RRC ID 49244
Author Eino A, Kageyama S, Uemura T, Annoh H, Saito T, Narita I, Waguri S, Komatsu M.
Title Sqstm1-GFP knock-in mice reveal dynamic actions of Sqstm1 during autophagy and under stress conditions in living cells.
Journal J Cell Sci
Abstract Sqstm1 serves as a signaling hub and receptor for selective autophagy. Consequently, dysregulation of Sqstm1 causes imbalances in signaling pathways and disrupts proteostasis, thereby contributing to the development of human diseases. Environmental stresses influence the level of Sqstm1 by altering its expression and/or autophagic degradation, and also changes the localization of Sqstm1, making it difficult to elucidate the actions and roles of this protein. In this study, we developed knock-in mice expressing Sqstm1 fused to GFP (Sqstm1-GFP(KI/+)). Using these Sqstm1-GFP(KI/+) mice, we revealed for the first time the dynamics of endogenous Sqstm1 in living cells. Sqstm1-GFP was translocated to a restricted area of LC3-positive structures, which primarily correspond to the inside of autophagosomes, and then degraded. Moreover, exposure to arsenite induced expression of Sqstm1-GFP, followed by accumulation of the fusion protein in large aggregates that were degraded by autophagy. Furthermore, suppression of autophagy in Sqstm1-GFP(KI/+) mouse livers caused accumulation of Sqstm1-GFP and formation of GFP-positive aggregate structures, leading to severe hepatic failure. These results indicate that Sqstm1-GFP(KI/+) mice are a useful tool for analyzing Sqstm1 in living cells and intact animals.
Volume 128(23)
Pages 4453-61
Published 2015-12-1
DOI 10.1242/jcs.180174
PII jcs.180174
PMID 26483381
PMC PMC4712822
MeSH Adaptor Proteins, Signal Transducing / biosynthesis* Adaptor Proteins, Signal Transducing / genetics Animals Autophagy* Gene Expression Regulation* Gene Knock-In Techniques Green Fluorescent Proteins / biosynthesis Green Fluorescent Proteins / genetics Heat-Shock Proteins / biosynthesis* Heat-Shock Proteins / genetics Humans Liver Failure / genetics Liver Failure / metabolism Mice Mice, Transgenic Microtubule-Associated Proteins / genetics Microtubule-Associated Proteins / metabolism Phagosomes / genetics Phagosomes / metabolism* Recombinant Fusion Proteins / biosynthesis Recombinant Fusion Proteins / genetics Sequestosome-1 Protein Stress, Physiological*
IF 4.573
Times Cited 5
Mice RBRC03941