Functional analysis of the WT1-BASP1 transcriptional repressor complex

WT1-BASP1转录抑制复合物的功能分析

• 批准号: 8246052
• 负责人: Stefan Roberts
• 金额: $ 29.37万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8246052
• 关键词: Adult; Apoptosis; Binding; Biology; Cell Line; Cells; Childhood; Clinical Trials; Complex; Data; Development; Disease; Embryo; Event; Gene Expression; Gene Targeting; Genes; Genetic Transcription; Goals; Growth; HDAC1 gene; Histone Deacetylase; Immunotherapy; Kidney; Light; Link; Malignant Childhood Neoplasm; Malignant Neoplasms; Malignant neoplasm of lung; Mediating; Modeling; Multiprotein Complexes; N-terminal; Nephroblastoma; Oncogenes; Oncogenic; Peptides; Phosphatidylinositol 4,5-Diphosphate; Phospholipids; Play; Process; Proteins; RNA Polymerase II; Regulation; Renal carcinoma; Role; Site; Solid; Transcription Coactivator; Transcription Repressor/Corepressor; Transcriptional Activation; Transcriptional Regulation; Tumor Suppressor Genes; Tumor Suppressor Proteins; WT1 Protein; WT1 gene; biological systems; cancer therapy; chromatin remodeling; cofactor; design; gene repression; insight; leukemia; malignant breast neoplasm; member; myristoylation; novel; podocyte; prohibitin; promoter; therapeutic target; transcription factor; tumor; tumorigenesis

DESCRIPTION (provided by applicant): The Wilms' tumor 1 protein is a developmental transcription factor that can either activate or repress genes involved in growth, apoptosis and differentiation. How these disparate activities of WT1 are regulated is not clear, but have important implications in determining its role in multiple cancers. Our long-term goal is to understand the mechanisms by which WT1 regulates transcription in development and disease. BASP1 is a critical regulator of WT1 that switches its function from a transcriptional activator to a repressor, and acts by binding to WT1 at the control regions of target genes. We have made the novel finding that the N-terminal myristoylation of BASP1 and the capacity of BASP1 to interact with phosphatidyinositol 4,5-bisphosphate (PIP2) is critical for its transcriptional cosuppressor function. Moreover, our recent data demonstrate that BASP1 is part of a large multiprotein complex that contains the transcriptional repressor prohibitin and histone deacetylase activity. The goal of the current proposal is to provide critical new insights into the mechanisms involved in the regulation of transcription by WT1-BASP1 and the novel role of PIP2. The specific aims are to; 1. Elucidate the mechanisms by which BASP1-PIP2 interactions control the transcription function of WT1. The role of PIP2 in transcriptional regulation by WT1-BASP1 through chromatin remodeling and RNA polymerase II activity will be investigated using ChIP, transcription analysis, and colocalization approaches. These studies will provide new insights into a novel mechanism of transcriptional repression by gene-specific regulators. 2. Isolate the components of the BASP1 complex and study their function in WT1 regulation. We have recently identified the transcriptional repressor prohibitin and histone deacetylase I as components of the BASP1 complex, which will be analyzed further to determine their mechanism of action. The other components of the complex will be identified and their role in BASP1-mediated transcriptional repression elucidated. 3. Determine the role of the BASP1 complex and PIP2 in the control of differentiation by WT1. A cell line model of podocyte differentiation that is dependent on the activities of WT1 and BASP1 will be employed to identify the critical components of the BASP1 complex, and uncover the role of PIP2 in WT1-dependent gene expression that drives the differentiation process. PUBLIC HEALTH RELEVANCE: The Wilms' tumor 1 protein WT1 acts as a tumor suppressor in childhood kidney cancer, but as an oncogene in adult malignancies. This proposal will study how the WT1 cofactor BASP1 regulates the activities of WT1. The results will provide insights into how WT1 is controlled and aid in the design of new treatments for WT1-dependent tumors.

描述（由申请人提供）： Wilms' tumor 1蛋白是一种发育转录因子，可以激活或抑制参与生长、凋亡和分化的基因。WT 1的这些不同活动是如何调节的尚不清楚，但在确定其在多种癌症中的作用方面具有重要意义。我们的长期目标是了解WT 1在发育和疾病中调节转录的机制。 BASP 1是WT 1的关键调节因子，其功能从转录激活因子转变为阻遏因子，并通过在靶基因的控制区与WT 1结合而起作用。我们发现BASP 1的N-末端肉豆蔻酰化和BASP 1与磷脂酰肌醇4，5-二磷酸（PIP 2）相互作用的能力对其转录共抑制功能至关重要。此外，我们最近的数据表明，BASP 1是一个大的多蛋白复合物，包含转录抑制剂抑制素和组蛋白脱乙酰酶活性的一部分。 当前提案的目标是为WT 1-BASP 1转录调控机制和PIP 2的新作用提供关键的新见解。具体目标是：1。阐明BASP 1-PIP 2相互作用控制WT 1转录功能的机制。将使用ChIP、转录分析和共定位方法研究PIP 2在WT 1-BASP 1通过染色质重塑和RNA聚合酶II活性进行转录调控中的作用。这些研究将为基因特异性调控因子抑制转录的新机制提供新的见解。2.分离BASP 1复合物的组分并研究它们在WT 1调节中的功能。我们最近已经确定了转录抑制物抑制素和组蛋白脱乙酰基酶I作为BASP 1复合物的组成部分，这将进一步分析，以确定其作用机制。将确定复合物的其他成分，并阐明它们在BASP 1介导的转录抑制中的作用。3.确定BASP 1复合物和PIP 2在WT 1控制分化中的作用。将采用依赖于WT 1和BASP 1活性的足细胞分化的细胞系模型来鉴定BASP 1复合物的关键组分，并揭示PIP 2在驱动分化过程的WT 1依赖性基因表达中的作用。 公共卫生相关性： 肾母细胞瘤1蛋白WT 1在儿童肾癌中作为肿瘤抑制因子，但在成人恶性肿瘤中作为癌基因。该提案将研究WT 1辅因子BASP 1如何调节WT 1的活动。这些结果将为WT 1如何控制提供见解，并有助于设计WT 1依赖性肿瘤的新治疗方法。