関連する実験動画
Updated: Feb 16, 2026
11:06
Method for the Isolation of Francisella tularensis Outer Membranes
Published on: June 29, 2010
17.6K
BamAの自己挿入は,ディダーマのFirmicutesの内外膜の再構築を駆動する
Polina Beskrovnaya1, Ameena Hashimi1, Danielle L Sexton1
1Department of Microbiology and Immunology, Life Sciences Institute, The University of British Columbia, Vancouver, BC, Canada.
Nature communications
|February 14, 2026
まとめ
ディダーム・ファームシューツにおけるエンドスポールの形成は,外膜の改造を伴う. 新しいタンパク質であるSonAとSonBは,発芽時に,既存のタンパク質とは独立して,外膜生体生成を駆動する.
科学分野:
- 微生物学 微生物学とは
- バクテリア細胞生物学
- タンパク質生化学 タンパク質生化学
背景:
- エンドスポラの形成は,Firmicutesの生存に不可欠です.
- アセトネマ・ロングム (Acetonema longum) のようなディダーマ菌は,発芽時に機能的外膜 (OM) になるユニークな外胞膜 (OsM) を有しています.
- ディダーマバクテリアの発芽中のOMのバイオゲネシスは,まだ十分に理解されていません.
研究 の 目的:
- ディダームの胞子発芽中の外膜 (OM) バイオゲネシスのメカニズムを調査する. Firmicutes.
- OMの改造と機能に関与する新しいタンパク質を特定する.
- OM形成におけるBAMA,SONA,SONBの役割を明らかにする.
主な方法:
- 比較プロテオミクスと遺伝子発現のプロファイリングを,さまざまな成長段階で比較する.
- 植物性,発芽性および成熟した胞子における外膜タンパク質 (OMP) 局所化の分析.
- キータンパク質のインビトロリポソーム挿入アッセイ.
主要な成果:
- BamAとLptDを含む外膜タンパク質 (OMP) は成熟した胞子に存在しないため,OMの生体生成は,事前に存在したOMPなしで起こることを示している.
- 2つの新しいタンパク質,SonA (ベータバレルOMP) とSonB (予測されたOMリポタンパク質) が特定され,保存されたオペロンでBamaと共発現することが判明しました.
- BamAとSonAは,リポソームに自発的に挿入することを実証し,OM形成のための自己組み立てメカニズムを示唆しました.
結論:
- Firmicutesは,OMPsの de novo合成と組み立てを含む活発なプロセスです.
- SonAとSonBは,OSMを機能的なOMに変換する上で重要な役割を果たしています.
- この発見は,Bamaと/またはSonaがOSMへの自己挿入を通じてOM形成を開始するモデルを支持しています.
関連する概念動画
01:12Porin Insertion in the Outer Mitochondrial Membrane
4.9K
Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
4.9K
01:11Protein Transport to the Outer Chloroplast Membrane
2.4K
Chloroplast outer membrane proteins encoded by the nucleus are synthesized in the cytosol. Soon after synthesis, they bind cytosolic factors such as 14-3-3 protein and the Hsp70 chaperones that keep these precursors in an unfolded state until their translocation.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
2.4K
02:54Nucleosome Remodeling
11.3K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
11.3K
01:27Bacterial Phylum Firmicutes
1.1K
Firmicutes is a diverse phylum of Gram-positive bacteria characterized by a low GC content in their genomes. This phylum includes organisms with monoderm or diderm cell envelopes, highlighting a complex evolutionary history. Firmicutes comprises several major orders, including Lactobacillales, Clostridiales, and Bacillales, which exhibit remarkable diversity in their morphology, metabolism, and ecological roles.The order Lactobacillales includes lactic acid bacteria, which are fermentative...
1.1K
01:37Energy to Drive Translocation
2.9K
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...
2.9K
01:40Bone Remodeling
40.5K
Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain bone mass and calcium homeostasis. While mechanical stress can stimulate turnover as part of the normal maintenance and reparative process, several hormones also regulate bone remodeling.
40.5K