Developmental & Molecular Mechanisms Employed by Chato, KRAB Zinc Finger Protein

发育性

• 批准号: 8278668
• 负责人: Maria J Garcia-Garcia
• 金额: $ 29.08万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8278668
• 关键词: Affect; Amphibia; Anterior; Anxiety; Behavior; Binding; Biological Assay; Boxing; Cells; Characteristics; Chimera organism; Chromatin; Complex; Congenital Abnormality; DNA; DNA Sequence; DNA Sequence Rearrangement; Defect; Development; Developmental Gene; Disease; Early Diagnosis; Embryo; Embryonic Development; Endoderm; Enzymes; Event; Family member; Gene Family; Gene Targeting; Genetic; Genetic Screening; Genetic Transcription; Goals; Human; Individual; Knowledge; Lead; Mammals; Mediating; Membrane; Molecular; Morphogenesis; Mus; Mutation; Neoplasm Metastasis; Neural Tube Defects; Neural tube; Phenotype; Physiological Processes; Pregnant Women; Prevention; Process; Proteins; Recruitment Activity; Regulation; Research; Research Project Grants; Risk Factors; Role; Shapes; Signal Pathway; Signal Transduction; Somites; Specificity; Spinal Dysraphism; Staging; TRIM Motif; Testing; Tissues; Transcription Repressor/Corepressor; Vertebrates; Wild Type Mouse; Xenopus; Yeasts; Yolk Sac; Zebrafish; Zinc Fingers; base; cell motility; chromatin immunoprecipitation; embryo tissue; imprint; in vivo; insight; interest; malformation; mammalian genome; mutant; novel; polarized cell; positional cloning; public health relevance; research study; stem cell differentiation; teleost; tool; yeast two hybrid system

DESCRIPTION (provided by applicant): The goal of the proposed research project is to understand the developmental and molecular mechanisms that control morphogenesis during mammalian development. Our research is focused on the study of convergent extension, a process that mediates elongation of tissues and involves highly coordinated rearrangements/movements of cells. Numerous devastating congenital malformations result from aberrant coordination of cell movements, but the genetic basis of these diseases is in most cases unknown, which impedes their early diagnosis and prevention. Studies in amphibian and teleost vertebrates have revealed that non-canonical Wnt signaling regulates convergent extension. However, studies in mouse have indicated that convergent extension might be regulated by additional molecular mechanisms in mammals. A phenotype-based forward genetic screen identified chato, a mouse mutation causing embryonic lethality and convergent extension phenotypes. Our analysis of chato mutants confirmed that chato is required for the proper rearrangement of cells that lead to definitive endoderm convergent extension. chato encodes ZFP568, a novel Kruppel-Associated-Box (KRAB) Zinc finger protein. Analysis of chato embryos suggests that chato does not implement non-canonical Wnt signaling, but rather controls mouse elongation through an independent molecular mechanism. One of the goals of this proposal is to identify the molecular effectors and signaling pathways employed by chato to control convergent extension. We are also interested in understanding the developmental mechanisms utilized by chato: In addition to their convergent extension defects, chato mutants also display malformations in morphogenesis of extraembryonic tissues, which might indicate a role for these supporting tissues in promoting convergent extension. We will perform experiments to test this hypothesis. We have divided our research plan into three specific aims: In Specific Aim 1, we will determine whether extraembryonic tissues influence convergent extension of the embryo by analyzing the phenotype of tetraploid chimeras and genetic mosaic embryos. The study of chatwo mutants has provided genetic evidence supporting a role for TRIM28 as a transcriptional co-repressor of ZFP568. In Specific Aim 2, we determine the factors that influence formation of ZFP568-TRIM28 complexes and the mechanisms that mediate the specificity of this complex to the control of convergent extension. Finally, in Specific Aim 3, we seek to identify direct and indirect targets of ZFP568 and ZFP568-TRIM28 complexes and determine the ultimate ZFP568 effectors that control convergent extension. Overall, results from our experiments will increase our understanding of the molecules that control mammalian morphogenesis and provide insights about the molecular mechanisms utilized by KRAB Zinc finger proteins. PUBLIC HEALTH RELEVANCE: This project seeks to understand what are the genes and developmental mechanisms that control mammalian convergent extension, a morphogenetic process that involves coordinated cell rearrangements. Numerous devastating congenital malformations result from aberrant coordination of cell movements. Therefore, our results will be important for the prevention and treatment of human birth defects.

描述（由申请人提供）：拟议研究项目的目标是了解哺乳动物发育过程中控制形态发生的发育和分子机制。我们的研究重点是会聚延伸的研究，这是一个介导组织伸长并涉及细胞高度协调的重排/运动的过程。许多毁灭性的先天性畸形是由于细胞运动的异常协调造成的，但这些疾病的遗传基础在大多数情况下是未知的，这阻碍了它们的早期诊断和预防。两栖类和硬骨鱼类脊椎动物的研究表明，非经典Wnt信号调节会聚延伸。然而，在小鼠中的研究表明，在哺乳动物中，会聚延伸可能受到其他分子机制的调节。一个基于表型的正向遗传筛选确定了chato，一种导致胚胎致死和会聚延伸表型的小鼠突变。我们对chato突变体的分析证实，chato是导致定形内胚层会聚延伸的细胞正确重排所必需的。Chato编码一种新的Kruppel相关盒（KRAB）锌指蛋白ZFP 568。chato胚胎的分析表明，chato不执行非经典的Wnt信号，而是通过一个独立的分子机制控制小鼠的伸长。这个建议的目标之一是确定的分子效应器和信号通路所采用的chato控制收敛延伸。我们也有兴趣了解利用chato的发育机制：除了他们的收敛延伸缺陷，chato突变体还显示畸形的胚外组织的形态发生，这可能表明这些支持组织在促进收敛延伸的作用。我们将通过实验来验证这一假设。我们将我们的研究计划分为三个具体目标：在具体目标1中，我们将通过分析四倍体嵌合体和遗传嵌合体胚胎的表型来确定胚外组织是否影响胚胎的会聚延伸。对chatwo突变体的研究提供了支持TRIM 28作为ZFP 568的转录共阻遏物的作用的遗传证据。在具体目标2中，我们确定了影响ZFP 568-TRIM 28复合物形成的因素以及介导该复合物特异性控制会聚延伸的机制。最后，在具体目标3中，我们试图确定ZFP 568和ZFP 568-TRIM 28复合物的直接和间接靶标，并确定控制会聚延伸的最终ZFP 568效应物。总的来说，我们的实验结果将增加我们对控制哺乳动物形态发生的分子的理解，并提供有关KRAB锌指蛋白所利用的分子机制的见解。 公共卫生相关性：该项目旨在了解控制哺乳动物会聚延伸的基因和发育机制，这是一个涉及协调细胞重排的形态发生过程。许多毁灭性的先天性畸形是由于细胞运动的异常协调造成的。因此，我们的研究结果将是重要的预防和治疗人类出生缺陷。