Protein translocation across the eukaryotic endoplasmic reticulum and bacterial plasma membranes

@article{Rapoport2007ProteinTA,
  title={Protein translocation across the eukaryotic endoplasmic reticulum and bacterial plasma membranes},
  author={T. Rapoport},
  journal={Nature},
  year={2007},
  volume={450},
  pages={663-669}
}
A decisive step in the biosynthesis of many proteins is their partial or complete translocation across the eukaryotic endoplasmic reticulum membrane or the prokaryotic plasma membrane. Most of these proteins are translocated through a protein-conducting channel that is formed by a conserved, heterotrimeric membrane-protein complex, the Sec61 or SecY complex. Depending on channel binding partners, polypeptides are moved by different mechanisms: the polypeptide chain is transferred directly into… Expand
Protein transport across the endoplasmic reticulum membrane
TLDR
Structural and biochemical data suggest mechanisms that enable the channel to function with different partners, to open across the membrane and to release laterally hydrophobic segments of membrane proteins into lipid. Expand
Mechanisms of Sec61/SecY-mediated protein translocation across membranes.
TLDR
Structural and biochemical data show how the channel opens during translocation, translocates soluble proteins, releases hydrophobic segments of membrane proteins into the lipid phase, and maintains the barrier for small molecules. Expand
Sec61/SecY-Mediated Protein Translocation Across Membranes
TLDR
Structural and biochemical data show how the channel opens during translocation, translocates soluble proteins, releases hydrophobic segments of membrane proteins into the lipid phase, and maintains the barrier for small molecules. Expand
Structural and Mechanistic Insights into Protein Translocation.
TLDR
Structural data and biochemical experiments have elucidated how channel partners, the ribosome in cotranslational translocation, and the eukaryotic ER chaperone BiP or the prokaryotic cytosolic SecA ATPase in posttranslated translocation move polypeptides unidirectionally across the membrane. Expand
Membrane protein insertion at the endoplasmic reticulum.
TLDR
The conceptual and mechanistic themes underlying these core membrane protein insertion pathways, the complexities that challenge the authors' understanding, and future directions to overcome these obstacles are reviewed. Expand
Protein transport across the endoplasmic reticulum
TLDR
In bacteria, thetranslocation of secretory and membrane proteinsoccurs through a homologous channel in the plasmamembrane, employing signal and TM sequences that are similar to those in eukaryotes. Expand
Cotranslational Translocation of Proteins into Microsomes: Methods
TLDR
Applications of this system have realised substantial insights into the mechanisms of protein targeting to the ER membrane and the insertion of a nascent polypeptide into the membrane. Expand
Endoplasmic reticulum targeting and insertion of tail-anchored membrane proteins by the GET pathway.
TLDR
The mechanism of the yeast GET pathway is focused on and a speculative analogy between its membrane insertion step and the ATPase-driven cycle of ABC transporters is made. Expand
Chapter 11 – Membrane Biogenesis
TLDR
Although many of the necessary components of this process have been identified, details of the mechanism remain elusive. Expand
Tail-anchored membrane protein insertion into the endoplasmic reticulum
TLDR
A recently discovered post-translational pathway using an entirely different set of factors involving transmembrane domain (TMD)-selective cytosolic chaperones and an accompanying receptor at the ER is discovered. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 109 REFERENCES
Molecular Mechanism of Membrane Protein Integration into the Endoplasmic Reticulum
TLDR
It is demonstrated that both the lumenal and the cytosolic domains of a membrane protein are synthesized while the ribosome is membrane bound, so that even cytosol domains come in contact with the translocation channel. Expand
Membrane-protein integration and the role of the translocation channel.
TLDR
A model of how the protein-conducting channel recognizes transmembrane segments, orients them properly with respect to the plane of the membrane and releases them into lipid is proposed. Expand
Protein translocation into proteoliposomes reconstituted from purified components of the endoplasmic reticulum membrane
TLDR
It is suggested that the Sec61p complex binds the ribosome during translocation and forms the postulated protein-conducting channel, indicating a surprising simplicity of the basic translocation machinery. Expand
Protein translocation by the Sec61/SecY channel.
TLDR
Structural studies illustrate how the protein-conducting channel translocates proteins across cellular membranes and integrates proteins containing hydrophobic transmembrane segments into lipid bilayers. Expand
The structure of ribosome-channel complexes engaged in protein translocation.
TLDR
The ribosome-channel junction may allow the direct transfer of polypeptides into the channel and provide a path for the egress of some nascent chains into the cytosol. Expand
Both Lumenal and Cytosolic Gating of the Aqueous ER Translocon Pore Are Regulated from Inside the Ribosome during Membrane Protein Integration
TLDR
The ribosome first recognizes the transmembrane segment and triggers long-range structural changes at the translocon that may be involved in shifting its function from translocation to integration, as shown by compartment-specific collisional quenching of fluorophores incorporated into the polypeptide. Expand
Recognition of transmembrane helices by the endoplasmic reticulum translocon
TLDR
The results indicate that direct protein–lipid interactions are critical during translocon-mediated membrane insertion, and the basic features of this code are determined, including a ‘biological’ hydrophobicity scale. Expand
Secretory proteins move through the endoplasmic reticulum membrane via an aqueous, gated pore
The environment of secretory proteins undergoing translocation across the ER membrane was determined by incorporating fluorescent probes into nascent chains during translation. Dyes were positionedExpand
Three-dimensional structure of the bacterial protein-translocation complex SecYEG
TLDR
The three-dimensional map, calculated from two-dimensional SecYEG crystals, reveals a sandwich of two membranes interacting through the extensive cytoplasmic domains, which may represent the closed state of the protein-conducting channel. Expand
The Aqueous Pore through the Translocon Has a Diameter of 40–60 Å during Cotranslational Protein Translocation at the ER Membrane
TLDR
Accessibility studies showed that the aqueous pore in a functioning translocon is 40-60 A in diameter, making it the largest hole observed to date in a membrane that must maintain a permeability barrier. Expand
...
1
2
3
4
5
...