在培养的纤维细胞中生物钟的分子机制
K Yagita1, F Tamanini, G T van Der Horst
1Division of Molecular Brain Science, Department of Brain Sciences, Kobe University Graduate School of Medicine, Chuo-ku, Kobe 650-0017, Japan.
Science (New York, N.Y.)
|April 17, 2001
概括
哺乳动物中的周围昼夜振荡器,就像上神核 (SCN) 中的振荡器一样,具有相同的分子机制. 功能性加密染色体 (mCry) 在中央和外围组织中对这些生物节奏至关重要.
科学领域:
- 时间生物学 时间生物学
- 分子生物学分子生物学
- 哺乳动物生理学哺乳动物生理学
背景情况:
- 哺乳动物中的中央昼夜节律起器是上神核 (SCN).
- 周围组织也含有昼夜振荡器,但它们与SCN相对的分子特征尚未完全理解.
- 加密染色体 (mCry) 是已知的哺乳动物昼夜时钟的组成部分.
研究的目的:
- 为了研究培养纤维细胞中外围昼夜振荡器的分子同一性.
- 将纤维细胞振荡器与哺乳动物的SCN振荡器进行比较.
- 确定加密染色体 (mCry) 在周围昼夜节律中的作用.
主要方法:
- 利用来自mCry突变小鼠的野生类型和mCry缺陷细胞系.
- 在培养纤维细胞中分析了已知的时钟基因的时间表达特征.
- 评估mRNA节律,蛋白质定位和昼夜振荡周期长度.
主要成果:
- 外围纤维细胞振荡器表现出与SCN振荡器相同的时间表达特征.
- 关键特征如mRNA节律分相 (例如,Bmal1和mPer基因) 和蛋白质核进入延迟被保留.
- 在mCry缺乏的细胞系中没有振荡,这证实了mCry的重要作用.
- 发现mCRY蛋白可以控制这些外周节律的周期长度.
结论:
- 哺乳动物纤维细胞中的周围昼夜振荡器在分子上与SCN心脏起器完全相同.
- 功能性加密染色体 (mCry) 对于中央和外围生物钟的运行是不可或缺的.
- 这些发现突出了在不同哺乳动物组织中基础的昼夜定时的保存分子机制.
相关概念视频
01:45Positive Regulator Molecules
To consistently produce healthy cells, the cell cycle—the process that generates daughter cells—must be precisely regulated.
02:45Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
02:19Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
02:36Cells Coordinate Growth and Proliferation
Cell size is a significant factor impacting cellular design, function, and fitness. There exists some internal coordination by which cells double their masses before division, thus, achieving homeostasis. Coordination between cell growth and proliferation depends on the checkpoints in between cell cycle phases. Loss of coordination or failure in the checkpoint mechanism can drive the cell to uncontrolled growth and loss of cellular function. Like dividing cells that coordinate cellular growth,...
02:19Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
01:27Molecular Factors Affecting Cell Division
Several external and internal factors influence the initiation and inhibition of cell division. For instance, the death of nearby cells or the release of human growth hormone (hGH) promotes cell division. In contrast, lack of hGH or crowding of cells can inhibit cell division.
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...
Several proteins function as internal regulators to ensure each cell cycle stage is completed faithfully before proceeding to the next. Regulator molecules may act directly or influence the activity or production of other...