TY - JOUR A1 - Salehi, Saeede A1 - Zare, Abdolhossein A1 - Prezza, Gianluca A1 - Bader, Jakob A1 - Schneider, Cornelius A1 - Fischer, Utz A1 - Meissner, Felix A1 - Mann, Matthias A1 - Briese, Michael A1 - Sendtner, Michael T1 - Cytosolic Ptbp2 modulates axon growth in motoneurons through axonal localization and translation of Hnrnpr JF - Nature Communications N2 - The neuronal RNA-binding protein Ptbp2 regulates neuronal differentiation by modulating alternative splicing programs in the nucleus. Such programs contribute to axonogenesis by adjusting the levels of protein isoforms involved in axon growth and branching. While its functions in alternative splicing have been described in detail, cytosolic roles of Ptbp2 for axon growth have remained elusive. Here, we show that Ptbp2 is located in the cytosol including axons and growth cones of motoneurons, and that depletion of cytosolic Ptbp2 affects axon growth. We identify Ptbp2 as a major interactor of the 3’ UTR of Hnrnpr mRNA encoding the RNA-binding protein hnRNP R. Axonal localization of Hnrnpr mRNA and local synthesis of hnRNP R protein are strongly reduced when Ptbp2 is depleted, leading to defective axon growth. Ptbp2 regulates hnRNP R translation by mediating the association of Hnrnpr with ribosomes in a manner dependent on the translation factor eIF5A2. Our data thus suggest a mechanism whereby cytosolic Ptbp2 modulates axon growth by fine-tuning the mRNA transport and local synthesis of an RNA-binding protein. KW - molecular neuroscience KW - RNA-binding proteins KW - RNA transport Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357639 VL - 14 ER - TY - JOUR A1 - Lüningschrör, Patrick A1 - Slotta, Carsten A1 - Heimann, Peter A1 - Briese, Michael A1 - Weikert, Ulrich M. A1 - Massih, Bita A1 - Appenzeller, Silke A1 - Sendtner, Michael A1 - Kaltschmidt, Christian A1 - Kaltschmidt, Barbara T1 - Absence of Plekhg5 Results in Myelin Infoldings Corresponding to an Impaired Schwann Cell Autophagy, and a Reduced T-Cell Infiltration Into Peripheral Nerves JF - Frontiers in Cellular Neuroscience N2 - Inflammation and dysregulation of the immune system are hallmarks of several neurodegenerative diseases. An activated immune response is considered to be the cause of myelin breakdown in demyelinating disorders. In the peripheral nervous system (PNS), myelin can be degraded in an autophagy-dependent manner directly by Schwann cells or by macrophages, which are modulated by T-lymphocytes. Here, we show that the NF-κB activator Pleckstrin homology containing family member 5 (Plekhg5) is involved in the regulation of both Schwann cell autophagy and recruitment of T-lymphocytes in peripheral nerves during motoneuron disease. Plekhg5-deficient mice show defective axon/Schwann cell units characterized by myelin infoldings in peripheral nerves. Even at late stages, Plekhg5-deficient mice do not show any signs of demyelination and inflammation. Using RNAseq, we identified a transcriptional signature for an impaired immune response in sciatic nerves, which manifested in a reduced number of CD4\(^+\) and CD8\(^+\) T-cells. These findings identify Plekhg5 as a promising target to impede myelin breakdown in demyelinating PNS disorders. KW - Schwann cells KW - autophagy KW - immune response KW - myelin KW - PLEKHG5 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-207538 SN - 1662-5102 VL - 14 ER - TY - JOUR A1 - Ji, Changhe A1 - Bader, Jakob A1 - Ramanathan, Pradhipa A1 - Hennlein, Luisa A1 - Meissner, Felix A1 - Jablonka, Sibylle A1 - Mann, Matthias A1 - Fischer, Utz A1 - Sendtner, Michael A1 - Briese, Michael T1 - Interaction of 7SK with the Smn complex modulates snRNP production JF - Nature Communications N2 - Gene expression requires tight coordination of the molecular machineries that mediate transcription and splicing. While the interplay between transcription kinetics and spliceosome fidelity has been investigated before, less is known about mechanisms regulating the assembly of the spliceosomal machinery in response to transcription changes. Here, we report an association of the Smn complex, which mediates spliceosomal snRNP biogenesis, with the 7SK complex involved in transcriptional regulation. We found that Smn interacts with the 7SK core components Larp7 and Mepce and specifically associates with 7SK subcomplexes containing hnRNP R. The association between Smn and 7SK complexes is enhanced upon transcriptional inhibition leading to reduced production of snRNPs. Taken together, our findings reveal a functional association of Smn and 7SK complexes that is governed by global changes in transcription. Thus, in addition to its canonical nuclear role in transcriptional regulation, 7SK has cytosolic functions in fine-tuning spliceosome production according to transcriptional demand. KW - Molecular neuroscience KW - RNA KW - RNA splicing KW - Transcription Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259125 VL - 12 IS - 1 ER - TY - JOUR A1 - Ghanawi, Hanaa A1 - Hennlein, Luisa A1 - Zare, Abdolhossein A1 - Bader, Jakob A1 - Salehi, Saeede A1 - Hornburg, Daniel A1 - Ji, Changhe A1 - Sivadasan, Rajeeve A1 - Drepper, Carsten A1 - Meissner, Felix A1 - Mann, Matthias A1 - Jablonka, Sibylle A1 - Briese, Michael A1 - Sendtner, Michael T1 - Loss of full-length hnRNP R isoform impairs DNA damage response in motoneurons by inhibiting Yb1 recruitment to chromatin JF - Nucleic Acids Research N2 - Neurons critically rely on the functions of RNA-binding proteins to maintain their polarity and resistance to neurotoxic stress. HnRNP R has a diverse range of post-transcriptional regulatory functions and is important for neuronal development by regulating axon growth. Hnrnpr pre-mRNA undergoes alternative splicing giving rise to a full-length protein and a shorter isoform lacking its N-terminal acidic domain. To investigate functions selectively associated with the full-length hnRNP R isoform, we generated a Hnrnpr knockout mouse (Hnrnpr\(^{tm1a/tm1a}\)) in which expression of full-length hnRNP R was abolished while production of the truncated hnRNP R isoform was retained. Motoneurons cultured from Hnrnpr\(^{tm1a/tm1a}\) mice did not show any axonal growth defects but exhibited enhanced accumulation of double-strand breaks and an impaired DNA damage response upon exposure to genotoxic agents. Proteomic analysis of the hnRNP R interactome revealed the multifunctional protein Yb1 as a top interactor. Yb1-depleted motoneurons were defective in DNA damage repair. We show that Yb1 is recruited to chromatin upon DNA damage where it interacts with gamma-H2AX, a mechanism that is dependent on full-length hnRNP R. Our findings thus suggest a novel role of hnRNP R in maintaining genomic integrity and highlight the function of its N-terminal acidic domain in this context. KW - nuclear ribonucleoprotein-R KW - determining gene-product KW - actin messenger RNA KW - comet assay KW - genome wide KW - spinal cord KW - YB-1 KW - SMN KW - interacts KW - enrichment Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-265687 VL - 49 IS - 21 ER - TY - JOUR A1 - Briese, Michael A1 - Sendtner, Michael T1 - Keeping the balance: the noncoding RNA 7SK as a master regulator for neuron development and function JF - BioEssays N2 - The noncoding RNA 7SK is a critical regulator of transcription by adjusting the activity of the kinase complex P-TEFb. Release of P-TEFb from 7SK stimulates transcription at many genes by promoting productive elongation. Conversely, P-TEFb sequestration by 7SK inhibits transcription. Recent studies have shown that 7SK functions are particularly important for neuron development and maintenance and it can thus be hypothesized that 7SK is at the center of many signaling pathways contributing to neuron function. 7SK activates neuronal gene expression programs that are key for terminal differentiation of neurons. Proteomics studies revealed a complex protein interactome of 7SK that includes several RNA-binding proteins. Some of these novel 7SK subcomplexes exert non-canonical cytosolic functions in neurons by regulating axonal mRNA transport and fine-tuning spliceosome production in response to transcription alterations. Thus, a picture emerges according to which 7SK acts as a multi-functional RNA scaffold that is integral for neuron homeostasis. KW - medicine Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256613 VL - 43 IS - 8 ER - TY - JOUR A1 - Briese, Michael A1 - Saal-Bauernschubert, Lena A1 - Lüningschrör, Patrick A1 - Moradi, Mehri A1 - Dombert, Benjamin A1 - Surrey, Verena A1 - Appenzeller, Silke A1 - Deng, Chunchu A1 - Jablonka, Sibylle A1 - Sendtner, Michael T1 - Loss of Tdp-43 disrupts the axonal transcriptome of motoneurons accompanied by impaired axonal translation and mitochondria function JF - Acta Neuropathologica Communications N2 - Protein inclusions containing the RNA-binding protein TDP-43 are a pathological hallmark of amyotrophic lateral sclerosis and other neurodegenerative disorders. The loss of TDP-43 function that is associated with these inclusions affects post-transcriptional processing of RNAs in multiple ways including pre-mRNA splicing, nucleocytoplasmic transport, modulation of mRNA stability and translation. In contrast, less is known about the role of TDP-43 in axonal RNA metabolism in motoneurons. Here we show that depletion of Tdp-43 in primary motoneurons affects axon growth. This defect is accompanied by subcellular transcriptome alterations in the axonal and somatodendritic compartment. The axonal localization of transcripts encoding components of the cytoskeleton, the translational machinery and transcripts involved in mitochondrial energy metabolism were particularly affected by loss of Tdp-43. Accordingly, we observed reduced protein synthesis and disturbed mitochondrial functions in axons of Tdp-43-depleted motoneurons. Treatment with nicotinamide rescued the axon growth defect associated with loss of Tdp-43. These results show that Tdp-43 depletion in motoneurons affects several pathways integral to axon health indicating that loss of TDP-43 function could thus make a major contribution to axonal pathomechanisms in ALS. KW - amyotrophic lateral sclerosis KW - Tdp-43 KW - axonal transcriptome KW - nicotinamide Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230322 VL - 8 ER - TY - JOUR A1 - Briese, Michael A1 - Saal, Lena A1 - Appenzeller, Silke A1 - Moradi, Mehri A1 - Baluapuri, Apoorva A1 - Sendtner, Michael T1 - Whole transcriptome profiling reveals the RNA content of motor axons JF - Nucleic Acids Research N2 - Most RNAs within polarized cells such as neurons are sorted subcellularly in a coordinated manner. Despite advances in the development of methods for profiling polyadenylated RNAs from small amounts of input RNA, techniques for profiling coding and non-coding RNAs simultaneously are not well established. Here, we optimized a transcriptome profiling method based on double-random priming and applied it to serially diluted total RNA down to 10 pg. Read counts of expressed genes were robustly correlated between replicates, indicating that the method is both reproducible and scalable. Our transcriptome profiling method detected both coding and long non-coding RNAs sized >300 bases. Compared to total RNAseq using a conventional approach our protocol detected 70% more genes due to reduced capture of ribosomal RNAs. We used our method to analyze the RNA composition of compartmentalized motoneurons. The somatodendritic compartment was enriched for transcripts with post-synaptic functions as well as for certain nuclear non-coding RNAs such as 7SK. In axons, transcripts related to translation were enriched including the cytoplasmic non-coding RNA 7SL. Our profiling method can be applied to a wide range of investigations including perturbations of subcellular transcriptomes in neurodegenerative diseases and investigations of microdissected tissue samples such as anatomically defined fiber tracts. KW - RNA KW - motor axons Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126800 ER -