Causal links between protein folding in the ER and events along the secretory pathway

Masato Takeuchi1, Yukio Kimata, Kenji Kohno

  • 1Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan.

Autophagy
|July 29, 2006
PubMed

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Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
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The ER is the hub of protein synthesis in a cell. It has robust systems to quality control protein folding and also for degradation of terminally misfolded proteins. Under normal conditions, a small proportion of misfolded proteins that cannot be salvaged need to be transported to the cytoplasm by the ER-associated degradation or ERAD pathways. However, if the ERAD cannot handle the misfolded proteins, the cell activates the unfolded protein response or UPR to adjust the protein folding...