Drosophila VDAC's Role in Mitochondrial Function

申请人简介(由申请人提供)：申请人是一名具有分子遗传学博士学位的合格儿科医生，正在寻求遗传学方面的奖学金。他对新陈代谢的遗传调控有着长期和持续的兴趣，特别是涉及线粒体功能和儿科线粒体疾病的分子机制。为了追求这些兴趣，他寻求相关的临床和研究培训，长期目标是帮助理解线粒体功能和生物发生的基本遗传和分子机制。这项申请提供了一种机制，可以实现一个直接的职业目标，即将申请者的研究经验扩展到果蝇遗传学、发育和电生理学领域，这是开发研究线粒体功能调节的新遗传模型所必需的。本研究旨在探讨果蝇电压依赖性阴离子通道(VDAC)各亚型的功能。VDAC是线粒体外膜中含量最丰富的蛋白质，它代表着小分子代谢物和离子穿过线粒体外膜的主要途径，这些物质和离子是线粒体依赖的能量代谢所必需的，并参与了多种调控的细胞过程，如细胞色素c依赖的细胞凋亡和通透性转换孔。随着最近对果蝇基因组的注释，已经鉴定出四个与真核细胞VDAC同源的基因，其中两个基因证实了酵母VDAC的功能互补。这四个基因将从转录结构、时空表达和体外生物物理特性方面进行表征。利用P元件介导的突变和RNA干扰，这些基因将产生一系列功能缺失的等位基因突变。这些果蝇VDAC的具体功能将通过评估VDAC功能丧失在形态、超微结构、细胞、生化和生理水平上的后果来确定。表现出易评分表型的突变体将被用于基因增强子/抑制子筛选，旨在识别与VDAC相互作用的基因，这些基因对线粒体功能和生物发生至关重要。通过识别线粒体调控的基本、保守的遗传途径，本研究将有助于了解线粒体的功能，并为未来在哺乳动物系统中作为人类线粒体疾病模型和潜在治疗靶点的研究提供新的基因。进行这项研究的环境特别适合于促进申请人的职业发展计划。贝勒医学院分子和人类遗传学系以其果蝇遗传学和协作氛围而闻名。通过监督研究、科学交流和精选课程的结合，申请者将获得成功过渡到独立调查人员所需的培训。

DESCRIPTION (provided by applicant): The applicant, a board eligible pediatrician with a Ph.D. in molecular genetics, is pursuing a fellowship in genetics. He has a long-standing and continued interest in the genetic regulation of metabolism, particularly with regards to the molecular mechanisms involved in mitochondrial function and pediatric mitochondrial disease. In pursuit of these interests, he has sought relevant clinical and research training with a long-term goal of contributing to the understanding of fundamental genetic and molecular mechanisms of mitochondrial function and biogenesis. This application provides a mechanism for achieving an immediate career goal of expanding the applicant's research experience to the fields of Drosophila genetics, development and electrophysiology necessary for the development of novel genetic models for the study of the regulation of mitochondrial function. The purpose of this study is to evaluate the specific functions of isoforms of the Voltage Dependent Anion Channel (VDAC) in Drosophila melanogaster. VDAC, the most abundant protein in the mitochondrial outer membrane, represents the main pathway across this membrane for small metabolites and ions that are essential for mitochondrial-dependent energy metabolism and has been implicated in various regulated cellular processes such as cytochrome-c dependent apoptosis and the permeability transition pore. With the recent annotation of the Drosophila genome, four genes with homology to eukaryotic VDACs have been identified, two of which demonstrate functional complementation of yeast VDAC. These four genes will be characterized in terms of transcript structure, temporal-spatial expression, and in vitro biophysical properties. An allelic series of loss of function mutations for these genes will be generated utilizing both P-element mediated mutagenesis and RNA interference. The specific functions of these Drosophila VDACs will be determined by assessing the consequences of loss of VDAC functions phenotypically on morphological, ultrastructural, cellular, biochemical, and physiological levels. Mutants that demonstrate easily scorable phenotypes will be utilized in genetic enhancer/suppressor screens designed to identify genes that interact with VDACs and are important for mitochondrial function and biogenesis. Through the identification of fundamental, conserved genetic pathways of mitochondrial regulation, this study will contribute to the understanding of mitochondrial function and highlight new genes for future study in mammalian systems as models for human mitochondrial disease and as potential therapeutic targets. The environment in which this study will be performed is uniquely suited for facilitating the applicant's career development plan. The Department of Molecular and Human Genetics at Baylor College of Medicine is renowned for its Drosophila genetics and its collaborative atmosphere. Through a combination of supervised research, scientific interchange, and selected coursework, the applicant will obtain the training necessary for a successful transition to an independent investigator.