Differential Modulation of Cav1.2 and Cav1.3

Cav1.2和Cav1.3的差分调制

• 批准号: 9298000
• 负责人: GREGORY Howard HOCKERMAN
• 金额: $ 22.4万
• 依托单位: PURDUE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-02-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9298000
• 关键词: Action Potentials; Affinity; Amino Acid Sequence; Amino Acids; Binding; Biological Assay; C-terminal; Calcium; Cardiac; Cardiac conduction system; Cardiovascular system; Cell Death; Cell physiology; Cells; Cessation of life; Code; Computer Simulation; Cyclic Amino Acids; Cytotoxic agent; DNA; Data; Dependence; Development; Diabetes Mellitus; Disease; Electrophysiology (science); Endocrine; Event; Functional disorder; Gated Ion Channel; Hypertrophy; Hypotension; Interferometry; Ion Channel Gating; Libraries; Ligands; Measures; Mediating; Molecular; Muscle; Muscle Cells; Neurons; Nifedipine; Oxidative Stress; Pancreas; Parents; Parkinson Disease; Pathologic; Peptides; Pharmaceutical Preparations; Pharmacology; Physiological; Play; Property; RNA Splicing; Role; Signal Transduction; Structure; Structure of beta Cell of islet; Tail; Toxin; Transmembrane Domain; Variant; Work; atrioventricular node; cardiac pacing; cytokine; dopaminergic neuron; extracellular; inhibitor/antagonist; insulin dependent diabetes mellitus onset; novel; novel strategies; patch clamp; peptidomimetics; protein aminoacid sequence; response; small molecule; small molecule inhibitor; small molecule libraries; therapy development; voltage

Summary- Electrical excitability and Ca2+ influx are key features of neurons, endocrine cells, and cardiovascular muscle. However, excessive Ca2+ influx can sensitize these cells to cytotoxic agents, and activate pathological cellular events. Ca influx via Cav1.3 L-type Ca channels is hypothesized to play a key 2+ 2+ role in the death of dopaminergic neurons in Parkinson's Disease, and in cytokine-mediated cell death in pancreatic beta cells during the onset of Type 1 diabetes. Therefore, the development of Cav1.3 inhibitors as potential treatments for Parkinson's disease and diabetes is being pursued. Current drugs that inhibit Cav1.3 also block the closely related channel Cav1.2. Selective Cav1.3 inhibitors would be desirable since they could potentially protect neurons and endocrine cells without inducing hypotension. We've found that the 60 amino acid extracellular IIIS5-3P loops of these channels confer distinct pharmacological properties, and shown that the isolated Cav1.2 IIIS5-3P loop can bind the toxin calcicludine using biolayer interferometry (BLI). In Aim 1, we'll screen a 2.5 x 10 membered, DNA-coded chemical library for binding to the IIIS5-3P loop of Cav1.2 or 8 Cav1.3., confirm binding using BLI, and assess the hits for the ability to selectively inhibit Cav1.2 or Cav1.3 activity using whole-cell electrophysiology. We've also found that the intracellular II-III loop of Cav1.3 selectively enhances inactivation of Cav1.3 but not that of Cav1.2 or a C-terminal truncated splice variant of Cav1.3. In Aim 2, we'll define the minimal peptide sequence within the Cav1.3 II-III loop that confers this activity, and define the role of auxiliary beta subunits and the C-terminal tail of Cav1.3 in the mechanism of action. Completion of these aims will provide structural templates for the development of Cav1.2-selective inhibitors, and two mechanistically distinct classes of Cav1.3-selective inhibitors.

总结-电兴奋性和Ca 2+内流是神经元、内分泌细胞和神经元的关键特征。 心血管肌肉然而，过量的Ca 2+流入可使这些细胞对细胞毒性剂敏感， 激活病理细胞事件。Ca内流通过Cav1.3 L-型Ca通道被假设为在钙通道的形成中起关键作用。 2+ 2+ 在帕金森氏病多巴胺能神经元死亡中的作用，以及在帕金森氏病多巴胺介导的细胞死亡中的作用。 1型糖尿病的早期症状有哪些？因此，Cav1.3抑制剂的开发， 帕金森病和糖尿病的潜在治疗方法正在研究中。目前抑制Cav1.3的药物 也阻断了密切相关的通道Cav1.2。选择性Cav1.3抑制剂将是期望的，因为它们可以 潜在地保护神经元和内分泌细胞而不诱导低血压。我们发现60个氨基酸 这些通道的酸性细胞外IIIS 5 - 3 P环赋予不同的药理学性质，并显示， 分离的Cav1.2IIIS5 - 3 P环可以使用生物层干涉测量法（BLI）结合毒素卡昔鲁定。在目标1中， 我们将筛选一个2.5 × 10元的DNA编码化学文库，用于结合Cav1.2或 8 骑士1.3，使用BLI确认结合，并评估命中选择性抑制Cav1.2或Cav1.3的能力 活性使用全细胞电生理学。我们还发现Cav1.3的细胞内II-III环 选择性地增强Cav1.3的失活，但不增强Cav1.2或Cav1.3的C末端截短剪接变体的失活。 Cav1.3在目标2中，我们将定义Cav1.3 II-III环内的最小肽序列， 活性，并定义辅助β亚基和Cav1.3的C-末端尾在 行动上这些目标的完成将为Cav1.2选择性的开发提供结构模板。 抑制剂，和两种机制上不同的Cav1.3选择性抑制剂。