Localization of the Lys, Asp, Glu, Leu tetrapeptide receptor to the Golgi complex and the intermediate compartment in mammalian cells

While the levels of the KDEL-R in the TGN of all cell types we examined under normal conditions were relatively low, our data suggest that when the cells are infected with viruses or treated at low or high temperatures, the protein shifts its distribution such that much higher levels are found in the TGN. These observations suggest that the shift of the KDEL-R towards the TGN may be a general response of the cell towards conditions of stress. It should be noted that, for all of the virally infected cells we used, host protein synthesis is effectively switched off. In these cases, the redistribution of the KDEL-R must be independent of host protein synthesis. Further studies will be necessary to determine whether this is a general response of ceils to situations of stress, as well as to work out the functional significance of such a shift in distribution.