1
|
Stewart RK, Nguyen P, Laederach A, Volkan PC, Sawyer JK, Fox DT. Orb2 enables rare-codon-enriched mRNA expression during Drosophila neuron differentiation. Nat Commun 2024; 15:5270. [PMID: 38902233 PMCID: PMC11190236 DOI: 10.1038/s41467-024-48344-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 04/25/2024] [Indexed: 06/22/2024] Open
Abstract
Regulation of codon optimality is an increasingly appreciated layer of cell- and tissue-specific protein expression control. Here, we use codon-modified reporters to show that differentiation of Drosophila neural stem cells into neurons enables protein expression from rare-codon-enriched genes. From a candidate screen, we identify the cytoplasmic polyadenylation element binding (CPEB) protein Orb2 as a positive regulator of rare-codon-dependent mRNA stability in neurons. Using RNA sequencing, we reveal that Orb2-upregulated mRNAs in the brain with abundant Orb2 binding sites have a rare-codon bias. From these Orb2-regulated mRNAs, we demonstrate that rare-codon enrichment is important for mRNA stability and social behavior function of the metabotropic glutamate receptor (mGluR). Our findings reveal a molecular mechanism by which neural stem cell differentiation shifts genetic code regulation to enable critical mRNA stability and protein expression.
Collapse
Affiliation(s)
- Rebeccah K Stewart
- Department of Pharmacology & Cancer Biology, Duke University, Durham, NC, USA
- Duke Regeneration Center, Duke University, Durham, NC, USA
| | - Patrick Nguyen
- Department of Pharmacology & Cancer Biology, Duke University, Durham, NC, USA
| | - Alain Laederach
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
| | | | - Jessica K Sawyer
- Department of Pharmacology & Cancer Biology, Duke University, Durham, NC, USA
- Duke Regeneration Center, Duke University, Durham, NC, USA
| | - Donald T Fox
- Department of Pharmacology & Cancer Biology, Duke University, Durham, NC, USA.
- Duke Regeneration Center, Duke University, Durham, NC, USA.
| |
Collapse
|
2
|
Schieweck R, Götz M. Pan-cellular organelles and suborganelles-from common functions to cellular diversity? Genes Dev 2024; 38:98-114. [PMID: 38485267 PMCID: PMC10982711 DOI: 10.1101/gad.351337.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/02/2024]
Abstract
Cell diversification is at the base of increasing multicellular organism complexity in phylogeny achieved during ontogeny. However, there are also functions common to all cells, such as cell division, cell migration, translation, endocytosis, exocytosis, etc. Here we revisit the organelles involved in such common functions, reviewing recent evidence of unexpected differences of proteins at these organelles. For instance, centrosomes or mitochondria differ significantly in their protein composition in different, sometimes closely related, cell types. This has relevance for development and disease. Particularly striking is the high amount and diversity of RNA-binding proteins at these and other organelles, which brings us to review the evidence for RNA at different organelles and suborganelles. We include a discussion about (sub)organelles involved in translation, such as the nucleolus and ribosomes, for which unexpected cell type-specific diversity has also been reported. We propose here that the heterogeneity of these organelles and compartments represents a novel mechanism for regulating cell diversity. One reason is that protein functions can be multiplied by their different contributions in distinct organelles, as also exemplified by proteins with moonlighting function. The specialized organelles still perform pan-cellular functions but in a cell type-specific mode, as discussed here for centrosomes, mitochondria, vesicles, and other organelles. These can serve as regulatory hubs for the storage and transport of specific and functionally important regulators. In this way, they can control cell differentiation, plasticity, and survival. We further include examples highlighting the relevance for disease and propose to examine organelles in many more cell types for their possible differences with functional relevance.
Collapse
Affiliation(s)
- Rico Schieweck
- Institute of Biophysics, National Research Council (CNR) Unit at Trento, 38123 Povo, Italy;
- Biomedical Center (BMC), Department of Physiological Genomics, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Magdalena Götz
- Biomedical Center (BMC), Department of Physiological Genomics, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany;
- Institute of Stem Cell Research, Helmholtz Center Munich, German Research Center for Environmental Health, 82152 Planegg-Martinsried, Germany
- SYNERGY, Excellence Cluster of Systems Neurology, Biomedical Center, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
Welle TM, Rajgor D, Garcia JD, Kareemo D, Zych SM, Gookin SE, Martinez TP, Dell’Acqua ML, Ford CP, Kennedy MJ, Smith KR. miRNA-mediated control of gephyrin synthesis drives sustained inhibitory synaptic plasticity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.12.570420. [PMID: 38168421 PMCID: PMC10760056 DOI: 10.1101/2023.12.12.570420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Activity-dependent protein synthesis is crucial for many long-lasting forms of synaptic plasticity. However, our understanding of the translational mechanisms controlling inhibitory synapses is limited. One distinct form of inhibitory long-term potentiation (iLTP) enhances postsynaptic clusters of GABAARs and the primary inhibitory scaffold, gephyrin, to promote sustained synaptic strengthening. While we previously found that persistent iLTP requires mRNA translation, the precise mechanisms controlling gephyrin translation during this process remain unknown. Here, we identify miR153 as a novel regulator of Gphn mRNA translation which controls gephyrin protein levels and synaptic clustering, ultimately impacting GABAergic synaptic structure and function. We find that iLTP induction downregulates miR153, reversing its translational suppression of Gphn mRNA and allowing for increased de novo gephyrin protein synthesis and synaptic clustering during iLTP. Finally, we find that reduced miR153 expression during iLTP is driven by an excitation-transcription coupling pathway involving calcineurin, NFAT and HDACs, which also controls the miRNA-dependent upregulation of GABAARs. Overall, this work delineates a miRNA-dependent post-transcriptional mechanism that controls the expression of the key synaptic scaffold, gephyrin, and may converge with parallel miRNA pathways to coordinate gene upregulation to maintain inhibitory synaptic plasticity.
Collapse
Affiliation(s)
- Theresa M. Welle
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
- T.M.W and D.R. contributed equally to this work
| | - Dipen Rajgor
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
- T.M.W and D.R. contributed equally to this work
| | - Joshua D. Garcia
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Dean Kareemo
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Sarah M. Zych
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Sara E. Gookin
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Tyler P. Martinez
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Christopher P. Ford
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Matthew J. Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| | - Katharine R. Smith
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, 12800 East 19th Avenue, Aurora, CO 80045
| |
Collapse
|
5
|
Stewart RK, Nguyen P, Laederach A, Volkan PC, Sawyer JK, Fox DT. Orb2 enables rare-codon-enriched mRNA expression during Drosophila neuron differentiation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.26.550700. [PMID: 37546801 PMCID: PMC10402044 DOI: 10.1101/2023.07.26.550700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Regulation of codon optimality is an increasingly appreciated layer of cell- and tissue-specific protein expression control. Here, we use codon-modified reporters to show that differentiation of Drosophila neural stem cells into neurons enables protein expression from rare-codon-enriched genes. From a candidate screen, we identify the cytoplasmic polyadenylation element binding (CPEB) protein Orb2 as a positive regulator of rare-codon-dependent expression in neurons. Using RNA sequencing, we reveal that Orb2-upregulated mRNAs in the brain with abundant Orb2 binding sites have a rare-codon bias. From these Orb2-regulated mRNAs, we demonstrate that rare-codon enrichment is important for expression control and social behavior function of the metabotropic glutamate receptor (mGluR). Our findings reveal a molecular mechanism by which neural stem cell differentiation shifts genetic code regulation to enable critical mRNA and protein expression.
Collapse
|
6
|
Schieweck R, Ciccopiedi G, Klau K, Popper B. Monosomes buffer translational stress to allow for active ribosome elongation. Front Mol Biosci 2023; 10:1158043. [PMID: 37304066 PMCID: PMC10253174 DOI: 10.3389/fmolb.2023.1158043] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023] Open
Abstract
Introduction: The synthesis of proteins is a fundamental process in the life-span of all cells. The activation of ribosomes on transcripts is the starting signal for elongation and, in turn, the translation of an mRNA. Thereby, most mRNAs circulate between single (monosomes) and multi ribosomal particles (polysomes), a process that defines their translational activity. The interplay between monosomes and polysomes is thought to crucially impact translation rate. How monosomes and polysomes are balanced during stress remains, however, elusive. Methods: Here, we set out to investigate the monosome and polysome levels as well as their kinetics under different translational stress conditions including mTOR inhibition, downregulation of the eukaryotic elongation factor 2 (eEF2) and amino acid depletion. Results: By using a timed ribosome runoff approach in combination with polysome profiling, we found that the used translational stressors show very distinct effects on translation. However, they all had in common that the activity of monosomes was preferentially affected. This adaptation seems to be needed for sufficient translation elongation. Even under harsh conditions such as amino acid starvation, we detected active polysomes while monosomes were mostly inactive. Hence, it is plausible that cells compensate the reduced availability of essential factors during stress by adapting the levels of active monosomes to favor sufficient elongation. Discussion: These results suggest that monosome and polysome levels are balanced under stress conditions. Together, our data argue for the existence of translational plasticity that ensure sufficient protein synthesis under stress conditions, a process that is necessary for cell survival and recovery.
Collapse
Affiliation(s)
- Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Munich, Germany
| | - Giuliana Ciccopiedi
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Munich, Germany
| | - Kenneth Klau
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Munich, Germany
| | - Bastian Popper
- Biomedical Center (BMC), Core Facility Animal Models, Ludwig-Maximilians-University, Munich, Germany
| |
Collapse
|
7
|
TDP-43 condensates and lipid droplets regulate the reactivity of microglia and regeneration after traumatic brain injury. Nat Neurosci 2022; 25:1608-1625. [PMID: 36424432 DOI: 10.1038/s41593-022-01199-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 10/11/2022] [Indexed: 11/27/2022]
Abstract
Decreasing the activation of pathology-activated microglia is crucial to prevent chronic inflammation and tissue scarring. In this study, we used a stab wound injury model in zebrafish and identified an injury-induced microglial state characterized by the accumulation of lipid droplets and TAR DNA-binding protein of 43 kDa (TDP-43)+ condensates. Granulin-mediated clearance of both lipid droplets and TDP-43+ condensates was necessary and sufficient to promote the return of microglia back to the basal state and achieve scarless regeneration. Moreover, in postmortem cortical brain tissues from patients with traumatic brain injury, the extent of microglial activation correlated with the accumulation of lipid droplets and TDP-43+ condensates. Together, our results reveal a mechanism required for restoring microglia to a nonactivated state after injury, which has potential for new therapeutic applications in humans.
Collapse
|
8
|
Ehses J, Schlegel M, Schröger L, Schieweck R, Derdak S, Bilban M, Bauer K, Harner M, Kiebler MA. The dsRBP Staufen2 governs RNP assembly of neuronal Argonaute proteins. Nucleic Acids Res 2022; 50:7034-7047. [PMID: 35687120 PMCID: PMC9262589 DOI: 10.1093/nar/gkac487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 05/10/2022] [Accepted: 05/26/2022] [Indexed: 12/24/2022] Open
Abstract
Mature microRNAs are bound by a member of the Argonaute (Ago1-4) protein family, forming the core of the RNA-induced silencing complex (RISC). Association of RISC with target mRNAs results in ribonucleoprotein (RNP) assembly involved in translational silencing or RNA degradation. Yet, the dynamics of RNP assembly and its underlying functional implications are unknown. Here, we have characterized the role of the RNA-binding protein Staufen2, a candidate Ago interactor, in RNP assembly. Staufen2 depletion resulted in the upregulation of Ago1/2 and the RISC effector proteins Ddx6 and Dcp1a. This upregulation was accompanied by the displacement of Ago1/2 from processing bodies, large RNPs implicated in RNA storage, and subsequent association of Ago2 with polysomes. In parallel, Staufen2 deficiency decreased global translation and increased dendritic branching. As the observed phenotypes can be rescued by Ago1/2 knockdown, we propose a working model in which both Staufen2 and Ago proteins depend on each other and contribute to neuronal homeostasis.
Collapse
Affiliation(s)
- Janina Ehses
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Melina Schlegel
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Luise Schröger
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Sophia Derdak
- Core Facilities, Medical University of Vienna, 1090 Vienna, Austria
| | - Martin Bilban
- Department of Laboratory Medicine and Core Facility Genomics, Medical University, of Vienna, 1090 Vienna, Austria
| | - Karl Bauer
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Max Harner
- Biomedical Center (BMC), Department for Cell Biology, Medical Faculty, Ludwig-Maximilians-University of Munich, 82152 Planegg-Martinsried, Germany
| | - Michael A Kiebler
- To whom correspondence should be addressed. Tel: +49 89 2180 75884; Fax: +49 89 2180 75885;
| |
Collapse
|
9
|
Bauer KE, Bargenda N, Schieweck R, Illig C, Segura I, Harner M, Kiebler MA. RNA supply drives physiological granule assembly in neurons. Nat Commun 2022; 13:2781. [PMID: 35589693 DOI: 10.1038/s41467-022-30067-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 04/11/2022] [Indexed: 11/09/2022] Open
Abstract
Membraneless cytoplasmic condensates of mRNAs and proteins, known as RNA granules, play pivotal roles in the regulation of mRNA fate. Their maintenance fine-tunes time and location of protein expression, affecting many cellular processes, which require complex protein distribution. Here, we report that RNA granules-monitored by DEAD-Box helicase 6 (DDX6)-disassemble during neuronal maturation both in cell culture and in vivo. This process requires neuronal function, as synaptic inhibition results in reversible granule assembly. Importantly, granule assembly is dependent on the RNA-binding protein Staufen2, known for its role in RNA localization. Altering the levels of free cytoplasmic mRNA reveals that RNA availability facilitates DDX6 granule formation. Specifically depleting RNA from DDX6 granules confirms RNA as an important driver of granule formation. Moreover, RNA is required for DDX6 granule assembly upon synaptic inhibition. Together, this data demonstrates how RNA supply favors RNA granule assembly, which not only impacts subcellular RNA localization but also translation-dependent synaptic plasticity, learning, and memory.
Collapse
Affiliation(s)
- Karl E Bauer
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Niklas Bargenda
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Rico Schieweck
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Christin Illig
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Inmaculada Segura
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany.,Max Planck Institute for Biological Intelligence (in foundation), Am Klopferspitz 18, 82152, Martinsried, Germany
| | - Max Harner
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany
| | - Michael A Kiebler
- BioMedical Center, Dept. Cell Biology and Anatomy, Medical Faculty, Ludwig Maximilians University, Großhaderner Str. 9, 82152, Planegg-Martinsried, Germany.
| |
Collapse
|
10
|
Harb K, Richter M, Neelagandan N, Magrinelli E, Harfoush H, Kuechler K, Henis M, Hermanns-Borgmeyer I, Calderon de Anda F, Duncan K. Pum2 and TDP-43 refine area-specific cytoarchitecture post-mitotically and modulate translation of Sox5, Bcl11b, and Rorb mRNAs in developing mouse neocortex. eLife 2022; 11:55199. [PMID: 35262486 PMCID: PMC8906809 DOI: 10.7554/elife.55199] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 02/25/2022] [Indexed: 12/15/2022] Open
Abstract
In the neocortex, functionally distinct areas process specific types of information. Area identity is established by morphogens and transcriptional master regulators, but downstream mechanisms driving area-specific neuronal specification remain unclear. Here, we reveal a role for RNA-binding proteins in defining area-specific cytoarchitecture. Mice lacking Pum2 or overexpressing human TDP-43 show apparent ‘motorization’ of layers IV and V of primary somatosensory cortex (S1), characterized by dramatic expansion of cells co-expressing Sox5 and Bcl11b/Ctip2, a hallmark of subcerebral projection neurons, at the expense of cells expressing the layer IV neuronal marker Rorβ. Moreover, retrograde labeling experiments with cholera toxin B in Pum2; Emx1-Cre and TDP43A315T mice revealed a corresponding increase in subcerebral connectivity of these neurons in S1. Intriguingly, other key features of somatosensory area identity are largely preserved, suggesting that Pum2 and TDP-43 may function in a downstream program, rather than controlling area identity per se. Transfection of primary neurons and in utero electroporation (IUE) suggest cell-autonomous and post-mitotic modulation of Sox5, Bcl11b/Ctip2, and Rorβ levels. Mechanistically, we find that Pum2 and TDP-43 directly interact with and affect the translation of mRNAs encoding Sox5, Bcl11b/Ctip2, and Rorβ. In contrast, effects on the levels of these mRNAs were not detectable in qRT-PCR or single-molecule fluorescent in situ hybridization assays, and we also did not detect effects on their splicing or polyadenylation patterns. Our results support the notion that post-transcriptional regulatory programs involving translational regulation and mediated by Pum2 and TDP-43 contribute to elaboration of area-specific neuronal identity and connectivity in the neocortex.
Collapse
Affiliation(s)
- Kawssar Harb
- Neuronal Translational Control Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Melanie Richter
- Institute of Developmental Neurophysiology, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Nagammal Neelagandan
- Neuronal Translational Control Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Elia Magrinelli
- Department of Basic Neuroscience, University of Geneva, Geneva, Switzerland
| | - Hend Harfoush
- Neuronal Translational Control Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Katrin Kuechler
- Neuronal Translational Control Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Melad Henis
- Institute of Developmental Neurophysiology, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.,Department of Anatomy and Histology, Faculty of Veterinary Medicine, New Valley University, New Valley, Egypt
| | - Irm Hermanns-Borgmeyer
- Transgenic Service Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Froylan Calderon de Anda
- Institute of Developmental Neurophysiology, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kent Duncan
- Neuronal Translational Control Group, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| |
Collapse
|
11
|
Salamon I, Rasin MR. Evolution of the Neocortex Through RNA-Binding Proteins and Post-transcriptional Regulation. Front Neurosci 2022; 15:803107. [PMID: 35082597 PMCID: PMC8784817 DOI: 10.3389/fnins.2021.803107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/16/2021] [Indexed: 12/24/2022] Open
Abstract
The human neocortex is undoubtedly considered a supreme accomplishment in mammalian evolution. It features a prenatally established six-layered structure which remains plastic to the myriad of changes throughout an organism’s lifetime. A fundamental feature of neocortical evolution and development is the abundance and diversity of the progenitor cell population and their neuronal and glial progeny. These evolutionary upgrades are partially enabled due to the progenitors’ higher proliferative capacity, compartmentalization of proliferative regions, and specification of neuronal temporal identities. The driving force of these processes may be explained by temporal molecular patterning, by which progenitors have intrinsic capacity to change their competence as neocortical neurogenesis proceeds. Thus, neurogenesis can be conceptualized along two timescales of progenitors’ capacity to (1) self-renew or differentiate into basal progenitors (BPs) or neurons or (2) specify their fate into distinct neuronal and glial subtypes which participate in the formation of six-layers. Neocortical development then proceeds through sequential phases of proliferation, differentiation, neuronal migration, and maturation. Temporal molecular patterning, therefore, relies on the precise regulation of spatiotemporal gene expression. An extensive transcriptional regulatory network is accompanied by post-transcriptional regulation that is frequently mediated by the regulatory interplay between RNA-binding proteins (RBPs). RBPs exhibit important roles in every step of mRNA life cycle in any system, from splicing, polyadenylation, editing, transport, stability, localization, to translation (protein synthesis). Here, we underscore the importance of RBP functions at multiple time-restricted steps of early neurogenesis, starting from the cell fate transition of transcriptionally primed cortical progenitors. A particular emphasis will be placed on RBPs with mostly conserved but also divergent evolutionary functions in neural progenitors across different species. RBPs, when considered in the context of the fascinating process of neocortical development, deserve to be main protagonists in the story of the evolution and development of the neocortex.
Collapse
|
12
|
RNA-binding protein dysfunction in neurodegeneration. Essays Biochem 2021; 65:975-986. [PMID: 34927200 DOI: 10.1042/ebc20210024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 11/28/2021] [Accepted: 11/30/2021] [Indexed: 11/17/2022]
Abstract
Protein homeostasis (proteostasis) is a prerequisite for cellular viability and plasticity. In particular, post-mitotic cells such as neurons rely on a tightly regulated safeguard system that allows for regulated protein expression. Previous investigations have identified RNA-binding proteins (RBPs) as crucial regulators of protein expression in nerve cells. However, during neurodegeneration, their ability to control the proteome is progressively disrupted. In this review, we examine the malfunction of key RBPs such as TAR DNA-binding protein 43 (TDP-43), Fused in Sarcoma (FUS), Staufen, Pumilio and fragile-X mental retardation protein (FMRP). Therefore, we focus on two key aspects of RBP dysfunctions in neurodegeneration: protein aggregation and dysregulation of their target RNAs. Moreover, we discuss how the chaperone system responds to changes in the RBP-controlled transcriptome. Based on recent findings, we propose a two-hit model in which both, harmful RBP deposits and target mRNA mistranslation contribute to neurodegeneration observed in RBPathologies.
Collapse
|
13
|
Behrens G, Edelmann SL, Raj T, Kronbeck N, Monecke T, Davydova E, Wong EH, Kifinger L, Giesert F, Kirmaier ME, Hohn C, de Jonge LS, Pisfil MG, Fu M, Theurich S, Feske S, Kawakami N, Wurst W, Niessing D, Heissmeyer V. Disrupting Roquin-1 interaction with Regnase-1 induces autoimmunity and enhances antitumor responses. Nat Immunol 2021; 22:1563-1576. [PMID: 34811541 PMCID: PMC8996344 DOI: 10.1038/s41590-021-01064-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/30/2021] [Indexed: 12/15/2022]
Abstract
Roquin and Regnase-1 proteins bind and post-transcriptionally regulate proinflammatory target messenger RNAs to maintain immune homeostasis. Either the sanroque mutation in Roquin-1 or loss of Regnase-1 cause systemic lupus erythematosus-like phenotypes. Analyzing mice with T cells that lack expression of Roquin-1, its paralog Roquin-2 and Regnase-1 proteins, we detect overlapping or unique phenotypes by comparing individual and combined inactivation. These comprised spontaneous activation, metabolic reprogramming and persistence of T cells leading to autoimmunity. Here, we define an interaction surface in Roquin-1 for binding to Regnase-1 that included the sanroque residue. Mutations in Roquin-1 impairing this interaction and cooperative regulation of targets induced T follicular helper cells, germinal center B cells and autoantibody formation. These mutations also improved the functionality of tumor-specific T cells by promoting their accumulation in the tumor and reducing expression of exhaustion markers. Our data reveal the physical interaction of Roquin-1 with Regnase-1 as a hub to control self-reactivity and effector functions in immune cell therapies.
Collapse
Affiliation(s)
- Gesine Behrens
- Institute for Immunology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
| | - Stephanie L Edelmann
- Research Unit Molecular Immune Regulation, Helmholtz Zentrum München, Munich, Germany
| | - Timsse Raj
- Institute for Immunology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
| | - Nina Kronbeck
- Institute for Immunology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
| | - Thomas Monecke
- Institute of Pharmaceutical Biotechnology, Ulm University, Ulm, Germany
| | - Elena Davydova
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Elaine H Wong
- Institute for Immunology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
| | - Lisa Kifinger
- Research Unit Molecular Immune Regulation, Helmholtz Zentrum München, Munich, Germany
| | - Florian Giesert
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Martin E Kirmaier
- Cancer and Immunometabolism Research Group at the Gene Center, Ludwig-Maximilians-Universität in Munich, Munich, Germany
- Department of Medicine III, LMU University Hospital, Ludwig-Maximilians-Universität in Munich, Munich, Germany
| | - Christine Hohn
- Institute for Immunology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
| | - Laura S de Jonge
- Research Unit Molecular Immune Regulation, Helmholtz Zentrum München, Munich, Germany
| | - Mariano Gonzalez Pisfil
- Core Facility Bioimaging and Walter-Brendel-Centre of Experimental Medicine at the Biomedical Center, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
| | - Mingui Fu
- Department of Basic Medical Science, School of Medicine, University of Missouri-Kansas City, Kansas City, MO, USA
| | - Sebastian Theurich
- Cancer and Immunometabolism Research Group at the Gene Center, Ludwig-Maximilians-Universität in Munich, Munich, Germany
- Department of Medicine III, LMU University Hospital, Ludwig-Maximilians-Universität in Munich, Munich, Germany
| | - Stefan Feske
- Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Naoto Kawakami
- Institute of Clinical Neuroimmunology, University Hospital and Biomedical Center, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- German Center for Neurodegenerative Diseases (DZNE) Site Munich, Munich, Germany
- Technische Universität München, Lehrstuhl für Entwicklungsgenetik c/o Helmholtz Zentrum München, Munich, Germany
| | - Dierk Niessing
- Institute of Pharmaceutical Biotechnology, Ulm University, Ulm, Germany
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Vigo Heissmeyer
- Institute for Immunology, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-Universität in Munich, Planegg-Martinsried, Germany.
- Research Unit Molecular Immune Regulation, Helmholtz Zentrum München, Munich, Germany.
| |
Collapse
|
14
|
RGS4 RNA Secondary Structure Mediates Staufen2 RNP Assembly in Neurons. Int J Mol Sci 2021; 22:ijms222313021. [PMID: 34884825 PMCID: PMC8657808 DOI: 10.3390/ijms222313021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 11/26/2022] Open
Abstract
RNA-binding proteins (RBPs) act as posttranscriptional regulators controlling the fate of target mRNAs. Unraveling how RNAs are recognized by RBPs and in turn are assembled into neuronal RNA granules is therefore key to understanding the underlying mechanism. While RNA sequence elements have been extensively characterized, the functional impact of RNA secondary structures is only recently being explored. Here, we show that Staufen2 binds complex, long-ranged RNA hairpins in the 3′-untranslated region (UTR) of its targets. These structures are involved in the assembly of Staufen2 into RNA granules. Furthermore, we provide direct evidence that a defined Rgs4 RNA duplex regulates Staufen2-dependent RNA localization to distal dendrites. Importantly, disrupting the RNA hairpin impairs the observed effects. Finally, we show that these secondary structures differently affect protein expression in neurons. In conclusion, our data reveal the importance of RNA secondary structure in regulating RNA granule assembly, localization and eventually translation. It is therefore tempting to speculate that secondary structures represent an important code for cells to control the intracellular fate of their mRNAs.
Collapse
|
15
|
Schieweck R, Schöneweiss EC, Harner M, Rieger D, Illig C, Saccà B, Popper B, Kiebler MA. Pumilio2 Promotes Growth of Mature Neurons. Int J Mol Sci 2021; 22:ijms22168998. [PMID: 34445704 PMCID: PMC8396670 DOI: 10.3390/ijms22168998] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 01/05/2023] Open
Abstract
RNA-binding proteins (RBPs) are essential regulators controlling both the cellular transcriptome and translatome. These processes enable cellular plasticity, an important prerequisite for growth. Cellular growth is a complex, tightly controlled process. Using cancer cells as model, we looked for RBPs displaying strong expression in published transcriptome datasets. Interestingly, we found the Pumilio (Pum) protein family to be highly expressed in all these cells. Moreover, we observed that Pum2 is regulated by basic fibroblast growth factor (bFGF). bFGF selectively enhances protein levels of Pum2 and the eukaryotic initiation factor 4E (eIF4E). Exploiting atomic force microscopy and in vitro pulldown assays, we show that Pum2 selects for eIF4E mRNA binding. Loss of Pum2 reduces eIF4E translation. Accordingly, depletion of Pum2 led to decreased soma size and dendritic branching of mature neurons, which was accompanied by a reduction in essential growth factors. In conclusion, we identify Pum2 as an important growth factor for mature neurons. Consequently, it is tempting to speculate that Pum2 may promote cancer growth.
Collapse
Affiliation(s)
- Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 München, Germany; (R.S.); (M.H.); (D.R.); (C.I.); (M.A.K.)
| | - Elisa-Charlott Schöneweiss
- Zentrum für Medizinische Biotechnologie (ZMB), University of Duisburg-Essen, 41541 Duisburg, Germany; (E.-C.S.); (B.S.)
| | - Max Harner
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 München, Germany; (R.S.); (M.H.); (D.R.); (C.I.); (M.A.K.)
| | - Daniela Rieger
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 München, Germany; (R.S.); (M.H.); (D.R.); (C.I.); (M.A.K.)
| | - Christin Illig
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 München, Germany; (R.S.); (M.H.); (D.R.); (C.I.); (M.A.K.)
| | - Barbara Saccà
- Zentrum für Medizinische Biotechnologie (ZMB), University of Duisburg-Essen, 41541 Duisburg, Germany; (E.-C.S.); (B.S.)
| | - Bastian Popper
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 München, Germany; (R.S.); (M.H.); (D.R.); (C.I.); (M.A.K.)
- Biomedical Center (BMC), Core Facility Animal Models, Ludwig-Maximilians-University, 82152 München, Germany
- Correspondence: ; Tel.: +49-89-2180-71996
| | - Michael A. Kiebler
- Biomedical Center (BMC), Department for Cell Biology & Anatomy, Medical Faculty, Ludwig-Maximilians-University, 82152 München, Germany; (R.S.); (M.H.); (D.R.); (C.I.); (M.A.K.)
| |
Collapse
|