A Role for PML in Genome Stability and DNA Damage Response

描述（申请人提供）：肿瘤抑制因子PML在多种细胞功能中起重要作用。近10年来在APL领域的研究已经积累了足够的信息，最终证明PML-RARA融合蛋白与急性早幼粒细胞白血病（APL）的发病机制有关。在接下来的5年里，我们将根据我们最近的一些发现，将这项资助的主要目标重新定位于PML在基因组稳定性和DNA损伤反应中的作用。我们的实验室最近报道了PML3在中心体复制和基因组稳定性中的重要作用。特异性敲除PML3导致中心体扩增，支持PML3在维持中心体完整性中的作用。我们进行了酵母双杂交筛选，并确定了几个有趣的pml3特异性相互作用蛋白。特别是PNK，一种通过碱基切除修复（BER）和非同源末端连接（NHEJ）修复DNA所必需的激酶/磷酸酶；UXT是一种新的中心体蛋白，是中心体调节因子Cdc14A的结合伙伴。我们的研究表明，PML的功能对于许多参与dna损伤反应的酶的ir诱导灶的形成是必不可少的。我们的主要假设是PML在有丝分裂期间维持中心体完整性以确保正确的染色体分离和DNA损伤反应中起重要作用。将实现下列具体目标：探讨PML3在调节中心体功能中的作用。有待验证的假设：PML3控制着中心体复制并在细胞周期进程中维持适当数量的中心体，PML3功能的丧失导致中心体扩增、染色体错分离、非整倍体和基因组不稳定。2. 了解pml3特异性相互作用蛋白的功能意义。假设有待验证：PML3特异性相互作用蛋白对中心体功能和维持基因组稳定性很重要。3. 探讨PML在DNA损伤应答中的作用。假设有待验证：PML通过调节DNA损伤修复和DNA复制相关的酶在DNA损伤应答中发挥重要作用。根据最近的报道，PML缺乏症在多种原发人类肿瘤中都有很高的发病率，了解PML在基因组稳定性和DNA损伤反应中的功能作用将为我们目前的致癌知识提供有价值的信息。

DESCRIPTION (provided by applicant): The tumor suppressor PML plays essential roles in multiple cellular functions. Investigations accomplished in the APL field over the past 10 years have accumulated sufficient information to conclusively demonstrate that PML-RARA fusion protein is responsible for the pathogenesis of acute promyelocytic leukemia (APL). Over the next 5 years we will redirect the major objectives of this grant to focus on PML's role in genome stability and DNA damage response based on several of our recent findings. Our laboratory recently reported an important role for PML3 in centrosome duplication and genome stability. Specific knockdown PML3 causes centrosome amplification supporting a role of PML3 in maintaining centrosome integrity. We performed yeast two-hybrid screening and have identified several interesting PML3-specific interacting proteins. Specially PNK, a kinase/phosphatase essential for DNA repair by base-excision repair (BER) and non-homologous end joining (NHEJ); UXT, a novel centrosomal protein and a binding partner of the centrosome regulator Cdc14A. Our study showed that PML functions are indispensable for the formation of IR-induced foci of many enzymes involve in DNA-damage response. Our main hypothesis is that PML plays important roles in maintaining centrosome integrity to ensure proper chromosome segregation during mitosis, and in DNA damage response. The following specific aims will be pursued: 1. To investigate a role for PML3 in regulating centrosome functions. Hypothesis to be tested: PML3 controls centrosome duplication and maintains an appropriate number of centrosome during cell cycle progression, loss of PML3 function leads to centorosme amplification, chromosome missegregation, aneuploidy, and genome instability. 2. To understand the functional significance of PML3-specific interacting proteins. Hypothesis to be tested: PML3- specific interacting proteins are important for centrosome functions and maintaining genome stability. 3. To investigate a role for PML in DNA damage response. Hypothesis to be tested: PML plays important role in DNA damage response by regulating the enzymes involved in DNA-damage repair and DNA replication. In light of the recent report that a high incidence of a PML-deficiency was found in a diverse origin of primary human tumors, understanding the functional roles of PML in genome stability and DNA damage response will provide valuable information to further our current knowledge in carcinogenesis.