端粒酶RNA生物发生包括由Sm和Lsm复合体的顺序结合
Wen Tang1, Ram Kannan, Marco Blanchette
1Howard Hughes Medical Institute, Kansas City, Missouri 64110, USA.
Nature
|March 27, 2012
概括
Sm和Lsm蛋白序列结合裂变酵母端粒酶RNA (TER1),指导其成熟. 这一过程涉及到结合体分裂,5'-cap通过Tgs1的高甲基化,以及对3'-end的保护,这对端粒酶生物发生至关重要.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 遗传学 是一个遗传学.
背景情况:
- 端粒酶可以抵消真核生物中的DNA损失,这对细胞稳定至关重要.
- 端粒酶的失调与癌症和退行性疾病有关.
- 了解端粒酶生物发生是治疗干预的关键.
研究的目的:
- 阐明Sm和Lsm蛋白在裂变酵母端粒酶RNA (TER1) 生物发生中的顺序作用.
- 描述结合体,Tgs1甲基酶和Sm/Lsm复合体在TER1处理中的参与.
主要方法:
- 研究了Sm和Lsm2-8复合体与TER1前体的关联.
- 分析了结合体裂变和5 - 帽高甲基化.
- 评估了这些复合体在保护成熟TER1.1中的作用.
主要成果:
- 证明了Sm环和Lsm2-8复合体对TER1.1的顺序结合.
- 显示 Sm 结合刺激了 spliceosomal cleavage 和 Tgs1 介导的高甲基化.
- 确认Lsm2-8复合物促进了催化子单元的结合和3端的保护.
结论:
- 定义了裂变酵母中端粒酶生物发生的逐步过程.
- 描述了Sm,Lsm复合体和Tgs1在TER1成熟中的新型作用.
- 提供了对端粒酶RNA处理的调节的见解.
相关概念视频
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.
Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
The Replisome
DNA replication is carried out by a large complex of proteins that act in a coordinated matter to achieve high-fidelity DNA replication. Together this complex is known as the DNA replication machinery or the replisome.
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
The synthesis of the leading and lagging strands is a highly coordinated process. To explain this, the “Trombone model” was proposed by Bruce Alberts in 1980. The DNA loop formation starts when a primer is synthesized on the parent lagging strand. The loop grows with the...
Translesion DNA Polymerases
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
LTR Retrotransposons
LTR retrotransposons are class I transposable elements with long terminal repeats flanking an internal coding region. These elements are less abundant in mammals compared to other class I transposable elements. About 8 percent of human genomic DNA comprises LTR retrotransposons. Some of the common examples of LTR retrotransposons are Ty elements in yeast and Copia elements in Drosophila.
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...

