NOVEL GENE DISCOVERED IN THE HEART

在心脏中发现的新基因

• 批准号: 2750649
• 负责人: WILLIAM C CLAYCOMB
• 金额: $ 20.09万
• 依托单位: LSU HEALTH SCIENCES CENTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-05 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2750649
• 关键词: cardiac myocytes; cell line; cell proliferation; developmental genetics; gene expression; genetic mapping; immunoprecipitation; laboratory rat; muscle proteins; nucleic acid sequence; tissue /cell culture; yeast two hybrid system

Development of the heart requires the precise spatial and temporal control of gene expression for proliferation and differentiation. During embryonic and early neonatal development, the heart grows by cell proliferation. Further growth is later established through cell enlargement, or cardiac hypertrophy. Cardiac muscle cell proliferation appears to be regulated by a separate program, distinct from the program which controls differentiation of the myocyte, unlike most other cell types. The mechanisms governing the control of cardiomyocyte proliferation are yet to be established. An understanding of these mechanisms will provide an avenue of opportunity to manipulate cellular proliferation to replace and/or repair damaged tissue sustained from cardiovascular disease. We have identified, cloned and sequenced a novel gene (TAP) in the heart which is expressed in association with myocyte proliferation. Preliminary western analysis show that the Tap protein is expressed only in the dividing cardiomyocyte and is virtually absent from the non dividing myocyte. Our hypothesis predicts that TAP is a necessary component of a signal transduction pathway required for cardiomyocyte proliferation. Our long term goal is to determine the function of Tap in the dividing myocyte. Our specific aims are to: (1) Identify cellular proteins which associated with Tap in the cardiomyocyte using the yeast two-hybrid screen and co-immunoprecipitation in order to determine how Tap may function in the cell. (2) To begin to functionally characterize Tap by over expressing and blocking its expression in cultured adult, 21-day postnatal and embryonic rat ventricular cardiomyocytes and in the HL-1 cardiac muscle cell line. Since this gene is entirely novel these studies will provide the first indication of the functional role of TAP in the myocyte, and provide a foundation for the design of rational, future in depth studies.

心脏的发育需要对增殖和分化的基因表达进行精确的空间和时间控制。 在胚胎和早期新生儿发育过程中，心脏通过细胞增殖而生长。 随后通过细胞增大或心脏肥大建立进一步的生长。 与大多数其他细胞类型不同，心肌细胞增殖似乎由单独的程序调节，该程序不同于控制肌细胞分化的程序。 控制心肌细胞增殖的机制尚未建立。 对这些机制的理解将为操纵细胞增殖以替换和/或修复因心血管疾病而受损的组织提供机会。我们已经鉴定、克隆并测序了心脏中的一个新基因（TAP），该基因的表达与心肌细胞增殖相关。 初步的 Western 分析表明 Tap 蛋白仅在分裂的心肌细胞中表达，并且在非分裂的心肌细胞中几乎不表达。 我们的假设预测 TAP 是心肌细胞增殖所需的信号转导途径的必要组成部分。我们的长期目标是确定 Tap 在分裂肌细胞中的功能。 我们的具体目标是：（1）利用酵母双杂交筛选和免疫共沉淀鉴定心肌细胞中与Tap相关的细胞蛋白，以确定Tap如何在细胞中发挥作用。 (2) 通过在培养的成年、出生后 21 天和胚胎大鼠心室心肌细胞以及 HL-1 心肌细胞系中过度表达和阻断 Tap 的表达，开始对 Tap 进行功能表征。 由于该基因是全新的，这些研究将首次表明 TAP 在肌细胞中的功能作用，并为设计合理的、未来的深入研究奠定基础。