Functional analysis of the dCAMTA Transcription factor

描述（由申请人提供）：拟议研究的长期目标是了解钙（一种通用信使）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起关键作用。钙稳态异常与衰老和许多人类疾病如阿尔茨海默病有关。钙的持久调节作用取决于基因表达的变化。细胞解码钙信号携带的信息并将其转化为基因表达的明显改变的机制知之甚少。一个流行的模型是Ca 2+通过不同的离子通道进入激活不同的转录因子。通过一系列蛋白激酶或磷酸酶的介导，Ca 2 +/钙调素刺激一系列转录因子。最近的生物信息学分析表明，存在直接被Ca 2 +/钙调素激活的转录因子，它们可以更快地响应Ca 2+信号。钙调素结合转录激活因子（CAMTAs）是近年来在植物中发现的一类新的候选转录因子。它们在动物中的同系物还有待研究。 我们已经分离出两个果蝇突变等位基因的dCAMTA，飞CAMTA基因，并检测到一个强大的和一致的表型，在这些突变体，这意味着一个受损的失活苍蝇光刺激的钙通道TRP。因此，我们计划使用果蝇感光细胞作为检测系统来研究这组新的Ca 2+调节的转录因子。分子和细胞生物学、遗传学、电生理学和钙成像方法的组合将用于：1。检验dCAMTA通过体内Ca 2 +/钙调蛋白结合激活的假设。2：检验dCAMTA存在于细胞质中并在激活后易位到细胞核中的假设。 3：检验dCAMTA蛋白形成同源多聚体的假设。 4.检验dCAMTA依赖于TRP通道激活感光细胞的假设。 5.检验dCAMTA功能丧失导致感光细胞中Ca 2+水平升高的假设。 6.确定dCAMTA的靶基因。

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.