MORT1 in Apoptosis of Malignant and Primary T cells

描述（由申请人提供）：Morti或FADD （Fas相关死亡结构域）最初被分离为传递Fas凋亡信号的适配器分子。FADD随后被证明是Fas以及其他属于肿瘤坏死因子受体超家族的含有死亡结构域的受体所减轻的细胞凋亡所必需的。然而，在研究FADD在体内的作用过程中，我们发现FADD在小鼠胚胎发生和T细胞增殖中也起着重要的作用。FADD缺陷小鼠在妊娠第11天左右在子宫内死亡，FADD-/- RAG-1-/-嵌合体的成熟T细胞功能缺陷。这些T细胞表现出细胞周期异常和细胞周期机制的异常调节。同样，对T细胞特异性fadd缺陷小鼠的表征表明，fadd缺陷导致T细胞在未成熟T细胞增殖阶段发育停滞。有趣的是，FADD在细胞周期的GJM期被g2im特异性激酶磷酸化，这表明FADD磷酸化可能在细胞周期进程中很重要。在这个应用中，我们提出了三个特定的目标，旨在了解FADD在增殖中的作用。在目的1中，将产生和分析磷酸化缺陷和组成性磷酸化的FADD小鼠。我们将进一步研究FADD磷酸化在细胞增殖、细胞凋亡和小鼠胚胎发生中的作用。在目的2中，将通过产生FADD突变小鼠来评估含有死亡结构域的受体在增殖和小鼠发育中的作用，该突变小鼠在FADD死亡结构域处含有点突变，从而削弱其适配功能。这将允许在没有任何死亡域受体功能的小鼠体内进行研究。在目标3中，将研究FADD在增殖过程中如何发挥作用的分子机制。DNA微阵列将用于评估FADD/- I细胞和表达磷酸化缺陷和死亡结构域缺陷FADD的I细胞的基因表达谱。酵母- 2杂交系统和生化分析将用于分离和表征新的fadd相互作用蛋白。成功完成这些目标将导致对细胞凋亡和增殖如何协调以及增殖如何主导癌细胞凋亡途径的重要理解。

DESCRIPTION (provided by applicant): Morti or FADD (Fas associated death domain) was initially isolated as an adapter molecule that transmits the Fas apoptotic signals. FADD was subsequently shown to be required for apoptosis mitigated by Fas as well as other death-domain containing receptors that belong to the tumor necrosis factor receptor superfamily. However, during the course of studying the role of FADD in vivo, it was discovered that FADD also plays an essential function in mouse embryogenesis and in T cell proliferation. FADD-deficient mice die in utero around day 11 of gestation and mature T cells in FADD-/- RAG-1-/- chimeras are functionally defective. These T cells exhibit cell cycle abnormalities and aberrant regulation of the cell cycle machinery. Similarly, characterization of T-cell specific FADD-deficient mice showed that FADD-deficiency leads to an arrest of T cell development at the stage of immature T cell proliferation. Interestingly, FADD is phosphorylated during GJM phase of the cell cycle by a G2IM-specific kinase, suggesting that FADD phosphorylation may be important during cell cycle progression. In this application, we propose three specific aims that are designed to understand how FADD functions in proliferation. In aim 1, phosphorylation-defective and constitutive phosphorylated FADD mice will be generated and analyzed. The role of FADD phosphorylation in proliferation and apoptosis as well as mouse embryogenesis will be studied. In aim 2, the role of death-domain containing receptors in proliferation and mouse development will be assessed by generating mutant FADD mice that contain a point mutation at the FADD death domain to cripple its adapter function. This should allow studies of mice devoid of any death-domain receptor function in vivo. In aim 3, the molecular mechanisms of how FADD might function during proliferation will be studied. DNA microarrays will be used to assess gene expression profile of FADD/- I cells and I cells expressing phosphorylation-defective and death-domain defective FADD. The yeast-two hybrid system and biochemical analysis will be used to isolate and characterize novel FADD-interacting proteins. Successful completion of these aims should lead to a significant understanding of how apoptosis and proliferation are coordinated and how proliferation might dominate over apoptotic pathway in cancer cells.