在体外通过转基因稳定转录因子-核细胞组合体进行核细胞核位移
1Department of Molecular Biology, Massachusetts General Hospital, Boston 02114.
概括
像GAL4这样的转录因子可以取代核体,核体是DNA结合结构. 这一发现揭示了通过改变DNA可访问性来调节基因的机制.
科学领域:
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 染色体动力学 染色体动力学
背景情况:
- 转录因子通过与特定的DNA序列结合来调节基因表达.
- 染色体结构,特别是核体,可以阻碍转录因子进入DNA.
- 了解转录因子如何克服染色素障碍对于基因调节至关重要.
研究的目的:
- 研究转录因子与核细胞相互作用并可能取代核细胞的机制.
- 为了确定单独的DNA结合域是否足以导致核子体不稳定.
主要方法:
- 利用酵母GAL4蛋白的DNA结合域作为模型转录因子.
- 研究了GAL4与孤立的核细胞核颗粒的相互作用.
- 通过使用竞争对手DNA,评估了由此产生的复合物的稳定性.
主要成果:
- GAL4与核细胞核颗粒结合,形成了一个不稳定的三元复合体,其中包含了基质子和DNA.
- 这种复合物在添加竞争性DNA后分离,产生自由核体或与裸体DNA结合的GAL4.
- 通过GAL4的核细胞破坏稳定性并不取决于其转录激活域.
结论:
- 调节因素,如GAL4,可以直接从DNA中取代核细胞核.
- 这种位移机制在体内可能对确定转录因子对促进剂和增强剂的结合至关重要.
- 研究结果提供了关于转录因子和染色体结构之间的动态相互作用的见解.
相关概念视频
Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...
Nuclear Protein Sorting
Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell.
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
Introduction to Nuclear Reprogramming
Nuclear reprogramming is the process of switching gene expression of one cell type to that of another cell type, usually from a differentiated cell state to an undifferentiated cell state. Differentiation occurs during processes such as development and morphogenesis, tissue regeneration, and malignancy. Cells can also be artificially induced to reprogram their gene expression by techniques such as nuclear transfer, induced pluripotency, and cell fusion. Such techniques have many applications in...
Methods of Nuclear Reprogramming
Nuclear reprogramming is a process of transforming one cell type into an unrelated cell type by epigenetic changes that alter the cell’s original gene expression pattern. Such epigenetic changes force cells to express a different set of genes, which play a significant role in inducing transformation into other cell types. Nuclear reprogramming offers applications in reproductive cloning for livestock propagation and regenerative medicine — developing patient-specific cells for injury repair.


