概括
研究人员调整了大肠杆菌的lac操作员和抑制剂,用于哺乳动物细胞. 这些遗传元素在生理上起作用,允许哺乳动物系统中的基因调节.
科学领域:
- 分子生物学分子生物学
- 哺乳动物细胞培养
- 基因规则 基因规则
背景情况:
- 细菌的lac操作提供了一个良好的基因调节特征系统.
- 适应 prokaryotic 调节元件用于真核系统对于先进的基因工程至关重要.
研究的目的:
- 为了研究哺乳动物细胞内的大肠杆菌乳液操作者和抑制器系统的功能.
- 为了确定乳酸抑制剂是否可以调节哺乳动物环境中由乳酸操作者驱动的基因表达.
主要方法:
- 构建含有与SV40早期促进体驱动记者基因 (大T抗原或氨基醇乙烯转移酶) 相关的lac操作体的等离子体.
- 在哺乳动物细胞中进行体外转录试验和体内基因表达研究.
- 与等离子体编码乳液抑制剂的共传染实验和IPTG (异烯β-D-1-thiogalactopyranoside) 的治疗.
主要成果:
- 细菌乳酸抑制剂在体外抑制了来自乳酸操作者含有促进物的转录.
- 基因表达 (大T抗原合成和CAT活性) 在体内被抑制,当LAC抑制剂存在时.
- 抑制是剂量依赖的,由IPTG可逆,证明生理功能.
- 压抑CAT活动与降低CATmRNA水平相关,表明转录控制.
结论:
- 大肠杆菌的调节元件可成功地适应并在哺乳动物细胞中生理功能.
- 这表明了使用细菌遗传调节系统在真核生物中控制基因表达的潜力.
- 这些发现为哺乳动物系统中可诱导的基因表达策略开辟了道路.
相关概念视频
02:09Operons
Prokaryotes can control gene expression through operons—DNA sequences consisting of regulatory elements and clustered, functionally related protein-coding genes. Operons use a single promoter sequence to initiate transcription of a gene cluster (i.e., a group of structural genes) into a single mRNA molecule. The terminator sequence ends transcription. An operator sequence, located between the promoter and structural genes, prohibits the operon’s transcriptional activity if bound by a repressor...
01:58Prokaryotic Transcriptional Activators and Repressors
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
02:04Co-activators and Co-repressors
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
01:58Prokaryotic Transcriptional Activators and Repressors
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
01:23Operon Model
The operon model represents a fundamental mechanism of gene regulation in prokaryotes, enabling coordinated expression of genes involved in related metabolic or functional pathways. Operons consist of structural genes, a promoter, and an operator, with transcription regulated by repressors, activators, and small effector molecules.Structure and Function of OperonsAn operon is a cluster of structural genes transcribed together under the control of a single promoter. The promoter region...
01:25Inducible Operons: lac Operon
The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside...