Mechanism of Lnk function in cytokin receptor signaling

Lnk在细胞因子受体信号传导中的功能机制

• 批准号: 7313765
• 负责人: Wei Tong
• 金额: $ 8.31万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7313765
• 关键词: biological signal transduction; cytokine receptors; erythropoietin; laboratory mouse; mass spectrometry; peptide library; phosphorylation; protein structure function; recombinant proteins; thrombopoietic factor; tissue /cell culture

DESCRIPTION (provided by applicant): Erythropoietin (Epo) and thrombopoietin (Tpo) are the primary cytokines regulating red blood cell production, and megakaryocyte and platelet development, respectively. The adaptor protein Lnk negatively regulates signaling transduction of the Epo receptor (EpoR) and Tpo receptor (mpl), thereby downregulating Tpo-mediated megakaryocytopoiesis and Epo-mediated erythropoiesis. Lnk inhibits the activity of cytokine receptor integral partner, the JAK2 tyrosine kinase. Furthermore, the Lnk SH2 domain is essential for its inhibitory functions, and the functional interaction between Lnk and the receptor/JAK2 complex is phosphorylation-dependent. The purpose of this grant is to unravel the mechanism that encodes how Lnk controls the quantitative response to cytokines, and whose dysregulation predisposes to leukemia. To accomplish this, biochemical, cellular, and mouse genetic approaches will be used with the focus on the Lnk SH2 domain and tyrosine residues. Recombinant peptide library screens will establish Lnk SH2 domain binding motifs and mass spectrometry (MS) will identify Lnk SH2 domain interacting proteins in vivo. Novel primary hematopoietic cell culture systems will be developed to investigate the interactions among Lnk, cytokine receptors, and JAK2. Moreover, the Lnk tyrosines that are phosphorylated in vivo and important for its function will be dissected. Importantly, the mechanisms of Lnk regulatory function will be tested within physiological contexts using gene-deficient primary hematopoietic cells and generating gene-ablated mice. Unchecked and sustained cytokine receptor signaling leads to oncogenic transformation, therefore understanding the cellular mechanisms by which Lnk controls the amplitude and duration of receptor signaling will shed significant light on cytokine receptor regulation in general. Through this proposed research, the applicant will receive training in structural and proteomics biology and will gain the necessary skills and knowledge to become an independent investigator.

描述（由申请人提供）：促红细胞生成素（Epo）和促血小板生成素（Tpo）分别是调节红细胞生成、巨核细胞和血小板发育的主要细胞因子。衔接蛋白Lnk负调节Epo受体（EpoR）和Tpo受体（mpl）的信号转导，从而下调Tpo介导的巨核细胞生成和Epo介导的红细胞生成。Lnk抑制细胞因子受体整合伴侣JAK 2酪氨酸激酶的活性。此外，Lnk SH 2结构域对于其抑制功能是必不可少的，并且Lnk与受体/JAK 2复合物之间的功能性相互作用是磷酸化依赖性的。这项资助的目的是解开编码Lnk如何控制对细胞因子的定量反应的机制，以及其失调易患白血病。为了实现这一点，生物化学，细胞和小鼠遗传学的方法将被用于重点Lnk SH 2结构域和酪氨酸残基。重组肽文库筛选将建立Lnk SH 2结构域结合基序，质谱（MS）将在体内鉴定Lnk SH 2结构域相互作用蛋白。将开发新的原代造血细胞培养系统以研究Lnk、细胞因子受体和JAK 2之间的相互作用。此外，Lnk酪氨酸，在体内磷酸化和重要的功能将被解剖。重要的是，Lnk调节功能的机制将在生理环境中使用基因缺陷的原代造血细胞和产生基因消除的小鼠进行测试。未经检查和持续的细胞因子受体信号传导导致致癌转化，因此理解Lnk控制受体信号传导的幅度和持续时间的细胞机制将对细胞因子受体调节产生重要影响。通过这项拟议的研究，申请人将接受结构和蛋白质组学生物学的培训，并将获得必要的技能和知识，成为一名独立的研究者。