1
|
Schlautmann LP, Lackmann JW, Altmüller J, Dieterich C, Boehm V, Gehring NH. Exon junction complex-associated multi-adapter RNPS1 nucleates splicing regulatory complexes to maintain transcriptome surveillance. Nucleic Acids Res 2022; 50:5899-5918. [PMID: 35640609 PMCID: PMC9178013 DOI: 10.1093/nar/gkac428] [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: 08/20/2021] [Revised: 05/05/2022] [Accepted: 05/10/2022] [Indexed: 12/04/2022] Open
Abstract
The exon junction complex (EJC) is an RNA-binding multi-protein complex with critical functions in post-transcriptional gene regulation. It is deposited on the mRNA during splicing and regulates diverse processes including pre-mRNA splicing and nonsense-mediated mRNA decay (NMD) via various interacting proteins. The peripheral EJC-binding protein RNPS1 was reported to serve two insufficiently characterized functions: suppressing mis-splicing of cryptic splice sites and activating NMD in the cytoplasm. The analysis of transcriptome-wide effects of EJC and RNPS1 knockdowns in different human cell lines supports the conclusion that RNPS1 can moderately influence NMD activity, but is not a globally essential NMD factor. However, numerous aberrant splicing events strongly suggest that the main function of RNPS1 is splicing regulation. Rescue analyses revealed that the RRM and C-terminal domain of RNPS1 both contribute partially to regulate RNPS1-dependent splicing events. We defined the RNPS1 core interactome using complementary immunoprecipitations and proximity labeling, which identified interactions with splicing-regulatory factors that are dependent on the C-terminus or the RRM domain of RNPS1. Thus, RNPS1 emerges as a multifunctional splicing regulator that promotes correct and efficient splicing of different vulnerable splicing events via the formation of diverse splicing-promoting complexes.
Collapse
Affiliation(s)
- Lena P Schlautmann
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50937 Cologne, Germany
| | - Jan-Wilm Lackmann
- CECAD Research Center, University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), University of Cologne, 50931 Cologne, Germany
| | - Christoph Dieterich
- Section of Bioinformatics and Systems Cardiology, Department of Internal Medicine III and Klaus Tschira Institute for Integrative Computational Cardiology, Heidelberg University Hospital, 69120 Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Volker Boehm
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50937 Cologne, Germany
| | - Niels H Gehring
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50937 Cologne, Germany
| |
Collapse
|
2
|
Nandi N, Zaidi Z, Tracy C, Krämer H. A phospho-switch at Acinus-Serine 437 controls autophagic responses to Cadmium exposure and neurodegenerative stress. eLife 2022; 11:72169. [PMID: 35037620 PMCID: PMC8794470 DOI: 10.7554/elife.72169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 01/14/2022] [Indexed: 12/09/2022] Open
Abstract
Neuronal health depends on quality control functions of autophagy, but mechanisms regulating neuronal autophagy are poorly understood. Previously, we showed that in Drosophila starvation-independent quality control autophagy is regulated by acinus (acn) and the Cdk5-dependent phosphorylation of its serine437 (Nandi et al., 2017). Here, we identify the phosphatase that counterbalances this activity and provides for the dynamic nature of acinus-serine437 (acn-S437) phosphorylation. A genetic screen identified six phosphatases that genetically interacted with an acn gain-of-function model. Among these, loss of function of only one, the PPM-type phosphatase Nil (CG6036), enhanced pS437-acn levels. Cdk5-dependent phosphorylation of acn-S437 in nil1 animals elevates neuronal autophagy and reduces the accumulation of polyQ proteins in a Drosophila Huntington’s disease model. Consistent with previous findings that Cd2+ inhibits PPM-type phosphatases, Cd2+ exposure elevated acn-S437 phosphorylation which was necessary for increased neuronal autophagy and protection against Cd2+-induced cytotoxicity. Together, our data establish the acn-S437 phosphoswitch as critical integrator of multiple stress signals regulating neuronal autophagy.
Collapse
Affiliation(s)
- Nilay Nandi
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Zuhair Zaidi
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Charles Tracy
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Helmut Krämer
- Department of Neuroscience, The University of Texas Southwestern Medical Center, Dallas, United States
| |
Collapse
|
3
|
Zhang Z, Yao M, Zhu G, Chen Y, Chen Y, Sun F, Zhang Y, Wang Q, Shen Z. Identification and subcellular localization of splicing factor arginine/serine-rich 10 in the microsporidian Nosema bombycis. J Invertebr Pathol 2020; 174:107441. [PMID: 32659232 DOI: 10.1016/j.jip.2020.107441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 07/02/2020] [Accepted: 07/06/2020] [Indexed: 12/14/2022]
Abstract
Splicing factors are important components of RNA editing in eukaryotic organisms and can produce many functional and coding genes, which is an indispensable step for the correct expression of corresponding proteins. In this study, we identified splicing factor arginine/serine-rich 10 protein in the microsporidian Nosema bombycis and named it NbSRSF10. The NbSRSF10 gene contains a complete ORF of 1449 bp in length that encodes a 482-amino acid polypeptide. The isoelectric point (pI) of the protein encoded by NbSRSF10 gene was 4.94. NbSRSF10 has a molecular weight of 54.6 kD and has no signal peptide. NbSRSF10 is comprised of arginine (11.41%), glutamic acid (11.41%) and serine (9.54%) among the total amino acids, and 7 α-helix, 7 β-sheet and 15 random coils in secondary structure, and contains 71 phosphorylation sites, 22 N-glycosylation sites and 20 O-glycosylation sites. The three-dimensional structure of NbSRSF10 is similar to that of transformer-2 beta of Homo sapiens (hTra2-β). Indirect immunofluorescence showed that the NbSRSF10 is localized in the cytoplasm of the dormant microsporidian spore and is transferred to the nuclei when N. bombycis develops into the proliferative and sporogonic phase. qPCR revealed that the relative expression of NbSRSF10 increased in the meronts stage and was found at a relatively low level in the sporogonic phase of development of N. bombycis, and was up-regulated again during infection in the host cell and early proliferative phase of second life cycle. These results suggested that the NbSRSF10 may participate in the whole life cycle and play an important role in transcription regulation of N. bombycis.
Collapse
Affiliation(s)
- Zhilin Zhang
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China
| | - Mingshuai Yao
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China
| | - Guanyu Zhu
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China
| | - Yong Chen
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China
| | - Ying Chen
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China
| | - Fuzhen Sun
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China
| | - Yiling Zhang
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu Province, China
| | - Qiang Wang
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu Province, China
| | - Zhongyuan Shen
- Jiangsu University of Science and Technology, Zhenjiang 212018, Jiangsu Province, China; Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212018, Jiangsu Province, China.
| |
Collapse
|
4
|
Biola-Clier M, Gaillard JC, Rabilloud T, Armengaud J, Carriere M. Titanium Dioxide Nanoparticles Alter the Cellular Phosphoproteome in A549 Cells. NANOMATERIALS 2020; 10:nano10020185. [PMID: 31973118 PMCID: PMC7074930 DOI: 10.3390/nano10020185] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/11/2020] [Accepted: 01/16/2020] [Indexed: 12/02/2022]
Abstract
TiO2 nanoparticles (NPs) are one of the most produced NPs worldwide and are used in many consumer products. Their impact on human health, especially through inhalation, has been studied for more than two decades. TiO2 is known for its strong affinity towards phosphates, and consequently interaction with cellular phosphates may be one of the mechanisms driving its toxicity. In the present study, we used a phosphoproteomics approach to document the interaction of TiO2-NP with phosphoproteins from A549 human pulmonary alveolar epithelial cells. Cells were exposed to 21 nm anatase/rutile TiO2-NPs, then their phosphopeptides were extracted and analyzed using shotgun proteomics. By comparing the phosphoprotein content, phosphorylation status and phosphorylation sites of exposed cells with that of control cells, our results show that by affecting the phosphoproteome, TiO2-NPs affect cellular processes such as apoptosis, linked with cell cycle and the DNA damage response, TP53 being central to these pathways. Other pathways including inflammation and molecular transport are also affected. These molecular mechanisms of TiO2-NP toxicity have been reported previously, our study shows for the first time that they may derive from phosphoproteome modulation, which could be one of their upstream regulators.
Collapse
Affiliation(s)
| | - Jean-Charles Gaillard
- Laboratoire Innovations technologiques pour la Détection et le Diagnostic (Li2D), Service de Pharmacologie et Immunoanalyse (SPI), CEA, INRA, F-30207 Bagnols-sur-Cèze, France;
| | - Thierry Rabilloud
- Chemistry and Biology of Metals, Univ. Grenoble Alpes, CNRS UMR5249, CEA, IRIG-DIESE-LCBM-ProMD, F-38054 Grenoble, France;
| | - Jean Armengaud
- Laboratoire Innovations technologiques pour la Détection et le Diagnostic (Li2D), Service de Pharmacologie et Immunoanalyse (SPI), CEA, INRA, F-30207 Bagnols-sur-Cèze, France;
- Correspondence: (J.A.); (M.C.)
| | - Marie Carriere
- Univ. Grenoble-Alpes, IRIG, SyMMES, CIBEST, F-38000 Grenoble, France;
- Correspondence: (J.A.); (M.C.)
| |
Collapse
|