Regulation of the melanocyte lineage by the AP2 transcription factor family

AP2 转录因子家族对黑素细胞谱系的调节

基本信息

批准号：
8743069
负责人：
Robert Aaron Cornell
金额：
$ 36.33万
依托单位：
UNIVERSITY OF IOWA
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-25 至 2016-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8743069
关键词：
Alleles Automobile Driving Back Binding Binding Sites Biochemical Biological Assay Biological Models Biology Branchio-Oculo-Facial Syndromes Cell Culture Techniques Cell Differentiation process Cell Maintenance ChIP-seq Congenital Megacolon DNA Binding Data Development Diagnosis Dimerization Dominant-Negative Mutation Dopachrome isomerase Elements Embryo Embryonic Development Enhancers Etiology Event Family Family member Functional RNA Gene Expression Genes Genetic Genetic Epistasis Gray unit of radiation dose Hair Homeostasis Human Knock-out Knowledge Life Light Mammals Methods Modeling Molecular Genetics Molecular Profiling Mus Mutation Neural Crest Oculocutaneous Albinism Outcome Output Patients Phenotype Physiology Piebaldism Pigmentation Disorders Pigmentation physiologic function Play Positioning Attribute Process Property Recovery Regulation Regulatory Element Reporter Research Risk Role Severities Skin Cancer Stem Cell Factor Stem cells System TFAP2A gene Testing Tietze&apos s Syndrome Tissues Transcription Factor 3 Transcription Factor AP-2 Alpha Transcriptional Regulation Variant Waardenburg syndrome Work Zebrafish adult stem cell base cell type craniofacial design developmental disease embryo tissue genetic regulatory protein in vitro testing in vivo interest knock-down melanocyte microphthalmia-associated transcription factor mutant novel novel therapeutics overexpression paralogous gene precursor cell premature prevent promoter protein function public health relevance stem cell differentiation transcription factor ultraviolet irradiation

项目摘要

DESCRIPTION (provided by applicant): Transcription factors are central players in the regulatory networks that control differentiation in all types of precursor cells and stem cells. Itis well known that transcription factors regulate gene expression, but it is unclear how they regulate differentiation. For instance, in some cases a given transcription factor promotes cell differentiation in one context, and prevents it in another. Melanocytes are an ideal model cell type to explore cellular developmental events because their differentiation is easily scored, they are not essential for life, and loss of melanocyte stem cells in mammals is readily apparent by the consequent hair graying. Moreover, mutations in genes encoding transcription factors and other regulatory molecules cause developmental disorders of pigmentation (e.g., Hirschsprung's disease, Tietz syndrome, Waardenburg syndrome types I- IV, piebaldism). Our long-term objective is to understand the regulatory network governing developmental events in the melanocyte lineage. Here we focus on the transcription factor Activator Protein 2 family (TFAP2A-E). TFAP2A appears to prevent differentiation of melanocyte stem cells, because dominant mutations in TFAP2A cause Branchio Oculo Facial Syndrome (BOFS), which features premature hair graying. By contrast, TFAP2A and its paralog TFAP2E appear to promote differentiation of embryonic melanocytes, as shown by our work in zebrafish. We hypothesize that within melanocyte precursors, TFAP2 proteins function redundantly, and in parallel with microphthalmia-associated transcription factor (MITF), a central regulator of melanocyte biology, to activate genes that effect melanocyte differentiation. To test this model we will conduct knock-down/add-back studies in zebrafish, generate appropriate tissue- specific double mutants in mice, and conduct functional analysis of the promoter of a gene mutually activated by TFAP2 proteins and MITF in cultured in human melanocytes. Next we will examine how TFAP2A functions to maintain melanocyte stem cells (MSC). We hypothesize that in this context, the key function of TFAP2A is to activate KIT. To test this notion we will use zebrafish again for epistasis tests, examine hair graying in a mouse with neural-crest-specific deletion of TFAP2A, and assess functional properties of TFAP2A variants associated with hair graying in BOFS. Finally, we will conduct systematic analyses of potential regulators of TFAP2A expression in melanocytes, and a global analysis of TFAP2A transcriptional targets in melanocytes, which together will position TFAP2A into a regulatory network in melanocytes. Our studies will shed light on novel genetic and molecular networks that underlie normal and pathological development of melanocytes. The new knowledge generated from this work will be of value specifically in the etiology of Waardenburg syndrome and BOFS. More generally, it will illuminate the transcriptional regulation of differentiation in a tractable model cell type.

描述（由申请人提供）：转录因子是控制所有类型的前体细胞和干细胞区分的调节网络中的核心参与者。众所周知，转录因子调节基因表达，但尚不清楚它们如何调节分化。例如，在某些情况下，给定的转录因子在一种情况下促进细胞分化，并在另一种情况下防止它。黑素细胞是探索细胞发育事件的理想模型细胞类型，因为它们的分化很容易评分，它们对生命不是必不可少的，并且随之而来的头发呈灰色，很容易看出哺乳动物中黑素细胞干细胞的丧失。此外，编码转录因子和其他调节分子的基因突变会引起色素沉着的发育障碍（例如，Hirschsprung病，Tietz综合征，Waardenburg综合征I-IV，IV，Piebaldism）。我们的长期目标是了解黑色素谱系中发展发展事件的监管网络。在这里，我们关注转录因子激活蛋白2家族（TFAP2A-E）。 TFAP2A似乎可以防止黑素细胞干细胞的分化，因为TFAP2A中的显性突变会导致oculo oculo面部综合征（BOFS），该突变具有过早的头发灰色。相比之下，TFAP2A及其旁系同源物TFAP2E似乎促进了胚胎黑素细胞的分化，如我们在斑马鱼中的作品所示。我们假设在黑素细胞前体中，TFAP2蛋白在黑色素相关的转录因子（MITF）（MITF）（MITF）（MITF）的中央调节剂（MITF）中并行，以激活有效的黑素细胞分化的基因。为了测试该模型，我们将在斑马鱼中进行敲低/添加的研究，在小鼠中产生适当的组织 - 特异性双突变体，并对由TFAP2蛋白和MITF在人类黑色素细胞中培养的基因互动的启动子进行功能分析。接下来，我们将研究TFAP2A如何保持黑素细胞干细胞（MSC）的功能。我们假设在这种情况下，TFAP2A的关键功能是激活套件。为了测试这一概念，我们将再次使用斑马鱼进行上学测试，检查具有TFAP2A的神经克雷峰特异性缺失的小鼠中的头发，并评估与BOF中头发灰色相关的TFAP2A变体的功能性能。最后，我们将对黑素细胞中TFAP2A表达的潜在调节剂进行系统分析，以及对黑色素细胞中TFAP2A转录靶标的全局分析，这些分析将TFAP2A共同将TFAP2A定位在黑色素细胞中的调节网络中。我们的研究将阐明黑色素细胞正常和病理发展的新型遗传和分子网络。这项工作产生的新知识将具有特殊价值，特别是在Waardenburg综合征和BOF的病因中。更一般而言，它将阐明可导致模型细胞类型中分化的转录调节。