Identifying Genes that Function in a Novel Signaling Pathway that Controls both Cell Adhesion and Initial Cell Fate Specification

识别在控制细胞粘附和初始细胞命运规范的新型信号通路中起作用的基因

• 批准号: 0444883
• 负责人: Daphne Blumberg
• 金额: --
• 依托单位: University of Maryland Baltimore County
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-15 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0444883&HistoricalAwards=false
• 关键词: Identifying; Genes; Function; Novel; Signaling

A protein sharing homology with anti-coaggulants known to competitively inhibit integrin receptor binding to fibrinogen has been described in a protist, Dictyostelium discoideum. This protein, AmpA, functions as a novel signaling molecule that plays both autocrine and paracrine roles controlling cell adhesion and cell fate specification during growth and development. Dictyostelium is a model system extensively used to study cell migration and development. AmpA functions to reduce cell-cell and cell-substrate adhesion, promoting migration of these cells facilitating their ability to forage for food. During the developmental phase of the life cycle the expression of the ampA gene is restricted to a small, but highly motile subset of cells whose migrations are necessary for proper morphogenesis. AmpA expression is essential for migration of these cells. It also acts as a lateral inhibitory signal that prevents adjacent cells from assuming a prespore fate. The simplest model for AmpA function is that it is a modulator of an integrin like receptor. Integrin receptors, however, have not been identified outside of metazoan organisms and there is no obvious integrin receptor that can be identified by sequence homology in Dictyostelium. The objective of this project is to identify the adhesion receptor that is modulated by interaction with the AmpA protein and to identify additional genes that are candidates to function in the AmpA modulated signaling pathway. Aim 1: will use biochemical and molecular genetic approaches to identify and characterize the receptor to which AmpA binds. Aim 2: will use a genetic approach, isolation of second site suppressor mutations, to identify additional genes that function in the AmpA mediated signal transduction pathways. Using AmpA as a probe to identify the adhesion receptors that are modulated by its action and to identify other genes that function downstream in the AmpA signaling pathway should help to elucidate the nature of cell-substrate adhesion and its modulation to promote cell migration and provide insight to how the metozoan integrin paradigm evolved. It should be noted that this project will involve graduate and undergraduate students, some of whom are members of under represented minorities. The research experience gained working on this project will contribute to their scientific education.

在原生生物盘基网柄菌中已经描述了一种与抗凝血剂具有同源性的蛋白质，该蛋白质已知竞争性抑制整合素受体与纤维蛋白原的结合。这种蛋白质 AmpA 作为一种新型信号分子发挥作用，在生长和发育过程中发挥自分泌和旁分泌作用，控制细胞粘附和细胞命运规范。盘基网柄菌是广泛用于研究细胞迁移和发育的模型系统。 AmpA 的作用是减少细胞与细胞和细胞与基质的粘附，促进这些细胞的迁移，从而提高它们觅食的能力。在生命周期的发育阶段，ampA 基因的表达仅限于一小部分但高度活动的细胞子集，其迁移对于正确的形态发生是必需的。 AmpA 表达对于这些细胞的迁移至关重要。它还充当侧向抑制信号，防止相邻细胞呈现前孢子命运。 AmpA 功能最简单的模型是它是整合素样受体的调节剂。然而，在后生动物生物体之外尚未鉴定出整联蛋白受体，并且盘基网柄菌中没有可以通过序列同源性来鉴定的明显整联蛋白受体。该项目的目标是鉴定通过与 AmpA 蛋白相互作用调节的粘附受体，并鉴定在 AmpA 调节的信号通路中发挥作用的候选基因。目标 1：将使用生化和分子遗传学方法来识别和表征 AmpA 结合的受体。目标 2：将使用遗传方法，分离第二位点抑制突变，以确定在 AmpA 介导的信号转导途径中起作用的其他基因。使用 AmpA 作为探针来识别受其作用调节的粘附受体，并识别在 AmpA 信号通路下游发挥作用的其他基因，应有助于阐明细胞-基质粘附的性质及其调节以促进细胞迁移并提供见解后生动物整合素范例如何进化。应该指出的是，该项目将涉及研究生和本科生，其中一些是代表性不足的少数族裔的成员。在该项目中获得的研究经验将有助于他们的科学教育。