まとめ
信号認識粒子 (SRP) とSec61p複合体を含む2つの信号認識イベントは,ERへのコトランスレーション性タンパク質輸送に不可欠です. 脂質は,この過程で信号配列の差別化にも重要な役割を果たす可能性があります.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- タンパク質の輸送
背景:
- エンドプラズマ網膜 (ER) へのタンパク質の転位は,細胞機能に不可欠です.
- 2つの主要なメカニズム,コトランスレーションとポストトランスレーションの輸送が関与しています.
- 信号認識イベントは,タンパク質がER膜に標的を絞ることを媒介する.
研究 の 目的:
- タンパク質輸送における信号認識イベントに関する現在の理解をレビューし,統合する.
- 信号認識粒子 (SRP) とSec61p複合体の役割を解明する.
- 信号配列認識における脂質の潜在的関与を探求する.
主な方法:
- 既存の文献と実験結果のレビュー.
- SRP,Sec61p複合体,および新生ポリペプチド関連複合体 (NAC) を含む研究の分析.
- 信号ペプチド機能における脂質-タンパク質相互作用の検討.
主要な成果:
- SRPとSec61p複合体の認識は,効率的なコトランスレーション ER転位に不可欠です.
- NACは,早期のリボソーム-Sec61p結合を防止することによって,特定の実験条件下でSRPの必要性を回避することができます.
- 脂質は,シグナル配列の差別に積極的に参加し,Sec61p複合体はより一般的な転位役割を果たす可能性があります.
結論:
- 効率的なコトランスレーション性タンパク質輸送には,SRPとSec61p複合体の調整された認識が必要です.
- シグナルシーケンス認識における脂質の役割は,さらなる調査が必要である.
- これらのメカニズムを理解することは,タンパク質の生体生成と細胞内のターゲティングを理解するために重要です.
関連する概念動画
ER Retrieval Pathway
In the secretory pathway, vesicles transport proteins from one cellular compartment to another in forward transport to deliver the protein to its correct location. Occasionally, misfolded proteins and incorrect proteins escape their original compartments, and a retrieval pathway is used to return the escaped proteins to their original compartment.
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
The ER uses many checkpoints to prevent the entry of incorrectly folded or a resident protein as cargo onto a transport vesicle. These mechanisms...
Directing Proteins to the Rough Endoplasmic Reticulum
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes, etc. Some of the proteins directed to ER are then trafficked via vesicles to other organelles within the cell or the extracellular environment through the Golgi complex. For example, the rough ER synthesizes soluble proteins for transportation to the lysosomes or secretion out of the cell. It can also synthesize transmembrane proteins that can...
Cotranslational Protein Translocation
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Insertion of Single-pass Transmembrane Proteins in the RER
Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane integral proteins that span the lipid bilayer and monotopic proteins that are attached to either side of the membrane but do not pass through it.
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Insertion of Multi-pass Transmembrane Proteins in the RER
The rough ER membrane synthesizes, assembles, and embeds transmembrane proteins in diverse topologies. These proteins function as transporters or channels and can remain in the ER membrane or are sent to the Golgi complex, lysosome, and cell membrane.
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
Post-translational Translocation of Proteins to the RER
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process called post-translational translocation. Similar to cotranslationally translocated proteins, these proteins also use the Sec translocon complex to enter the ER lumen.
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...


