bcl-x,一个与bcl-2相关的基因,其功能是作为细胞亡细胞死亡的主导调节器
L H Boise1, M González-García, C E Postema
1Howard Hughes Medical Institute, Department of Medicine, University of Chicago, Illinois 60637.
Cell
|August 27, 1993
概括
我们发现了bcl-x,这是一种调节受程序细胞死亡 (细胞亡) 的基因. 它的两种形式,bcl-xL和bcl-xS,在细胞存活和死亡方面具有相反的作用,影响细胞循环和寿命.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 遗传学 是一个遗传学.
背景情况:
- 编程细胞死亡或细胞亡对于发育和组织平衡至关重要.
- BCL-2基因家族在调节亡中发挥着关键作用.
- 了解亡的新型调节者对于各种生物过程至关重要.
研究的目的:
- 隔离和描述与BCL-2相关的新型基因.
- 研究不同bcl-x基因产物在调节亡中的功能.
- 在体内确定bcl-x异型的表达模式.
主要方法:
- 对bcl-x基因的隔离.
- 通过替代拼接对bcl-xmRNA的分析.
- 稳定的bcl-xL转化为依赖IL-3的细胞系.
- 在增长因子被取消后评估细胞死亡.
- 在不同组织中bcl-xmRNA的体内表达分析.
主要成果:
- 该bcl-x基因通过替代拼接产生两个不同的mRNA物种:bcl-xL和bcl-xS.
- 在缺乏生长因子的细胞中,bcl-xL蛋白与bcl-2类似地抑制细胞死亡.
- 该bcl-xS蛋白质对抗bcl-2的促进生存的作用.
- 在快速翻转的细胞 (如淋巴细胞) 中bcl-xS的表达很高,而bcl-xL在长寿细胞 (如成年大脑) 中被发现.
结论:
- bcl-x基因是编程细胞死亡的bcl-2-独立调节者.
- 替代拼接产生功能上不同的bcl-x异型,在亡中起相反的作用.
- bcl-x在促进和抑制编程细胞死亡方面发挥着重要作用.
- bcl-x异型的差异表达表明它们在调节细胞存活和循环中的组织特异性作用.
相关概念视频
01:31The Intrinsic Apoptotic Pathway
7.2K
Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
7.2K
01:17The Extrinsic Apoptotic Pathway
6.9K
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
6.9K
01:24Caspases
12.9K
Caspase, a family of cysteine proteases, serve as effectors in apoptosis. The ced3 gene in C.elegans was first identified to be involved in apoptosis. This gene encodes the ced-3 caspase that is similar to the interleukin-1-beta converting enzyme or ICE in mammals. In addition to apoptosis, caspases also function in the inflammatory response. Inflammatory caspases are essential in activating pro-inflammatory cytokines that recruit immune cells and block the replication of pathogens inside...
12.9K
01:30Apoptosis
12.5K
Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size...
12.5K
02:23Abnormal Proliferation
4.8K
Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the...
4.8K
01:23Negative Regulator Molecules
37.0K
Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
37.0K