线粒体拼接需要一种来自新型螺旋酶家族的蛋白质
B Séraphin1, M Simon, A Boulet
1Institut Curie-Biologie, Orsay, France.
Nature
|January 5, 1989
概括
核基因MSS116对于酵母中的线粒体拼接至关重要. 它的蛋白质产物pMSS116表现出RNA螺旋酶活性,影响细胞染色体b和COX1转录的拼接.
科学领域:
- 分子生物学分子生物学
- 线粒体遗传学 线粒体遗传学
背景情况:
- 线粒体拼接中的核编码蛋白质的理解很少.
- 之前的研究已经确定了在酵母中参与线粒体拼接的蛋白质.
研究的目的:
- 为了研究核基因MSS116在线粒体拼接中的功能.
- 确定MSS116蛋白 (pMSS116) 在酵母线粒体基因表达中的作用.
主要方法:
- 对MSS116基因进行基因分析.
- 对MSS116蛋白的序列分析.
- 与已知的蛋白质进行同质性比较.
主要成果:
- 在MSS116中发生的突变直接影响细胞染色体b (cob) 和细胞染色体c氧化酶子单元I (cox1) 内的剪接.
- 该MSS116蛋白与翻译启动因子eIF-4A和人类p68.8相同.
- 保存的氨基酸块表明pMSS116具有RNA酶活性.
结论:
- 蛋白质MSS116是线粒体拼接机械的重要组成部分.
- pMSS116可能作为RNA螺旋酶,参与线粒体RNA处理.
- 这一发现揭示了线粒体基因表达的复杂调节.
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...
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RNA Splicing
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Mitochondrial Protein Sorting
Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death. Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
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Mitochondrial Precursor Proteins
Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70 chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial precursors...
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Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
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Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...


