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）最初作为传递Fas凋亡信号的衔接子分子分离。FADD随后被证明是由Fas以及属于肿瘤坏死因子受体超家族的其他含有死亡结构域的受体减轻的细胞凋亡所需的。然而，在研究FADD在体内的作用的过程中，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天左右死于子宫内，并且FADD-/- RAG-1-/-嵌合体中的成熟T细胞是功能缺陷的。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。类似地，T细胞特异性FADD缺陷小鼠的表征表明，FADD缺陷导致T细胞发育在未成熟T细胞增殖阶段的停滞。有趣的是，FADD在细胞周期的GJM期被G2 IM特异性激酶磷酸化，表明FADD磷酸化在细胞周期进程中可能是重要的。在这个应用程序中，我们提出了三个具体的目标，旨在了解FADD如何在增殖中发挥作用。在目的1中，将产生并分析磷酸化缺陷型和组成型磷酸化FADD小鼠。将研究FADD磷酸化在增殖和凋亡以及小鼠胚胎发生中的作用。在目的2中，将通过产生突变FADD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，所述突变FADD小鼠在FADD死亡结构域处含有点突变以削弱其衔接子功能。这将允许对缺乏任何死亡结构域受体功能的小鼠进行体内研究。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型和死亡结构域缺陷型FADD的I细胞的基因表达谱。酵母双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。这些目标的成功完成将导致对凋亡和增殖如何协调以及增殖如何在癌细胞中主导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.