Chapter 15
Transmembrane Transport in Endoplasmic Reticulum and Peroxisomes
![The Endoplasmic Reticulum](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12123.jpg)
The endoplasmic reticulum or ER makes up for more than half of the membranes in a cell and accounts for 10% of total cell volume. It is also the…
![Smooth Endoplasmic Reticulum](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12124.jpg)
Smooth endoplasmic reticulum or smooth ER is a sub-organelle with specialized functions in animal cells and plant cells. It is often associated with…
![Directing Proteins to the Rough Endoplasmic Reticulum](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12125.jpg)
The organelle-specific signaling sequences direct proteins synthesized in the cytosol to their final destination like ER, mitochondria, peroxisomes,…
![Protein Translocation Machinery on the ER Membrane](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12553.jpg)
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent…
![Post-translational Translocation of Proteins to the RER](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12247.jpg)
A sizable fraction of proteins destined for ER are first synthesized in the cell cytosol and then transported across the ER membrane–a process…
![Insertion of Single-pass Transmembrane Proteins in the RER](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12127.jpg)
Integral membrane proteins are proteins adhered to the lipid bilayer of a cell organelle or membrane. They can be of two types: transmembrane…
![Tail-anchoring of Proteins in the ER Membrane](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12129.jpg)
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single…
![GPI Anchoring of Proteins in the ER Membrane](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12215.jpg)
GPI-anchoring is a post-translational, reversible protein modification that is ubiquitous in eukaryotes. Such proteins are primarily present on the…
![Protein Folding Quality Check in the RER](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12131.jpg)
ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone…
![Export of Misfolded Proteins out of the ER](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12248.jpg)
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for…
![Regulation of the Unfolded Protein Response](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12249.jpg)
Inositol-requiring kinase one or IRE1 is the most conserved eukaryotic unfolded protein response (UPR) receptor. It is a type I transmembrane protein…
![Synthesis of Phosphatidylcholine in the ER Membrane](https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/12216.jpg)
The ER synthesizes lipids for building cell membranes and performing cellular functions such as energy storage and signaling. The lipid synthesis…
![Mitochondria and Endoplasmic Reticulum Imaging by Correlative Light and Volume Electron Microscopy](https://cloudfront.jove.com/files/thumbs/59750_t.png)
Cellular organelles, such as mitochondria and endoplasmic reticulum (ER), create a network to perform a variety of functions. These highly curved…
![Single Molecule Fluorescence Energy Transfer Study of Ribosome Protein Synthesis](https://cloudfront.jove.com/files/thumbs/62664_t.png)
The ribosome is a large ribonucleoprotein complex that assembles proteins processively along mRNA templates. The diameter of the ribosome is…