Regulation of mitochondrial function by ARL2 and its putative effector ELMOD2

ARL2 及其推定效应子 ELMOD2 对线粒体功能的调节

基本信息

批准号：
9180707
负责人：
Laura Elizabeth Newman
金额：
$ 0.54万
依托单位：
EMORY UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-12-01 至 2016-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9180707
关键词：
ARL2 gene Affect Animal Model Binding Biological Assay Biology Blindness Cell Death Cell physiology Cells Crista ampullaris Defect Disease Dominant-Negative Mutation Electron Microscopy Electron Transport Essential Genes Family GTPase-Activating Proteins Gene Proteins Genetic Screening Guanosine Triphosphate Phosphohydrolases Health Heart Diseases Human Impairment Inner mitochondrial membrane Knowledge Lead Link Location Maintenance Malignant Neoplasms Membrane Fusion Microtubules Mitochondria Mitochondrial Matrix Modeling Monomeric GTP-Binding Proteins Morphology Neurodegenerative Disorders Normal Cell OPA1 gene Organelles Pathway interactions Phenocopy Phenotype Play Process Production Proteins Regulation Retinal Degeneration Role Series Signal Pathway Signal Transduction Site Small Interfering RNA Testing cell motility experimental study genetic regulatory protein human disease knock-down member mitochondrial dysfunction mitochondrial metabolism mutant public health relevance response

项目摘要

DESCRIPTION (provided by applicant): Mitochondria are important and dynamic organelles that produce energy for the cell, and mitochondrial defects underlie several human diseases. We have found that loss of the small GTPase ARL2 severely impairs mitochondrial function. Specifically, loss of ARL2 activity causes defects in mitochondrial morphology, motility, and ATP production. We have also found that knockdown of an ARL2 GTPase activating protein (GAP), ELMOD2, also causes defects in morphology, motility, and ATP production. Because both ARL2 and ELMOD2 localize to the mitochondrial matrix, can bind to each other, and produce the same phenotypes upon knockdown, they are likely members of an important mitochondrial signaling pathway. Additionally, loss of ARL2 and ELMOD2 phenocopy the loss of OPA1, an important regulator of cristae, which are critical for mitochondrial ATP production. Therefore, I hypothesize that ARL2 signaling through ELMOD2 in the mitochondrial matrix is required for proper maintenance of mitochondrial morphology, motility, and ATP production, through regulation of cristae morphology. In Aim 1 I will determine if matrix-targeted ARL2 and ELMOD2 can rescue the mitochondrial defects resulting from ARL2 and ELMOD2 knockdown, which will test my model that ARL2 and ELMOD2 act from within the matrix. To test if ELMOD2 acts as an ARL2 effector, I will generate point mutants of ARL2 that cannot bind ELMOD2, which will determine if ARL2 binding to ELMOD2 is required for its mitochondrial functions. I will also use a GAP dead ELMOD2 mutant, ELMOD2[R167K], to determine if ELMOD2 GAP activity for ARL2 is required for mitochondrial function. In Aim 2 I will use electron microscopy to determine the sub-mitochondrial localization of ARL2 and ELMOD2, and test my hypothesis that their knockdown alters cristae morphology. Studying these evolutionarily conserved proteins will inform us about proper mitochondrial function, which can be used for the study of many human diseases.

描述（由申请人提供）：线粒体是为细胞产生能量的重要和动态细胞器，线粒体缺陷是几种人类疾病的基础。我们发现，小GTPase ARL2的损失严重损害了线粒体功能。具体而言，ARL2活性的丧失会导致线粒体形态，运动性和ATP产生的缺陷。我们还发现，ARL2 GTPase激活蛋白（GAP），ELMOD2的敲低也会导致形态学，运动性和ATP产生缺陷。由于ARL2和ELMOD2都位于线粒体基质，可以彼此结合并在敲低时产生相同的表型，因此它们可能是重要的线粒体信号传导途径的成员。另外，ARL2和Elmod2表观的丧失OPA1的损失，OPA1的损失是CRISTAE的重要调节剂，这对于线粒体ATP的产生至关重要。因此，我假设通过调节CRISTAE形态来适当维持线粒体形态，运动性和ATP的产生，需要通过线粒体基质中的ELMOD2信号传导。在AIM 1中，我将确定矩阵靶向的ARL2和ELMOD2是否可以挽救由ARL2和ELMOD2敲低导致的线粒体缺陷，这将测试我的模型ARL2和ELMOD2 ACT从矩阵中。为了测试ELMOD2是否充当ARL2效应子，我将生成无法结合ELMOD2的ARL2的点突变体，这将确定ARL2是否与其线粒体函数需要与Elmod2结合。我还将使用GAP DEAD ELMOD2突变体Elmod2 [R167K]来确定线粒体功能是否需要ARL2的ELMOD2间隙活性。在AIM 2中，我将使用电子显微镜来确定ARL2和ELMOD2的亚构体定位，并检验我的敲低改变Cristae形态的假设。研究这些进化保守的蛋白质将告知我们适当的线粒体功能，可用于研究许多人类疾病。