A novel protein regulating thymocyte development

主要研究者/项目负责人（上、中、前）：Gascoigne，Nicholas R. J. 1 R 01 AI 073870 - 01 A2 已经鉴定了一种新的基因/蛋白质，其主要在胸腺细胞发育期间表达。基因敲除小鼠表明，它是正常胸腺细胞正选择所必需的。初步数据表明，它与磷脂酶C-γ（PLC-γ）和Itk相互作用，这两种酶对早期肿瘤的发生至关重要。 在通过TCR的信号传导阶段，以及与共济失调毛细血管扩张突变（ATM），细胞周期检查点的主要调节剂，测试DNA损伤。本申请旨在确定这种蛋白质的功能，并确定它如何与发育中的胸腺细胞的信号级联相互作用。在正选择信号传导之前和期间，基因敲除胸腺细胞中基因表达谱的变化将被检测。 鉴定蛋白质的潜在功能区域将被确定和分析其在胸腺细胞发育中的作用，包括核定位序列，ATM磷酸化位点，SH 3结合位点等。将使用FRET显微镜和荧光互补研究与Itk和PLC-γ的相互作用的动力学。诱导细胞死亡或分化， 发展T细胞对于避免自身免疫和建立功能性免疫系统至关重要。这种新发现的蛋白质似乎可以调节这些过程，因此该项目将揭示这种新蛋白质的功能。

Principal Investigator/Program Director (Last, first, middle): Gascoigne, Nicholas R.J. 1 R01 AI073870-01A2 A novel gene/protein has been identified which is expressed predominantly during thymocyte development. A knockout mouse shows that it is required for normal thymocyte positive selection. Preliminary data indicate that it interacts with phospholipase C-gamma (PLC-gamma) and Itk, both enzymes crucial to early stages in signaling via the TCR, as well as with Ataxia telangiectasia mutated (ATM), a master regulator of cell cycle checkpoints that tests for DNA damage. This application aims to identify the function of this protein and to determine how it interacts with the signaling cascades in developing thymocytes. Changes in gene expression profiles in the knockout thymocytes before and during positive selection signaling will be identified. Potential functional regions of the protein will be identified and analyzed for their role in developing thymocytes, including a nuclear localization sequence, a site for phosphorylation by ATM, an SH3-binding site and others. The dynamics of the interaction with Itk and PLC-gamma will be investigated using FRET microscopy and fluorescence complementation. The induction of cell death or differentiation in developing T cells is crucial for avoiding autoimmunity, and for building a functional immune system. This newly discovered protein appears to regulate these processes, thus this project will uncover how this novel protein functions.