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，其标志是面部异常，上肢缺陷，杂毛，胃肠道缺陷，认知延迟和迟缓的生长。最近发现基因NIPBL中的突变引起CDL，为临床异质性疾病的分子基础提供了第一条线索。 NIPBL蛋白与果蝇黑色素蛋白蛋白Nipped-B同源，该蛋白通过远程增强子参与基因激活。我发现了NIPBL与异染色质蛋白1家族（HP1）之间的相互作用，该家族为NIPBL提供了第一个定义的分子缔合，并指出了NIPBL在基于染色体素基因调控中的生物学作用。此外，酵母中的NIPBL和HP1同源物在姐妹染色质被内是在将复制的染色体保持在一起直至有丝分裂的。已经区分了两种主要类型的染色质，即异染色质和全染色质，它们用于将真核基因组组织到功能域中。这样的领域是可遗传的，并且在表观遗传水平上起作用。那就是它们独立于潜在的DNA序列，但高度依赖于染色质蛋白复合物。表观遗传基因调节经常在发育过程中使用，对于细胞稳态至关重要。异染色质的主要特征是沉默的基因，冷凝DNA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，而HP1的降低会导致细胞异常的生长。我们建议NIPBL和HP1形成调节基因表达的复杂，并且在CDLS个体中破坏了该功能。我们将通过确定NIPBL是否影响HP1基因沉默的HP1活性来检验这一假设，该假设使用突变的NIPBL在人和小鼠细胞中的HP1基因沉默。我们还将在细胞中定位和分离NIPBL-HP1复合物，并检查由HP1和NIPBL共同调节的基因的染色质结构。这些研究将使人们更好地了解CDL中NIPBL突变引起的分子缺陷，并启动一项重要的研究，该研究可能会典型地体现出在发育过程中表观遗传控制丧失的复杂疾病。