title: BAG3 regulates total MAP1LC3B protein levels through a translational but not transcriptional mechanism.
abstract: Autophagy is mainly regulated by post-translational and lipid modifications of ATG proteins. In some scenarios, the induction of autophagy is accompanied by increased levels of certain ATG mRNAs such as MAP1LC3B/LC3B, ATG5 or ATG12. However, little is known about the regulation of ATG protein synthesis at the translational level. The cochaperone of the HSP70 system BAG3 (BCL2-associated athanogene 3) has been associated to LC3B lipidation through an unknown mechanism. In the present work, we studied how BAG3 controls autophagy in HeLa and HEK293 cells. Our results showed that BAG3 regulates the basal amount of total cellular LC3B protein by controlling its mRNA translation. This effect was apparently specific to LC3B because other ATG protein levels were not affected. BAG3 knockdown did not affect LC3B lipidation induced by nutrient deprivation or proteasome inhibition. We concluded that BAG3 maintains the basal amount of LC3B protein by controlling the translation of its mRNA in HeLa and HEK293 cells.
authors.affiliation: a Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, University of Chile , Santiago , Chile.
authors.forename: Andrea E
authors.initials: AE
authors.lastname: Rodríguez
authors.affiliation: a Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, University of Chile , Santiago , Chile.
authors.forename: Camila
authors.initials: C
authors.lastname: López-Crisosto
authors.affiliation: a Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, University of Chile , Santiago , Chile.
authors.forename: Daniel
authors.initials: D
authors.lastname: Peña-Oyarzún
authors.affiliation: a Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, University of Chile , Santiago , Chile.
authors.forename: Daniela
authors.initials: D
authors.lastname: Salas
authors.affiliation: a Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, University of Chile , Santiago , Chile.
authors.forename: Valentina
authors.initials: V
authors.lastname: Parra
authors.affiliation: a Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, University of Chile , Santiago , Chile.
authors.forename: Clara
authors.initials: C
authors.lastname: Quiroga
authors.affiliation: c Institute of Pathobiochemistry, University Medical Center, Johannes Gutenberg University Mainz , Mainz , Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Morawe
authors.affiliation: a Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, University of Chile , Santiago , Chile.
authors.forename: Mario
authors.initials: M
authors.lastname: Chiong
authors.affiliation: c Institute of Pathobiochemistry, University Medical Center, Johannes Gutenberg University Mainz , Mainz , Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Behl
authors.affiliation: a Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical and Pharmaceutical Sciences & Faculty of Medicine, University of Chile , Santiago , Chile.|b Center for Molecular Studies of the Cell (CEMC), Institute for Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile , Santiago , Chile.|d Department of Internal Medicine (Cardiology Division) , University of Texas Southwestern Medical Center , Dallas , TX , USA.
authors.forename: Sergio
authors.initials: S
authors.lastname: Lavandero
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008247:Lysosomes / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D014176:Protein Biosynthesis; D059748:Proteolysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; C414431:BAG3 protein, human; D008055:Lipids; C502070:MAP1LC3B protein, human; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D046988:Proteasome Endopeptidase Complex
keywords: ATG8; BAG3; LC3; MAP1LC3B; autophagy; cochaperone