Browsing by Subject "SRP68"

The signal recognition particle (SRP) targets newly synthesized secretory and membrane proteins from the cytosol to the translocon complex on the endoplasmic reticulum membrane. This highly specific co-translational protein targeting is essential for proteostasis by preventing the accumulation of proteins in the cytosol and the mistargeting of proteins. Defects in the SRP68 and SRP72 subunits of eukaryotic SRP have been linked to various inflammatory muscle diseases such as myopathy and myositis. The full role of these subunits in protein targeting and regulation of targeting is unknown. Previously the yeast SRP72 subunit has been degraded using an auxin-inducible degron (AID) system to explore the effect of depletion on protein targeting and cell viability, but the mammalian SRP72-AID has not yet been studied. The aim of this study was to deplete the mammalian SRP68 and SRP72 subunits using the AID system. This study revealed that in the case of SRP68-AID, approximately 65% of the protein is degraded after 2 hours. Respectively, 75% of SRP72-AID degrades after 2 hours and 85% after 4 hours. However, complete depletion of subunits was not achieved during 24 hours of auxin treatment. Quantification of depletion also showed that the strongest decrease in SRP occurs during the first 2 hours. This study demonstrated that mammalian SRP subunits can be depleted using the AID system, providing a good basis for further research to examine the effect of subunit depletion on protein targeting. This may help to solve the mechanisms of diseases associated with SRP68 and SRP72 defects and to develop therapeutics for them.