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）：Noonan综合征（NS）是一种常染色体显性疾病，发生的频率约为1：2,000。大约50％的NS患者在人类PTPN11基因中包含功能收益突变，该基因编码含SH2域的蛋白酪氨酸磷酸酶SHP-2。 NS患者表现出各种各样的临床表现，最著名的是先天性心脏病（CHD）。 CHD发生在多达80％的NS患者中，使PTPN11/SHP-2突变成为CHD最常见的非染色体原因。因此，改变的酪酶磷酸化是CHD基础的基础。这项研究的广泛目标是揭示NS相关SHP-2突变如何引起CHD的分子基础。尽管许多工作已经确定，RAS/细胞外信号调节激酶1和2（ERK1/2）途径的激活增强了NS介导的CHD的因果，因此NS相关的SHP-2突变通过这些机制与RAS/ERK1/2的病理生理信号传导有关。我们建议确定与NS相关的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，我们已经确定与含有ITIM的跨膜糖蛋白优先相互作用的NS相关SHP-2突变体。我们假设NS相关的SHP-2突变体的膜接近失调会使引起RAS/ERK1/2信号传导的底物的混杂性去磷酸化。这些ITIM/NS-SHP-2相互作用对对RAS/ERK1/2的信号的贡献将定义。与NS介导的RAS/ERK1/2活性有关的底物将以参与NS相关的SHP-2突变体信号传导来鉴定和表征。在特定目标二中，已经确定含有跨膜糖蛋白的ITIM在NS小鼠模型中被确定为催产硫磷酸化。我们将确定NS诱导的酪氨酸激酶（S），并结合遗传和生化方法的组合决定了这种酪氨酸激酶是否能够传播增强的ERK1/2激活以及随后与NS相关的心脏缺陷。第三个目标将检验NS相关SHP-2突变体的膜募集改变的病理生理贡献，作为NS介导的心脏缺陷的决定因素。我们将通过采用遗传方法来干预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冠心病中与NS相关的SHP-2突变体的直接靶标提供新的见解，并可能揭示出意外的作用，对于这种疾病中的新和已建立的信号分子。鉴定CHD涉及的靶标还将揭示用于治疗的新型治疗策略，以及评估与NS相关的CHD的预后工具。