Cells that are subjected to a variety of stresses, such as heat shock, make fundamental changes in the way they process misfolded proteins in order to retrieve, where possible, proteins that have not been damaged fatally. In looking at the stress response of cells, VanSlyke and Musil noticed changes in the way that misfolded proteins within the endoplasmic reticulum (ER) are processed. Generally, misfolded or incompletely assembled proteins are transported out of the ER and into the cytosol for degradation by proteasomes. However, in stressed cells, this dislocation reaction appears to be less efficient, allowing proteins that might previously have been removed from the ER to complete their folding and assembly and subsequently to be transported to the cell surface. The authors specifically examined the folding and transport of components of gap junctions, and the net effect of stress was the assembly of excess functional gap junctions at the cell surface.—SMH
J. Cell Biol. 157, 381 (2002).