Analysis of Noelin, a Neural Crest Competence Factor

神经嵴能力因子 Noelin 的分析

• 批准号: 6473678
• 负责人: Marianne Bronner
• 金额: $ 33.52万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-15 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6473678
• 关键词: biological signal transduction; biomarker; cell migration; confocal scanning microscopy; electroporation; embryo /fetus; embryogenesis; gene mutation; gene targeting; genetically modified animals; glycoproteins; green fluorescent proteins; immunoprecipitation; laboratory mouse; neural crest; neural information processing; neural plasticity; neural plate /tube; protein binding; protein structure function; yeast two hybrid system

DESCRIPTION (provided by the applicant): The vertebrate neural crest appears to form via an inductive interaction between the non-neural ectoderm and the neural plate, thus requiring both a source of inducer (the ectoderm) and a competent receiving tissue (the neural plate). Molecules expressed in the early neural plate may be involved in rendering the tissue "competent" to respond to neural crest induction. By screening neural crest/tube libraries, we have identified a secreted factor, Noelin-1, which is expressed in the prospective avian neural plate and may play a role in making the neural tube competent to form neural crest. Noelin-1 mRNA predicts a protein with a signal peptide, N-glycosylation sites and an olfactomedin-related domain; it is secreted when over-expressed in frog oocytes. Noelin-1 mRNA is expressed in a graded pattern in the closing neural tube, with highest expression in the neural folds and no detectable expression at the ventral midline. The proposed experiments will extend the preliminary findings to further characterize the role of Noelin-1 in early embryonic development. Our working premise is that Noelin-1 bestows competence onto neural tube cells to form neural crest. Noelin is expressed in the intermediate neural plate at a time that correlates with the neural plate's ability to respond to induction by the non-neural ectoderm. Recent work from our laboratory suggests that Wnts may be the initial neural crest inducers and that BMPs may function later to maintain/expand newly-induced neural crest population. Thus, Noelin promises to be a particularly exciting factor since little is known about biological properties underlying tissue competence and how competence factors interact with inducers. We hypothesize that: (1) Noelin-1 renders the neural plate competent to respond to an inductive signal from the surface ectoderm by functioning as a co-receptor; (2) maintenance of neural crest markers in the dorsal neural tube may involve a combination of Noelin plus BMP or other neural tube signals; and (3) Noelin expression is repressed by ventral neural tube signals like Sonic hedgehog. We will test these hypotheses by isolating Noelin binding partners, determining its functional requirements and analyzing the tissue/cellular interactions that mediate its expression. The goal of this proposal is to further characterize the function of Noelin-1 at the molecular and cellular level. Specific experiments will: (1) Determine the nature of molecules that interact with Noelin-1. (2) Determine the function of Noelin in imparting competence to neural tube cells to generate neural crest. (3) Generate and characterize the phenotype of Noelin-1 null mutant. (4) Examine the environmental regulation of Noelin-1 expression.

描述（由申请人提供）：脊椎动物的神经嵴似乎 通过非神经外胚层和神经外胚层之间的诱导相互作用形成 神经板，因此需要诱导物来源（外胚层）和 有能力的接收组织（神经板）。早期表达的分子 神经板可能参与使组织“有能力”做出反应 神经嵴诱导。通过筛选神经嵴/管文库，我们有 鉴定出一种分泌因子 Noelin-1，它在预期中表达 禽类神经板，可能在使神经管有能力发挥作用 形成神经嵴。 Noelin-1 mRNA 预测带有信号肽的蛋白质， N-糖基化位点和 olfactomedin 相关结构域；它是在什么时候分泌的 在青蛙卵母细胞中过度表达。 Noelin-1 mRNA 以分级模式表达 在闭合神经管中表达最高，在神经皱襞中表达最高，无 在腹侧中线可检测到表达。拟议的实验将 扩展初步研究结果以进一步表征 Noelin-1 在 早期胚胎发育。我们的工作前提是Noelin-1赋予 神经管细胞形成神经嵴的能力。诺林表达为 中间神经板在与神经板相关的时间 对非神经外胚层诱导作出反应的能力。最近的工作来自 我们的实验室表明 Wnts 可能是最初的神经嵴诱导剂 BMP 可能稍后发挥作用以维持/扩展新诱导的神经嵴 人口。因此，诺林有望成为一个特别令人兴奋的因素，因为 对于组织能力的生物学特性知之甚少， 能力因素如何与诱导剂相互作用。 我们假设：(1) Noelin-1 使神经板有能力做出反应 通过充当来自表面外胚层的感应信号 共受体； (2)背神经管神经嵴标记物的维持 可能涉及 Noelin 与 BMP 或其他神经管信号的组合；和 (3) Noelin 表达受到 Sonic 等腹侧神经管信号的抑制 刺猬。我们将通过分离 Noelin 结合伙伴来测试这些假设， 确定其功能要求并分析组织/细胞 介导其表达的相互作用。该提案的目标是 进一步表征Noelin-1在分子和细胞方面的功能 等级。具体实验将： (1) 确定分子的性质 与Noelin-1 相互作用。 (2)确定Noelin的传授功能 神经管细胞产生神经嵴的能力。 (3)生成并 表征 Noelin-1 无效突变体的表型。 (4) 检查 Noelin-1 表达的环境调节。