结合体分裂产生了端粒酶RNA的3'端
Jessica A Box1, Jeremy T Bunch, Wen Tang
1Stowers Institute for Medical Research, Kansas City, Missouri 64110, USA.
Nature
|December 5, 2008
概括
端粒RNA (TER1) 需要处理才能实现端粒酶的功能. 结合体独特地分裂TER1以产生其成熟的3'端,这对于染色体维护至关重要.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 处理RNA处理RNA处理
背景情况:
- 端粒保护染色体末端,并由端粒酶合成.
- 端粒酶利用RNA子单元作为反转录的模板.
- 端粒酶RNA的成熟过程,特别是它的3'端,以前是未知的.
研究的目的:
- 为了阐明在Schizosaccharomyces pombe中为端粒酶RNA (TER1) 成熟的3'端生成的机制.
- 研究RNA处理在产生功能端粒酶中的作用.
- 确定 TER1 成熟过程中所涉及的因素.
主要方法:
- 描述TER1成熟路径的特征.
- 对TER1转录的结合体分裂反应的分析.
- 在具有抑制或改变处理途径的细胞中测量端粒长度.
主要成果:
- 端粒酶RNA转录 (TER1) 必须经过处理以形成功能端粒酶.
- 结合酶体执行初始裂变反应,生成TER1.1的成熟3'端.
- 这种裂变发生在没有外结合的情况下,释放活性RNA形式.
- 抑制这种第一个结合体分裂或结合完成导致不活跃的TER1和端粒缩短.
结论:
- 结合体体对TER1的3'端处理对端粒酶的功能至关重要.
- 这代表了RNA成熟的新机制,利用结合体介导的特定位点裂变.
- 结合体在产生功能性端粒酶RNA中起着意想不到的作用.
相关概念视频
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
Pre-mRNA Processing: Modification of pre-mRNA Ends
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell...
mRNA Stability and Gene Expression
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Cis-acting Elements involved in mRNA stability


