代替スプライシングによる神秘的なペロキシソーマルターゲティングと,真菌におけるコドン読み込みを停止する
Johannes Freitag1, Julia Ast, Michael Bölker
1Department of Biology, Philipps University Marburg, Karl-von-Frisch-Strasse 8, D-35032 Marburg, Germany.
Nature
|May 25, 2012
まとめ
GAPDHやPGKのようなグリコリチス酵素は,真菌の細胞質とペロキシソームの両方で存在し,毒性やリドックスホメオスタシスに影響を及ぼします. これらの酵素は,二重標的化のための隠された信号を有しており,タンパク質の局所化に対するより広範な意味を示唆しています.
科学分野:
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
- 菌類学 菌類学とは
背景:
- ペロキシソームは,脂肪酸の代謝に関与する重要な真核細胞器官である.
- 糖分解は,主に細胞プラズマで起こる基本的な代謝経路です.
研究 の 目的:
- 菌類のペロキシソームにおけるグリコリチス酵素の存在とターゲティングメカニズムを調査する.
- 菌類の病原体におけるペロキシソーマルグリコリチス酵素の機能的重要性を決定する.
主な方法:
- パーオキシソーマルターゲティング信号 (PTS1) を特定するためのバイオ情報分析.
- リボソームの読み込みと代替スプライシング分析を含む分子生物学技術.
- ウスティラゴの変異分析は,毒性の評価とレドックス・ホメオスタシスを可能とする.
主要な成果:
- 核糖分解酵素 (GAPDH,PGK) は,さまざまな真菌種における細胞質とペロキシソームの両方で発見されました.
- 暗号的なPTS1モチーフは,転写後に活性化され,ペロキシソーマル標的を媒介する.
- 種特有のメカニズム (リボソームの読み込み,代替スプライシング) によって,ペロキシソーム酵素のイソフォームが生成されます.
- ペロキシソーマルGAPDHとPGKは,ウスティラゴ菌の毒性にとって不可欠であり,酸化還元バランスに寄与する.
結論:
- 糖溶性酵素のペロキシソームへの二重標的化は,真菌における保存現象である.
- ペロキシソーマルグリコール酵素は,真菌の病原性および細胞の恒常性において重要な役割を果たします.
- 隠されたPTS1モチーフの発見は,他の細胞質タンパク質も二重局所化を示す可能性があることを示唆しています.
関連する概念動画
Protein Import into the Peroxisomes
Cells contain membrane-bound organelles called peroxisomes that oxidize organic molecules by transferring hydrogen atoms to oxygen, producing hydrogen peroxide. Peroxisomes enzymatically convert the released hydrogen peroxide into water and oxygen.
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Nonsense-mediated mRNA Decay
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Nonsense-mediated mRNA Decay
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Riboswitches
Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
Alternative RNA Splicing
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
Alternative RNA Splicing
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...


