@article{GhanawiHennleinZareetal.2021, author = {Ghanawi, Hanaa and Hennlein, Luisa and Zare, Abdolhossein and Bader, Jakob and Salehi, Saeede and Hornburg, Daniel and Ji, Changhe and Sivadasan, Rajeeve and Drepper, Carsten and Meissner, Felix and Mann, Matthias and Jablonka, Sibylle and Briese, Michael and Sendtner, Michael}, title = {Loss of full-length hnRNP R isoform impairs DNA damage response in motoneurons by inhibiting Yb1 recruitment to chromatin}, series = {Nucleic Acids Research}, volume = {49}, journal = {Nucleic Acids Research}, number = {21}, doi = {10.1093/nar/gkab1120}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265687}, pages = {12284-12305}, year = {2021}, abstract = {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.}, language = {en} } @article{DombertSivadasanSimonetal.2014, author = {Dombert, Benjamin and Sivadasan, Rajeeve and Simon, Christian M. and Jablonka, Sibylle and Sendtner, Michael}, title = {Presynaptic Localization of Smn and hnRNP R in Axon Terminals of Embryonic and Postnatal Mouse Motoneurons}, doi = {10.1371/journal.pone.0110846}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-113655}, year = {2014}, abstract = {Spinal muscular atrophy (SMA) is caused by deficiency of the ubiquitously expressed survival motoneuron (SMN) protein. SMN is crucial component of a complex for the assembly of spliceosomal small nuclear ribonucleoprotein (snRNP) particles. Other cellular functions of SMN are less characterized so far. SMA predominantly affects lower motoneurons, but the cellular basis for this relative specificity is still unknown. In contrast to nonneuronal cells where the protein is mainly localized in perinuclear regions and the nucleus, Smn is also present in dendrites, axons and axonal growth cones of isolated motoneurons in vitro. However, this distribution has not been shown in vivo and it is not clear whether Smn and hnRNP R are also present in presynaptic axon terminals of motoneurons in postnatal mice. Smn also associates with components not included in the classical SMN complex like RNA-binding proteins FUS, TDP43, HuD and hnRNP R which are involved in RNA processing, subcellular localization and translation. We show here that Smn and hnRNP R are present in presynaptic compartments at neuromuscular endplates of embryonic and postnatal mice. Smn and hnRNP R are localized in close proximity to each other in axons and axon terminals both in vitro and in vivo. We also provide new evidence for a direct interaction of Smn and hnRNP R in vitro and in vivo, particularly in the cytosol of motoneurons. These data point to functions of SMN beyond snRNP assembly which could be crucial for recruitment and transport of RNA particles into axons and axon terminals, a mechanism which may contribute to SMA pathogenesis.}, language = {en} }