P53 AND UV REGULATION OF P53 BINDING PROTEIN BBP/53BP2

P53 和 P53 结合蛋白 BBP/53BP2 的 UV 调节

• 批准号: 6089852
• 负责人: CHARLES D LOPEZ
• 金额: $ 13.29万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-07 至 2005-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6089852
• 关键词: DNA damage; binding proteins; cell line; gene induction /repression; neoplasm /cancer genetics; p53 gene /protein; radiation genetics; tissue /cell culture; ultraviolet radiation

DESCRIPTION (Applicant's Description): The tumor suppressor p53 gene is mutated in over 50 percent of human cancers and plays a pivotal role in mediating the cellular responses to genotoxic stress. Therefore, it is critical to our understanding of cancer to study the complex pathways defined by p53-interacting proteins. Bbp/53BP2 protein binds to wild-type p53; the crystal structure of the p53-Bbp/53BP2 complex reveals the Bbp/53BP2 binding site on p53 consists of evolutionarily conserved regions frequently mutated in cancer. Bbp/53BP2 also interacts in vitro with the apoptosis regulating protein Bcl-2, enhances p53-mediated transcriptional activation, and impedes c e l l cycle progression. However, the mechanisms regulating Bbp/53BP2 expression are unknown. The candidate has found that wild-type (but not mutant) p53 can suppress Bbp/53BP2 protein expression, but that Bbp/53BP2 protein is induced following UV-irradiation. Thus, wild-type p53 is a key regulator of its binding partner Bbp/53BP2, and this regulation is modulated by UV-induced DNA-damage. The long-range goal of this project is to understand how the function of Bbp/53BP2 relates to cancer. The objective of this proposal is to determine how Bbp/53BP2 expression is regulated and how this affects cellular physiology. The central hypothesis of this proposal is that Bbp/53BP2 protein complexed to wild-type p53 is degraded in unstressed cells but not in UV-damaged cells, resulting in the upregulation of Bbp/53BP2 protein in response to UV-irradiation. The rationale for the proposed research is that once the mechanisms regulating Bbp/53BP2 expression are known, then the in vivo consequences of its interactions with p53 and Bcl-2 can be studied. The hypothesis will be tested by pursuing three specific aims: 1). Determine how wild-type p53 downregulates Bbp/53BP2 expression, 2). Determine how UV-irradiation upregulates Bbp/53BP2 expression, and 3). Determine the role of Bbp/53BP2 expression in the cellular response to UV-irradiation. The proposed work is innovative because it capitalizes on Bbp/53BP2 and p53 inducible cell lines to study the functional consequences of their interaction in the presence or absence of cellular damage. It is expected that this approach will identify p53-dependent and UV-damage inducible mechanisms controlling Bbp/53BP2. This is significant because understanding how Bbp/53BP2 is modulated by p53 and UV- irradiation will define new regulatory pathways involved in the cellular response to DNA-damage. The proposed training program is in a dynamic research environment with extensive intellectual and technical support. Thus, the candidate will acquire the skills to secure a faculty position in academic medical oncology.

描述（申请人的描述）：肿瘤抑制基因 p53 是 在超过 50% 的人类癌症中发生突变，并在 介导细胞对基因毒性应激的反应。 因此，它是 研究定义的复杂途径对于我们理解癌症至关重要 通过 p53 相互作用蛋白。 Bbp/53BP2 蛋白与野生型 p53 结合；这 p53-Bbp/53BP2 复合物的晶体结构揭示了 Bbp/53BP2 结合 p53 上的位点由进化上保守的区域组成，这些区域经常发生突变 癌症。 Bbp/53BP2 也在体外与细胞凋亡调节相互作用 蛋白 Bcl-2，增强 p53 介导的转录激活，并阻碍 细胞周期进程。 然而，调节 Bbp/53BP2 的机制 表达方式未知。 候选人发现野生型（但不是 突变体）p53可以抑制Bbp/53BP2蛋白表达，但Bbp/53BP2 蛋白质在紫外线照射后被诱导。 因此，野生型p53是关键 其结合伙伴 Bbp/53BP2 的调节器，并且该调节受到调节 由紫外线引起的 DNA 损伤。该项目的长期目标是了解 Bbp/53BP2 的功能与癌症有何关系。 此举的目的 提议是确定 Bbp/53BP2 表达是如何调节的以及如何调节 影响细胞生理学。该提案的中心假设是 与野生型 p53 复合的 Bbp/53BP2 蛋白在未受应激的细胞中被降解 但在紫外线损伤的细胞中则不然，导致 Bbp/53BP2 上调 蛋白质对紫外线照射的反应。拟议研究的理由 一旦调节 Bbp/53BP2 表达的机制已知，那么 它与 p53 和 Bcl-2 相互作用的体内后果可以是 研究过。 该假设将通过追求三个具体目标来检验：1）。 确定野生型 p53 如何下调 Bbp/53BP2 表达，2)。决定 紫外线照射如何上调 Bbp/53BP2 表达，以及 3)。确定 Bbp/53BP2 表达在细胞对紫外线照射的反应中的作用。这 拟议的工作具有创新性，因为它利用了 Bbp/53BP2 和 p53 诱导细胞系来研究它们相互作用的功能后果 在存在或不存在细胞损伤的情况下。预计这 方法将确定 p53 依赖性和紫外线损伤诱导机制 控制 Bbp/53BP2。这很重要，因为了解 Bbp/53BP2 如何 受 p53 调节，紫外线照射将定义新的调控途径 参与细胞对 DNA 损伤的反应。拟议的培训计划 处于一个充满活力的研究环境中，拥有广泛的知识和技术 支持。 因此，候选人将获得获得教师资格的技能 在学术肿瘤学中的地位。