIQs to modulate the steady state and temporal activity of CaM. Characterize the relative ability of SNIQs to modulate the Ca2+ binding properties of CaM in the presence of CaM-dependent protein kinase II, calcineurin or cAMP phosphodiesterase. Determine the effect of SNIQs on CaM-dependent activity of these proteins. Define the structural basis for modulation of Ca2+ binding to CaM by SNIQs.

PEP-19，神经元和神经统治是小型神经元素基序（SNIQS）钙调蛋白（CAM）结合 在整个神经系统中，蛋白质具有很高的丰度。 Neurogranin敲除小鼠展览 改变学习和记忆，并在神经元Ca2+动力学和多个神经元中具有多种缺陷 信号通路。这表明SNIQS在CAM依赖性细胞调节中起着基本作用， 但是缺乏实验证据来支持可以解释这些机制的统一机制 多样化的效果。 SNIQS唯一已知的活性是在存在下结合钙调蛋白的能力或 没有Ca2+。我们提出了小说的发现，即SniqS极大地加速了本质上的慢速动力学 Ca2+与CAM的C域结合，以实现PEP-19或A的Ca2+交换速率大大提高 神经素蛋白的Ca2+亲和力大大降低。我们还表明，SNIQ可以影响Ca2+结合到CAM 即使存在另一种Ca2+依赖性的CAM结合蛋白。这些观察表明 SNIQ调节CAM对其在神经元中经历的各种CA2+信号的反应的潜力，以及 它们对富含CAM的神经元室的信号转导具有广泛的影响 凸轮结合蛋白。该提案中的实验将定义生化和结构基础 通过SNIQS调制Ca2+与CAM的结合。目的是： 识别SNIQ中的Ca2+调节域，并确定与其他CAM配对时它们是否起作用 结合基序。 定义定义Ca2+，CAM和SNIQ之间动态相互作用的量化结合和速率常数 SNIQ调节CAM的稳态和时间活动的能力。 表征SNIQ在存在下调节Ca2+结合特性的相对能力 CAM依赖性蛋白激酶II，钙调神经酶或CAMP磷酸二酯酶确定 这些蛋白质的CAM依赖性活性的SNIQ。 定义通过SNIQS调制Ca2+结合CAM的结构基础。