Using sorting signals to retain proteins in endoplasmic reticulum

Abstract

Publisher Summary This chapter describes the use of sorting signals to retain proteins in endoplasmic reticulum. It is desirable to express an altered form of a secreted or membrane protein such that it remains in the endoplasmic reticulum (ER). This approach can be used to accumulate high levels of a particular protein, to test whether the location of a transmembrane protein is important for its activity, to modify the properties of the ER, or to prevent export of a protein by expressing a retained version of a polypeptide with which it interacts. The expression system used depends on the application, however, in most cases the desired localization is readily achieved by appending an ER sorting signal to the protein of interest. The strategy differs depending on whether the protein is soluble or is an integral membrane component. The context of the signal may be important in some cases.