タンパク質の使い捨て性と進化の速さ
1enter for Computational Genetics and Biological Modeling, Department of Biological Sciences, Stanford University, California, USA. aehirsch@stanford.edu
Nature
|June 29, 2001
まとめ
タンパク質の必要性,すなわち,タンパク質が生物にとってどれほど不可欠であるか,その進化速度と相関しています. イーストとワームで確認されたこの発見は,この関係を検出する以前の困難を説明しています.
科学分野:
- 進化生物学の進化生物学について
- ゲノミクスゲノミクスとは
- 分子生物学は分子生物学である.
背景:
- タンパク質の進化の速度は,生物のフィットネスに対するタンパク質の重要性の低下とともに増加すると仮定されています.
- これは,より欠かせないタンパク質がより弱い浄化選択を受けているためであり,わずかに有害な突然変異がより早く蓄積することを可能にします.
- これまでの研究では,この関係が確認できず,一部では,必須遺伝子と非必須遺伝子の進化速度の違いが示されていない.
研究 の 目的:
- タンパク質の欠用性と進化の速度の関係を,欠用性の定量的尺度を用いて調査する.
- タンパク質の使い捨て性が,単純な必須/非必須の分類よりより正確に進化の速度に影響を与えるかどうかを判断する.
- タンパク質の利用可能性と進化の速度の間の関係の進化的保存を評価する.
主な方法:
- 酵母における単一遺伝子消去の高通量成長アッセイを使用して,タンパク質の可用性の定量評価.
- 21の完全に注釈されたゲノムの比較シーケンス分析による進化速度の推定.
- タンパク質の利用可能性と進化の速度を相関させるための統計的分析.
主要な成果:
- タンパク質の利用可能性と進化の速度の間には,非常に有意な正の相関が認められた.
- この関係は,単純な本質的対非本質的二分論よりも微妙であり,以前の確認の失敗した試みを説明します.
- 酵母におけるタンパク質の使い捨て性と進化の速度の間の確認された関係は,ネマトードワームなどの他の種において保存され,予測可能である.
結論:
- タンパク質の可用性は,進化の速度の重要な予測要因である.
- 無用性の定量的な測定は,タンパク質の機能の重要性と進化の速度との間の保存された関係を明らかにします.
- この研究は,以前の矛盾する発見を調和させ,タンパク質の進化を理解するためのより正確なモデルを提供します.
関連する概念動画
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
02:26Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
01:24Protein Diffusion in the Membrane
Proteins show rotational as well as lateral diffusion across the membrane. The lateral diffusion of proteins was confirmed through the cell fusion experiment where mouse and human cells were fused, resulting in hybrid cells. When the human and mouse cells fused, the specific membrane proteins on human and mouse cells were marked with the red and green-fluorescent markers, respectively. Initially, the red and green fluorescence was located on the respective hemisphere of the cell. As time...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
01:26Bacterial Protein Maturation
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...