1
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Song Y, Wang L, Xu M, Lu X, Wang Y, Zhang L. Molecular and functional characterization of porcine poly C binding protein 1 (PCBP1). BMC Vet Res 2024; 20:25. [PMID: 38218813 PMCID: PMC10787444 DOI: 10.1186/s12917-023-03861-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 12/20/2023] [Indexed: 01/15/2024] Open
Abstract
BACKGROUND Poly C Binding Protein 1 (PCBP1) belongs to the heterogeneous nuclear ribonucleoprotein family. It is a multifunctional protein that participates in several functional circuits and plays a variety of roles in cellular processes. Although PCBP1 has been identified in several mammals, its function in porcine was unclear. RESULTS In this study, we cloned the gene of porcine PCBP1 and analyzed its evolutionary relationships among different species. We found porcine PCBP1 protein sequence was similar to that of other animals. The subcellular localization of PCBP1 in porcine kidney cells 15 (PK-15) cells was analyzed by immunofluorescence assay (IFA) and revealed that PCBP1 was mainly localized to the nucleus. Reverse transcription-quantitative PCR (RT-qPCR) was used to compare PCBP1 mRNA levels in different tissues of 30-day-old pigs. Results indicated that PCBP1 was expressed in various tissues and was most abundant in the liver. Finally, the effects of PCBP1 on cell cycle and apoptosis were investigated following its overexpression or knockdown in PK-15 cells. The findings demonstrated that PCBP1 knockdown arrested cell cycle in G0/G1 phase, and enhanced cell apoptosis. CONCLUSIONS Porcine PCBP1 is a highly conserved protein, plays an important role in determining cell fate, and its functions need further study.
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Affiliation(s)
- Yue Song
- Molecule Biology Laboratory of Zhengzhou Normal University, Zhengzhou Henan, 450044, China
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Linqing Wang
- Molecule Biology Laboratory of Zhengzhou Normal University, Zhengzhou Henan, 450044, China.
| | - Menglong Xu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Xiuxiang Lu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Yumin Wang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, 450046, China
| | - Limeng Zhang
- Molecule Biology Laboratory of Zhengzhou Normal University, Zhengzhou Henan, 450044, China
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2
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Lo R, Gonçalves-Carneiro D. Sensing nucleotide composition in virus RNA. Biosci Rep 2023; 43:BSR20230372. [PMID: 37606964 PMCID: PMC10500230 DOI: 10.1042/bsr20230372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/10/2023] [Accepted: 08/22/2023] [Indexed: 08/23/2023] Open
Abstract
Nucleotide composition plays a crucial role in the structure, function and recognition of RNA molecules. During infection, virus RNA is exposed to multiple endogenous proteins that detect local or global compositional biases and interfere with virus replication. Recent advancements in RNA:protein mapping technologies have enabled the identification of general RNA-binding preferences in the human proteome at basal level and in the context of virus infection. In this review, we explore how cellular proteins recognise nucleotide composition in virus RNA and the impact these interactions have on virus replication. Protein-binding G-rich and C-rich sequences are common examples of how host factors detect and limit infection, and, in contrast, viruses may have evolved to purge their genomes from such motifs. We also give examples of how human RNA-binding proteins inhibit virus replication, not only by destabilising virus RNA, but also by interfering with viral protein translation and genome encapsidation. Understanding the interplay between cellular proteins and virus RNA composition can provide insights into host-virus interactions and uncover potential targets for antiviral strategies.
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Affiliation(s)
- Raymon Lo
- Imperial College London, Department of Infectious Disease, Imperial College London, London, U.K
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3
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Li D, Guo J, Jia R. Epigenetic Control of Cancer Cell Proliferation and Cell Cycle Progression by HNRNPK via Promoting Exon 4 Inclusion of Histone Code Reader SPIN1. J Mol Biol 2023; 435:167993. [PMID: 36736887 DOI: 10.1016/j.jmb.2023.167993] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 01/27/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023]
Abstract
Heterogeneous nuclear ribonucleoprotein K (HNRNPK, hnRNP K), a multifunctional RNA/DNA binding protein, mainly regulates transcription, translation and RNA splicing, and then plays oncogenic roles in many cancers. However, the related mechanisms remain largely unknown. Here, we found that HNRNPK can partially epigenetically regulate cancer cell proliferation via increasing transcription and exon 4-inclusion of SPIN1, an important oncogenic histone code reader. This exon 4 skipping event of SPIN1 generates a long non-coding RNA, followed by the downregulation of SPIN1 protein. SPIN1 is one of the most significantly co-expressed genes of HNRNPK in thirteen TCGA cancers. Our further studies revealed HNRNPK knockdown significantly inhibited cell growth and cell cycle progression in oral squamous cell carcinoma (OSCC) cells and promoted cell apoptosis. Overexpression of SPIN1 was able to partially rescue the growth inhibition triggered by HNRNPK knockdown. Moreover, CCND1 (Cyclin D1), a key cell cycle regulator and oncogene, epigenetically up-regulated by SPIN1, was also positively regulated by HNRNPK. In addition, we discovered that HNRNPK promoted SPIN1 exon 4 inclusion by interacting with an intronic splicing enhancer in intron 4. Collectively, our study suggests a novel epigenetic regulatory pathway of HNRNPK in OSCC, mediated by controlling the transcription activity and alternative splicing of SPIN1 gene.
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Affiliation(s)
- Di Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Jihua Guo
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Endodontics, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
| | - Rong Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
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4
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Singh AK, Chen Q, Nguyen C, Meerzaman D, Singer DS. Cohesin regulates alternative splicing. SCIENCE ADVANCES 2023; 9:eade3876. [PMID: 36857449 PMCID: PMC9977177 DOI: 10.1126/sciadv.ade3876] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
Cohesin, a trimeric complex that establishes sister chromatid cohesion, has additional roles in chromatin organization and transcription. We report that among those roles is the regulation of alternative splicing through direct interactions and in situ colocalization with splicing factors. Degradation of cohesin results in marked changes in splicing, independent of its effects on transcription. Introduction of a single cohesin point mutation in embryonic stem cells alters splicing patterns, demonstrating causality. In primary human acute myeloid leukemia, mutations in cohesin are highly correlated with distinct patterns of alternative splicing. Cohesin also directly interacts with BRD4, another splicing regulator, to generate a pattern of splicing that is distinct from either factor alone, documenting their functional interaction. These findings identify a role for cohesin in regulating alternative splicing in both normal and leukemic cells and provide insights into the role of cohesin mutations in human disease.
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Affiliation(s)
- Amit K. Singh
- Experimental Immunology Branch, Center for Cancer Research, Bethesda, MD, USA
- Computational Genomics and Bioinformatics Branch, Center for Biomedical Informatics and Information Technology, National Cancer Institute, Bethesda, MD, USA
| | - Qingrong Chen
- Computational Genomics and Bioinformatics Branch, Center for Biomedical Informatics and Information Technology, National Cancer Institute, Bethesda, MD, USA
| | - Cu Nguyen
- Computational Genomics and Bioinformatics Branch, Center for Biomedical Informatics and Information Technology, National Cancer Institute, Bethesda, MD, USA
| | - Daoud Meerzaman
- Computational Genomics and Bioinformatics Branch, Center for Biomedical Informatics and Information Technology, National Cancer Institute, Bethesda, MD, USA
| | - Dinah S. Singer
- Experimental Immunology Branch, Center for Cancer Research, Bethesda, MD, USA
- Computational Genomics and Bioinformatics Branch, Center for Biomedical Informatics and Information Technology, National Cancer Institute, Bethesda, MD, USA
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5
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Martinelli M, Aguilar G, Lee DS, Kromer A, Nguyen N, Wilkins BJ, Akimova T, Beier UH, Ghanem LR. The poly(C)-binding protein Pcbp2 is essential for CD4 + T cell activation and proliferation. iScience 2022; 26:105860. [PMID: 36632062 PMCID: PMC9826892 DOI: 10.1016/j.isci.2022.105860] [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: 06/16/2022] [Revised: 11/16/2022] [Accepted: 12/18/2022] [Indexed: 12/24/2022] Open
Abstract
The RNA-binding protein Pcbp2 is widely expressed in the innate and adaptive immune systems and is essential for mouse development. To determine whether Pcbp2 is required for CD4+ T cell development and function, we derived mice with conditional Pcbp2 deletion in CD4+ T cells and assessed their overall phenotype and proliferative responses to activating stimuli. We found that Pcbp2 is essential for T conventional cell (Tconv) proliferation, working through regulation of co-stimulatory signaling. Pcbp2 deficiency in the CD4+ lineage did not impact Treg abundance in vivo or function in vitro. In addition, our data demonstrate a clear association between Pcbp2 control of Runx1 exon 6 splicing in CD4+ T cells and a specific role for Pcbp2 in the maintenance of peripheral CD4+ lymphocyte population size. Last, we show that Pcbp2 function is required for optimal in vivo Tconv cell activation in a T cell adoptive transfer colitis model system.
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Affiliation(s)
- Massimo Martinelli
- Division of Gastroenterology, Hepatology and Nutrition Division, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA,Department of Translational Medical Science, Section of Pediatrics, University of Naples “Federico II”, Naples 80131, Italy
| | - Gabrielle Aguilar
- Division of Gastroenterology, Hepatology and Nutrition Division, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - David S.M. Lee
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA,Institute for Biomedical Informatics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrew Kromer
- Division of Gastroenterology, Hepatology and Nutrition Division, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Nhu Nguyen
- Division of Gastroenterology, Hepatology and Nutrition Division, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Benjamin J. Wilkins
- Division of Anatomic Pathology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA,Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tatiana Akimova
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ulf H. Beier
- Division of Nephrology, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Louis R. Ghanem
- Division of Gastroenterology, Hepatology and Nutrition Division, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA,Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA,Corresponding author
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6
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Sen S, Bal SK, Yadav S, Mishra P, G VV, Rastogi R, Mukhopadhyay CK. Intracellular pathogen Leishmania intervenes in iron loading into ferritin by cleaving chaperones in host macrophages as an iron acquisition strategy. J Biol Chem 2022; 298:102646. [PMID: 36309090 PMCID: PMC9700016 DOI: 10.1016/j.jbc.2022.102646] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/05/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
Iron (Fe) sequestration is one of the most important strategies of the host to control the growth and survival of invading pathogens. Ferritin (Ft) plays a pivotal role in the sequestration mechanism of mammalian hosts by storing Fe. Recent evidence suggests that poly(rC)-binding proteins (PCBPs) act as chaperones for loading Fe into Ft. Incidentally, modulation of host PCBPs in respect to storing Fe in Ft during any infection remains unexplored. Among PCBPs, PCBP1 and PCBP2 are present in every cell type and involved in interacting with Ft for Fe loading. Leishmania donovani (LD) resides within macrophages during the mammalian stage of infection, causing life-threatening visceral leishmaniasis. Here, we reveal the ability of LD to cleave PCBP1 and PCBP2 in host monocytes/macrophages. LD cleaves PCBP1-FLAG into two fragments and PCBP2-FLAG into multiple fragments, thus affecting their interactions with Ft and resulting in decreased Fe loading into Ft. LD-derived culture supernatant or exosome-enriched fractions are also able to cleave PCBPs, suggesting involvement of a secreted protease of the parasite. Using an immune-depletion experiment and transgenic mutants, we confirmed the involvement of zinc-metalloprotease GP63 in cleaving PCBPs. We further revealed that by cleaving host PCBPs, Leishmania could inhibit Fe loading into Ft to accumulate available Fe for higher intracellular growth. This is the first report of a novel strategy adopted by a mammalian pathogen to interfere with Fe sequestration into Ft by cleaving chaperones for its survival advantage within the host.
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7
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Wang J, Sun D, Wang M, Cheng A, Zhu Y, Mao S, Ou X, Zhao X, Huang J, Gao Q, Zhang S, Yang Q, Wu Y, Zhu D, Jia R, Chen S, Liu M. Multiple functions of heterogeneous nuclear ribonucleoproteins in the positive single-stranded RNA virus life cycle. Front Immunol 2022; 13:989298. [PMID: 36119073 PMCID: PMC9478383 DOI: 10.3389/fimmu.2022.989298] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/12/2022] [Indexed: 11/13/2022] Open
Abstract
The heterogeneous nuclear ribonucleoproteins (hnRNPs) are a diverse family of RNA binding proteins that are implicated in RNA metabolism, such as alternative splicing, mRNA stabilization and translational regulation. According to their different cellular localization, hnRNPs display multiple functions. Most hnRNPs were predominantly located in the nucleus, but some of them could redistribute to the cytoplasm during virus infection. HnRNPs consist of different domains and motifs that enable these proteins to recognize predetermined nucleotide sequences. In the virus-host interactions, hnRNPs specifically bind to viral RNA or proteins. And some of the viral protein-hnRNP interactions require the viral RNA or other host factors as the intermediate. Through various mechanisms, hnRNPs could regulate viral translation, viral genome replication, the switch of translation to replication and virion release. This review highlights the common features and the distinguish roles of hnRNPs in the life cycle of positive single-stranded RNA viruses.
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Affiliation(s)
- Jingming Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- *Correspondence: Anchun Cheng,
| | - Yukun Zhu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Xuming Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu City, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu City, China
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8
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Zheng Y, Zhou Z, Wei R, Xiao C, Zhang H, Fan T, Zheng B, Li C, He J. The RNA-binding protein PCBP1 represses lung adenocarcinoma progression by stabilizing DKK1 mRNA and subsequently downregulating β-catenin. J Transl Med 2022; 20:343. [PMID: 35907982 PMCID: PMC9338556 DOI: 10.1186/s12967-022-03552-y] [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: 05/10/2022] [Accepted: 07/24/2022] [Indexed: 12/02/2022] Open
Abstract
Background PolyC-RNA-binding protein 1 (PCBP1) functions as a tumour suppressor and RNA regulator that is downregulated in human cancers. Here, we aimed to reveal the biological function of PCBP1 in lung adenocarcinoma (LUAD). Methods First, PCBP1 was identified as an important biomarker that maintains LUAD through The Cancer Genome Atlas (TCGA) project screening and confirmed by immunohistochemistry and qPCR. Via colony formation, CCK8, IncuCyte cell proliferation, wound healing and Transwell assays, we confirmed that PCBP1 was closely related to the proliferation and migration of LUAD cells. The downstream gene DKK1 was discovered by RNA sequencing of PCBP1 knockdown cells. The underlying mechanisms were further investigated using western blot, qPCR, RIP, RNA pulldown and mRNA stability assays. Results We demonstrate that PCBP1 is downregulated in LUAD tumour tissues. The reduction in PCBP1 promotes the proliferation, migration and invasion of LUAD in vitro and in vivo. Mechanistically, the RNA-binding protein PCBP1 represses LUAD by stabilizing DKK1 mRNA. Subsequently, decreased expression of the DKK1 protein relieves the inhibitory effect on the Wnt/β-catenin signalling pathway. Taken together, these results show that PCBP1 acts as a tumour suppressor gene, inhibiting the tumorigenesis of LUAD. Conclusions We found that PCBP1 inhibits LUAD development by upregulating DKK1 to inactivate the Wnt/β-catenin pathway. Our findings highlight the potential of PCBP1 as a promising therapeutic target. Supplementary Information The online version contains supplementary material available at 10.1186/s12967-022-03552-y.
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Affiliation(s)
- Yujia Zheng
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zheng Zhou
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ran Wei
- Department of Colorectal Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Chu Xiao
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hao Zhang
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Tao Fan
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bo Zheng
- Department of Pathology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Chunxiang Li
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Jie He
- Department of Thoracic Surgery, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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9
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Chen Y, Dou Z, Chen X, Zhao D, Che T, Su W, Qu T, Zhang T, Xu C, Lei H, Li Q, Zhang H, Di C. Overexpression of splicing factor poly(rC)-binding protein 1 elicits cycle arrest, apoptosis induction, and p73 splicing in human cervical carcinoma cells. J Cancer Res Clin Oncol 2022; 148:3475-3484. [PMID: 35896897 DOI: 10.1007/s00432-022-04170-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 06/20/2022] [Indexed: 12/24/2022]
Abstract
PURPOSE Splicing factor poly(rC)-binding protein 1 (PCBP1) is a novel tumor suppressor that is downregulated in several cancers thereby regulating tumor formation and metastasis. However, the involvement of PCBP1 in apoptosis of cancer cells and the molecular mechanism remains elusive. On this basis, we sought to investigate the role of splicing factor PCBP1 in the apoptosis in human cervical cancer cells. METHODS To investigate PCBP1 functions in vitro, we overexpressed PCBP1 in human cervical cancer cells. A series of cytological function assays were employed to study to the role of PCBP1 in cell proliferation, cell cycle arrest and apoptosis. RESULTS Overexpression of PCBP1 was found to greatly repress proliferation of HeLa cells in a time-dependent manner. It also induced a significant increase in G2/M phase arrest and apoptosis. Furthermore, overexpressed PCBP1 favored the production of long isoforms of p73, thereby inducing upregulated ratio of Bax/Bcl-2, the release of cytochrome c and the expression of caspase-3. CONCLUSION Our results revealed that PCBP1 played a vital role in p73 splicing, cycle arrest and apoptosis induction in human cervical carcinoma cells. Targeting PCBP1 may be a potential therapeutic strategy for cervical cancer therapy.
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Affiliation(s)
- Yuhong Chen
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Zhihui Dou
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Xiaohua Chen
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Dapeng Zhao
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Tuanjie Che
- Laboratory of Precision Medicine and Translational Medicine, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou Science and Technology Town Hospital, Suzhou, 215153, China.,Key Laboratory of Functional Genomic and Molecular Diagnosis of Gansu Province, Lanzhou, 730030, China
| | - Wei Su
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Tao Qu
- Department of Biotherapy Center, Gansu Provincial Hospital, Lanzhou, Gansu, China
| | - Taotao Zhang
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Caipeng Xu
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Huiweng Lei
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Qiang Li
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China. .,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China. .,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China. .,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China. .,Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
| | - Hong Zhang
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China. .,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China. .,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China. .,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China. .,Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
| | - Cuixia Di
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China. .,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, 730000, China. .,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100039, China. .,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, 100039, China. .,Department of Heavy Ion Radiation Medicine, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, China.
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10
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Li M, Yang X, Zhang G, Wang L, Zhu Z, Zhang W, Huang H, Gao R. Heterogeneous nuclear ribonucleoprotein K promotes the progression of lung cancer by inhibiting the p53‐dependent signaling pathway. Thorac Cancer 2022; 13:1311-1321. [PMID: 35352475 PMCID: PMC9058298 DOI: 10.1111/1759-7714.14387] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 12/04/2022] Open
Abstract
Background Heterogeneous nuclear ribonucleoprotein K (hnRNPK) is a nucleic acid‐binding protein. Reportedly, hnRNPK is overexpressed in many human tumors, and such overexpression is associated with poor prognosis, implicating the role of hnRNPK as an oncogene during tumorigenesis. In this study, hnRNPK expression in lung cancer tissues was investigated. Methods Briefly, hnRNPK was knocked down in lung cancer cell lines, and effects of knockdown on the cell proliferation, migration, and cell cycle were assessed using a cell counting kit‐8 (CCK‐8) assay, colony formation assay, transwell assay and flow cytometry. The effects of hnRNPK knockdown on the p53‐dependent signaling pathway were examined using western blotting. Finally, the effect of hnRNPK knockdown on tumor growth was verified in vivo using a lung cancer xenograft mouse model. Results hnRNPK knockdown inhibited the cell proliferation, migration and cell cycle. In addition to phenotypic changes, hnRNPK knockdown upregulated expressions of pCHK1, pCHK2, and p53,p21,cyclin D1, thereby mediating the DNA damage response (DDR). The regulatory function of hnRNPK during p53/p21/cyclin D1 signaling in hnRNPK‐knockdown A549 cells was confirmed by suppressed the protein expression of associated signaling pathways, which inhibited DDR. Conclusion hnRNPK plays a crucial role in the progression of lung cancer, ultimately affecting survival rate. Inhibition of progression of lung cancer cells induced by hnRNPK‐knockdown is dependent on activation of p53 by the p53/p21/cyclin D1 pathway.
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Affiliation(s)
- Mengyuan Li
- National Human Diseases Animal Model Resource Center, The Institute of Laboratory Animal Science Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
- NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
| | - Xingjiu Yang
- National Human Diseases Animal Model Resource Center, The Institute of Laboratory Animal Science Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
- NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
| | - Guoxin Zhang
- National Human Diseases Animal Model Resource Center, The Institute of Laboratory Animal Science Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
- NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
| | - Le Wang
- NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
| | - Ziwei Zhu
- NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
| | - Wenlong Zhang
- National Human Diseases Animal Model Resource Center, The Institute of Laboratory Animal Science Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
- NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
| | - Hao Huang
- NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
| | - Ran Gao
- National Human Diseases Animal Model Resource Center, The Institute of Laboratory Animal Science Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China
- NHC Key Laboratory of Human Disease Comparative Medicine Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases Beijing China
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11
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Zhao H, Wei Z, Shen G, Chen Y, Hao X, Li S, Wang R. Poly(rC)-binding proteins as pleiotropic regulators in hematopoiesis and hematological malignancy. Front Oncol 2022; 12:1045797. [PMID: 36452487 PMCID: PMC9701828 DOI: 10.3389/fonc.2022.1045797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Poly(rC)-binding proteins (PCBPs), a defined subfamily of RNA binding proteins, are characterized by their high affinity and sequence-specific interaction with poly-cytosine (poly-C). The PCBP family comprises five members, including hnRNP K and PCBP1-4. These proteins share a relatively similar structure motif, with triple hnRNP K homology (KH) domains responsible for recognizing and combining C-rich regions of mRNA and single- and double-stranded DNA. Numerous studies have indicated that PCBPs play a prominent role in hematopoietic cell growth, differentiation, and tumorigenesis at multiple levels of regulation. Herein, we summarized the currently available literature regarding the structural and functional divergence of various PCBP family members. Furthermore, we focused on their roles in normal hematopoiesis, particularly in erythropoiesis. More importantly, we also discussed and highlighted their involvement in carcinogenesis, including leukemia and lymphoma, aiming to clarify the pleiotropic roles and molecular mechanisms in the hematopoietic compartment.
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Affiliation(s)
- Huijuan Zhao
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang, China.,Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Ziqing Wei
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Guomin Shen
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang, China.,Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Yixiang Chen
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang, China.,Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Xueqin Hao
- Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Sanqiang Li
- Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Rong Wang
- Department of Clinical Laboratory, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, China
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12
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HnRNP K mislocalisation is a novel protein pathology of frontotemporal lobar degeneration and ageing and leads to cryptic splicing. Acta Neuropathol 2021; 142:609-627. [PMID: 34274995 PMCID: PMC8423707 DOI: 10.1007/s00401-021-02340-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 02/08/2023]
Abstract
Heterogeneous nuclear ribonucleoproteins (HnRNPs) are a group of ubiquitously expressed RNA-binding proteins implicated in the regulation of all aspects of nucleic acid metabolism. HnRNP K is a member of this highly versatile hnRNP family. Pathological redistribution of hnRNP K to the cytoplasm has been linked to the pathogenesis of several malignancies but, until now, has been underexplored in the context of neurodegenerative disease. Here we show hnRNP K mislocalisation in pyramidal neurons of the frontal cortex to be a novel neuropathological feature that is associated with both frontotemporal lobar degeneration and ageing. HnRNP K mislocalisation is mutually exclusive to TDP-43 and tau pathological inclusions in neurons and was not observed to colocalise with mitochondrial, autophagosomal or stress granule markers. De-repression of cryptic exons in RNA targets following TDP-43 nuclear depletion is an emerging mechanism of potential neurotoxicity in frontotemporal lobar degeneration and the mechanistically overlapping disorder amyotrophic lateral sclerosis. We silenced hnRNP K in neuronal cells to identify the transcriptomic consequences of hnRNP K nuclear depletion. Intriguingly, by performing RNA-seq analysis we find that depletion of hnRNP K induces 101 novel cryptic exon events. We validated cryptic exon inclusion in an SH-SY5Y hnRNP K knockdown and in FTLD brain exhibiting hnRNP K nuclear depletion. We, therefore, present evidence for hnRNP K mislocalisation to be associated with FTLD and for this to induce widespread changes in splicing.
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13
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Mohanty BK, Karam JA, Howley BV, Dalton AC, Grelet S, Dincman T, Streitfeld WS, Yoon JH, Balakrishnan L, Chazin WJ, Long DT, Howe PH. Heterogeneous nuclear ribonucleoprotein E1 binds polycytosine DNA and monitors genome integrity. Life Sci Alliance 2021; 4:4/9/e202000995. [PMID: 34272328 PMCID: PMC8321654 DOI: 10.26508/lsa.202000995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/01/2021] [Accepted: 07/02/2021] [Indexed: 11/24/2022] Open
Abstract
hnRNP E1 binds polycytosine tracts of DNA and monitors genome integrity. Heterogeneous nuclear ribonucleoprotein E1 (hnRNP E1) is a tumor suppressor protein that binds site- and structure-specifically to RNA sequences to regulate mRNA stability, facilitate alternative splicing, and suppress protein translation on several metastasis-associated mRNAs. Here, we show that hnRNP E1 binds polycytosine-rich DNA tracts present throughout the genome, including those at promoters of several oncogenes and telomeres and monitors genome integrity. It binds DNA in a site- and structure-specific manner. hnRNP E1-knockdown cells displayed increased DNA damage signals including γ-H2AX at its binding sites and also showed increased mutations. UV and hydroxyurea treatment of hnRNP E1-knockdown cells exacerbated the basal DNA damage signals with increased cell cycle arrest, activation of checkpoint proteins, and monoubiquitination of proliferating cell nuclear antigen despite no changes in deubiquitinating enzymes. DNA damage caused by genotoxin treatment localized to hnRNP E1 binding sites. Our work suggests that hnRNP E1 facilitates functions of DNA integrity proteins at polycytosine tracts and monitors DNA integrity at these sites.
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Affiliation(s)
- Bidyut K Mohanty
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Joseph Aq Karam
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Breege V Howley
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Annamarie C Dalton
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Simon Grelet
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
| | - Toros Dincman
- Division of Hematology and Oncology, Department of Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - William S Streitfeld
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Je-Hyun Yoon
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Lata Balakrishnan
- Department of Biology, School of Science, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
| | - Walter J Chazin
- Departments of Biochemistry and Chemistry and Center for Structural Biology, Vanderbilt University, Nashville, TN, USA
| | - David T Long
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Philip H Howe
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA .,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
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14
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Yuan C, Chen M, Cai X. Advances in poly(rC)-binding protein 2: Structure, molecular function, and roles in cancer. Biomed Pharmacother 2021; 139:111719. [PMID: 34233389 DOI: 10.1016/j.biopha.2021.111719] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 04/29/2021] [Accepted: 05/07/2021] [Indexed: 02/08/2023] Open
Abstract
Poly(rC)-binding protein 2 (PCBP2) is an RNA-binding protein that is characterized by its ability to interact with poly(C) with high affinity in a sequence-specific manner. PCBP2 contains three K homology domains, which are consensus RNA-binding domains that play a role in recognizing and combining with RNA and DNA. The specific structure and localization of PCBP2 lay the foundation for its multiple roles in transcriptional, posttranscriptional, and translational processes, even in iron metabolism. Numerous studies have indicated that PCBP2 expression is increased in many cancer types. PCBP2 is considered as an oncogene that promotes tumorigenesis, development of cancer cells, and metastasis. Here, we summarized the current evidence regarding PCBP2 in the proliferation, migration, invasion of cancer cells, and drug resistance, aiming to clarify the molecular mechanisms of PCBP2 in cancer. Results from this review suggest that an in-depth study of PCBP2 in cancer may provide novel biomarkers for prognostic or therapeutic purposes.
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Affiliation(s)
- Chendong Yuan
- Department of Vascular Surgery, Zhuji Affiliated Hospital of Shaoxing University, Zhuji, Zhejiang 311800, China.
| | - Mingxiang Chen
- Department of Cardiovascular surgery, The Third Affiliated Hospital of Chongqing Medical University, Chongqing, Yubei 401120, China.
| | - Xiaolu Cai
- Department of Oncological Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
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15
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Zhang X, Di C, Chen Y, Wang J, Su R, Huang G, Xu C, Chen X, Long F, Yang H, Zhang H. Multilevel regulation and molecular mechanism of poly (rC)-binding protein 1 in cancer. FASEB J 2020; 34:15647-15658. [PMID: 33058239 DOI: 10.1096/fj.202000911r] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 09/02/2020] [Accepted: 09/15/2020] [Indexed: 01/07/2023]
Abstract
Poly (rC)-binding protein 1 (PCBP1), an RNA- or DNA-binding protein with a relative molecular weight of 38 kDa, which is characterized by downregulation in many cancer types. Numerous cases have indicated that PCBP1 could be considered as a tumor suppressor to inhibit tumorigenesis, development, and metastasis. In the current review, we described the multilevel regulatory roles of PCBP1, including gene transcription, alternative splicing, and translation of many cancer-related genes. Additionally, we also provided a brief overview about the inhibitory effect of PCBP1 on most common tumors. More importantly, we summarized the current research status about PCBP1 in hypoxic microenvironment, autophagy, apoptosis, and chemotherapy of cancer cells, aiming to clarify the molecular mechanisms of PCBP1 in cancer. Taken together, in-depth study of PCBP1 in cancer may provide new ideas for cancer therapy.
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Affiliation(s)
- Xuetian Zhang
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Cuixia Di
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Yuhong Chen
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Jing Wang
- School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Ruowei Su
- The First Affiliated Hospital, School of Medicine, Xiamen University, Xiamen, China
| | - Guomin Huang
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Caipeng Xu
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Xiaohua Chen
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Feng Long
- Gansu University of Traditional Chinese Medicine, Lanzhou, China
| | - Hongying Yang
- School of Radiation Medicine and Protection, Medical College of Soochow, Soochow, China
| | - Hong Zhang
- Bio-Medical Research Center, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.,Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.,School of Nuclear Science and Technology, University of Chinese Academy of Sciences, Beijing, China
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16
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Gong B, Wang X, Li B, Li Y, Lu R, Zhang K, Li B, Ma Y, Li Y. miR-205-5p inhibits thymic epithelial cell proliferation via FA2H-TFAP2A feedback regulation in age-associated thymus involution. Mol Immunol 2020; 122:173-185. [PMID: 32371259 DOI: 10.1016/j.molimm.2020.04.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 03/02/2020] [Accepted: 04/13/2020] [Indexed: 12/28/2022]
Abstract
Thymic epithelial cells (TECs) are essential regulators of T cell development and selection. microRNAs (miRNAs) play critical roles in regulating TECs proliferation during thymus involution. miR-205-5p is highly expressed in TECs and increases with age. However, the function and potential mechanism of miR-205-5p in TECs are not clear. miRNA expression was profiled using TECs from male and female mice at 1 and 3 months old. A total of 325 differentially expressed miRNAs (DEMs) were detected at different ages in two sexes. 24 of the DEMs had the same trend between males and females. Among them, miR-205-5p had the highest fold change. Our results showed that the expression of miR-205-5p was dramatically increased in TECs from 1 to 9 months old mice. miR-205-5p mimic inhibited TECs proliferation. Moreover, we confirmed that Fa2h was the direct target gene of miR-205-5p and FA2H was significantly decreased in TECs with increased expression of miR-205-5p. Silencing of Fa2h inhibited TECs proliferation. Furthermore, we found that the expression of Tfap2a could be promoted by FA2H and that TFAP2A could interact with miR-205-5p in TECs. Overall, miR-205-5p is an important regulator of TECs proliferation and regulates age-associated thymus involution via the miR-205-5p-FA2H-TFAP2A feedback regulatory circuit. miR-205-5p might act as a potential biomarker in TECs for age-related thymus involution.
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Affiliation(s)
- Bishuang Gong
- College of Veterinary Medicine, South China Agricultural University, China
| | - Xintong Wang
- College of Veterinary Medicine, South China Agricultural University, China
| | - Boning Li
- the Department of Cardiology, Shenzhen Children's Hospital, Shenzhen, China
| | - Ying Li
- College of Veterinary Medicine, South China Agricultural University, China
| | - Rui Lu
- College of Veterinary Medicine, South China Agricultural University, China
| | - Kaizhao Zhang
- College of Veterinary Medicine, South China Agricultural University, China
| | - Bingxin Li
- College of Veterinary Medicine, South China Agricultural University, China
| | - Yongjiang Ma
- College of Veterinary Medicine, South China Agricultural University, China.
| | - Yugu Li
- College of Veterinary Medicine, South China Agricultural University, China.
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17
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Jiang H, Hou P, He H, Wang H. Cell apoptosis regulated by interaction between viral gene alpha 3 and host heterogeneous nuclear ribonucleoprotein K facilitates bovine ephemeral fever virus replication. Vet Microbiol 2020; 240:108510. [DOI: 10.1016/j.vetmic.2019.108510] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023]
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18
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Li M, Zhang W, Yang X, Liu H, Cao L, Li W, Wang L, Zhang G, Gao R. Downregulation of HNRNPK in human cancer cells inhibits lung metastasis. Animal Model Exp Med 2019; 2:291-296. [PMID: 31942561 PMCID: PMC6930993 DOI: 10.1002/ame2.12090] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Lung cancer frequently occurs in the clinic, leading to poor prognosis and high mortality. Markers for early diagnosis of lung cancer are scarce, and further potential therapeutic targets are also urgently needed. METHOD We established a new mouse model in which the specific gene HNRNPK (heterogeneous nuclear ribonucleoprotein K) was downregulated after administration of doxycycline. The lung metastatic nodules were investigated using bioluminescence imaging, micro-CT, and autopsy quantification. RESULTS Compared with the short hairpin negative control group, less lung metastatic nodules were formed in the short hairpin RNA group. CONCLUSION Downregulation of HNRNPK in cancer cells can inhibit lung metastasis.
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Affiliation(s)
- Mengyuan Li
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Wenlong Zhang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Xingjiu Yang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Hongfei Liu
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Lin Cao
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Weisha Li
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Le Wang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Guoxin Zhang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Ran Gao
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
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19
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Grelet S, Howe PH. hnRNP E1 at the crossroads of translational regulation of epithelial-mesenchymal transition. ACTA ACUST UNITED AC 2019; 5. [PMID: 31681852 PMCID: PMC6824538 DOI: 10.20517/2394-4722.2018.85] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The epithelial-mesenchymal transition (EMT), in which cells undergo a switch from a polarized, epithelial phenotype to a highly motile fibroblastic or mesenchymal phenotype is fundamental during embryonic development and can be reactivated in a variety of diseases including cancer. Spatio-temporally-regulated mechanisms are constantly orchestrated to allow cells to adapt to their constantly changing environments when disseminating to distant organs. Although numerous transcriptional regulatory factors are currently well-characterized, the post-transcriptional control of EMT requires continued investigation. The hnRNP E1 protein displays a major role in the control of tumor cell plasticity by regulating the translatome through multiple non-redundant mechanisms, and this role is exemplified when E1 is absent. hnRNP E1 binding to RNA molecules leads to direct or indirect translational regulation of specific sets of proteins: (1) hnRNP E1 binding to specific targets has a direct role in translation by preventing elongation of translation; (2) hnRNP E1-dependent alternative splicing can prevent the generation of a competing long non-coding RNA that acts as a decoy for microRNAs (miRNAs) involved in translational inhibition of EMT master regulators; (3) hnRNP E1 binding to the 3’ untranslated region of transcripts can also positively regulate the stability of certain mRNAs to improve their translation. Globally, hnRNP E1 appears to control proteome reprogramming during cell plasticity, either by direct or indirect regulation of protein translation.
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Affiliation(s)
- Simon Grelet
- Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425, USA.,Department of Biochemistry, Medical University of South Carolina, Charleston, South Carolina 29425, USA
| | - Philip H Howe
- Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina 29425, USA.,Department of Biochemistry, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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Shin CH, Kim HH. Functional roles of heterogeneous nuclear ribonucleoprotein K in post-transcriptional gene regulation. PRECISION AND FUTURE MEDICINE 2018. [DOI: 10.23838/pfm.2018.00107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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21
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Ghanem LR, Kromer A, Silverman IM, Ji X, Gazzara M, Nguyen N, Aguilar G, Martinelli M, Barash Y, Liebhaber SA. Poly(C)-Binding Protein Pcbp2 Enables Differentiation of Definitive Erythropoiesis by Directing Functional Splicing of the Runx1 Transcript. Mol Cell Biol 2018; 38:e00175-18. [PMID: 29866654 PMCID: PMC6066754 DOI: 10.1128/mcb.00175-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/10/2018] [Accepted: 05/26/2018] [Indexed: 12/14/2022] Open
Abstract
Formation of the mammalian hematopoietic system is under a complex set of developmental controls. Here, we report that mouse embryos lacking the KH domain poly(C) binding protein, Pcbp2, are selectively deficient in the definitive erythroid lineage. Compared to wild-type controls, transcript splicing analysis of the Pcbp2-/- embryonic liver reveals accentuated exclusion of an exon (exon 6) that encodes a highly conserved transcriptional control segment of the hematopoietic master regulator, Runx1. Embryos rendered homozygous for a Runx1 locus lacking this cassette exon (Runx1ΔE6) effectively phenocopy the loss of the definitive erythroid lineage in Pcbp2-/- embryos. These data support a model in which enhancement of Runx1 cassette exon 6 inclusion by Pcbp2 serves a critical role in development of hematopoietic progenitors and constitutes a critical step in the developmental pathway of the definitive erythropoietic lineage.
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Affiliation(s)
- Louis R Ghanem
- Gastroenterology, Hepatology and Nutrition Division, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrew Kromer
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ian M Silverman
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xinjun Ji
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Matthew Gazzara
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nhu Nguyen
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gabrielle Aguilar
- Gastroenterology, Hepatology and Nutrition Division, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Massimo Martinelli
- Gastroenterology, Hepatology and Nutrition Division, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Translational Medical Science, Section of Pediatrics, University of Naples Federico II, Naples, Italy
| | - Yoseph Barash
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stephen A Liebhaber
- Department of Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Ji X, Humenik J, Yang D, Liebhaber SA. PolyC-binding proteins enhance expression of the CDK2 cell cycle regulatory protein via alternative splicing. Nucleic Acids Res 2018; 46:2030-2044. [PMID: 29253178 PMCID: PMC5829739 DOI: 10.1093/nar/gkx1255] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 12/01/2017] [Accepted: 12/05/2017] [Indexed: 11/13/2022] Open
Abstract
The PolyC binding proteins (PCBPs) impact alternative splicing of a subset of mammalian genes that are enriched in basic cellular functions. Here, we focus our analysis on PCBP-controlled cassette exon-splicing within the cell cycle control regulator cyclin-dependent kinase-2 (CDK2) transcript. We demonstrate that PCBP binding to a C-rich polypyrimidine tract (PPT) preceding exon 5 of the CDK2 transcript enhances cassette exon inclusion. This splice enhancement is U2AF65-independent and predominantly reflects actions of the PCBP1 isoform. Remarkably, PCBPs' control of CDK2 ex5 splicing has evolved subsequent to mammalian divergence via conversion of constitutive exon 5 inclusion in the mouse CDK2 transcript to PCBP-responsive exon 5 alternative splicing in humans. Importantly, exclusion of exon 5 from the hCDK2 transcript dramatically represses the expression of CDK2 protein with a corresponding perturbation in cell cycle kinetics. These data highlight a recently evolved post-transcriptional pathway in primate species with the potential to modulate cell cycle control.
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Affiliation(s)
- Xinjun Ji
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jesse Humenik
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Daphne Yang
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stephen A Liebhaber
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Howley BV, Howe PH. TGF-beta signaling in cancer: post-transcriptional regulation of EMT via hnRNP E1. Cytokine 2018; 118:19-26. [PMID: 29396052 DOI: 10.1016/j.cyto.2017.12.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 12/29/2017] [Indexed: 12/12/2022]
Abstract
The TGFβ signaling pathway is a critical regulator of cancer progression in part through induction of the epithelial to mesenchymal transition (EMT). This process is aberrantly activated in cancer cells, facilitating invasion of the basement membrane, survival in the circulatory system, and dissemination to distant organs. The mechanisms through which epithelial cells transition to a mesenchymal state involve coordinated transcriptional and post-transcriptional control of gene expression. One such mechanism of control is through the RNA binding protein hnRNP E1, which regulates splicing and translation of a cohort of EMT and stemness-associated transcripts. A growing body of evidence indicates a major role for hnRNP E1 in the control of epithelial cell plasticity, especially in the context of carcinoma progression. Here, we review the multiple mechanisms through which hnRNP E1 functions to control EMT and metastatic progression.
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Affiliation(s)
- Breege V Howley
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
| | - Philip H Howe
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.
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24
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Huang H, Han Y, Yang X, Li M, Zhu R, Hu J, Zhang X, Wei R, Li K, Gao R. HNRNPK inhibits gastric cancer cell proliferation through p53/p21/CCND1 pathway. Oncotarget 2017; 8:103364-103374. [PMID: 29262567 PMCID: PMC5732733 DOI: 10.18632/oncotarget.21873] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 10/03/2017] [Indexed: 12/26/2022] Open
Abstract
Gastric cancer (GC) is one of the most common human cancers. The molecular mechanisms underlying GC carcinogenesis and progression are still not well understood. In this study, we showed that heterogeneous nuclear ribonucleoprotein K (HNRNPK) was an effective prognostic marker for GC patients especially in early stage. Overexpression of HNRNPK can retard tumor cell proliferation and colony formation in vitro and inhibit tumor growth in vivo through p53/p21/CCND1 axis. Bioinformatics analyses indicated that HNRNPK associated genes were enriched in cell cycle and DNA replication process. Protein-protein interaction network showed that HNRNPK was physically interacted with p53, p21 and other cancer related genes. Besides, GSEA showed that HNRNPK expression was positively correlated with GAMMA radiation response and DNA repair, while negatively correlated with angiogenesis, TGF-β and Hedgehog pathway activation. Finally, several chemicals including Glycine that may repress GC progression through upregulating HNRNPK are suggested. Our study demonstrated that HNRNPK may play as a tumor suppressor in gastric cancer and could be a potential therapeutic target for GC.
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Affiliation(s)
- Hao Huang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences, Beijing 100021, P. R. China
| | - Yong Han
- Department of Pathology, Zhejiang Provincial People's Hospital, Hangzhou 310014, Zhejiang, P. R. China.,People's Hospital of Hangzhou Medical College, Hangzhou 310014, Zhejiang, P. R. China.,Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Hangzhou 310014, Zhejiang, P. R. China
| | - Xingjiu Yang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences, Beijing 100021, P. R. China
| | - Mengyuan Li
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences, Beijing 100021, P. R. China
| | - Ruimin Zhu
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences, Beijing 100021, P. R. China
| | - Juanjuan Hu
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences, Beijing 100021, P. R. China
| | - Xiaowei Zhang
- Department of Gynaecology and Obstetrics, Civil Aviation General Hospital, Beijing 100123, P. R. China
| | - Rongfei Wei
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences, Beijing 100021, P. R. China
| | - Kejuan Li
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences, Beijing 100021, P. R. China
| | - Ran Gao
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences, Beijing 100021, P. R. China
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Chakraborty A, Mukherjee S, Saha S, De S, Sengupta Bandyopadhyay S. Phorbol-12-myristate-13-acetate-mediated stabilization of leukemia inhibitory factor ( lif) mRNA: involvement of Nucleolin and PCBP1. Biochem J 2017; 474:2349-2363. [PMID: 28512205 DOI: 10.1042/bcj20170051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/06/2017] [Accepted: 05/15/2017] [Indexed: 01/09/2023]
Abstract
Leukemia inhibitory factor (LIF) is a potent pleiotropic cytokine involved in diverse biological activities, thereby requiring precise spatial and temporal control of its expression. The present study reveals that enhanced expression of LIF in response to PMA (phorbol-12-myristate-13-acetate) in human histiocytic lymphoma cell line U937 largely happens through stabilization of its mRNA. Functional characterization of the long 3'-untranslated region of human lif mRNA revealed several conserved sequences with conventional cis-acting elements. A 216 nucleotide containing proximal cis-element with two AUUUA pentamers and four poly-rC sequences demonstrated significant mRNA destabilizing potential, which, on treatment with PMA, showed stabilizing activity. Affinity chromatography followed by western blot and RNA co-immunoprecipitation of PMA-treated U937 extract identified Nucleolin and PCBP1 as two protein trans-factors interacting with lif mRNA, specifically to the proximal non-conventional AU-rich region. PMA induced nucleo-cytoplasmic translocation of both Nucleolin and PCBP1. RNA-dependent in vivo co-association of both these proteins with lif mRNA was demonstrated by decreased co-precipitation in the presence of RNase. Ectopic overexpression of Nucleolin showed stabilization of both intrinsic lif mRNA and gfp reporter, whereas knockdown of Nucleolin and PCBP1 demonstrated a significant decrease in both lif mRNA and protein levels. Collectively, this report establishes the stabilization of lif mRNA by PMA, mediated by the interactions of two RNA-binding proteins, Nucleolin and PCBP1 with a proximal cis-element.
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Affiliation(s)
- Alina Chakraborty
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
| | - Srimoyee Mukherjee
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
| | - Sucharita Saha
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
| | - Soumasree De
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
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Protein 4.1R Exon 16 3' Splice Site Activation Requires Coordination among TIA1, Pcbp1, and RBM39 during Terminal Erythropoiesis. Mol Cell Biol 2017; 37:MCB.00446-16. [PMID: 28193846 DOI: 10.1128/mcb.00446-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 02/03/2017] [Indexed: 12/18/2022] Open
Abstract
Exon 16 of protein 4.1R encodes a spectrin/actin-binding peptide critical for erythrocyte membrane stability. Its expression during erythroid differentiation is regulated by alternative pre-mRNA splicing. A UUUUCCCCCC motif situated between the branch point and the 3' splice site is crucial for inclusion. We show that the UUUU region and the last three C residues in this motif are necessary for the binding of splicing factors TIA1 and Pcbp1 and that these proteins appear to act in a collaborative manner to enhance exon 16 inclusion. This element also activates an internal exon when placed in a corresponding intronic position in a heterologous reporter. The impact of these two factors is further enhanced by high levels of RBM39, whose expression rises during erythroid differentiation as exon 16 inclusion increases. TIA1 and Pcbp1 associate in a complex containing RBM39, which interacts with U2AF65 and SF3b155 and promotes U2 snRNP recruitment to the branch point. Our results provide a mechanism for exon 16 3' splice site activation in which a coordinated effort among TIA1, Pcbp1, and RBM39 stabilizes or increases U2 snRNP recruitment, enhances spliceosome A complex formation, and facilitates exon definition through RBM39-mediated splicing regulation.
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27
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Li F, Zhang Y, Chen S, Wang M, Jia R, Zhu D, Liu M, Sun K, Yang Q, Wu Y, Chen X, Cheng A. Identification of the Nuclear Localization Signal Region of Duck Enteritis Virus UL14 and Its Interaction with VP16. Intervirology 2017; 59:187-196. [PMID: 28178699 DOI: 10.1159/000452711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 10/19/2016] [Indexed: 12/19/2022] Open
Abstract
OBJECT Duck enteritis virus (DEV) is a member of the Alphaherpesvirinae viruses. VP16 and pUL14 are both predicted to be tegument proteins of DEV. METHODS An indirect immunofluorescence assay (IFA) was performed for preliminary analysis of the colocalization of pUL14 and VP16, which detected their subcellular localization in duck embryo fibroblasts (DEFs) during virus replication. The coexpression of pUL14 and VP16 was detected in transfected DEFs. A bimolecular fluorescence complementation (BiFC) assay was used to confirm a direct interaction between pUL14 and VP16. To better characterize the nuclear localization domain of pUL14, we designed a series of deletion mutants and transfected them with VP16. RESULTS Our IFA findings indicated that pUL14 binds to VP16 in the cytoplasm and that pUL14 leads VP16 import into the nucleus during DEV replication. The BiFC assay revealed the presence of pUL14 and VP16 complexes. Furthermore, 1-98 amino acid (aa) at the N-terminus of pUL14 played a role in the nuclear localization signal (NLS) region and promoted translocation of VP16 into the nucleus to complete the virus life cycle. CONCLUSIONS Our findings indicated that pUL14 could transport VP16 into the nucleus and that the N-terminal 1-98 aa may contain the NLS domain of pUL14.
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Affiliation(s)
- FangJie Li
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, PR China
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28
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Jang S, Shin H, Lee J, Kim Y, Bak G, Lee Y. Regulation of BC200 RNA-mediated translation inhibition by hnRNP E1 and E2. FEBS Lett 2017; 591:393-405. [PMID: 28027391 DOI: 10.1002/1873-3468.12544] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 12/21/2016] [Accepted: 12/21/2016] [Indexed: 12/28/2022]
Abstract
The long noncoding RNA BC200 (brain cytoplasmic RNA, 200 nucleotides) acts as a translational modulator of local protein synthesis at dendrites. BC200 RNA has been shown to inhibit translation in vitro, but it remains unknown how this translation inhibition might be controlled in a cell. Here, we performed yeast three-hybrid screening and identified hnRNP E1 and hnRNP E2 as BC200 RNA-interacting proteins. We found that: these hnRNA proteins could restore BC200 RNA-inhibited translation; BC200 RNA interacts with hnRNP E1 and E2 mainly through its unique 3' C-rich domain; and the RNA binding specificities and modes of the two proteins differed somewhat. Our results offer new insights into the regulation of BC200 RNA-mediated translation inhibition.
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Affiliation(s)
| | | | - Jungmin Lee
- Department of Chemistry, KAIST, Daejeon, Korea
| | - Youngmi Kim
- Department of Chemistry, KAIST, Daejeon, Korea
| | - Geunu Bak
- Department of Chemistry, KAIST, Daejeon, Korea
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29
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Extent of pre-translational regulation for the control of nucleocytoplasmic protein localization. BMC Genomics 2016; 17:472. [PMID: 27342569 PMCID: PMC4919871 DOI: 10.1186/s12864-016-2854-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 06/22/2016] [Indexed: 11/18/2022] Open
Abstract
Background Appropriate protein subcellular localization is essential for proper cellular function. Central to the regulation of protein localization are protein targeting motifs, stretches of amino acids serving as guides for protein entry in a specific cellular compartment. While the use of protein targeting motifs is modulated in a post-translational manner, mainly by protein conformational changes and post-translational modifications, the presence of these motifs in proteins can also be regulated in a pre-translational manner. Here, we investigate the extent of pre-translational regulation of the main signals controlling nucleo-cytoplasmic traffic: the nuclear localization signal (NLS) and the nuclear export signal (NES). Results Motif databases and manual curation of the literature allowed the identification of 175 experimentally validated NLSs and 120 experimentally validated NESs in human. Following mapping onto annotated transcripts, these motifs were found to be modular, most (73 % for NLS and 88 % for NES) being encoded entirely in only one exon. The presence of a majority of these motifs is regulated in an alternative manner at the transcript level (61 % for NLS and 72 % for NES) while the remaining motifs are present in all coding isoforms of their encoding gene. NLSs and NESs are pre-translationally regulated using four main mechanisms: alternative transcription/translation initiation, alternative translation termination, alternative splicing of the exon encoding the motif and frameshift, the first two being by far the most prevalent mechanisms. Quantitative analysis of the presence of these motifs using RNA-seq data indicates that inclusion of these motifs can be regulated in a tissue-specific and a combinatorial manner, can be altered in disease states in a directed way and that alternative inclusion of these motifs is often used by proteins with diverse interactors and roles in diverse pathways, such as kinases. Conclusions The pre-translational regulation of the inclusion of protein targeting motifs is a prominent and tightly-regulated mechanism that adds another layer in the control of protein subcellular localization. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2854-4) contains supplementary material, which is available to authorized users.
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Yanatori I, Richardson DR, Imada K, Kishi F. Iron Export through the Transporter Ferroportin 1 Is Modulated by the Iron Chaperone PCBP2. J Biol Chem 2016; 291:17303-18. [PMID: 27302059 DOI: 10.1074/jbc.m116.721936] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Indexed: 12/15/2022] Open
Abstract
Ferroportin 1 (FPN1) is an iron export protein found in mammals. FPN1 is important for the export of iron across the basolateral membrane of absorptive enterocytes and across the plasma membrane of macrophages. The expression of FPN1 is regulated by hepcidin, which binds to FPN1 and then induces its degradation. Previously, we demonstrated that divalent metal transporter 1 (DMT1) interacts with the intracellular iron chaperone protein poly(rC)-binding protein 2 (PCBP2). Subsequently, PCBP2 receives iron from DMT1 and then disengages from the transporter. In this study, we investigated the function of PCBP2 in iron export. Mammalian genomes encode four PCBPs (i.e. PCBP1-4). Here, for the first time, we demonstrated using both yeast and mammalian cells that PCBP2, but not PCBP1, PCBP3, or PCBP4, binds with FPN1. Importantly, iron-loaded, but not iron-depleted, PCBP2 interacts with FPN1. The PCBP2-binding domain of FPN1 was identified in its C-terminal cytoplasmic region. The silencing of PCBP2 expression suppressed FPN1-dependent iron export from cells. These results suggest that FPN1 exports iron received from the iron chaperone PCBP2. Therefore, it was found that PCBP2 modulates cellular iron export, which is an important physiological process.
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Affiliation(s)
- Izumi Yanatori
- From the Department of Molecular Genetics, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan and
| | - Des R Richardson
- the Molecular Pharmacology and Pathology Program, Department of Pathology, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Kiyoshi Imada
- From the Department of Molecular Genetics, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan and
| | - Fumio Kishi
- From the Department of Molecular Genetics, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan and
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Geuens T, Bouhy D, Timmerman V. The hnRNP family: insights into their role in health and disease. Hum Genet 2016; 135:851-67. [PMID: 27215579 PMCID: PMC4947485 DOI: 10.1007/s00439-016-1683-5] [Citation(s) in RCA: 641] [Impact Index Per Article: 80.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/09/2016] [Indexed: 12/14/2022]
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) represent a large family of RNA-binding proteins (RBPs) that contribute to multiple aspects of nucleic acid metabolism including alternative splicing, mRNA stabilization, and transcriptional and translational regulation. Many hnRNPs share general features, but differ in domain composition and functional properties. This review will discuss the current knowledge about the different hnRNP family members, focusing on their structural and functional divergence. Additionally, we will highlight their involvement in neurodegenerative diseases and cancer, and the potential to develop RNA-based therapies.
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Affiliation(s)
- Thomas Geuens
- Peripheral Neuropathy Group, VIB Molecular Genetics Department, University of Antwerp-CDE, Parking P4, Building V, Room 1.30, Universiteitsplein 1, 2610, Antwerp, Belgium
- Neurogenetics Laboratory, Institute Born Bunge, University of Antwerp, Antwerp, Belgium
| | - Delphine Bouhy
- Peripheral Neuropathy Group, VIB Molecular Genetics Department, University of Antwerp-CDE, Parking P4, Building V, Room 1.30, Universiteitsplein 1, 2610, Antwerp, Belgium
- Neurogenetics Laboratory, Institute Born Bunge, University of Antwerp, Antwerp, Belgium
| | - Vincent Timmerman
- Peripheral Neuropathy Group, VIB Molecular Genetics Department, University of Antwerp-CDE, Parking P4, Building V, Room 1.30, Universiteitsplein 1, 2610, Antwerp, Belgium.
- Neurogenetics Laboratory, Institute Born Bunge, University of Antwerp, Antwerp, Belgium.
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Ji X, Park JW, Bahrami-Samani E, Lin L, Duncan-Lewis C, Pherribo G, Xing Y, Liebhaber SA. αCP binding to a cytosine-rich subset of polypyrimidine tracts drives a novel pathway of cassette exon splicing in the mammalian transcriptome. Nucleic Acids Res 2016; 44:2283-97. [PMID: 26896798 PMCID: PMC4797308 DOI: 10.1093/nar/gkw088] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 02/03/2016] [Indexed: 12/17/2022] Open
Abstract
Alternative splicing (AS) is a robust generator of mammalian transcriptome complexity. Splice site specification is controlled by interactions of cis-acting determinants on a transcript with specific RNA binding proteins. These interactions are frequently localized to the intronic U-rich polypyrimidine tracts (PPT) located 5′ to the majority of splice acceptor junctions. αCPs (also referred to as polyC-binding proteins (PCBPs) and hnRNPEs) comprise a subset of KH-domain proteins with high affinity and specificity for C-rich polypyrimidine motifs. Here, we demonstrate that αCPs promote the splicing of a defined subset of cassette exons via binding to a C-rich subset of polypyrimidine tracts located 5′ to the αCP-enhanced exonic segments. This enhancement of splice acceptor activity is linked to interactions of αCPs with the U2 snRNP complex and may be mediated by cooperative interactions with the canonical polypyrimidine tract binding protein, U2AF65. Analysis of αCP-targeted exons predicts a substantial impact on fundamental cell functions. These findings lead us to conclude that the αCPs play a direct and global role in modulating the splicing activity and inclusion of an array of cassette exons, thus driving a novel pathway of splice site regulation within the mammalian transcriptome.
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Affiliation(s)
- Xinjun Ji
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Juw Won Park
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, USA KBRIN Bioinformatics Core, University of Louisville, Louisville, KY 40202, USA
| | - Emad Bahrami-Samani
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lan Lin
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Christopher Duncan-Lewis
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Gordon Pherribo
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yi Xing
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Stephen A Liebhaber
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Breitkopf SB, Yuan M, Helenius KP, Lyssiotis CA, Asara JM. Triomics Analysis of Imatinib-Treated Myeloma Cells Connects Kinase Inhibition to RNA Processing and Decreased Lipid Biosynthesis. Anal Chem 2015; 87:10995-1006. [PMID: 26434776 PMCID: PMC5585869 DOI: 10.1021/acs.analchem.5b03040] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The combination of metabolomics, lipidomics, and phosphoproteomics that incorporates triple stable isotope labeling by amino acids in cell culture (SILAC) protein labeling, as well as (13)C in vivo metabolite labeling, was demonstrated on BCR-ABL-positive H929 multiple myeloma cells. From 11 880 phosphorylation sites, we confirm that H929 cells are primarily signaling through the BCR-ABL-ERK pathway, and we show that imatinib treatment not only downregulates phosphosites in this pathway but also upregulates phosphosites on proteins involved in RNA expression. Metabolomics analyses reveal that BCR-ABL-ERK signaling in H929 cells drives the pentose phosphate pathway (PPP) and RNA biosynthesis, where pathway inhibition via imatinib results in marked PPP impairment and an accumulation of RNA nucleotides and negative regulation of mRNA. Lipidomics data also show an overall reduction in lipid biosynthesis and fatty acid incorporation with a significant decrease in lysophospholipids. RNA immunoprecipitation studies confirm that RNA degradation is inhibited with short imatinib treatment and transcription is inhibited upon long imatinib treatment, validating the triomics results. These data show the utility of combining mass spectrometry-based "-omics" technologies and reveals that kinase inhibitors may not only downregulate phosphorylation of their targets but also induce metabolic events via increased phosphorylation of other cellular components.
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Affiliation(s)
- Susanne B. Breitkopf
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, United States
- Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Min Yuan
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, United States
| | - Katja P. Helenius
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Costas A. Lyssiotis
- Department of Molecular and Integrative Physiology and Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John M. Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, United States
- Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, United States
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Wagener R, Aukema SM, Schlesner M, Haake A, Burkhardt B, Claviez A, Drexler HG, Hummel M, Kreuz M, Loeffler M, Rosolowski M, López C, Möller P, Richter J, Rohde M, Betts MJ, Russell RB, Bernhart SH, Hoffmann S, Rosenstiel P, Schilhabel M, Szczepanowski M, Trümper L, Klapper W, Siebert R. ThePCBP1gene encoding poly(rc) binding protein i is recurrently mutated in Burkitt lymphoma. Genes Chromosomes Cancer 2015; 54:555-64. [DOI: 10.1002/gcc.22268] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 05/11/2015] [Indexed: 12/19/2022] Open
Affiliation(s)
- Rabea Wagener
- Institute of Human Genetics, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein; Campus Kiel Kiel Germany
| | - Sietse M. Aukema
- Institute of Human Genetics, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein; Campus Kiel Kiel Germany
| | - Matthias Schlesner
- Deutsches Krebsforschungszentrum Heidelberg (DKFZ), Division Theoretical Bioinformatics; Heidelberg Germany
| | - Andrea Haake
- Institute of Human Genetics, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein; Campus Kiel Kiel Germany
| | - Birgit Burkhardt
- Non-Hodgkin Lymphoma Berlin-Frankfurt-Münster Group Study Center, Department of Pediatric Hematology and Oncology, University Children's Hospital; Münster Germany
| | - Alexander Claviez
- Department of Pediatrics; University Hospital Schleswig-Holstein Campus Kiel/Christian-Albrechts University; Kiel Germany
| | - Hans G. Drexler
- Leibniz-Institute DSMZ- German Collection of Microorganisms and Cell Cultures GmbH; Braunschweig Germany
| | - Michael Hummel
- Institute of Pathology, Campus Benjamin Franklin, Charité-Universitätsmedizin; Berlin Germany
| | - Markus Kreuz
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig; Germany
| | - Markus Loeffler
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig; Germany
| | - Maciej Rosolowski
- Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig; Germany
| | - Cristina López
- Institute of Human Genetics, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein; Campus Kiel Kiel Germany
| | - Peter Möller
- Institute of Pathology, Universitätsklinikum Ulm; Ulm Germany
| | - Julia Richter
- Institute of Human Genetics, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein; Campus Kiel Kiel Germany
| | - Marius Rohde
- Department of Pediatric Hematology and Oncology; Justus Liebig University; Giessen Germany
| | - Matthew J. Betts
- Cell Networks, Bioquant, University of Heidelberg; Heidelberg Germany
| | - Robert B. Russell
- Cell Networks, Bioquant, University of Heidelberg; Heidelberg Germany
| | - Stephan H. Bernhart
- Transcriptome Bioinformatics, LIFE Research Center for Civilization Diseases, University of Leipzig; Leipzig Germany
| | - Steve Hoffmann
- Transcriptome Bioinformatics, LIFE Research Center for Civilization Diseases, University of Leipzig; Leipzig Germany
| | - Philip Rosenstiel
- Institute of Clinical Molecular Biology, University Hospital Schleswig-Holstein Campus Kiel/Christian-Albrechts University Kiel; Kiel Germany
| | - Markus Schilhabel
- Institute of Clinical Molecular Biology, University Hospital Schleswig-Holstein Campus Kiel/Christian-Albrechts University Kiel; Kiel Germany
| | - Monika Szczepanowski
- Institute of Hematopathology, University Hospital Schleswig-Holstein Campus Kiel/Christian-Albrechts University Kiel; Germany
| | - Lorenz Trümper
- Department of Hematology and Oncology; Georg-August University of Göttingen; Germany
| | - Wolfram Klapper
- Institute of Hematopathology, University Hospital Schleswig-Holstein Campus Kiel/Christian-Albrechts University Kiel; Germany
| | - Reiner Siebert
- Institute of Human Genetics, Christian-Albrechts-University Kiel and University Hospital Schleswig-Holstein; Campus Kiel Kiel Germany
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Barboro P, Ferrari N, Balbi C. Emerging roles of heterogeneous nuclear ribonucleoprotein K (hnRNP K) in cancer progression. Cancer Lett 2014; 352:152-9. [DOI: 10.1016/j.canlet.2014.06.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/26/2014] [Accepted: 06/29/2014] [Indexed: 12/18/2022]
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Abstract
DMT1 (divalent metal transporter 1) is the main iron importer found in animals, and ferrous iron is taken up by cells via DMT1. Once ferrous iron reaches the cytosol, it is subjected to subcellular distribution and delivered to various sites where iron is required for a variety of biochemical reactions in the cell. Until now, the mechanism connecting the transporter and cytosolic distribution had not been clarified. In the present study, we have identified PCBP2 [poly(rC)-binding protein 2] as a DMT1-binding protein. The N-terminal cytoplasmic region of DMT1 is the binding domain for PCBP2. An interaction between DMT1 and PCBP1, which is known to be a paralogue of PCBP2, could not be demonstrated in vivo or in vitro. Iron uptake and subsequent ferritin expression were suppressed by either DMT1 or PCBP2 knockdown. Iron-associated DMT1 could interact with PCBP2 in vitro, whereas iron-chelated DMT1 could not. These results indicate that ferrous iron imported by DMT1 is transferred directly to PCBP2. Moreover, we demonstrated that PCBP2 could bind to ferroportin, which exports ferrous iron out of the cell. These findings suggest that PCBP2 can transfer ferrous iron from DMT1 to the appropriate intracellular sites or ferroportin and could function as an iron chaperone.
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Huo LR, Liang JT, Zou JH, Wang LY, Li Q, Wang XM. Possible novel roles of poly(rC)-binding protein 1 in SH-SY5Y neurocytes: an analysis using a dynamic Bayesian network. Neurosci Bull 2014; 28:282-90. [PMID: 22622828 DOI: 10.1007/s12264-012-1242-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE Poly(rC)-binding protein 1 (PCBP1) belongs to the heterogeneous nuclear ribonucleoprotein family and participates in transcriptional and translational regulation. Previous work has identified transcripts targeted by both knockdown and overexpression of PCBP1 in SH-SY5Y neuroblastoma cells using a microarray or ProteomeLab protein fractionation 2-dimensions (PF-2D) and quadrupole time-of-flight mass spectrometer. The present study aimed to further determine whether these altered transcripts from major pathways (such as Wnt signaling, TGF-β signaling, cell cycling, and apoptosis) and two other genes, H2AFX and H2BFS (screened by PF-2D), have spatial relationships. METHODS The genes were studied by qRT-PCR, and dynamic Bayesian network analysis was used to rebuild the coordination network of these transcripts. RESULTS PCBP1 controlled the expression or activity of the seven transcripts. Moreover, PCBP1 indirectly regulated MAP2K2, FOS, FST, TP53 and WNT7B through H2AFX or regulated these genes through SAT. In contrast, TP53 and WNT7B are regulated by other genes. CONCLUSION The seven transcripts and PCBP1 are closely associated in a spatial interaction network.
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Affiliation(s)
- Li-Rong Huo
- Department of Physiology, Key Laboratory for Neurodegenerative Disorders of Ministry of Education, Capital Medical University, Beijing 100069, China
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38
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Zheng D, Tian B. RNA-binding proteins in regulation of alternative cleavage and polyadenylation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 825:97-127. [PMID: 25201104 DOI: 10.1007/978-1-4939-1221-6_3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Almost all eukaryotic pre-mRNAs are processed at the 3' end by the cleavage and polyadenylation (C/P) reaction, which preludes termination of transcription and gives rise to the poly(A) tail of mature mRNA. Genomic studies in recent years have indicated that most eukaryotic mRNA genes have multiple cleavage and polyadenylation sites (pAs), leading to alternative cleavage and polyadenylation (APA) products. APA isoforms generally differ in their 3' untranslated regions (3' UTRs), but can also have different coding sequences (CDSs). APA expands the repertoire of transcripts expressed from the genome, and is highly regulated under various physiological and pathological conditions. Growing lines of evidence have shown that RNA-binding proteins (RBPs) play important roles in regulation of APA. Some RBPs are part of the machinery for C/P; others influence pA choice through binding to adjacent regions. In this chapter, we review cis elements and trans factors involved in C/P, the significance of APA, and increasingly elucidated roles of RBPs in APA regulation. We also discuss analysis of APA using transcriptome-wide techniques as well as molecular biology approaches.
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Affiliation(s)
- Dinghai Zheng
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey (UMDNJ)-New Jersey Medical School, 185 South Orange Ave., Newark, NJ, 07103, USA
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Ho JJD, Marsden PA. Competition and collaboration between RNA-binding proteins and microRNAs. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 5:69-86. [PMID: 24124109 DOI: 10.1002/wrna.1197] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 08/21/2013] [Accepted: 08/27/2013] [Indexed: 01/08/2023]
Abstract
Posttranscriptional regulation of mRNA species represents a major regulatory checkpoint in the control of gene expression. Historically, RNA-binding proteins (RBPs) have been regarded as the primary regulators of mRNA stability and translation. More recently, however, microRNAs have emerged as a class of potent and pervasive posttranscriptional rheostats that similarly affect mRNA stability and translation. The observation that both microRNAs and RBPs regulate mRNA stability and translation has initiated a newer area of research that involves the examination of dynamic interactions between these two important classes of posttranscriptional regulators, the myriad of factors that influence these biological interactions, and ultimately, their effects on target mRNAs. Specifically, microRNAs and RBPs can act synergistically to effect mRNA destabilization and translational inhibition. They can also engage in competition with each other and exert opposing effects on target mRNAs. To date, several key studies have provided critical details regarding the mechanisms and principles of interaction between these molecules. Additionally, these findings raise important questions regarding the regulation of these interactions, including the roles of posttranslational modification, subcellular localization, target inhibition versus activation, and changes in expression levels of these regulatory factors, especially under stimulus- and cell-specific conditions. Indeed, further experimentation is warranted to address these key issues that pertain to the collaboration and competition between microRNAs and RBPs. Significantly, the elucidation of these important details bears critical implications for disease management, especially for those diseases in which these cellular factors are dysregulated.
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Affiliation(s)
- J J David Ho
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; Department of Medicine, Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
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Kang DH, Song KY, Wei LN, Law PY, Loh HH, Choi HS. Novel function of the poly(c)-binding protein α-CP2 as a transcriptional activator that binds to single-stranded DNA sequences. Int J Mol Med 2013; 32:1187-94. [PMID: 24026233 PMCID: PMC4432725 DOI: 10.3892/ijmm.2013.1488] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 08/29/2013] [Indexed: 11/10/2022] Open
Abstract
α-complex protein 2 (α-CP2) is known as an RNA-binding protein that interacts in a sequence-specific manner with single-stranded polycytosine [poly(C)]. This protein is involved in various post-transcriptional regulations, such as mRNA stabilization and translational regulation. In this study, the full-length mouse α-CP2 gene was expressed in an insoluble form with an N-terminal histidine tag in Escherichia coli and purified for homogeneity using affinity column chromatography. Its identity was confirmed using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Recombinant α-CP2 was expressed and refolded. The protein folding conditions for denatured α-CP2 were optimized. DNA and RNA electrophoretic mobility shift assays demonstrated that the recombinant α-CP2 is capable of binding to both single-stranded DNA and RNA poly(C) sequences. Furthermore, plasmids expressing α-CP2 activated the expression of a luciferase reporter when co-transfected with a single-stranded (pGL-SS) construct containing a poly(C) sequence. To our knowledge, this study demonstrates for the first time that α-CP2 functions as a transcriptional activator by binding to a single-stranded poly(C) sequence.
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Affiliation(s)
- Duk-Hee Kang
- Division of Nephrology, Department of Internal Medicine, Ewha Medical Research Institute, Ewha Womans University School of Medicine, Yangcheon‑gu, Seoul 158-710, Republic of Korea
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41
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Active stabilization of human endothelial nitric oxide synthase mRNA by hnRNP E1 protects against antisense RNA and microRNAs. Mol Cell Biol 2013; 33:2029-46. [PMID: 23478261 DOI: 10.1128/mcb.01257-12] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Human endothelial nitric oxide synthase (eNOS) mRNA is highly stable in endothelial cells (ECs). Posttranscriptional regulation of eNOS mRNA stability is an important component of eNOS regulation, especially under hypoxic conditions. Here, we show that the human eNOS 3' untranslated region (3' UTR) contains multiple, evolutionarily conserved pyrimidine (C and CU)-rich sequence elements that are both necessary and sufficient for mRNA stabilization. Importantly, RNA immunoprecipitations and RNA electrophoretic mobility shift assays (EMSAs) revealed the formation of heterogeneous nuclear ribonucleoprotein E1 (hnRNP E1)-containing RNP complexes at these 3'-UTR elements. Knockdown of hnRNP E1 decreased eNOS mRNA half-life, mRNA levels, and protein expression. Significantly, these stabilizing RNP complexes protect eNOS mRNA from the inhibitory effects of its antisense transcript sONE and 3'-UTR-targeting small interfering RNAs (siRNAs), as well as microRNAs, specifically, hsa-miR-765, which targets eNOS mRNA stability determinants. Hypoxia disrupts hnRNP E1/eNOS 3'-UTR interactions via increased Akt-mediated serine phosphorylation (including serine 43) and increased nuclear localization of hnRNP E1. These mechanisms account, at least in part, for the decrease in eNOS mRNA stability under hypoxic conditions. Thus, the stabilization of human eNOS mRNA by hnRNP E1-containing RNP complexes serves as a key protective mechanism against the posttranscriptional inhibitory effects of antisense RNA and microRNAs under basal conditions but is disrupted under hypoxic conditions.
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42
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Kang DH, Song KY, Choi HS, Law PY, Wei LN, Loh HH. Novel dual-binding function of a poly (C)-binding protein 3, transcriptional factor which binds the double-strand and single-stranded DNA sequence. Gene 2012; 501:33-8. [PMID: 22521865 DOI: 10.1016/j.gene.2012.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 03/30/2012] [Accepted: 04/02/2012] [Indexed: 10/28/2022]
Abstract
Poly(C)-binding proteins (PCBPs) are generally known as RNA-binding proteins that interact in a sequence-specific manner with single-stranded poly(C) sequences. These proteins are mainly involved in various posttranscriptional regulations (e.g., mRNA stabilization or translational activation/silencing). This study reports a novel dual-binding function for PCBP3, a member of the PCBP family. Recombinant PCBP3 was purified using affinity column chromatography and its identity confirmed by MALDI-TOF mass spectrometry. The protein folding conditions of the purified and renatured PCBP3 were optimized. Electrophoretic mobility shift assays demonstrated that the recombinant PCBP3 is capable of binding to both double- and single-strand poly(C) sequences. Furthermore, plasmids expressing PCBP3 repressed the expression of luciferase reporters when cotransfected with single-strand (pGL-SS) and double-strand (pGL-DS) constructs containing poly(C) sequences in their promoters. This study demonstrates for the first time that PCBP3 can function as a repressor dependent on binding to single-strand and double-stranded poly(C) sequences.
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Affiliation(s)
- Duk-Hee Kang
- Division of Nephrology Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul 158-710, South Korea
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43
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Yoga YMK, Traore DAK, Sidiqi M, Szeto C, Pendini NR, Barker A, Leedman PJ, Wilce JA, Wilce MCJ. Contribution of the first K-homology domain of poly(C)-binding protein 1 to its affinity and specificity for C-rich oligonucleotides. Nucleic Acids Res 2012; 40:5101-14. [PMID: 22344691 PMCID: PMC3367169 DOI: 10.1093/nar/gks058] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Poly-C-binding proteins are triple KH (hnRNP K homology) domain proteins with specificity for single stranded C-rich RNA and DNA. They play diverse roles in the regulation of protein expression at both transcriptional and translational levels. Here, we analyse the contributions of individual αCP1 KH domains to binding C-rich oligonucleotides using biophysical and structural methods. Using surface plasmon resonance (SPR), we demonstrate that KH1 makes the most stable interactions with both RNA and DNA, KH3 binds with intermediate affinity and KH2 only interacts detectibly with DNA. The crystal structure of KH1 bound to a 5′-CCCTCCCT-3′ DNA sequence shows a 2:1 protein:DNA stoichiometry and demonstrates a molecular arrangement of KH domains bound to immediately adjacent oligonucleotide target sites. SPR experiments, with a series of poly-C-sequences reveals that cytosine is preferred at all four positions in the oligonucleotide binding cleft and that a C-tetrad binds KH1 with 10 times higher affinity than a C-triplet. The basis for this high affinity interaction is finally detailed with the structure determination of a KH1.W.C54S mutant bound to 5′-ACCCCA-3′ DNA sequence. Together, these data establish the lead role of KH1 in oligonucleotide binding by αCP1 and reveal the molecular basis of its specificity for a C-rich tetrad.
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Affiliation(s)
- Yano M K Yoga
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC Australia
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44
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Abstract
The normal accumulation of β-globin protein in terminally differentiating erythroid cells is critically dependent on the high stability of its encoding mRNA. The molecular basis for this property, though, is incompletely understood. Factors that regulate β-globin mRNA within the nucleus of early erythroid progenitors are unlikely to account for the constitutively high half-life of β-globin mRNA in the cytoplasm of their anucleate erythroid progeny. We conducted in vitro protein-RNA binding analyses that identified a cytoplasm-restricted β-globin messenger ribonucleoprotein (mRNP) complex in both cultured K562 cells and erythroid-differentiated human CD34(+) cells. This novel mRNP targets a specific guanine-rich pentanucleotide in a region of the β-globin 3'untranslated region that has recently been implicated as a determinant of β-globin mRNA stability. Subsequent affinity-enrichment analyses identified AUF-1 and YB-1, 2 cytoplasmic proteins with well-established roles in RNA biology, as trans-acting components of the mRNP. Factor-depletion studies conducted in vivo demonstrated the importance of the mRNP to normal steady-state levels of β-globin mRNA in erythroid precursors. These data define a previously unrecognized mechanism for the posttranscriptional regulation of β-globin mRNA during normal erythropoiesis, providing new therapeutic targets for disorders of β-globin gene expression.
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45
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Yoga YMK, Traore DAK, Wilce JA, Wilce MCJ. Mutation and crystallization of the first KH domain of human polycytosine-binding protein 1 (PCBP1) in complex with DNA. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:1257-61. [PMID: 22102042 PMCID: PMC3212377 DOI: 10.1107/s1744309111028004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 07/12/2011] [Indexed: 11/11/2022]
Abstract
Polycytosine-binding proteins (PCBPs) are triple KH-domain proteins that play an important role in the regulation of translation of eukaryotic mRNA. They are also utilized by viral RNA and have been shown to interact with ssDNA. Underlying their function is the specific recognition of C-rich nucleotides by their KH domains. However, the structural basis of this recognition is only partially understood. Here, the preparation of a His-tagged KH domain is described, representing the first domain of PCBP1 that incorporates a C54S mutation as well as the addition of a C-terminal tryptophan. This construct has facilitated the preparation of highly diffracting crystals in complex with C-rich DNA (sequence ACCCCA). Crystals of the KH1-DNA complex were grown using the hanging-drop vapour-diffusion method in 0.1 M phosphate-citrate pH 4.2, 40%(v/v) PEG 300. X-ray diffraction data were collected to 1.77 Å resolution and the diffraction was consistent with space group P2(1), with unit-cell parameters a = 38.59, b = 111.88, c = 43.42 Å, α = γ = 90.0, β = 93.37°. The structure of the KH1-DNA complex will further our insight into the basis of cytosine specificity by PCBPs.
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Affiliation(s)
- Yano M. K. Yoga
- Department of Biochemistry and Molecular Biology, Monash University, VIC 3800, Australia
| | - Daouda A. K. Traore
- Department of Biochemistry and Molecular Biology, Monash University, VIC 3800, Australia
| | - Jacqueline A. Wilce
- Department of Biochemistry and Molecular Biology, Monash University, VIC 3800, Australia
| | - Matthew C. J. Wilce
- Department of Biochemistry and Molecular Biology, Monash University, VIC 3800, Australia
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Chaudhury A, Hussey GS, Howe PH. 3'-UTR-mediated post-transcriptional regulation of cancer metastasis: beginning at the end. RNA Biol 2011; 8:595-9. [PMID: 21654215 PMCID: PMC3360070 DOI: 10.4161/rna.8.4.16018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 04/19/2011] [Accepted: 04/28/2011] [Indexed: 02/03/2023] Open
Abstract
Epithelial-mesenchymal transition (EMT) and the underlying mechanisms and signaling pathways regulating such transitions have generated a lot of interest among cancer researchers. Much of this can be attributed to the apparent similarities in the molecular processes regulating embryonic EMT that can be recapitulated during tumor progression and metastasis. It appears that both embryonic and oncogenic EMT are regulated by an intricate interplay of transcriptional and post-transcriptional programs, and the recent discovery of a transcript-selective translational regulatory pathway controlling expression of EMT-associated mRNAs demonstrates the high fidelity and tight regulation associated with the process of EMT and metastatic progression. Heterogeneous nuclear ribonucleoprotein E1 (hnRNP E1) is emerging as a critical and integral modulator of TGFβ-induced EMT and subsequent tumor metastasis. Through its RNA-binding ability, hnRNP E1 binds distinct 3'-UTR structural elements present in mRNA transcripts required for EMT and translationally silences their expression. Translational silencing, mediated by hnRNP E1, occurs specifically at the translation elongation step through effects on the eukaryotic elongation factor-1 A1 (eEF1A1), and is relieved by Akt2-mediated phosphorylation. Interestingly, modulation of either the steady-state expression or the posttranscriptional modification of hnRNP E1 has a temporo-spatial effect on translational repression, tumorigenesis and cancer metastasis.
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Affiliation(s)
- Arindam Chaudhury
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
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47
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Ji X, Kong J, Liebhaber SA. An RNA-protein complex links enhanced nuclear 3' processing with cytoplasmic mRNA stabilization. EMBO J 2011; 30:2622-33. [PMID: 21623344 DOI: 10.1038/emboj.2011.171] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 04/19/2011] [Indexed: 01/09/2023] Open
Abstract
Post-transcriptional controls are critical to gene regulation. These controls are frequently based on sequence-specific binding of trans-acting proteins to cis-acting motifs on target RNAs. Prior studies have revealed that the KH-domain protein, αCP, binds to a 3' UTR C-rich motif of hα-globin mRNA and contributes to its cytoplasmic stability. Here, we report that this 3' UTR αCP complex regulates the production of mature α-globin mRNA by enhancing 3' processing of the hα-globin transcript. We go on to demonstrate that this nuclear activity reflects enhancement of both the cleavage and the polyadenylation reactions and that αCP interacts in vivo with core components of the 3' processing complex. Consistent with its nuclear processing activity, our studies reveal that αCP assembles co-transcriptionally at the hα-globin chromatin locus and that this loading is selectively enriched at the 3' terminus of the gene. The demonstrated linkage of nuclear processing with cytoplasmic stabilization via a common RNA-protein complex establishes a basis for integration of sequential controls critical to robust and sustained expression of a target mRNA.
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Affiliation(s)
- Xinjun Ji
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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48
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Chaudhury A, Chander P, Howe PH. Heterogeneous nuclear ribonucleoproteins (hnRNPs) in cellular processes: Focus on hnRNP E1's multifunctional regulatory roles. RNA (NEW YORK, N.Y.) 2010; 16:1449-62. [PMID: 20584894 PMCID: PMC2905745 DOI: 10.1261/rna.2254110] [Citation(s) in RCA: 208] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) comprise a family of RNA-binding proteins. The complexity and diversity associated with the hnRNPs render them multifunctional, involved not only in processing heterogeneous nuclear RNAs (hnRNAs) into mature mRNAs, but also acting as trans-factors in regulating gene expression. Heterogeneous nuclear ribonucleoprotein E1 (hnRNP E1), a subgroup of hnRNPs, is a KH-triple repeat containing RNA-binding protein. It is encoded by an intronless gene arising from hnRNP E2 through a retrotransposition event. hnRNP E1 is ubiquitously expressed and functions in regulating major steps of gene expression, including pre-mRNA processing, mRNA stability, and translation. Given its wide-ranging functions in the nucleus and cytoplasm and interaction with multiple proteins, we propose a post-transcriptional regulon model that explains hnRNP E1's widespread functional diversity.
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Affiliation(s)
- Arindam Chaudhury
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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Huo LR, Ju W, Yan M, Zou JH, Yan W, He B, Zhao XL, Jenkins EC, Brown WT, Zhong N. Identification of differentially expressed transcripts and translatants targeted by knock-down of endogenous PCBP1. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:1954-64. [PMID: 20624489 DOI: 10.1016/j.bbapap.2010.07.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2009] [Revised: 06/29/2010] [Accepted: 07/01/2010] [Indexed: 11/30/2022]
Abstract
PCBP1 is a member of the hnRNP family and participates in the regulation of transcription and translation. Previously, we identified transcripts targeted by overexpression of exogenous PCBP1. To further determine if these altered transcripts may also be targeted by a lack of PCBP1, we depleted endogenous PCBP1 in human SH-SY5Y cells. We identified 941 transcripts with the Affymetrix and 1362 with the Agilent expression platforms. There were 375 transcripts identified by both platforms, including 328 down-regulated and 47 up-regulated. The identified transcripts could be grouped into neuronal, cell signaling, metabolic, developmental, and differentiation categories, with pathway involvement in Wnt signaling, TGF beta signaling, translation factors and nuclear receptors. A proteomic profiling study with a two-dimensional chromatographic platform showed global translational changes over a range of isoelectric points (pI)=4.84-8.42. This study identifies the transcripts affected by knock-down of endogenous PCBP1 and compares them to the transcripts affected by overexpression of PCBP1.
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Affiliation(s)
- Li-Rong Huo
- Peking University Center of Medical Genetics, Beijing 100083, China
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Fujimura K, Katahira J, Kano F, Yoneda Y, Murata M. Selective localization of PCBP2 to cytoplasmic processing bodies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:878-87. [PMID: 19230839 DOI: 10.1016/j.bbamcr.2009.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 01/29/2009] [Accepted: 02/02/2009] [Indexed: 12/16/2022]
Abstract
Processing bodies (P-bodies) are cytoplasmic domains that have been implicated in critical steps of the regulation of gene expression, including mRNA decay and post-transcriptional gene silencing. Previously, we reported that PCBP2 (Poly-(rC) Binding Protein 2), a facilitator of IRES-mediated translation, is a novel P-body component. Interestingly, PCBP2 is recruited to only a subset of Dcp1a-positive P-bodies, which may reflect functional diversity among these structures. In this study, we examined the selective P-body localization of PCBP2 in detail. Co-localization studies between Dcp1a and PCBP2 revealed that PCBP2 is present in approximately 40% of P-bodies. While PCBP2 was more likely to reside in larger P-bodies, P-body size did not seem to be the sole determinant, and puromycin-induced enlargement of P-bodies only modestly increased the percentage of PCBP2-positive P-bodies. Photobleaching experiments demonstrated that the accumulation of PCBP2 to specific P-bodies is a dynamic process, which does not involve the protein's transcription-dependent nucleo-cytoplasmic shuttling activity. Finally, we found that PCBP1, a close relative of PCBP2, localizes to P-bodies in a similar manner to PCBP2. Taken together, these results establish the compositional diversity among P-bodies, and that PCBP2, probably in complex with other mRNP factors, may dynamically recognize such differences and accumulate to specific P-bodies.
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Affiliation(s)
- Ken Fujimura
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
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