Calcium Release-Activated Calcium current - Investigation of a calcium signaling pathway in non-excitable cells

钙释放激活的钙电流 - 非兴奋性细胞中钙信号通路的研究

• 批准号: 30798536
• 负责人: Professorin Dr. Christine Peinelt
• 金额: --
• 依托单位: Queens Center for Biomedical Research (QCBR)
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2007-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/30798536?language=en
• 关键词: Calcium; Release; Activated; current; Investigation

Changes in intracellular calcium concentration ([Ca2+]i) play a critical role in cellular responses to the extracellular environment by regulating cellular processes1, 2. Release of Ca2+ from intracellular stores and entry of extracellular Ca2+ generate intracellular calcium signals3. Depletion of distinct Ca2+ stores results in store-operated Ca2+ influx (SOC) in non-excitable mammalian cells4. The best studied SOC current is the Calcium Release Activated Calcium current (ICRAC)5. ICRAC plays an important role in many cellular processes such as Ca2+ signaling, gene expression and cell proliferation6-8. However, the molecular identity of the ICRAC protein is still unclear, although evidence towards this goal is emerging9. Physiologically, intracellular Ca2+ stores are depleted by binding inositol-1,4,5-trisphosphate (InsP3) to the inositol-1,4,5-trisphosphate receptor (InsP3R) located in the membrane of the endoplasmic reticulum (ER)10, 11.A small interference RNA (siRNA) approach based on the genome of Drosophila melanogaster has been initiated to identify the ICRAC protein. I propose patch-clamp analyses of selected siRNAs that lead to a significantly reduced Ca2+ signal in a Fluorometric Imaging Plate Reader (FLIPR) pre-screen (Specific Aim 1).Three isoforms of the InsP3R are known (type I, II and III). Distinct cellular Ca2+ stores could be generated depending on the expression of a specific set of InsP3R. I propose to evaluate the contribution of each InsP3R isoform in its ability to couple to Ca2+ influx through ICRAC in B lymphocytes (Specific Aim 2).

细胞内钙离子浓度（[Ca 2 +]i）的变化通过调节细胞过程在细胞对细胞外环境的反应中起着关键作用1，2。Ca 2+从细胞内储存的释放和细胞外Ca 2+的进入产生细胞内钙信号3。消耗不同的Ca 2+商店导致非兴奋性哺乳动物细胞中的商店操作的Ca 2+内流（SOC）4。研究得最好的SOC电流是钙释放活性钙电流（ICRAC）5。ICRAC在许多细胞过程中起重要作用，如Ca 2+信号传导、基因表达和细胞增殖6 -8。然而，ICRAC蛋白的分子身份仍然不清楚，尽管朝着这个目标的证据正在出现9。生理上，细胞内钙库通过将肌醇-1，4，5-三磷酸（InsP 3）与位于内质网（ER）膜上的肌醇-1，4，5-三磷酸受体（InsP 3R）结合而耗尽10，11。基于果蝇基因组的小干扰RNA（siRNA）方法已经开始鉴定ICRAC蛋白。我提议对选定的siRNAs进行膜片钳分析，这些siRNAs在荧光成像读板仪（FLIPR）预筛选中导致Ca 2+信号显着减少（具体目标1）。InsP 3 R的三种亚型是已知的（I型、II型和III型）。不同的细胞Ca 2+商店可以产生依赖于一组特定的InsP 3R的表达。我建议评价每种InsP 3 R亚型在B淋巴细胞中通过ICRAC与Ca 2+内流偶联的能力中的贡献（具体目标2）。