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Popper B, Bürkle M, Ciccopiedi G, Marchioretto M, Forné I, Imhof A, Straub T, Viero G, Götz M, Schieweck R. Ribosome inactivation regulates translation elongation in neurons. J Biol Chem 2024; 300:105648. [PMID: 38219816 PMCID: PMC10869266 DOI: 10.1016/j.jbc.2024.105648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/10/2023] [Accepted: 01/02/2024] [Indexed: 01/16/2024] Open
Abstract
Cellular plasticity is crucial for adapting to ever-changing stimuli. As a result, cells consistently reshape their translatome, and, consequently, their proteome. The control of translational activity has been thoroughly examined at the stage of translation initiation. However, the regulation of ribosome speed in cells is widely unknown. In this study, we utilized a timed ribosome runoff approach, along with proteomics and transmission electron microscopy, to investigate global translation kinetics in cells. We found that ribosome speeds vary among various cell types, such as astrocytes, induced pluripotent human stem cells, human neural stem cells, and human and rat neurons. Of all cell types studied, mature cortical neurons exhibit the highest rate of translation. This finding is particularly remarkable because mature cortical neurons express the eukaryotic elongation factor 2 (eEF2) at lower levels than other cell types. Neurons solve this conundrum by inactivating a fraction of their ribosomes. As a result, the increase in eEF2 levels leads to a reduction of inactive ribosomes and an enhancement of active ones. Processes that alter the demand for active ribosomes, like neuronal excitation, cause increased inactivation of redundant ribosomes in an eEF2-dependent manner. Our data suggest a novel regulatory mechanism in which neurons dynamically inactivate ribosomes to facilitate translational remodeling. These findings have important implications for developmental brain disorders characterized by, among other things, aberrant translation.
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Affiliation(s)
- Bastian Popper
- Core Facility Animal Models, Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - Martina Bürkle
- Department of Physiological Genomics, Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - Giuliana Ciccopiedi
- Department for Cell Biology & Anatomy, Biomedical Center (BMC), LMU Munich, Munich, Germany; Graduate School of Systemic Neurosciences, LMU Munich, Munich, Germany
| | - Marta Marchioretto
- Institute of Biophysics, National Research Council (CNR) Unit at Trento, Povo, Italy
| | - Ignasi Forné
- Protein Analysis Unit, Department for Molecular Biology, Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - Axel Imhof
- Protein Analysis Unit, Department for Molecular Biology, Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - Tobias Straub
- Bioinformatics Core Facility, Department of Molecular Biology, Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - Gabriella Viero
- Institute of Biophysics, National Research Council (CNR) Unit at Trento, Povo, Italy
| | - Magdalena Götz
- Department of Physiological Genomics, Biomedical Center (BMC), LMU Munich, Munich, Germany; Institute of Stem Cell Research, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany; SYNERGY, Excellence Cluster of Systems Neurology, Biomedical Center (BMC), LMU Munich, Munich, Germany
| | - Rico Schieweck
- Department of Physiological Genomics, Biomedical Center (BMC), LMU Munich, Munich, Germany; Department for Cell Biology & Anatomy, Biomedical Center (BMC), LMU Munich, Munich, Germany; Institute of Biophysics, National Research Council (CNR) Unit at Trento, Povo, Italy.
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