MYELOID REGULATION OF CD18 TRANSCRIPTION

CD18 转录的骨髓调控

• 批准号: 2143991
• 负责人: ALAN G ROSMARIN
• 金额: $ 12.52万
• 依托单位: MIRIAM HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2143991
• 关键词: CD antigens; DNA binding protein; DNA footprinting; cell differentiation; cell growth regulation; cholecalciferol; gel mobility shift assay; genetic enhancer element; genetic promoter element; genetic regulation; genetic regulatory element; genetic transcription; genetically modified animals; integrins; laboratory mouse; leukocyte adhesion molecules; myeloid stem cell; phorbols; polymerase chain reaction; retinoate; tissue /cell culture; transcription factor; transfection

Differentiation is intimately linked to tightly regulated temporal, quantitative,and tissue-specific gene expression. Knowledge of the molecular control of gene expression during myeloid differentiation is limited by a paucity of well defined models for this process. CD18 is the Beta chain of the leukocyte integrins, a family of antigens which mediate cell adhesive functions that are critical to the immune and inflammatory responses. In adequate expression of CD18 causes the severe immunodeficiency known as Leukocyte Adhesion Deficiency (LAD). Because CD18 transcription increases markedly during myeloid differentiation, this gene provides a relevant model for lineage-specific gene transcription during myeloid differentiation. The CD18 gene has been cloned, and the promoter and flanking regions isolated. The CD18 promoter contains potential AP-1, CREB, and Oct sites; a binding site for the leukocyte specific transcription factor PU.1; a putative myeloid specific element; and a potential retinoic acid response element. The CD18 promoter directs expression in a leukocyte-specific manner, and is responsive to phorbol ester and retinoic acid induced myeloid differentiation. By sequential deletion, a region encoding high level myeloid activity was localized. Binding to two sites in this region by PU.1 is required for high level myeloid activity of the CD18 promoter. Scanning mutagenesis of the promoter localized other positive and negative regulatory elements. Numerous nuclear proteins bind to the CD18 promoter in electrophoretic mobility shift assay (EMSA) and DNAse I footprinting. Some of these factors, including other ets family members and the Sp1 transcription factor, have now been identified. This proposal seeks to identify the cis DNA elements and the trans acting factors which regulate CD18 expression. Transient and stable transection will be used to define the functional DNA elements which control lineage- specific and inducible CD18 expression EMSA and DNAse I footprinting will be used to further characterize nuclear factors which bind to CD18 regulatory DNA elements. Greater understanding of the molecular control of CD18 expression may have an impact on the pathogenesis and therapy of LAD. Because chromosomal rearrangements in some forms of acute leukemia generate novel proteins which resemble transcription factors, myeloid trans acting factors may play an important etiologic role in leukemia.

分化与严格调节的时间密切相关， 定量和组织特异性基因表达。 了解 髓样分化过程中基因表达的分子控制是 受此过程定义明确的模型的限制。 CD18是 白细胞整合蛋白的β链，这是一个抗原家族 介导对免疫至关重要的细胞粘附功能 炎症反应。 在充分表达CD18中会导致严重 免疫缺陷称为白细胞粘附缺乏症（LAD）。 因为 CD18转录在髓样分化期间明显增加， 该基因为谱系特异性基因提供了相关模型 髓样分化过程中的转录。 CD18基因已经 克隆，启动子和侧翼区域分离出来。 CD18 启动子包含潜在的AP-1，CREB和OCT位点；一个结合位点 白细胞特异性转录因子pu.1;推定的髓样 特定元素；以及潜在的视黄酸反应元件。 这 CD18启动子以白细胞特异性的方式指导表达，并且 对佛波尔酯和视黄酸的反应诱导髓样 分化。 按顺序删除，编码高水平的区域 髓样活动是局部的。 通过 PU.1是CD18启动子的高水平髓样活性所必需的。 启动子的扫描诱变将其他阳性和 负调节元素。 许多核蛋白与CD18结合 电泳迁移率分析（EMSA）和DNase I的启动子I 足迹。 其中一些因素，包括其他ETS家庭成员 现在已经确定了SP1转录因子。 这 提案旨在确定顺式DNA元素和反式代理 调节CD18表达的因素。 瞬态和稳定的横向 将用于定义控制谱系的功能性DNA元件 特定且可诱导的CD18表达EMSA和DNase I足迹将 用于进一步表征与CD18结合的核因子 调节性DNA元素。 对分子对照的更多了解 CD18表达可能会影响 小伙子。 因为某些形式的急性白血病中的染色体重排 产生类似于转录因子的新型蛋白质，髓样 反式作用因素可能在白血病中起重要的病因作用。