A role for the CdLS gene NIPBL in HP1 gene silencing

CdLS 基因 NIPBL 在 HP1 基因沉默中的作用

• 批准号: 7356463
• 负责人: IAN D. KRANTZ
• 金额: $ 24.21万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-15 至 2011-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7356463
• 关键词: Abnormal Cell; Affect; Binding; Biological; Biological Assay; Bruck-de Lange syndrome; California; Cell Nucleus; Cells; Characteristics; Child; Chromatin; Chromatin Structure; Chromosomes; Cognitive; Complex; Congenital Disorders; DNA; DNA Sequence; Defect; Development; Developmental Process; Disease; Dose; Drosophila melanogaster; Drosophila melanogaster Proteins; Drosophila nipped-B protein; Embryo; Enhancers; Epigenetic Process; Euchromatin; Face; Family; Fibroblasts; Gene Activation; Gene Expression; Gene Expression Regulation; Gene Silencing; Gene Targeting; Genes; Genetic; Genetic Transcription; Genome; Grant; Growth; Heterochromatin; Hirsutism; Homeostasis; Homologous Gene; Human; Individual; Laboratories; Lead; Limb Development; Localized; Low Birth Weight Infant; Mediating; Mental Retardation; Microcephaly; Mitosis; Molecular; Monitor; Mus; Mutation; Organ; Output; Patients; Pattern; Pennsylvania; Plant Roots; Promoter Regions; Protein Family; Proteins; Regulation; Regulatory Pathway; Role; Role playing therapy; Sequence Analysis; Sister Chromatid; Testing; Transcriptional Regulation; Universities; Upper Extremity; Yeasts; base; cell growth; chromatin protein; cohesion; gastrointestinal; heterochromatin-specific nonhistone chromosomal protein HP-1; loss of function; lymphoblast; mouse model; mutant; novel; nuclease; promoter; protein function; tool

DESCRIPTION (provided by applicant): Cornelia de Lange Syndrome (CdLS) is a congenital multisystem disorder marked by facial abnormalities, upper limb defects, hirsutism, gastrointestinal defects, cognitive delays and retarded growth. Recently mutations in the gene NIPBL were found to cause CdLS, providing the first clue to the molecular basis for clinically heterogeneous disease. The NIPBL protein is homologous to the Drosophila melanogaster protein, Nipped-B, which participates in gene activation by remote enhancers. I have uncovered an interaction between NIPBL and the heterochromatin protein 1 family (HP1) that provides the first defined molecular association for NIPBL and points to a possible biological role for NIPBL in chromatin-based gene regulation. In addition, both NIPBL and HP1 homologs in yeast have roles in sister chromatid cohesion, which keeps duplicated chromosomes together until mitosis. Two major types of chromatin have been distinguished, heterochromatin and euchromatin, which serve to organize eukaryotic genomes into functional domains. Such domains are heritable and function at an epigenetic level; that is they are independent of the underlying DNA sequence but are highly dependent on chromatin protein complexes. Epigenetic gene regulation is frequently employed during development and is essential for cell homeostasis. The main features of heterochromatin are silenced genes, condensed DNA and the presence of the HP1 protein. HP1 is a dose dependent regulator of epigenetic gene silencing and reductions in HP1 can lead to abnormal cell growth. We propose that NIPBL and HP1 form a complex that regulates gene expression and this function is disrupted in CdLS individuals. We will test this hypothesis by determining whether NIPBL affects HP1 activity in established assays for HP1 gene silencing in human and mouse cells with mutant NIPBL. We will also localize and isolate NIPBL-HP1 complex in cells and examine chromatin structure for those genes that are co-regulated by HP1 and NIPBL. These studies will lead to a better understanding of the molecular defects arising from NIPBL mutation in CdLS and initiates an important study that potentially exemplifies complex diseases that have roots in loss of epigenetic control during development.

描述（由申请人提供）： Cornelia de Lange 综合征 (CdLS) 是一种先天性多系统疾病，其特征为面部异常、上肢缺陷、多毛症、胃肠道缺陷、认知迟缓和生长迟缓。最近发现 NIPBL 基因突变会导致 CdLS，这为了解临床异质性疾病的分子基础提供了第一个线索。 NIPBL 蛋白与果蝇蛋白 Nipped-B 同源，后者通过远程增强子参与基因激活。我发现了 NIPBL 和异染色质蛋白 1 家族 (HP1) 之间的相互作用，为 NIPBL 提供了第一个明确的分子关联，并指出 NIPBL 在基于染色质的基因调控中可能发挥的生物学作用。此外，酵母中的 NIPBL 和 HP1 同源物在姐妹染色单体凝聚力中发挥作用，从而将重复的染色体保持在一起直至有丝分裂。染色质有两种主要类型：异染色质和常染色质，它们用于将真核基因组组织成功能域。这些结构域是可遗传的，并且在表观遗传水平上发挥作用；也就是说，它们独立于潜在的 DNA 序列，但高度依赖于染色质蛋白复合物。表观遗传基因调控在发育过程中经常使用，对于细胞稳态至关重要。异染色质的主要特征是基因沉默、DNA 浓缩和 HP1 蛋白的存在。 HP1 是表观遗传基因沉默的剂量依赖性调节剂，HP1 的减少可导致细胞生长异常。我们认为 NIPBL 和 HP1 形成调节基因表达的复合物，并且该功能在 CdLS 个体中被破坏。我们将通过在具有突变 NIPBL 的人和小鼠细胞中进行 HP1 基因沉默的既定测定中确定 NIPBL 是否影响 HP1 活性来检验这一假设。我们还将在细胞中定位和分离 NIPBL-HP1 复合物，并检查 HP1 和 NIPBL 共同调节的基因的染色质结构。这些研究将有助于更好地理解 CdLS 中 NIPBL 突变引起的分子缺陷，并启动一项重要的研究，该研究可能举例说明源于发育过程中表观遗传控制丧失的复杂疾病。