Functional analysis of the dCAMTA Transcription factor

dCAMTA 转录因子的功能分析

• 批准号: 6674712
• 负责人: HONG-SHENG LI
• 金额: $ 38.23万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6674712
• 关键词: Drosophilidae; antibody; calcium channel; calcium flux; calcium ion; calmodulin; cell line; complementary DNA; cytoplasm; electrophysiology; gene expression; genetic regulation; genetically modified animals; point mutation; protein binding; protein kinase C; protein localization; protein protein interaction; protein structure function; transcription factor; visual photoreceptor

DESCRIPTION (provided by applicant): The long-term goal of the proposed research is to understand how calcium, a universal messenger, regulates gene expression and cell activities. Calcium ions are pivotal in the regulation of a variety of cellular processes. Abnormal calcium homeostasis has been implicated in aging and in numerous human diseases, such as Alzheimer's disease. The enduring regulatory effects of calcium depend on changes in gene expression. The mechanisms by which cells decode the information carried by calcium signals and convert them into distinct alterations in gene expression is poorly understood. A prevailing model is that Ca2+ entry through different ion channels activates distinct transcription factors. Through the mediation of a series of protein kinases or phosphatases, Ca2+/calmodulin stimulates a range of transcription factors. Recent bioinformatic analyses have suggested the existence of transcription factors that are activated directly by Ca2+/calmodulin, which could respond to Ca2+ signals more quickly. A group of candidates, the calmodulin-binding transcription activators (CAMTAs) were recently identified in plants. Their homologs in animals have yet to be studied. We have isolated two Drosophila mutant alleles of dCAMTA, the fly CAMTA gene, and detected a strong and consistent phenotype in these mutants that implies an impaired deactivation of the fly light-stimulated Ca2+ channel TRP. Therefore we plan to use the fly photoreceptor cells as an assay system to study this new group of Ca2+-regulated transcription factors. A combination of molecular and cell biological, genetic, electrophysiological and calcium imaging approaches will be used to: 1. Test the hypothesis that dCAMTA is activated through Ca2+/calmodulin-binding in vivo. 2: Test the hypothesis that dCAMTA exists in the cytoplasm and translocates into the nuclei upon activation. 3: Test the hypothesis that dCAMTA proteins form homomultimers. 4. Test the hypothesis that dCAMTA depends on TRP channels for activation in the photoreceptor cells. 5. Test the hypothesis that the loss of dCAMTA function leads to increased Ca2+ level in the photoreceptor cells. 6. Determine the target genes of dCAMTA.

描述（由申请人提供）：拟议的研究的长期目标是了解钙，通用信使如何调节基因表达和细胞活性。钙离子在调节多种细胞过程中是关键的。钙稳态异常与衰老和许多人类疾病有关，例如阿尔茨海默氏病。钙的持久调节作用取决于基因表达的变化。细胞解码通过钙信号携带的信息并将其转化为基因表达的不同变化的机制是很少了解的。盛行的模型是通过不同的离子通道进入CA2+进入不同的转录因子。通过一系列蛋白激酶或磷酸酶的介导，Ca2+/钙调蛋白刺激了一系列转录因子。最近的生物信息学分析表明，存在CA2+/钙调蛋白直接激活的转录因子的存在，这些因素可以更快地对Ca2+信号响应。最近在植物中发现了一组候选者，即钙调蛋白结合转录激活剂（CAMTA）。他们在动物中的同源物尚未研究。 我们已经隔离了蝇camta基因的dcamta的两个果蝇突变等位基因，并在这些突变体中检测到了强，一致的表型，这意味着苍蝇刺激的Ca2+ CA2+通道TRP的失活受损。因此，我们计划将蝇光感受器细胞用作测定系统，以研究这一新的CA2+调节转录因子。分子和细胞生物学，遗传，电生理和钙成像方法的结合将用于：1。测试DCAMTA通过体内通过Ca2+/钙调蛋白结合激活的假设。 2：检验DCAMTA在细胞质中存在并在激活后易位到核的假设。 3：检验DCAMTA蛋白形成同源物的假设。 4.检验DCAMTA取决于TRP通道的假设在感光细胞中激活。 5。检验以下假设：DCAMTA功能的丧失会导致感光细胞中Ca2+水平升高。 6。确定DCAMTA的靶基因。