関連する実験動画
Updated: Jul 16, 2026
10:24
Visualization of Endoplasmic Reticulum Localized mRNAs in Mammalian Cells
Published on: December 17, 2012
Sec61p と BiP は,ポリペプチドの ER への転位を直接促進する
S L Sanders1, K M Whitfield, J P Vogel
1Department of Molecular and Cell Biology, Howard Hughes Medical Research Institute, University of California, Berkeley 94720.
Cell
|April 17, 1992
まとめ
Sec61pは,分泌タンパク質の転位をエンドプラズマ網膜 (ER) に直接支援する. BiP (Kar2p) は,Sec61pをこのプロセスで支援し,第2の転位段階でも機能します.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- タンパク質の転位 タンパク質の転位
背景:
- 分泌タンパク質は,適切な折りたたみと機能のために,エンドプラズマ網膜 (ER) をターゲットにします.
- ER膜のトランスロケーションには,Sec61pとBiP (Kar2p) を含む複雑なタンパク質機構が含まれています.
研究 の 目的:
- ERタンパク質転位におけるSec61p,BiP,および関連因子の役割を調査する.
- 分泌タンパク質がER膜を横断するメカニズムを解明する.
主な方法:
- トランスロケーション中のタンパク質の相互作用を研究するために,クロスリンク技術を使用する.
- SEC62,SEC63,KAR2の遺伝子変異を用いて,転位とタンパク質の相互作用への影響を評価した.
- 転位プロセスのATPの必要性を調査する.
主要な成果:
- SEC62とSEC63の変異は,Sec61pのクロスリンクを転位分泌タンパク質に阻害しました.
- ATPは,Sec61pと分泌タンパク質の相互作用に不可欠でした.
- いくつかのkar2変異がSec61pのクロスリンクに影響した一方で,重度の転位欠陥を持つ1つのアレルは,この相互作用を変更しませんでした.
結論:
- Sec61pは,ER膜を横断する分泌タンパク質の転位に直接的な役割を果たします.
- BiP (Kar2p) は,タンパク質転位周期の少なくとも2つの異なる段階に参加しています.
関連する概念動画
01:34Directing 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...
01:20Cotranslational 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...
01:26Insertion 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...
01:29Insertion 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...
01:27Post-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...
01:28Protein Translocation Machinery on the ER Membrane
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.