C21, a Transcriptional Regulator in Hematopoiesis

C21，造血转录调节因子

• 批准号: 6546959
• 负责人: ROSS S BASCH
• 金额: $ 37.91万
• 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/6546959
• 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（由申请人提供）：C21 基因编码在转录调节中发挥作用的蛋白质家族。 C21 在小鼠造血细胞中的过度表达会改变骨髓发育，表明该家族的成员参与调节干细胞分化。 3T3 成纤维细胞中过度表达 C21 会增加其对凋亡刺激的抵抗力。 C21 与一类核辅阻遏物形成复合物，其中最著名的哺乳动物形式是 N-CoR（核受体辅阻遏物）和 SMRT（类视黄醇和甲状腺受体的沉默介体）。 C21 与辅阻遏物结合，似乎会干扰泛素介导的辅阻遏物蛋白水解，导致辅阻遏物浓度升高。该家族成员在胎儿造血组织以及许多造血细胞系中高水平表达。与许多 WD40 蛋白一样，C21 家族成员似乎通过充当接头或桥来发挥作用，促进不直接相互作用的蛋白质的相互作用。该提案提出了四个目标。 目标 1. 鉴定与 C21 相互作用的蛋白质。 C21 家族蛋白充当适配器，将必须进行功能性相互作用但彼此之间缺乏内在亲和力的分子聚集在一起。相互作用分子的识别对于理解 C21 家族如何调节转录至关重要。目标 2. 确定 C21 如何改变转录调控。目标 3. 通过确定受这种相互作用调节的途径来分析 C21 与阻遏物复合物相互作用的后果。将使用从成纤维细胞、造血细胞系和胚胎干 (ES) 细胞中获得的 cDNA 来探测微芯片表达阵列，这些细胞有条件地过表达 C21，以确定响应 C21 表达变化的途径。目标 4. 确定体内相互作用的功能后果。将研究转基因小鼠和培养物中 C21 cDNA 的过度表达和定向删除的影响。小鼠胚胎干细胞（ESC）将用于分析C21 cDNA过度表达对早期造血发育的影响，并通过研究视黄酸诱导HL60和U937髓系白血病细胞的分化来检查其对骨髓发育的影响。