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：
8832130
负责人：
Robert Aaron Cornell
金额：
$ 2.15万
依托单位：
UNIVERSITY OF IOWA
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：
2014-04-08 至 2015-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8832130
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 Health 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 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前体细胞和干细胞分化的调节网络中的核心角色。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，而在另一种情况下阻止细胞分化。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进行评分，它们不是生命所必需的，而且哺乳动物中黑素细胞干细胞的损失很容易通过随后的头发变白而明显看出。此外，编码转录因子和其他调节分子的基因突变导致色素沉着发育障碍（例如先天性巨结肠症、蒂茨综合征、I-IV型瓦登堡综合征、花斑症）。我们的长期目标是了解控制黑素细胞谱系发育事件的调控网络。在这里，我们重点关注转录因子激活蛋白 2 家族 (TFAP2A-E)。 TFAP2A 似乎可以阻止黑素细胞干细胞的分化，因为 TFAP2A 的显性突变会导致鳃眼面部综合征 (BOFS)，其特征是头发过早变白。相比之下，我们在斑马鱼中的研究表明，TFAP2A 及其旁系同源物 TFAP2E 似乎促进胚胎黑素细胞的分化。我们假设，在黑素细胞前体中，TFAP2 蛋白功能冗余，并与黑素细胞生物学的中心调节因子小眼相关转录因子 (MITF) 并行，激活影响黑素细胞分化的基因。为了测试这个模型，我们将在斑马鱼中进行敲除/回加研究，在小鼠中产生适当的组织特异性双突变体，并对在人类黑素细胞中培养的 TFAP2 蛋白和 MITF 相互激活的基因启动子进行功能分析。接下来我们将研究 TFAP2A 如何发挥维持黑素细胞干细胞 (MSC) 的作用。我们假设在这种情况下，TFAP2A 的关键功能是激活 KIT。为了测试这个概念，我们将再次使用斑马鱼进行上位性测试，检查具有神经嵴特异性删除 TFAP2A 的小鼠的头发变白，并评估与 BOFS 中头发变白相关的 TFAP2A 变体的功能特性。最后，我们将对黑素细胞中TFAP2A表达的潜在调节因子进行系统分析，并对黑素细胞中TFAP2A转录靶标进行全局分析，共同将TFAP2A定位到黑素细胞的调节网络中。我们的研究将揭示黑素细胞正常和病理发育背后的新型遗传和分子网络。这项工作产生的新知识对于瓦登堡综合征和 BOFS 的病因学特别有价值。更一般地说，它将阐明易处理的模型细胞类型中分化的转录调控。