Transcription Factor Collectives in Vertebrate Wnt Signaling

脊椎动物 Wnt 信号转导中的转录因子集合

• 批准号: 8927242
• 负责人: KENNETH M CADIGAN
• 金额: $ 30.06万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8927242
• 关键词: Adult; Affect; Animals; Attention; Bacteria; Binding; Binding Sites; Bioinformatics; Biological Assay; Cell Culture Techniques; Cell physiology; Cells; ChIP-seq; Chromatin; Clustered Regularly Interspaced Short Palindromic Repeats; Colorectal Cancer; Consensus; DNA Binding; Data; Development; Embryo; Engineering; Family; Female; Gene Expression; Gene Expression Regulation; Gene Targeting; Genetic Polymorphism; Genetic Transcription; Genome; Genomic DNA; Goals; Homeobox; Homeostasis; Human; Individual; Inflammatory Bowel Diseases; Intestines; Lead; Limb Bud; Link; Maintenance; Malignant Neoplasms; Maps; Modeling; Mus; Mutagenesis; Mutation; Nuclear; Paneth Cells; Pathway interactions; Pattern; Pharmaceutical Preparations; Play; Point Mutation; Positioning Attribute; Process; Proliferating; Prosencephalon; Proteins; Publishing; Recruitment Activity; Reporter; Reporting; Risk; Role; Signal Transduction; Site; Surveys; TCF Transcription Factor; Testing; Testis; Tissues; To specify; Transcriptional Activation; Work; antimicrobial; beta catenin; c-myc Genes; cell behavior; genome-wide; genome-wide analysis; hindbrain; in vivo; interest; intestinal crypt; intestinal epithelium; member; mutant; novel; protein protein interaction; public health relevance; sex determination; small hairpin RNA; stem cell population; transcription factor

 DESCRIPTION (provided by applicant): Wnts are secreted proteins that regulate cell behavior through several pathways, the best characterized of which is Wnt/ß-catenin signaling, which plays many important roles in animal development and adult tissue homeostasis. For example, in intestinal crypts, the pathway is required to maintain stem cell populations, and is also needed to specify Paneth cells, which secrete anti-microbial proteins to keep gut bacteria in check. Misregulation of the pathway is associated with colorectal cancer (CRC) and inflammatory bowel disorders. Wnt signaling promotes nuclear accumulation of ß-catenin, which is then recruited to Wnt responsive cis- regulatory modules (W-CRMs) by members of the TCF/LEF1 (TCF) family of transcription factors (TFs). Once there, ß-catenin acts as a potent activator of Wnt target gene transcription. Several genome-wide studies have linked TCF occupancy with other TFs in the genome. This clustering of TFs has been termed a "TF collective". However, the mechanisms underlying functional interactions between TCFs and other TFs are poorly understood. We have characterized two W-CRMs from the human axin2 and c-myc genes in detail using cell culture. The c-myc W-CRM is of interest because it contains a polymorphism in a TCF site linked to increased colorectal cancer (CRC) in humans. Our preliminary data support a model where TCFs work with several other TFs to achieve Wnt activation of these W-CRMs. We will characterize the physical and functional interactions between these factors, to understand how a TF collective containing TCFs operates. We have found that the c-myc W-CRM is active in several tissues in mouse embryos and given its link to CRC in humans, we will examine its activity in the adult mouse intestine. We will also test whether the factors important for activating this W-CRM in cell culture are also required in mouse tissues. One of these factors is Sox9, a TF which is which is typically thought of as an antagonist of Wnt/ß-catenin signaling, but which also cooperates with TCFs to activate the c-myc W-CRM. This cooperation may explain why TCFs and Sox9 are both required for Paneth cell formation in the intestine. In addition, Sox9 is required for testis formation and XY individuals with Sox9 mutations often develop as females. We are characterizating Sox9 mutants that specifically affect its ability to act with or against Wnt signaling. We propose to engineer mice with these mutations, to determine whether these activities underlie its role in Paneth cell specification and sex determination. This work will increase our understanding of the role of Wnt signaling in CRC as well as inflammatory bowel disorders that affect Paneth cell function.

 描述（由适用提供）：Wnt是分泌的蛋白质，通过多种途径调节细胞行为，其最佳特征是Wnt/ß-catenin信号传导，在动物发育和成人组织稳态中起着许多重要作用。例如，在肠道隐窝中，需要该途径来维持干细胞群体，并且还需要指定paneth细胞，paneth细胞是秘密抗微生物蛋白来控制肠道细菌。该途径的正调与结直肠癌（CRC）和炎症性肠道疾病有关。 Wnt信号传导促进了β-catenin的核积累，然后将其募集到TCF/LEF1（TCF）转录因子（TFS）家族的成员（TFS）。到达那里后，ß-catenin充当Wnt靶基因转录的潜在激活剂。全基因组的几项研究已将TCF占用率与基因组中的其他TF联系起来。 TFS的这种聚类已被称为“ TF集体”。但是，TCF与其他TF之间的功能相互作用的基础机制知之甚少。我们使用细胞培养详细介绍了来自人Axin2和C-MYC基因的两个W-CRM。 C-MYC W-CRM引起了人们的关注，因为它在与人类中结直肠癌（CRC）有关的TCF部位中包含多态性。我们的初步数据支持一个模型，其中TCF与其他几个TF一起工作以实现这些W-CRM的Wnt激活。我们将表征这些因素之间的物理和功能相互作用，以了解包含TCF的TF集体的运作方式。我们发现C-Myc W-CRM在小鼠胚胎的几个组织中活跃，并在人类中与CRC有联系，我们将检查其在成年小鼠肠中的活性。我们还将测试小鼠组织中还需要在细胞培养中激活该W-CRM的因素是否重要。这些因素之一是Sox9，它通常被认为是Wnt/ß-catenin信号传导的拮抗剂，但它也与TCF协调以激活C-MYC W-CRM。这种合作可以解释为什么TCFS和SOX9都需要肠细胞形成。此外，睾丸形成和具有SOX9突变的XY个体通常会形成Sox9通常会形成女性。我们正在表征Sox9突变体，这些突变体特别影响其与Wnt信号传导作用或反对的能力。我们建议用这些突变来设计小鼠，以确定这些活动在Paneth细胞规范和性别确定中的作用是否是其作用。这项工作将提高我们对Wnt信号在CRC中的作用以及影响Paneth细胞功能的炎症性肠道疾病的理解。