C21, a Transcriptional Regulator in Hematopoiesis

C21，造血转录调节因子

• 批准号: 6667252
• 负责人: ROSS S BASCH
• 金额: $ 38.03万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6667252
• 关键词: cell differentiation; cell growth regulation; cell line; clinical research; cytogenetics; fibroblasts; flow cytometry; gene expression; genetic regulation; genetically modified animals; hematopoiesis; immunoprecipitation; laboratory mouse; mass spectrometry; matrix assisted laser desorption ionization; microarray technology; myeloid stem cell; protein protein interaction; site directed mutagenesis; transcription factor; yeast two hybrid system

DESCRIPTION (provided by applicant): The C21 gene encodes a family of proteins that play a role in transcriptional regulation. Over-expression of C21 in mouse hematopoietic cells alters myeloid development and suggest that members of this family are involved in regulating stem cell differentiation. Over-expressing C21 in 3T3 fibroblasts increases their resistance to apoptotic stimuli. C21 forms a complex with the class of nuclear co repressors of which the best known mammalian forms are N-CoR (nuclear receptor co-repressor) and SMRT (silencing mediator of retinoid and thyroid receptor). C21 binds to the co-repressors and appears to interfere with the ubiquitin-mediated proteolysis of the co-repressors, causing an elevation of the co-repressor concentration. Members of the family are expressed at high levels in fetal hematopoietic tissues as well as in many hematopoietic cell lines. Like many WD40 proteins, C21 family members appear to act by serving as an adaptor or bridge, facilitating the interaction of proteins that do not interact directly. Four Aims are addressed in this proposal. Aim 1. To identify the proteins that interact with C21. C21 family proteins act as adaptors, bringing together molecules that must interact functionally but that lack intrinsic affinity for each other. The identification of the interacting molecules is critical for any understanding of how C21 family to regulate transcription. Aim 2. To determine how C21 alters transcriptional regulation. Aim 3. To analyze the consequences of the interaction of C21 with the repressor complex by identifying the pathways regulated by this interaction. Microchip expression arrays will be probed with cDNAs obtained from fibroblasts, hematopoietic cell lines and embryonic stem (ES) cells that conditionally over-express C21 to identify the pathways that respond to alterations in C21 expression. Aim 4. To identify the functional consequences of the interaction in vivo. The effects of over-expression and targeted deletion of C21 cDNA in transgenic mice and in culture will be studied. Mouse embryonic stem cells (ESC) will be used to analyze the effects of over-expression of C21 cDNA on early hematopoietic development and the effects on myeloid development will be examined by studying the retinoic acid-induced differentiation of HL60 and U937 myeloid leukemia cells.

描述(申请人提供)：C21基因编码一个蛋白质家族，在转录调控中发挥作用。小鼠造血细胞中C21的过度表达改变了髓系细胞的发育，并表明该家族的成员参与了干细胞分化的调节。在3T3成纤维细胞中过表达C21可增强其对凋亡刺激的抵抗力。C21与核共抑制子形成复合体，其中最常见的哺乳动物形式是N-COR(核受体共抑制子)和SMRT(维甲酸和甲状腺受体沉默介体)。C21与共抑制子结合，似乎干扰了泛素介导的共抑制子的蛋白分解，导致共抑制子浓度升高。该家族成员在胎儿造血组织和许多造血细胞系中高水平表达。像许多WD40蛋白一样，C21家族成员似乎通过充当适配器或桥梁来发挥作用，促进不直接相互作用的蛋白质之间的相互作用。这项提案涉及四个目标。目的1.鉴定与C21相互作用的蛋白质。C21家族蛋白充当接头，将必须在功能上相互作用但彼此缺乏内在亲和力的分子聚集在一起。相互作用分子的鉴定对于理解C21家族如何调控转录至关重要。目的2.确定C21如何改变转录调控。目的3.通过确定C21与抑制子复合体相互作用的调控途径，分析这种相互作用的后果。微芯片表达阵列将与从成纤维细胞、造血细胞系和有条件地过度表达C21的胚胎干细胞中获得的cDNA进行探测，以确定对C21表达变化做出反应的途径。目的4.确定体内相互作用的功能后果。将研究C21基因在转基因小鼠和培养中的过度表达和靶向缺失的影响。利用小鼠胚胎干细胞(ESC)分析C21基因过表达对早期造血发育的影响，并通过研究维甲酸对HL60和U937髓系白血病细胞的诱导分化作用来研究其对髓系发育的影响。