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)是一种以面部畸形、上肢缺陷、多毛症、胃肠道缺陷、认知障碍和生长迟缓为特征的先天性多系统疾病。最近，基因NIPBL的突变被发现导致了CDLS，为临床上异质性疾病的分子基础提供了第一条线索。NIPBL蛋白与果蝇黑腹蛋白NIPP-B同源，NIPB参与远程增强子激活基因。我已经发现了NIPBL和异染色质蛋白1家族(HP1)之间的相互作用，这为NIPBL提供了第一个明确的分子联系，并指出了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同源物都在姐妹染色单体凝聚中发挥作用，使复制的染色体保持在一起，直到有丝分裂。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区。这些结构域是可遗传的，并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质复合体。表观遗传基因调控在发育过程中经常被使用，并且对于细胞内稳态是必不可少的。异染色质的主要特征是沉默的基因、浓缩的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因子，HP1的减少可导致细胞异常生长。我们认为NIPBL和HP1形成一个调节基因表达的复合体，这一功能在CDLS个体中被破坏。我们将通过确定NIPBL是否影响HP1活性来验证这一假设，在已建立的具有突变NIPBL的人和小鼠细胞中HP1基因沉默的测试中。我们还将在细胞中定位和分离NIPBL-HP1复合体，并检查那些由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CDL中NIPBL突变引起的分子缺陷，并启动一项重要的研究，潜在地例证复杂的疾病，这些疾病的根源是在发育过程中失去表观遗传控制。