1
|
Stanković D, Tain LS, Uhlirova M. Xrp1 governs the stress response program to spliceosome dysfunction. Nucleic Acids Res 2024; 52:2093-2111. [PMID: 38303573 PMCID: PMC10954486 DOI: 10.1093/nar/gkae055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 01/03/2024] [Accepted: 01/16/2024] [Indexed: 02/03/2024] Open
Abstract
Co-transcriptional processing of nascent pre-mRNAs by the spliceosome is vital to regulating gene expression and maintaining genome integrity. Here, we show that the deficiency of functional U5 small nuclear ribonucleoprotein particles (snRNPs) in Drosophila imaginal cells causes extensive transcriptome remodeling and accumulation of highly mutagenic R-loops, triggering a robust stress response and cell cycle arrest. Despite compromised proliferative capacity, the U5 snRNP-deficient cells increased protein translation and cell size, causing intra-organ growth disbalance before being gradually eliminated via apoptosis. We identify the Xrp1-Irbp18 heterodimer as the primary driver of transcriptional and cellular stress program downstream of U5 snRNP malfunction. Knockdown of Xrp1 or Irbp18 in U5 snRNP-deficient cells attenuated JNK and p53 activity, restored normal cell cycle progression and growth, and inhibited cell death. Reducing Xrp1-Irbp18, however, did not rescue the splicing defects, highlighting the requirement of accurate splicing for cellular and tissue homeostasis. Our work provides novel insights into the crosstalk between splicing and the DNA damage response and defines the Xrp1-Irbp18 heterodimer as a critical sensor of spliceosome malfunction and mediator of the stress-induced cellular senescence program.
Collapse
Affiliation(s)
- Dimitrije Stanković
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne 50931, Germany
| | - Luke S Tain
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne 50931, Germany
| | - Mirka Uhlirova
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne 50931, Germany
| |
Collapse
|
2
|
Black CS, Whelan TA, Garside EL, MacMillan AM, Fast NM, Rader SD. Spliceosome assembly and regulation: insights from analysis of highly reduced spliceosomes. RNA (NEW YORK, N.Y.) 2023; 29:531-550. [PMID: 36737103 PMCID: PMC10158995 DOI: 10.1261/rna.079273.122] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 01/06/2023] [Indexed: 05/06/2023]
Abstract
Premessenger RNA splicing is catalyzed by the spliceosome, a multimegadalton RNA-protein complex that assembles in a highly regulated process on each intronic substrate. Most studies of splicing and spliceosomes have been carried out in human or S. cerevisiae model systems. There exists, however, a large diversity of spliceosomes, particularly in organisms with reduced genomes, that suggests a means of analyzing the essential elements of spliceosome assembly and regulation. In this review, we characterize changes in spliceosome composition across phyla, describing those that are most frequently observed and highlighting an analysis of the reduced spliceosome of the red alga Cyanidioschyzon merolae We used homology modeling to predict what effect splicing protein loss would have on the spliceosome, based on currently available cryo-EM structures. We observe strongly correlated loss of proteins that function in the same process, for example, in interacting with the U1 snRNP (which is absent in C. merolae), regulation of Brr2, or coupling transcription and splicing. Based on our observations, we predict splicing in C. merolae to be inefficient, inaccurate, and post-transcriptional, consistent with the apparent trend toward its elimination in this lineage. This work highlights the striking flexibility of the splicing pathway and the spliceosome when viewed in the context of eukaryotic diversity.
Collapse
Affiliation(s)
- Corbin S Black
- Department of Chemistry and Biochemistry, University of Northern British Columbia, Prince George, British Columbia, Canada V2N 4Z9
- Department of Anatomy and Cell Biology, McGill University, Montréal, Quebec, Canada H3A 0C7
| | - Thomas A Whelan
- Biodiversity Research Center and Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Erin L Garside
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
| | - Andrew M MacMillan
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
| | - Naomi M Fast
- Biodiversity Research Center and Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Stephen D Rader
- Department of Chemistry and Biochemistry, University of Northern British Columbia, Prince George, British Columbia, Canada V2N 4Z9
| |
Collapse
|
3
|
Sarafidou T, Galliopoulou E, Apostolopoulou D, Fragkiadakis GA, Moschonas NK. Reconstruction of a Comprehensive Interactome and Experimental Data Analysis of FRA10AC1 May Provide Insights into Its Biological Role in Health and Disease. Genes (Basel) 2023; 14:genes14030568. [PMID: 36980839 PMCID: PMC10048706 DOI: 10.3390/genes14030568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 02/14/2023] [Accepted: 02/21/2023] [Indexed: 03/03/2023] Open
Abstract
FRA10AC1, the causative gene for the manifestation of the FRA10A fragile site, encodes a well-conserved nuclear protein characterized as a non-core spliceosomal component. Pre-mRNA splicing perturbations have been linked with neurodevelopmental diseases. FRA10AC1 variants have been, recently, causally linked with severe neuropathological and growth retardation phenotypes. To further elucidate the participation of FRA10AC1 in spliceosomal multiprotein complexes and its involvement in neurological phenotypes related to splicing, we exploited protein–protein interaction experimental data and explored network information and information deduced from transcriptomics. We confirmed the direct interaction of FRA10AC1with ESS2, a non-core spliceosomal protein, mapped their interacting domains, and documented their tissue co-localization and physical interaction at the level of intracellular protein stoichiometries. Although FRA10AC1 and SF3B2, a major core spliceosomal protein, were shown to interact under in vitro conditions, the endogenous proteins failed to co-immunoprecipitate. A reconstruction of a comprehensive, strictly binary, protein–protein interaction network of FRA10AC1 revealed dense interconnectivity with many disease-associated spliceosomal components and several non-spliceosomal regulatory proteins. The topological neighborhood of FRA10AC1 depicts an interactome associated with multiple severe monogenic and multifactorial neurodevelopmental diseases mainly referring to spliceosomopathies. Our results suggest that FRA10AC1 involvement in pre-mRNA processing might be strengthened by interconnecting splicing with transcription and mRNA export, and they propose the broader role(s) of FRA10AC1 in cell pathophysiology.
Collapse
Affiliation(s)
- Theologia Sarafidou
- Department of Biochemistry and Biotechnology, University of Thessaly, Viopolis, 41500 Larissa, Greece
- Correspondence: (T.S.); (N.K.M.)
| | - Eleni Galliopoulou
- Department of Biochemistry and Biotechnology, University of Thessaly, Viopolis, 41500 Larissa, Greece
| | | | - Georgios A. Fragkiadakis
- Department of Nutrition and Dietetics Sciences, Hellenic Mediterranean University, Tripitos, 72300 Siteia, Greece
| | - Nicholas K. Moschonas
- School of Medicine, University of Patras, 26500 Patras, Greece
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas (FORTH/ICE-HT), 26504 Patras, Greece
- Correspondence: (T.S.); (N.K.M.)
| |
Collapse
|
4
|
Mohammadi A, Sorensen GL, Pilecki B. MFAP4-Mediated Effects in Elastic Fiber Homeostasis, Integrin Signaling and Cancer, and Its Role in Teleost Fish. Cells 2022; 11:cells11132115. [PMID: 35805199 PMCID: PMC9265350 DOI: 10.3390/cells11132115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
Microfibrillar-associated protein 4 (MFAP4) is an extracellular matrix (ECM) protein belonging to the fibrinogen-related domain superfamily. MFAP4 is highly expressed in elastin-rich tissues such as lung, blood vessels and skin. MFAP4 is involved in organization of the ECM, regulating proper elastic fiber assembly. On the other hand, during pathology MFAP4 actively contributes to disease development and progression due to its interactions with RGD-dependent integrin receptors. Both tissue expression and circulating MFAP4 levels are associated with various disorders, including liver fibrosis and cancer. In other experimental models, such as teleost fish, MFAP4 appears to participate in host defense as a macrophage-specific innate immune molecule. The aim of this review is to summarize the accumulating evidence that indicates the importance of MFAP4 in homeostasis as well as pathological conditions, discuss its known biological functions with special focus on elastic fiber assembly, integrin signaling and cancer, as well as describe the reported functions of non-mammalian MFAP4 in fish. Overall, our work provides a comprehensive overview on the role of MFAP4 in health and disease.
Collapse
|
5
|
Kanaan R, Medlej-Hashim M, Jounblat R, Pilecki B, Sorensen GL. Microfibrillar-associated protein 4 in health and disease. Matrix Biol 2022; 111:1-25. [DOI: 10.1016/j.matbio.2022.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/04/2022] [Accepted: 05/24/2022] [Indexed: 10/18/2022]
|
6
|
Tao L, Liu YF, Zhang H, Li HZ, Zhao FP, Wang FY, Zhang RS, Di R, Chu MX. Genome-wide association study and inbreeding depression on body size traits in Qira black sheep (Ovis aries). Anim Genet 2021; 52:560-564. [PMID: 34096079 DOI: 10.1111/age.13099] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2021] [Indexed: 12/24/2022]
Abstract
Qira black sheep is a famous indigenous sheep breed in China. The objectives of this study are to identify candidate genes related to body size, and to estimate the level of inbreeding depression on body size based on runs of homozygosity in Qira black sheep. Here, 188 adult Qira black sheep were genotyped with a high density (630 K) SNP chip and genome-wide association study for body weight and body size traits (including withers height, body slanting length, tail length, chest girth, chest width, and chest depth) were performed using an additive linear model. In consequence, 12 genome- and chromosome-wide significant SNPs and, accordingly, six candidate genes involved in muscle differentiation, metabolism and cell processes were identified. Of them, ZNF704 (zinc finger protein 704) was identified for body weight; AK2 (adenylate kinase 2) and PARK2 (parkin RBR E3 ubiquitin protein ligase) for tail length; MOCOS (molybdenum cofactor sulfurase) and ELP2 (elongator acetyltransferase complex subunit 2) for chest width; and MFAP1 (microfibril associated protein 1) for chest girth. Additionally, inbreeding depressions on body size were observed in the current herd. These results will provide insightful understandings into the genetic mechanisms of adult body size, and into the conservation and utilization of Qira black sheep.
Collapse
Affiliation(s)
- L Tao
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Y F Liu
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.,College of Life Science and Food Engineering, Hebei University of Engineering, Handan, 056038, China
| | - H Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.,College of Life Science and Food Engineering, Hebei University of Engineering, Handan, 056038, China
| | - H Z Li
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - F P Zhao
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - F Y Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - R S Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - R Di
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - M X Chu
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| |
Collapse
|
7
|
Zheng Q, Chen X, Qiao C, Wang M, Chen W, Luan X, Yan Y, Shen C, Fang J, Hu X, Zheng B, Wu Y, Yu J. Somatic CG6015 mediates cyst stem cell maintenance and germline stem cell differentiation via EGFR signaling in Drosophila testes. Cell Death Discov 2021; 7:68. [PMID: 33824283 PMCID: PMC8024382 DOI: 10.1038/s41420-021-00452-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/21/2021] [Accepted: 03/18/2021] [Indexed: 11/09/2022] Open
Abstract
Stem cell niche is regulated by intrinsic and extrinsic factors. In the Drosophila testis, cyst stem cells (CySCs) support the differentiation of germline stem cells (GSCs). However, the underlying mechanisms remain unclear. In this study, we found that somatic CG6015 is required for CySC maintenance and GSC differentiation in a Drosophila model. Knockdown of CG6015 in CySCs caused aberrant activation of dpERK in undifferentiated germ cells in the Drosophila testis, and disruption of key downstream targets of EGFR signaling (Dsor1 and rl) in CySCs results in a phenotype resembling that of CG6015 knockdown. CG6015, Dsor1, and rl are essential for the survival of Drosophila cell line Schneider 2 (S2) cells. Our data showed that somatic CG6015 regulates CySC maintenance and GSC differentiation via EGFR signaling, and inhibits aberrant activation of germline dpERK signals. These findings indicate regulatory mechanisms of stem cell niche homeostasis in the Drosophila testis.
Collapse
Affiliation(s)
- Qianwen Zheng
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Xia Chen
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Chen Qiao
- Department of Clinical Pharmacy, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Min Wang
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Wanyin Chen
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Xiaojin Luan
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Yidan Yan
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Cong Shen
- State Key Laboratory of Reproductive Medicine, Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Gusu School, Nanjing Medical University, 215002, Suzhou, Jiangsu, P.R. China
| | - Jie Fang
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Xing Hu
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China
| | - Bo Zheng
- State Key Laboratory of Reproductive Medicine, Center for Reproduction and Genetics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Gusu School, Nanjing Medical University, 215002, Suzhou, Jiangsu, P.R. China.
| | - Yibo Wu
- Human Reproductive and Genetic Center, Affiliated Hospital of Jiangnan University, 214062, Wuxi, Jiangsu, P.R. China.
| | - Jun Yu
- Department of Gynecology, the Affiliated Hospital of Jiangsu University, Jiangsu University, 212001, Zhenjiang, Jiangsu, P.R. China.
| |
Collapse
|
8
|
Dopie J, Sweredoski MJ, Moradian A, Belmont AS. Tyramide signal amplification mass spectrometry (TSA-MS) ratio identifies nuclear speckle proteins. J Cell Biol 2021; 219:151914. [PMID: 32609799 PMCID: PMC7480118 DOI: 10.1083/jcb.201910207] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 04/03/2020] [Accepted: 05/13/2020] [Indexed: 12/11/2022] Open
Abstract
We present a simple ratio method to infer protein composition within cellular structures using proximity labeling approaches but compensating for the diffusion of free radicals. We used tyramide signal amplification (TSA) and label-free mass spectrometry (MS) to compare proteins in nuclear speckles versus centromeres. Our “TSA-MS ratio” approach successfully identified known nuclear speckle proteins. For example, 96% and 67% of proteins in the top 30 and 100 sorted proteins, respectively, are known nuclear speckle proteins, including proteins that we validated here as enriched in nuclear speckles. We show that MFAP1, among the top 20 in our list, forms droplets under certain circumstances and that MFAP1 expression levels modulate the size, stability, and dynamics of nuclear speckles. Localization of MFAP1 and its binding partner, PRPF38A, in droplet-like nuclear bodies precedes formation of nuclear speckles during telophase. Our results update older proteomic studies of nuclear speckles and should provide a useful reference dataset to guide future experimental dissection of nuclear speckle structure and function.
Collapse
Affiliation(s)
- Joseph Dopie
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL
| | - Michael J Sweredoski
- Proteome Exploration Laboratory, Department of Biology and Biological Engineering, Beckman Institute, California Institute of Technology, Pasadena, CA
| | - Annie Moradian
- Proteome Exploration Laboratory, Department of Biology and Biological Engineering, Beckman Institute, California Institute of Technology, Pasadena, CA
| | - Andrew S Belmont
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL
| |
Collapse
|
9
|
Petasny M, Bentata M, Pawellek A, Baker M, Kay G, Salton M. Splicing to Keep Cycling: The Importance of Pre-mRNA Splicing during the Cell Cycle. Trends Genet 2020; 37:266-278. [PMID: 32950269 DOI: 10.1016/j.tig.2020.08.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/09/2020] [Accepted: 08/18/2020] [Indexed: 12/16/2022]
Abstract
Pre-mRNA splicing is a fundamental process in mammalian gene expression, and alternative splicing plays an extensive role in generating protein diversity. Because the majority of genes undergo pre-mRNA splicing, most cellular processes depend on proper spliceosome function. We focus on the cell cycle and describe its dependence on pre-mRNA splicing and accurate alternative splicing. We outline the key cell-cycle factors and their known alternative splicing isoforms. We discuss different levels of pre-mRNA splicing regulation such as post-translational modifications and changes in the expression of splicing factors. We describe the effect of chromatin dynamics on pre-mRNA splicing during the cell cycle. In addition, we focus on spliceosome component SF3B1, which is mutated in many types of cancer, and describe the link between SF3B1 and its inhibitors and the cell cycle.
Collapse
Affiliation(s)
- Mayra Petasny
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Mercedes Bentata
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Andrea Pawellek
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | - Mai Baker
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Gillian Kay
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Maayan Salton
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel.
| |
Collapse
|
10
|
Depletion of the MFAP1/SPP381 Splicing Factor Causes R-Loop-Independent Genome Instability. Cell Rep 2020; 28:1551-1563.e7. [PMID: 31390568 PMCID: PMC6693559 DOI: 10.1016/j.celrep.2019.07.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 03/18/2019] [Accepted: 07/01/2019] [Indexed: 01/19/2023] Open
Abstract
THO/TREX is a conserved complex with a role in messenger ribonucleoprotein biogenesis that links gene expression and genome instability. Here, we show that human THO interacts with MFAP1 (microfibrillar-associated protein 1), a spliceosome-associated factor. Interestingly, MFAP1 depletion impairs cell proliferation and genome integrity, increasing γH2AX foci and DNA breaks. This phenotype is not dependent on either transcription or RNA-DNA hybrids. Mutations in the yeast orthologous gene SPP381 cause similar transcription-independent genome instability, supporting a conserved role. MFAP1 depletion has a wide effect on splicing and gene expression in human cells, determined by transcriptome analyses. MFAP1 depletion affects a number of DNA damage response (DDR) genes, which supports an indirect role of MFAP1 on genome integrity. Our work defines a functional interaction between THO and RNA processing and argues that splicing factors may contribute to genome integrity indirectly by regulating the expression of DDR genes rather than by a direct role.
Collapse
|
11
|
Zhu S, Ye L, Bennett S, Xu H, He D, Xu J. Molecular structure and function of microfibrillar-associated proteins in skeletal and metabolic disorders and cancers. J Cell Physiol 2020; 236:41-48. [PMID: 32572962 DOI: 10.1002/jcp.29893] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/11/2020] [Accepted: 06/11/2020] [Indexed: 12/16/2022]
Abstract
Microfibrillar-associated proteins (MFAPs) are extracellular matrix glycoproteins, which play a role in microfibril assembly, elastinogenesis, and tissue homeostasis. MFAPs consist of five subfamily members, including MFAP1, MFAP2, MFAP3, MFAP4, and MFAP5. Among these, MFAP2 and MFAP5 are most closely related, and exhibit very limited amino acid sequence homology with MFAP1, MFAP3, and MFAP4. Gene expression profiling analysis reveals that MFAP2, MFAP5, and MFAP4 are specifically expressed in osteoblastic like cells, whereas MFAP1 and MFAP3 are more ubiquitously expressed, indicative of their diverse role in the tropism of tissues. Molecular structural analysis shows that each MFAP family member has distinct features, and functional evidence reveals discrete purposes of individual MFAPs. Animal studies indicate that MFAP2-deficient mice exhibit progressive osteopenia with elevated receptor activator of NF-κB ligand (RANKL) expression, whereas MFAP5-deficient mice are neutropenic, and MFAP4-deficient mice displayed emphysema-like pathology and the impaired formation of neointimal hyperplasia. Emerging data also suggest that MFAPs are involved in cancer progression and fat metabolism. Further understanding of tissue-specific pathophysiology of MFAPs might offer potential novel therapeutic targets for related diseases, such as skeletal and metabolic disorders, and cancers.
Collapse
Affiliation(s)
- Sipin Zhu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.,Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, Australia
| | - Lin Ye
- Department of Orthopaedic Surgery, Lishui Municipal Central Hospital, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui, Zhejiang, China
| | - Samuel Bennett
- Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, Australia
| | - Huazi Xu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Dengwei He
- Department of Orthopaedic Surgery, Lishui Municipal Central Hospital, The Fifth Affiliated Hospital of Wenzhou Medical University, Lishui, Zhejiang, China
| | - Jiake Xu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.,Division of Regenerative Biology, School of Biomedical Sciences, University of Western Australia, Perth, Australia
| |
Collapse
|
12
|
Yang J, Song H, Chen L, Cao K, Zhang Y, Li Y, Hao X. Integrated analysis of microfibrillar-associated proteins reveals MFAP4 as a novel biomarker in human cancers. Epigenomics 2019; 11:1635-1651. [DOI: 10.2217/epi-2018-0080] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Aim: The potential functions and underlying mechanism of microfibrillar-associated proteins (MFAPs) are explored in human cancers. Materials & methods: Here, we examined the expression profiles, prognostic values, epigenetic and genetic alterations of MFAPs in human cancers from public omics repository. Results: Among MFAPs family, MFAP4 was frequently downregulated in the most human cancers and high mRNA expression of MFAP4 significantly correlated with better overall survival in breast cancer. DNA hypermethylation in the promoter of MFAP4 decreased its mRNA expression. MFAP4 strongly associated with pathway in impairment and alteration of the elastic fibers. Conclusion: This integrated analysis provides new insights into MFAPs in human cancers and indicates that MFAP4 could be used as novel biomarker for developing therapies against human cancers.
Collapse
Affiliation(s)
- Jue Yang
- The State Key Laboratory of Functions & Applications of Medicinal Plants, Guizhou Medical University, Guiyang 550014, PR China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province & Chinese Academic of Sciences, Guiyang 550014, PR China
| | - Hui Song
- The Key Laboratory of Endemic & Ethnic Diseases, Guizhou Medical University, Ministry of Education, Guiyang 550004, PR China
- The Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guizhou Province, Guiyang 550004, PR China
| | - Li Chen
- Guiyang University of Chinese Medicine, School of Pharmaceutical Sciences, Guiyang 550025, PR China
| | - Kun Cao
- Department of General Surgery, Affiliated Hospital of Guizhou Medical University, Guiyang 550001, PR China
| | - Yongqiang Zhang
- Guizhou University, School of Pharmaceutical Sciences, Guiyang, 550025, PR China
| | - Yanmei Li
- The State Key Laboratory of Functions & Applications of Medicinal Plants, Guizhou Medical University, Guiyang 550014, PR China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province & Chinese Academic of Sciences, Guiyang 550014, PR China
| | - Xiaojiang Hao
- The State Key Laboratory of Functions & Applications of Medicinal Plants, Guizhou Medical University, Guiyang 550014, PR China
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province & Chinese Academic of Sciences, Guiyang 550014, PR China
| |
Collapse
|
13
|
Fernández-Espartero CH, Rizzo A, Fulford AD, Falo-Sanjuan J, Goutte-Gattat D, Ribeiro PS. Prp8 regulates oncogene-induced hyperplastic growth in Drosophila. Development 2018; 145:dev.162156. [PMID: 30333215 PMCID: PMC6262796 DOI: 10.1242/dev.162156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 10/10/2018] [Indexed: 01/08/2023]
Abstract
Although developmental signalling pathways control tumourigenic growth, the cellular mechanisms that abnormally proliferating cells rely on are still largely unknown. Drosophila melanogaster is a genetically tractable model that is used to study how specific genetic changes confer advantageous tumourigenic traits. Despite recent efforts, the role of deubiquitylating enzymes in cancer is particularly understudied. We performed a Drosophila in vivo RNAi screen to identify deubiquitylating enzymes that modulate RasV12-induced hyperplastic growth. We identified the spliceosome core component Prp8 as a crucial regulator of Ras-, EGFR-, Notch- or RET-driven hyperplasia. Loss of prp8 function alone decreased cell proliferation, increased cell death, and affected cell differentiation and polarity. In hyperplasia, Prp8 supported tissue overgrowth independently of caspase-dependent cell death. The depletion of prp8 efficiently blocked Ras-, EGFR- and Notch-driven tumours but, in contrast, enhanced tumours that were driven by oncogenic RET, suggesting a context-specific role in hyperplasia. These data show, for the first time, that Prp8 regulates hyperplasia, and extend recent observations on the potential role of the spliceosome in cancer. Our findings suggest that targeting Prp8 could be beneficial in specific tumour types. Summary: Prp8 has been identified as a modulator of oncogenic growth in multiple Drosophila cancer models, which suggests the spliceosome as a potential context-dependent target in cancers.
Collapse
Affiliation(s)
- Cecilia H Fernández-Espartero
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Alberto Rizzo
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Alexander D Fulford
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Julia Falo-Sanjuan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Damien Goutte-Gattat
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Paulo S Ribeiro
- Centre for Tumour Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| |
Collapse
|
14
|
Anufrieva KS, Shender VО, Arapidi GP, Pavlyukov MS, Shakhparonov MI, Shnaider PV, Butenko IO, Lagarkova MA, Govorun VM. Therapy-induced stress response is associated with downregulation of pre-mRNA splicing in cancer cells. Genome Med 2018; 10:49. [PMID: 29950180 PMCID: PMC6020472 DOI: 10.1186/s13073-018-0557-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 06/07/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Abnormal pre-mRNA splicing regulation is common in cancer, but the effects of chemotherapy on this process remain unclear. METHODS To evaluate the effect of chemotherapy on slicing regulation, we performed meta-analyses of previously published transcriptomic, proteomic, phosphoproteomic, and secretome datasets. Our findings were verified by LC-MS/MS, western blotting, immunofluorescence, and FACS analyses of multiple cancer cell lines treated with cisplatin and pladienolide B. RESULTS Our results revealed that different types of chemotherapy lead to similar changes in alternative splicing by inducing intron retention in multiple genes. To determine the mechanism underlying this effect, we analyzed gene expression in 101 cell lines affected by ɣ-irradiation, hypoxia, and 10 various chemotherapeutic drugs. Strikingly, оnly genes involved in the cell cycle and pre-mRNA splicing regulation were changed in a similar manner in all 335 tested samples regardless of stress stimuli. We revealed significant downregulation of gene expression levels in these two pathways, which could be explained by the observed decrease in splicing efficiency and global intron retention. We showed that the levels of active spliceosomal proteins might be further post-translationally decreased by phosphorylation and export into the extracellular space. To further explore these bioinformatics findings, we performed proteomic analysis of cisplatin-treated ovarian cancer cells. Finally, we demonstrated that the splicing inhibitor pladienolide B impairs the cellular response to DNA damage and significantly increases the sensitivity of cancer cells to chemotherapy. CONCLUSIONS Decreased splicing efficiency and global intron retention is a novel stress response mechanism that may promote survival of malignant cells following therapy. We found that this mechanism can be inhibited by pladienolide B, which significantly increases the sensitivity of cancer cells to cisplatin which makes it a good candidate drug for improving the efficiency of cancer therapy.
Collapse
Affiliation(s)
- Ksenia S Anufrieva
- Laboratory of Proteomics, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russia.
- Laboratory of Cell Biology, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia.
- Systems Biology Lab, Moscow Institute of Physics and Technology (State University), Moscow, Region, 141701, Russia.
| | - Victoria О Shender
- Laboratory of Proteomics, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russia.
- Laboratory of Cell Biology, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia.
| | - Georgij P Arapidi
- Laboratory of Proteomics, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russia
- Laboratory of Cell Biology, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
- Systems Biology Lab, Moscow Institute of Physics and Technology (State University), Moscow, Region, 141701, Russia
| | - Marat S Pavlyukov
- Laboratory of Membrane Bioenergetics, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russia
| | - Michail I Shakhparonov
- Laboratory of Membrane Bioenergetics, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russia
| | - Polina V Shnaider
- Laboratory of Proteomics, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russia
- Laboratory of Cell Biology, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Ivan O Butenko
- Laboratory of Proteomic Analysis, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Maria A Lagarkova
- Laboratory of Cell Biology, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| | - Vadim M Govorun
- Laboratory of Proteomics, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, Moscow, 117997, Russia
- Laboratory of Proteomic Analysis, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, 119435, Russia
| |
Collapse
|
15
|
Salas-Armenteros I, Pérez-Calero C, Bayona-Feliu A, Tumini E, Luna R, Aguilera A. Human THO-Sin3A interaction reveals new mechanisms to prevent R-loops that cause genome instability. EMBO J 2017; 36:3532-3547. [PMID: 29074626 DOI: 10.15252/embj.201797208] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 09/22/2017] [Accepted: 09/28/2017] [Indexed: 11/09/2022] Open
Abstract
R-loops, formed by co-transcriptional DNA-RNA hybrids and a displaced DNA single strand (ssDNA), fulfill certain positive regulatory roles but are also a source of genomic instability. One key cellular mechanism to prevent R-loop accumulation centers on the conserved THO/TREX complex, an RNA-binding factor involved in transcription elongation and RNA export that contributes to messenger ribonucleoprotein (mRNP) assembly, but whose precise function is still unclear. To understand how THO restrains harmful R-loops, we searched for new THO-interacting factors. We found that human THO interacts with the Sin3A histone deacetylase complex to suppress co-transcriptional R-loops, DNA damage, and replication impairment. Functional analyses show that histone hypo-acetylation prevents accumulation of harmful R-loops and RNA-mediated genomic instability. Diminished histone deacetylase activity in THO- and Sin3A-depleted cell lines correlates with increased R-loop formation, genomic instability, and replication fork stalling. Our study thus uncovers physical and functional crosstalk between RNA-binding factors and chromatin modifiers with a major role in preventing R-loop formation and RNA-mediated genome instability.
Collapse
Affiliation(s)
- Irene Salas-Armenteros
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Consejo Superior de Investigaciones Científicas-Universidad Pablo de Olavide-Universidad de Sevilla, Seville, Spain
| | - Carmen Pérez-Calero
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Consejo Superior de Investigaciones Científicas-Universidad Pablo de Olavide-Universidad de Sevilla, Seville, Spain
| | - Aleix Bayona-Feliu
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Consejo Superior de Investigaciones Científicas-Universidad Pablo de Olavide-Universidad de Sevilla, Seville, Spain
| | - Emanuela Tumini
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Consejo Superior de Investigaciones Científicas-Universidad Pablo de Olavide-Universidad de Sevilla, Seville, Spain
| | - Rosa Luna
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Consejo Superior de Investigaciones Científicas-Universidad Pablo de Olavide-Universidad de Sevilla, Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Consejo Superior de Investigaciones Científicas-Universidad Pablo de Olavide-Universidad de Sevilla, Seville, Spain
| |
Collapse
|
16
|
Rode S, Ohm H, Zipfel J, Rumpf S. The spliceosome-associated protein Mfap1 binds to VCP in Drosophila. PLoS One 2017; 12:e0183733. [PMID: 28837687 PMCID: PMC5570293 DOI: 10.1371/journal.pone.0183733] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/09/2017] [Indexed: 12/14/2022] Open
Abstract
Posttranscriptional regulation of gene expression contributes to many developmental transitions. Previously, we found that the AAA chaperone Valosin-Containing Protein (VCP) regulates ecdysone-dependent dendrite pruning of Drosophila class IV dendritic arborization (c4da) neurons via an effect on RNA metabolism. In a search for RNA binding proteins associated with VCP, we identified the spliceosome-associated protein Mfap1, a component of the tri-snRNP complex. Mfap1 is a nucleolar protein in neurons and its levels are regulated by VCP. Mfap1 binds to VCP and TDP-43, a disease-associated RNA-binding protein. via distinct regions in its N- and C-terminal halfs. Similar to vcp mutations, Mfap1 overexpression causes c4da neuron dendrite pruning defects and mislocalization of TDP-43 in these cells, but genetic analyses show that Mfap1 is not a crucial VCP target during dendrite pruning. Finally, rescue experiments with a lethal mfap1 mutant show that the VCP binding region is not essential for Mfap1 function, but may act to increase its stability or activity.
Collapse
Affiliation(s)
- Sandra Rode
- Institute for Neurobiology, University of Münster, Badestrasse 9, Münster, Germany
| | - Henrike Ohm
- Institute for Neurobiology, University of Münster, Badestrasse 9, Münster, Germany
| | - Jaqueline Zipfel
- Institute for Neurobiology, University of Münster, Badestrasse 9, Münster, Germany
| | - Sebastian Rumpf
- Institute for Neurobiology, University of Münster, Badestrasse 9, Münster, Germany
- * E-mail:
| |
Collapse
|
17
|
Lapek JD, Lewinski MK, Wozniak JM, Guatelli J, Gonzalez DJ. Quantitative Temporal Viromics of an Inducible HIV-1 Model Yields Insight to Global Host Targets and Phospho-Dynamics Associated with Protein Vpr. Mol Cell Proteomics 2017; 16:1447-1461. [PMID: 28606917 DOI: 10.1074/mcp.m116.066019] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/22/2017] [Indexed: 12/12/2022] Open
Abstract
The mechanisms by which human immunodeficiency virus (HIV) circumvents and coopts cellular machinery to replicate and persist in cells are not fully understood. HIV accessory proteins play key roles in the HIV life cycle by altering host pathways that are often dependent on post-translational modifications (PTMs). Thus, the identification of HIV accessory protein host targets and their PTM status is critical to fully understand how HIV invades, avoids detection and replicates to spread infection. To date, a comprehensive characterization of HIV accessory protein host targets and modulation of their PTM status does not exist. The significant gap in knowledge regarding the identity and PTMs of HIV host targets is due, in part, to technological limitations. Here, we applied current mass spectrometry techniques to define mechanisms of viral protein action by identifying host proteins whose abundance is affected by the accessory protein Vpr and the corresponding modulation of down-stream signaling pathways, specifically those regulated by phosphorylation. By utilizing a novel, inducible HIV-1 CD4+ T-cell model system expressing either the wild type or a vpr-negative viral genome, we overcame challenges associated with synchronization and infection-levels present in other models. We report identification and abundance dynamics of over 7000 proteins and 28,000 phospho-peptides. Consistent with Vpr's ability to impair cell-cycle progression, we observed Vpr-mediated modulation of spindle and centromere proteins, as well as Aurora kinase A and cyclin-dependent kinase 4 (CDK4). Unexpectedly, we observed evidence of Vpr-mediated modulation of the activity of serine/arginine-rich protein-specific kinases (SRPKs), suggesting a possible role for Vpr in the regulation of RNA splicing. This study presents a new experimental system and provides a data-resource that lays the foundation for validating host proteins and phosphorylation-pathways affected by HIV-1 and its accessory protein Vpr.
Collapse
Affiliation(s)
- John D Lapek
- From the ‡Department of Pharmacology.,§Skaggs School of Pharmacy and Pharmaceutical Sciences
| | - Mary K Lewinski
- §Skaggs School of Pharmacy and Pharmaceutical Sciences.,¶San Diego Veterans Affairs Healthcare System, San Diego, California 92161, and
| | - Jacob M Wozniak
- From the ‡Department of Pharmacology.,§Skaggs School of Pharmacy and Pharmaceutical Sciences
| | - John Guatelli
- ¶San Diego Veterans Affairs Healthcare System, San Diego, California 92161, and.,the ‖Department of Medicine, University of California San Diego, La Jolla, California 92093
| | - David J Gonzalez
- From the ‡Department of Pharmacology, .,§Skaggs School of Pharmacy and Pharmaceutical Sciences
| |
Collapse
|
18
|
Ulrich AKC, Wahl MC. Human MFAP1 is a cryptic ortholog of the Saccharomyces cerevisiae Spp381 splicing factor. BMC Evol Biol 2017; 17:91. [PMID: 28335716 PMCID: PMC5364666 DOI: 10.1186/s12862-017-0923-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 02/23/2017] [Indexed: 01/14/2023] Open
Abstract
Background Pre-mRNA splicing involves the stepwise assembly of a pre-catalytic spliceosome, followed by its catalytic activation, splicing catalysis and disassembly. Formation of the pre-catalytic spliceosomal B complex involves the incorporation of the U4/U6.U5 tri-snRNP and of a group of non-snRNP B-specific proteins. While in Saccharomyces cerevisiae the Prp38 and Snu23 proteins are recruited as components of the tri-snRNP, metazoan orthologs of Prp38 and Snu23 associate independently of the tri-snRNP as members of the B-specific proteins. The human spliceosome contains about 80 proteins that lack obvious orthologs in yeast, including most of the B-specific proteins apart from Prp38 and Snu23. Conversely, the tri-snRNP protein Spp381 is one of only five S. cerevisiae splicing factors without a known human ortholog. Results Using InParanoid, a state-of-the-art method for ortholog inference between pairs of species, and systematic BLAST searches we identified the human B-specific protein MFAP1 as a putative ortholog of the S. cerevisiae tri-snRNP protein Spp381. Bioinformatics revealed that MFAP1 and Spp381 share characteristic structural features, including intrinsic disorder, an elongated shape, solvent exposure of most residues and a trend to adopt α-helical structures. In vitro binding studies showed that human MFAP1 and yeast Spp381 bind their respective Prp38 proteins via equivalent interfaces and that they cross-interact with the Prp38 proteins of the respective other species. Furthermore, MFAP1 and Spp381 both form higher-order complexes that additionally include Snu23, suggesting that they are parts of equivalent spliceosomal sub-complexes. Finally, similar to yeast Spp381, human MFAP1 partially rescued a growth defect of the temperature-sensitive mutant yeast strain prp38-1. Conclusions Human B-specific protein MFAP1 structurally and functionally resembles the yeast tri-snRNP-specific protein Spp381 and thus qualifies as its so far missing ortholog. Our study indicates that the yeast Snu23-Prp38-Spp381 triple complex was evolutionarily reprogrammed from a tri-snRNP-specific module in yeast to the B-specific Snu23-Prp38-MFAP1 module in metazoa, affording higher flexibility in spliceosome assembly and thus, presumably, in splicing regulation. Electronic supplementary material The online version of this article (doi:10.1186/s12862-017-0923-1) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Alexander K C Ulrich
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Takustr. 6, D-14195, Berlin, Germany.
| | - Markus C Wahl
- Laboratory of Structural Biochemistry, Freie Universität Berlin, Takustr. 6, D-14195, Berlin, Germany. .,Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, Albert-Einstein-Straße 15, D-12489, Berlin, Germany.
| |
Collapse
|
19
|
Abramczuk MK, Burkard TR, Rolland V, Steinmann V, Duchek P, Jiang Y, Wissel S, Reichert H, Knoblich JA. The splicing co-factor Barricade/Tat-SF1, is required for cell cycle and lineage progression in Drosophila neural stem cells. Development 2017; 144:3932-3945. [DOI: 10.1242/dev.152199] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 09/11/2017] [Indexed: 12/25/2022]
Abstract
Stem cells need to balance self-renewal and differentiation for correct tissue development and homeostasis. Defects in this balance can lead to developmental defects or tumor formation. In recent years, mRNA splicing has emerged as one important mechanism regulating cell fate decisions. Here we address the role of the evolutionary conserved splicing co-factor Barricade (Barc)/Tat-SF1/CUS2 in Drosophila neural stem cell (neuroblast) lineage formation. We show that Barc is required for the generation of neurons during Drosophila brain development by ensuring correct neural progenitor proliferation and differentiation. Barc associates with components of the U2 small nuclear ribonucleic proteins (snRNP), and its depletion causes alternative splicing in form of intron retention in a subset of genes. Using bioinformatics analysis and a cell culture based splicing assay, we found that Barc-dependent introns share three major traits: they are short, GC rich and have weak 3' splice sites. Our results show that Barc, together with the U2snRNP, plays an important role in regulating neural stem cell lineage progression during brain development and facilitates correct splicing of a subset of introns.
Collapse
Affiliation(s)
- Monika K. Abramczuk
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Dr. Bohr-Gasse 3, Vienna, Austria
| | - Thomas R. Burkard
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Dr. Bohr-Gasse 3, Vienna, Austria
- Research Institute of Molecular Pathology (IMP), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria
| | - Vivien Rolland
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Dr. Bohr-Gasse 3, Vienna, Austria
- Current address: Commonwealth Scientific and Industrial Research Organisation (CSIRO), Agriculture and Food, Canberra, ACT 2601, Australia
| | - Victoria Steinmann
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Dr. Bohr-Gasse 3, Vienna, Austria
| | - Peter Duchek
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Dr. Bohr-Gasse 3, Vienna, Austria
| | - Yanrui Jiang
- Biozentrum, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
- Current address: D-BSSE ETH Zürich, Mattenstrasse 26, CH-4058 Basel, Switzerland
| | - Sebastian Wissel
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Dr. Bohr-Gasse 3, Vienna, Austria
| | - Heinrich Reichert
- Biozentrum, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Juergen A. Knoblich
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Dr. Bohr-Gasse 3, Vienna, Austria
| |
Collapse
|
20
|
Kim JH, Lee JE. Mitotic control by mRNA splicing regulators ensures primary cilia formation. Anim Cells Syst (Seoul) 2016; 21:17-22. [PMID: 30460047 DOI: 10.1080/19768354.2016.1261738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 11/14/2016] [Indexed: 10/20/2022] Open
Abstract
The biogenesis of the primary cilium is coordinated with cell cycle exit/re-entry in most types of cells. After serum starvation, the cilia-generating cells enter quiescence and produce the primary cilium; upon re-addition of serum, they re-enter the cell cycle and resorb the cilium. We previously identified novel mechanisms to link cell cycle progression and ciliogenesis by high-content genome-wide RNAi cell-based screening. In the present study, we pay attention to reveal the impact of mRNA splicing on cilia assembly after mitosis of cell cycle. We demonstrate that splicing regulators such as SON and XAB2 play an important role in mitosis exit, and thus affect ciliogenesis in G1/G0 phases. Knockdown of the splicing regulators in hTERT-RPE1 cells caused abnormal G2/M arrest under both serum addition and serum starvation, indicating defects in mitosis exit. Moreover, the knockdown cells failed to assemble the cilia under serum starvation and an inhibition of mRNA splicing using SSA, a spliceosome inhibitor, also revealed ciliogenesis defect. Finally, we show that the SSA-treated zebrafish display abnormal vascular development as a ciliary defect. These findings suggest the pivotal role of mRNA splicing regulators in cilia assembly and underscore the importance of mitotic regulation in ciliogenesis.
Collapse
Affiliation(s)
- Ji Hyun Kim
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea
| | - Ji Eun Lee
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea.,Samsung Genome Institute (SGI), Samsung Medical Center, Seoul, South Korea
| |
Collapse
|
21
|
Karamysheva Z, Díaz-Martínez LA, Warrington R, Yu H. Graded requirement for the spliceosome in cell cycle progression. Cell Cycle 2016; 14:1873-83. [PMID: 25892155 DOI: 10.1080/15384101.2015.1039209] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Genome stability is ensured by multiple surveillance mechanisms that monitor the duplication, segregation, and integrity of the genome throughout the cell cycle. Depletion of components of the spliceosome, a macromolecular machine essential for mRNA maturation and gene expression, has been associated with increased DNA damage and cell cycle defects. However, the specific role for the spliceosome in these processes has remained elusive, as different cell cycle defects have been reported depending on the specific spliceosome subunit depleted. Through a detailed cell cycle analysis after spliceosome depletion, we demonstrate that the spliceosome is required for progression through multiple phases of the cell cycle. Strikingly, the specific cell cycle phenotype observed after spliceosome depletion correlates with the extent of depletion. Partial depletion of a core spliceosome component results in defects at later stages of the cell cycle (G2 and mitosis), whereas a more complete depletion of the same component elicits an early cell cycle arrest in G1. We propose a quantitative model in which different functional dosages of the spliceosome are required for different cell cycle transitions.
Collapse
Affiliation(s)
- Zemfira Karamysheva
- a Department of Physiology; University of Texas Southwestern Medical Center ; Dallas , TX , USA
| | | | | | | |
Collapse
|
22
|
Schütze T, Ulrich AKC, Apelt L, Will CL, Bartlick N, Seeger M, Weber G, Lührmann R, Stelzl U, Wahl MC. Multiple protein-protein interactions converging on the Prp38 protein during activation of the human spliceosome. RNA (NEW YORK, N.Y.) 2016; 22:265-77. [PMID: 26673105 PMCID: PMC4712676 DOI: 10.1261/rna.054296.115] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 11/17/2015] [Indexed: 05/22/2023]
Abstract
Spliceosomal Prp38 proteins contain a conserved amino-terminal domain, but only higher eukaryotic orthologs also harbor a carboxy-terminal RS domain, a hallmark of splicing regulatory SR proteins. We show by crystal structure analysis that the amino-terminal domain of human Prp38 is organized around three pairs of antiparallel α-helices and lacks similarities to RNA-binding domains found in canonical SR proteins. Instead, yeast two-hybrid analyses suggest that the amino-terminal domain is a versatile protein-protein interaction hub that possibly binds 12 other spliceosomal proteins, most of which are recruited at the same stage as Prp38. By quantitative, alanine surface-scanning two-hybrid screens and biochemical analyses we delineated four distinct interfaces on the Prp38 amino-terminal domain. In vitro interaction assays using recombinant proteins showed that Prp38 can bind at least two proteins simultaneously via two different interfaces. Addition of excess Prp38 amino-terminal domain to in vitro splicing assays, but not of an interaction-deficient mutant, stalled splicing at a precatalytic stage. Our results show that human Prp38 is an unusual SR protein, whose amino-terminal domain is a multi-interface protein-protein interaction platform that might organize the relative positioning of other proteins during splicing.
Collapse
Affiliation(s)
- Tonio Schütze
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Alexander K C Ulrich
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Luise Apelt
- Max-Planck Institute for Molecular Genetics, Otto-Warburg Laboratory, D-14195 Berlin, Germany
| | - Cindy L Will
- Max Planck Institute for Biophysical Chemistry, Department of Cellular Biochemistry, D-37077 Göttingen, Germany
| | - Natascha Bartlick
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Martin Seeger
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Gert Weber
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| | - Reinhard Lührmann
- Max Planck Institute for Biophysical Chemistry, Department of Cellular Biochemistry, D-37077 Göttingen, Germany
| | - Ulrich Stelzl
- Max-Planck Institute for Molecular Genetics, Otto-Warburg Laboratory, D-14195 Berlin, Germany University of Graz, Institute of Pharmaceutical Sciences (IPW), Pharmaceutical Chemistry, A-8010 Graz, Austria
| | - Markus C Wahl
- Freie Universität Berlin, Laboratory of Structural Biochemistry, D-14195 Berlin, Germany
| |
Collapse
|
23
|
Mecham RP, Gibson MA. The microfibril-associated glycoproteins (MAGPs) and the microfibrillar niche. Matrix Biol 2015; 47:13-33. [PMID: 25963142 DOI: 10.1016/j.matbio.2015.05.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 10/23/2022]
Abstract
The microfibril-associated glycoproteins MAGP-1 and MAGP-2 are extracellular matrix proteins that interact with fibrillin to influence microfibril function. The two proteins are related through a 60 amino acid matrix-binding domain but their sequences differ outside of this region. A distinguishing feature of both proteins is their ability to interact with TGFβ family growth factors, Notch and Notch ligands, and multiple elastic fiber proteins. MAGP-2 can also interact with αvβ3 integrins via a RGD sequence that is not found in MAGP-1. Morpholino knockdown of MAGP-1 expression in zebrafish resulted in abnormal vessel wall architecture and altered vascular network formation. In the mouse, MAGP-1 deficiency had little effect on elastic fibers in blood vessels and lung but resulted in numerous unexpected phenotypes including bone abnormalities, hematopoietic changes, increased fat deposition, diabetes, impaired wound repair, and a bleeding diathesis. Inactivation of the gene for MAGP-2 in mice produced a neutropenia yet had minimal effects on bone or adipose homeostasis. Double knockouts had phenotypes characteristic of each individual knockout as well as several additional traits only seen when both genes are inactivated. A common mechanism underlying all of the traits associated with the knockout phenotypes is altered TGFβ signaling. This review summarizes our current understanding of the function of the MAGPs and discusses ideas related to their role in growth factor regulation.
Collapse
Affiliation(s)
- Robert P Mecham
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Mark A Gibson
- School of Medical Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia
| |
Collapse
|
24
|
Sundaramoorthy S, Vázquez-Novelle MD, Lekomtsev S, Howell M, Petronczki M. Functional genomics identifies a requirement of pre-mRNA splicing factors for sister chromatid cohesion. EMBO J 2014; 33:2623-42. [PMID: 25257310 PMCID: PMC4282572 DOI: 10.15252/embj.201488244] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 08/03/2014] [Accepted: 08/18/2014] [Indexed: 12/20/2022] Open
Abstract
Sister chromatid cohesion mediated by the cohesin complex is essential for chromosome segregation during cell division. Using functional genomic screening, we identify a set of 26 pre-mRNA splicing factors that are required for sister chromatid cohesion in human cells. Loss of spliceosome subunits increases the dissociation rate of cohesin from chromatin and abrogates cohesion after DNA replication, ultimately causing mitotic catastrophe. Depletion of splicing factors causes defective processing of the pre-mRNA encoding sororin, a factor required for the stable association of cohesin with chromatin, and an associated reduction of sororin protein level. Expression of an intronless version of sororin and depletion of the cohesin release protein WAPL suppress the cohesion defect in cells lacking splicing factors. We propose that spliceosome components contribute to sister chromatid cohesion and mitotic chromosome segregation through splicing of sororin pre-mRNA. Our results highlight the loss of cohesion as an early cellular consequence of compromised splicing. This may have clinical implications because SF3B1, a splicing factor that we identify to be essential for cohesion, is recurrently mutated in chronic lymphocytic leukaemia.
Collapse
Affiliation(s)
- Sriramkumar Sundaramoorthy
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms Hertfordshire, UK
| | - María Dolores Vázquez-Novelle
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms Hertfordshire, UK
| | - Sergey Lekomtsev
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms Hertfordshire, UK
| | - Michael Howell
- High-throughput Screening Laboratory, Cancer Research UK London Research Institute, London, UK
| | - Mark Petronczki
- Cell Division and Aneuploidy Laboratory, Cancer Research UK London Research Institute, Clare Hall Laboratories, South Mimms Hertfordshire, UK
| |
Collapse
|
25
|
Transcript maturation in apicomplexan parasites. Curr Opin Microbiol 2014; 20:82-7. [PMID: 24934558 DOI: 10.1016/j.mib.2014.05.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/19/2014] [Accepted: 05/20/2014] [Indexed: 01/21/2023]
Abstract
The complex life cycles of apicomplexan parasites are associated with dynamic changes of protein repertoire. In Toxoplasma gondii, global analysis of gene expression demonstrates that dynamic changes in mRNA levels unfold in a serial cascade during asexual replication and up to 50% of encoded genes are unequally expressed in development. Recent studies indicate transcription and mRNA processing have important roles in fulfilling the 'just-in-time' delivery of proteins to parasite growth and development. The prominence of post-transcriptional mechanisms in the Apicomplexa was demonstrated by mechanistic studies of the critical RNA-binding proteins and regulatory kinases. However, it is still early in our understanding of how transcription and post-transcriptional mechanisms are balanced to produce adequate numbers of specialized forms that is required to complete the parasite life cycle.
Collapse
|
26
|
Unexpected role of the steroid-deficiency protein ecdysoneless in pre-mRNA splicing. PLoS Genet 2014; 10:e1004287. [PMID: 24722212 PMCID: PMC3983036 DOI: 10.1371/journal.pgen.1004287] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 02/20/2014] [Indexed: 11/19/2022] Open
Abstract
The steroid hormone ecdysone coordinates insect growth and development, directing the major postembryonic transition of forms, metamorphosis. The steroid-deficient ecdysoneless1 (ecd1) strain of Drosophila melanogaster has long served to assess the impact of ecdysone on gene regulation, morphogenesis, or reproduction. However, ecd also exerts cell-autonomous effects independently of the hormone, and mammalian Ecd homologs have been implicated in cell cycle regulation and cancer. Why the Drosophila ecd1 mutants lack ecdysone has not been resolved. Here, we show that in Drosophila cells, Ecd directly interacts with core components of the U5 snRNP spliceosomal complex, including the conserved Prp8 protein. In accord with a function in pre-mRNA splicing, Ecd and Prp8 are cell-autonomously required for survival of proliferating cells within the larval imaginal discs. In the steroidogenic prothoracic gland, loss of Ecd or Prp8 prevents splicing of a large intron from CYP307A2/spookier (spok) pre-mRNA, thus eliminating this essential ecdysone-biosynthetic enzyme and blocking the entry to metamorphosis. Human Ecd (hEcd) can substitute for its missing fly ortholog. When expressed in the Ecd-deficient prothoracic gland, hEcd re-establishes spok pre-mRNA splicing and protein expression, restoring ecdysone synthesis and normal development. Our work identifies Ecd as a novel pre-mRNA splicing factor whose function has been conserved in its human counterpart. Whether the role of mammalian Ecd in cancer involves pre-mRNA splicing remains to be discovered.
Collapse
|
27
|
Klusza S, Novak A, Figueroa S, Palmer W, Deng WM. Prp22 and spliceosome components regulate chromatin dynamics in germ-line polyploid cells. PLoS One 2013; 8:e79048. [PMID: 24244416 PMCID: PMC3820692 DOI: 10.1371/journal.pone.0079048] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 09/18/2013] [Indexed: 12/15/2022] Open
Abstract
During Drosophila oogenesis, the endopolyploid nuclei of germ-line nurse cells undergo a dramatic shift in morphology as oogenesis progresses; the easily-visible chromosomes are initially polytenic during the early stages of oogenesis before they transiently condense into a distinct '5-blob' configuration, with subsequent dispersal into a diffuse state. Mutations in many genes, with diverse cellular functions, can affect the ability of nurse cells to fully decondense their chromatin, resulting in a '5-blob arrest' phenotype that is maintained throughout the later stages of oogenesis. However, the mechanisms and significance of nurse-cell (NC) chromatin dispersal remain poorly understood. Here, we report that a screen for modifiers of the 5-blob phenotype in the germ line isolated the spliceosomal gene peanuts, the Drosophila Prp22. We demonstrate that reduction of spliceosomal activity through loss of peanuts promotes decondensation defects in NC nuclei during mid-oogenesis. We also show that the Prp38 spliceosomal protein accumulates in the nucleoplasm of nurse cells with impaired peanuts function, suggesting that spliceosomal recycling is impaired. Finally, we reveal that loss of additional spliceosomal proteins impairs the full decondensation of NC chromatin during later stages of oogenesis, suggesting that individual spliceosomal subcomplexes modulate expression of the distinct subset of genes that are required for correct morphology in endopolyploid nurse cells.
Collapse
Affiliation(s)
- Stephen Klusza
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Amanda Novak
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Shirelle Figueroa
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - William Palmer
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| | - Wu-Min Deng
- Department of Biological Science, Florida State University, Tallahassee, Florida, United States of America
| |
Collapse
|
28
|
Chen PH, Lee CI, Weng YT, Tarn WY, Tsao YP, Kuo PC, Hsu PH, Huang CW, Huang CS, Lee HH, Wu JT, Chen SL. BCAS2 is essential for Drosophila viability and functions in pre-mRNA splicing. RNA (NEW YORK, N.Y.) 2013; 19:208-218. [PMID: 23249746 PMCID: PMC3543084 DOI: 10.1261/rna.034835.112] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Accepted: 11/14/2012] [Indexed: 06/01/2023]
Abstract
Here, we show that dBCAS2 (CG4980, human Breast Carcinoma Amplified Sequence 2 ortholog) is essential for the viability of Drosophila melanogaster. We find that ubiquitous or tissue-specific depletion of dBCAS2 leads to larval lethality, wing deformities, impaired splicing, and apoptosis. More importantly, overexpression of hBCAS2 rescues these defects. Furthermore, the C-terminal coiled-coil domain of hBCAS2 binds directly to CDC5L and recruits hPrp19/PLRG1 to form a core complex for splicing in mammalian cells and can partially restore wing damage induced by knocking down dBCAS2 in flies. In summary, Drosophila and human BCAS2 share a similar function in RNA splicing, which affects cell viability.
Collapse
Affiliation(s)
- Po-Han Chen
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Chia-I Lee
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Yu-Tzu Weng
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Woan-Yuh Tarn
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
| | - Yeou-Ping Tsao
- Department of Ophthalmology, Mackay Memorial Hospital, Taipei 104, Taiwan
| | - Ping-Chang Kuo
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Pang-Hung Hsu
- Department of Life Science, College of Life Sciences, National Taiwan Ocean University, Keelung 202, Taiwan
- Institute of Bioscience and Biotechnology, College of Life Sciences, National Taiwan Ocean University, Keelung 202, Taiwan
| | - Chu-Wei Huang
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Chiun-Sheng Huang
- Department of Surgery, College of Medicine, National Taiwan University and Hospital, Taipei 100, Taiwan
| | - Hsiu-Hsiang Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - June-Tai Wu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Department of Medical Research, National Taiwan University Hospital, Taipei 100, Taiwan
| | - Show-Li Chen
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| |
Collapse
|
29
|
Dubatolova TD, Volkova EI, Omelyanchuk LV. Drosophila splicing factor SF2 knock-down mutant shows altered cell-cycle in vivo. Cell Biol Int 2013; 37:187-90. [PMID: 23319380 DOI: 10.1002/cbin.10019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 11/01/2012] [Indexed: 12/12/2022]
Abstract
Pioneering single gene study documents pre-mRNA processing proteins participation in the cell-cycle regulation of multi-cellular animals (Andersen and Tapon, 2008, J Biol Chem 283: 31256-67). Whole-genome RNAi screen in Drosophila tissue-culture cell lines demonstrates that 17 genes involved in RNA-processing are required for G2/M check-point function (Kondo and Perrimon, 2011, Sci Signal 4: rs1). In particular, the silencing of Splicing Factor 2 (SF2) increases the number of G2(M) cells. We have measured the absolute duration of cell-cycle phases in SF2 depleted flies with the use of flow cytometry and growth parameters of GFP marked mosaic clones. For SF2 mutant cells, G1 = 1.89 h, G2(M) = 7.22 h and S = 1.30 h compared with G1 = 2.25 h, G2(M) = 4.86 h and S = 1.28 h for control normal cells. Thus, G2(M) phase appears to be longer in SF2 silenced cells, supporting the evidence that this splicing protein participates in G2-M check-point function.
Collapse
Affiliation(s)
- Tatiana D Dubatolova
- Institute of Chemical Biology and Fundamental Medicine SB RAS, Lavrentieva 10, Novosibirsk 630090, Russia
| | | | | |
Collapse
|
30
|
The Caenorhabditis elegans gene mfap-1 encodes a nuclear protein that affects alternative splicing. PLoS Genet 2012; 8:e1002827. [PMID: 22829783 PMCID: PMC3400559 DOI: 10.1371/journal.pgen.1002827] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 05/25/2012] [Indexed: 12/02/2022] Open
Abstract
RNA splicing is a major regulatory mechanism for controlling eukaryotic gene expression. By generating various splice isoforms from a single pre–mRNA, alternative splicing plays a key role in promoting the evolving complexity of metazoans. Numerous splicing factors have been identified. However, the in vivo functions of many splicing factors remain to be understood. In vivo studies are essential for understanding the molecular mechanisms of RNA splicing and the biology of numerous RNA splicing-related diseases. We previously isolated a Caenorhabditis elegans mutant defective in an essential gene from a genetic screen for suppressors of the rubberband Unc phenotype of unc-93(e1500) animals. This mutant contains missense mutations in two adjacent codons of the C. elegans microfibrillar-associated protein 1 gene mfap-1. mfap-1(n4564 n5214) suppresses the Unc phenotypes of different rubberband Unc mutants in a pattern similar to that of mutations in the splicing factor genes uaf-1 (the C. elegans U2AF large subunit gene) and sfa-1 (the C. elegans SF1/BBP gene). We used the endogenous gene tos-1 as a reporter for splicing and detected increased intron 1 retention and exon 3 skipping of tos-1 transcripts in mfap-1(n4564 n5214) animals. Using a yeast two-hybrid screen, we isolated splicing factors as potential MFAP-1 interactors. Our studies indicate that C. elegans mfap-1 encodes a splicing factor that can affect alternative splicing. RNA splicing removes intervening intronic sequences from pre–mRNA transcripts and joins adjacent exonic sequences to generate functional messenger RNAs. The in vivo functions of numerous factors that regulate splicing remain to be understood. From a genetic screen for suppressors of the rubberband Unc phenotype caused by the Caenorhabditis elegans unc-93(e1500) mutation, we isolated a mutation that affects a highly conserved essential gene, mfap-1. MFAP-1 is a nuclear protein that is broadly expressed. MFAP-1 can affect the alternative splicing of tos-1, an endogenous reporter gene for splicing, and is required for the altered splicing at a cryptic 3′ splice site of tos-1. mfap-1 enhances the effects of the gene uaf-1 (splicing factor U2AF large subunit) in suppressing the rubberband Unc phenotype of unc-93(e1500) animals. Our studies provide in vivo evidence that MFAP-1 functions as a splicing factor.
Collapse
|
31
|
Cromar GL, Xiong X, Chautard E, Ricard-Blum S, Parkinson J. Toward a systems level view of the ECM and related proteins: a framework for the systematic definition and analysis of biological systems. Proteins 2012; 80:1522-44. [PMID: 22275077 DOI: 10.1002/prot.24036] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 12/19/2011] [Accepted: 12/29/2011] [Indexed: 12/20/2022]
Abstract
Advances in high throughput 'omic technologies are starting to provide unprecedented insights into how components of biological systems are organized and interact. Key to exploiting these datasets is the definition of the components that comprise the system of interest. Although a variety of knowledge bases exist that capture such information, a major challenge is determining how these resources may be best utilized. Here we present a systematic curation strategy to define a systems-level view of the human extracellular matrix (ECM)--a three-dimensional meshwork of proteins and polysaccharides that impart structure and mechanical stability to tissues. Employing our curation strategy we define a set of 357 proteins that represent core components of the ECM, together with an additional 524 genes that mediate related functional roles, and construct a map of their physical interactions. Topological properties help identify modules of functionally related proteins, including those involved in cell adhesion, bone formation and blood clotting. Because of its major role in cell adhesion, proliferation and morphogenesis, defects in the ECM have been implicated in cancer, atherosclerosis, asthma, fibrosis, and arthritis. We use MeSH annotations to identify modules enriched for specific disease terms that aid to strengthen existing as well as predict novel gene-disease associations. Mapping expression and conservation data onto the network reveal modules evolved in parallel to convey tissue-specific functionality on otherwise broadly expressed units. In addition to demonstrating an effective workflow for defining biological systems, this study crystallizes our current knowledge surrounding the organization of the ECM.
Collapse
Affiliation(s)
- Graham L Cromar
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | | | | | | | | |
Collapse
|
32
|
Ren L, McLean JR, Hazbun TR, Fields S, Vander Kooi C, Ohi MD, Gould KL. Systematic two-hybrid and comparative proteomic analyses reveal novel yeast pre-mRNA splicing factors connected to Prp19. PLoS One 2011; 6:e16719. [PMID: 21386897 PMCID: PMC3046128 DOI: 10.1371/journal.pone.0016719] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 12/23/2010] [Indexed: 11/19/2022] Open
Abstract
Prp19 is the founding member of the NineTeen Complex, or NTC, which is a spliceosomal subcomplex essential for spliceosome activation. To define Prp19 connectivity and dynamic protein interactions within the spliceosome, we systematically queried the Saccharomyces cerevisiae proteome for Prp19 WD40 domain interaction partners by two-hybrid analysis. We report that in addition to S. cerevisiae Cwc2, the splicing factor Prp17 binds directly to the Prp19 WD40 domain in a 1:1 ratio. Prp17 binds simultaneously with Cwc2 indicating that it is part of the core NTC complex. We also find that the previously uncharacterized protein Urn1 (Dre4 in Schizosaccharomyces pombe) directly interacts with Prp19, and that Dre4 is conditionally required for pre-mRNA splicing in S. pombe. S. pombe Dre4 and S. cerevisiae Urn1 co-purify U2, U5, and U6 snRNAs and multiple splicing factors, and dre4Δ and urn1Δ strains display numerous negative genetic interactions with known splicing mutants. The S. pombe Prp19-containing Dre4 complex co-purifies three previously uncharacterized proteins that participate in pre-mRNA splicing, likely before spliceosome activation. Our multi-faceted approach has revealed new low abundance splicing factors connected to NTC function, provides evidence for distinct Prp19 containing complexes, and underscores the role of the Prp19 WD40 domain as a splicing scaffold.
Collapse
Affiliation(s)
- Liping Ren
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Janel R. McLean
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Tony R. Hazbun
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
- Department of Genome Sciences and Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Stanley Fields
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
- Department of Genome Sciences and Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Craig Vander Kooi
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Melanie D. Ohi
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Kathleen L. Gould
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, University of Washington, Seattle, Washington, United States of America
| |
Collapse
|
33
|
Hofmann JC, Husedzinovic A, Gruss OJ. The function of spliceosome components in open mitosis. Nucleus 2010; 1:447-59. [PMID: 21327086 DOI: 10.4161/nucl.1.6.13328] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 08/09/2010] [Accepted: 08/13/2010] [Indexed: 12/15/2022] Open
Abstract
Spatial separation of eukaryotic cells into the nuclear and cytoplasmic compartment permits uncoupling of DNA transcription from translation of mRNAs and allows cells to modify newly transcribed pre mRNAs extensively. Intronic sequences (introns), which interrupt the coding elements (exons), are excised ("spliced") from pre-mRNAs in the nucleus to yield mature mRNAs. This not only enables alternative splicing as an important source of proteome diversity, but splicing is also an essential process in all eukaryotes and knock-out or knock-down of splicing factors frequently results in defective cell proliferation and cell division. However, higher eukaryotes progress through cell division only after breakdown of the nucleus ("open mitosis"). Open mitosis suppresses basic nuclear functions such as transcription and splicing, but allows separate, mitotic functions of nuclear proteins in cell division. Mitotic defects arising after loss-of-function of splicing proteins therefore could be an indirect consequence of compromised splicing in the closed nucleus of the preceding interphase or reflect a direct contribution of splicing proteins to open mitosis. Although experiments to directly distinguish between these two alternatives have not been reported, indirect evidence exists for either hypotheses. In this review, we survey published data supporting an indirect function of splicing in open mitosis or arguing for a direct function of spliceosomal proteins in cell division.
Collapse
|