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: 8631091
• 负责人: KATHRYN MEDLER
• 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/8631091
• 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.

描述（由申请人提供）： Wilms 肿瘤 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。 WT1 的这些不同活性是如何调节的尚不清楚，但对于确定其在多种癌症中的作用具有重要意义。我们的长期目标是了解 WT1 在发育和疾病中调节转录的机制。 BASP1 是 WT1 的关键调节因子，可将其功能从转录激活因子转换为阻遏因子，并通过在靶基因的控制区域与 WT1 结合来发挥作用。我们的新发现是，BASP1 的 N 端肉豆蔻酰化以及 BASP1 与磷脂酰肌醇 4,5-二磷酸 (PIP2) 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，BASP1 是一个大型多蛋白复合物的一部分，该复合物包含转录抑制因子抑制素和组蛋白脱乙酰酶活性。 当前提案的目标是为 WT1-BASP1 转录调节所涉及的机制和 PIP2 的新作用提供重要的新见解。具体目标是： 1. 阐明BASP1-PIP2相互作用控制WT1转录功能的机制。将使用 ChIP、转录分析和共定位方法研究 PIP2 在 WT1-BASP1 通过染色质重塑和 RNA 聚合酶 II 活性进行转录调节中的作用。这些研究将为基因特异性调控因子转录抑制的新机制提供新的见解。 2. 分离BASP1复合物的组成部分并研究它们在WT1调节中的功能。我们最近确定了转录阻遏蛋白抑制素和组蛋白脱乙酰酶 I 是 BASP1 复合物的组成部分，将对其进行进一步分析以确定其作用机制。该复合物的其他成分将被鉴定，并阐明它们在 BASP1 介导的转录抑制中的作用。 3. 确定 BASP1 复合物和 PIP2 在 WT1 分化控制中的作用。依赖于 WT1 和 BASP1 活性的足细胞分化细胞系模型将用于鉴定 BASP1 复合物的关键成分，并揭示 PIP2 在驱动分化过程的 WT1 依赖性基因表达中的作用。