Signaling by gain-of-function SHP-2 mutants in Noonan syndrome

努南综合征中功能获得性 SHP-2 突变体的信号传导

• 批准号: 8622206
• 负责人: Anton M Bennett
• 金额: $ 36.69万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-05-01 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8622206
• 关键词: Adhesions; Antibodies; Binding; Binding Proteins; Biochemical; Candidate Disease Gene; Cardiovascular system; Cell membrane; Cells; Clinical; Complex; Congenital Heart Defects; Defect; Development; Disease; Event; Exhibits; Frequencies; Genes; Genetic; Genetic Models; Glycoproteins; Goals; Growth Factor; Heart; Human; ITIM; Live Birth; Maps; Mediating; Membrane; Mitogen-Activated Protein Kinases; Modeling; Molecular; Molecular Conformation; Mus; Mutate; Mutation; Myocardium; Noonan Syndrome; PTPN11 gene; Pathogenesis; Pathway interactions; Patients; Phosphorylation; Phosphotransferases; Play; Protein Dephosphorylation; Protein Tyrosine Kinase; Protein Tyrosine Phosphatase; Proteomics; Recruitment Activity; Research; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Site; Testing; Therapeutic; United States; Work; Zebrafish; base; cardiogenesis; congenital heart disorder; developmental disease; extracellular; gain of function; gain of function mutation; human MPZL1 protein; insight; mouse model; mutant; prognostic; src Homology Region 2 Domain; tool

DESCRIPTION (provided by applicant): Noonan syndrome (NS) is an autosomal dominant disorder that occurs with a frequency of ~ 1:2,000 live births. Approximately 50% of NS patients contain a gain-of-function mutation in the human PTPN11 gene which encodes for the SH2 domain-containing protein tyrosine phosphatase, SHP-2. NS patients exhibit a diverse array of clinical manifestations, most notably, congenital heart disease (CHD). CHD occurs in up to 80% of NS patients, making PTPN11/SHP-2 mutations the most common non-chromosomal cause of CHD. Therefore, altered tyrosyl phosphorylation underlies the basis for CHD. The broad goal of this research is to uncover the molecular basis for how NS-associated SHP-2 mutations give rise to CHD. Although much work has established that enhanced activation of the Ras/extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway is causal to NS-mediated CHD the precise mechanisms through which NS-associated SHP-2 mutations engage in pathophysiological signaling to Ras/ERK1/2 remains unknown. We propose to identify the direct upstream and downstream targets of NS-associated SHP-2 mutants and determine if these targets are involved in the development of NS-mediated CHD. In the first aim, we have identified that NS-associated SHP- 2 mutants interact preferentially with ITIM-containing transmembrane glycoproteins. We hypothesize that dysregulated membrane proximity by NS-associated SHP-2 mutants engages promiscuous dephosphorylation of substrates that evoke Ras/ERK1/2 signaling. The contribution of these ITIM/NS-SHP-2 interactions to signal to Ras/ERK1/2 will be defined. The substrates involved in NS-mediated Ras/ERK1/2 activity will be identified and characterized for their involvement in NS-associated SHP-2 mutant signaling. In specific aim two, the ITIM containing transmembrane glycoproteins have been identified to be hypertyrosyl phosphorylated in a mouse model of NS. We will identify the NS-induced tyrosine kinase(s) and using a combination of genetic and biochemical approaches determine whether this tyrosine kinase(s) propagates enhanced ERK1/2 activation and subsequently NS-related cardiac defects. The third aim will test the pathophysiological contribution of altered membrane recruitment of NS-associated SHP-2 mutants as a determinant of NS-mediated cardiac defects. We will accomplish this by employing genetic approaches to interfere with the recruitment of NS- associated SHP-2 to the membrane. The completion of these studies will yield new insight into the direct targets of NS-associated SHP-2 mutants in CHD, and may reveal unanticipated roles, for new and established, signaling molecules in this disease. The identification of targets involved in CHD will also reveal new modes of therapeutic strategies in which to treat, and prognostic tools in which to evaluate, NS-related CHD.

描述（由申请人提供）：努南综合征 (NS) 是一种常染色体显性遗传疾病，其发生频率约为 1:2,000 活产。大约 50% 的 NS 患者在人类 PTPN11 基因中含有功能获得性突变，该基因编码含有 SH2 结构域的蛋白酪氨酸磷酸酶 (SHP-2)。 NS 患者表现出多种临床表现，最明显的是先天性心脏病 (CHD)。高达 80% 的 NS 患者会发生 CHD，这使得 PTPN11/SHP-2 突变成为 CHD 最常见的非染色体原因。因此，酪氨酰磷酸化的改变是冠心病的基础。这项研究的主要目标是揭示 NS 相关 SHP-2 突变如何引起 CHD 的分子基础。尽管大量工作已证实 Ras/细胞外信号调节激酶 1 和 2 (ERK1/2) 通路的激活增强是 NS 介导的 CHD 的原因，但 NS 相关的 SHP-2 突变参与病理生理信号传导的确切机制Ras/ERK1/2 仍然未知。我们建议鉴定 NS 相关 SHP-2 突变体的直接上游和下游靶标，并确定这些靶标是否参与 NS 介导的 CHD 的发展。在第一个目标中，我们已经确定 NS 相关的 SHP-2 突变体优先与包含 ITIM 的跨膜糖蛋白相互作用。我们假设 NS 相关的 SHP-2 突变体导致的膜邻近失调会引起底物的混杂去磷酸化，从而引发 Ras/ERK1/2 信号传导。这些 ITIM/NS-SHP-2 相互作用对 Ras/ERK1/2 信号的贡献将被定义。涉及 NS 介导的 Ras/ERK1/2 活性的底物将被鉴定并表征其参与 NS 相关的 SHP-2 突变体信号传导。在具体目标二中，含有跨膜糖蛋白的 ITIM 已被鉴定在 NS 小鼠模型中被高酪氨酰磷酸化。我们将鉴定 NS 诱导的酪氨酸激酶，并结合遗传和生化方法确定该酪氨酸激酶是否会传播增强的 ERK1/2 激活以及随后的 NS 相关心脏缺陷。第三个目标将测试 NS 相关 SHP-2 突变体的膜募集改变作为 NS 介导的心脏缺陷的决定因素的病理生理学贡献。我们将通过采用遗传方法干扰 NS 相关的 SHP-2 向膜的募集来实现这一目标。这些研究的完成将为先天性心脏病中 NS 相关 SHP-2 突变体的直接靶点提供新的见解，并可能揭示新的和已建立的信号分子在这种疾病中的意想不到的作用。 CHD 相关靶标的识别还将揭示治疗 NS 相关 CHD 的新治疗策略模式和评估 NS 相关 CHD 的预后工具。