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Chang YK, Lin YJ, Cheng CY, Tsai PC, Wang CY, Nielsen BL, Liu HJ. Nucleocytoplasmic shuttling of BEFV M protein-modulated by lamin A/C and chromosome maintenance region 1 through a transcription-, carrier- and energy-dependent pathway. Vet Microbiol 2024; 291:110026. [PMID: 38364467 DOI: 10.1016/j.vetmic.2024.110026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/30/2024] [Accepted: 02/07/2024] [Indexed: 02/18/2024]
Abstract
This study demonstrates for the first time that the matrix (M) protein of BEFV is a nuclear targeting protein that shuttles between the nucleus and the cytoplasm in a transcription-, carrier-, and energy-dependent manner. Experiments performed in both intact cells and digitonin-permeabilized cells revealed that M protein targets the nucleolus and requires carrier, cytosolic factors or energy input. By employing sequence and mutagenesis analyses, we have determined both nuclear localization signal (NLS) 6KKGKSK11 and nuclear export signal (NES) 98LIITSYL TI106 of M protein that are important for the nucleocytoplasmic shuttling of M protein. Furthermore, we found that both lamin A/C and chromosome maintenance region 1 (CRM-1) proteins could be coimmunoprecipitated and colocalized with the BEFV M protein. Knockdown of lamin A/C by shRNA and inhibition of CRM-1 by leptomycin B significantly reduced virus yield. Collectively, this study provides novel insights into nucleocytoplasmic shuttling of the BEFV M protein modulated by lamin A/C and CRM-1 and by a transcription- and carrier- and energy-dependent pathway.
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Affiliation(s)
- Yu-Kang Chang
- Department of Medical Research, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan, ROC; Depertment of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Yi-Jyum Lin
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Ching-Yuan Cheng
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC
| | - Pei-Chien Tsai
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Chi-Young Wang
- Department of Veterinary Medicine, National Chung Hsing University, Taichung 402, Taiwan, ROC; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Brent L Nielsen
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, USA
| | - Hung-Jen Liu
- Institute of Molecular Biology, National Chung Hsing University, Taichung 402, Taiwan, ROC; Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan, ROC; The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung, Taiwan, ROC; Ph.D Program in Translational Medicine, National Chung Hsing University, Taichung, Taiwan, ROC; Rong Hsing Research Center for Translational Medicine, National Chung Hsing, Taiwan, ROC.
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2
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Moraes IR, de Oliveira HC, Fontes MRM. Structural basis of nuclear transport for NEIL DNA glycosylases mediated by importin-alpha. Biochim Biophys Acta Proteins Proteom 2024; 1872:140974. [PMID: 38065227 DOI: 10.1016/j.bbapap.2023.140974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/18/2023] [Accepted: 11/30/2023] [Indexed: 01/10/2024]
Abstract
NEIL glycosylases, including NEIL1, NEIL2, and NEIL3, play a crucial role in the base excision DNA repair pathway (BER). The classical importin pathway mediated by importin α/β and cargo proteins containing nuclear localization sequences (NLS) is the most common transport mechanism of DNA repair proteins to the nucleus. Previous studies have identified putative NLSs located at the C-terminus of NEIL3 and NEIL1. Crystallographic, bioinformatics, calorimetric (ITC), and fluorescence assays were used to investigate the interaction between NEIL1 and NEIL3 putative NLSs and importin-α (Impα). Our findings showed that NEIL3 contains a typical cNLS, with medium affinity for the major binding site of Impα. In contrast, crystallographic analysis of NEIL1 NLS revealed its binding to Impα, but with high B-factors and a lack of electron density at the linker region. ITC and fluorescence assays indicated no detectable affinity between NEIL1 NLS and Impα. These data suggest that NEIL1 NLS is a non-classical NLS with low affinity to Impα. Additionally, we compared the binding mode of NEIL3 and NEIL1 with Mus musculus Impα to human isoforms HsImpα1 and HsImpα3, which revealed interesting binding differences for HsImpα3 variant. NEIL3 is a classical medium affinity monopartite NLS, while NEIL1 is likely to be an unclassical low-affinity bipartite NLS. The base excision repair pathway is one of the primary systems involved in repairing DNA. Thus, understanding the mechanisms of nuclear transport of NEIL proteins is crucial for comprehending the role of these proteins in DNA repair and disease development.
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Affiliation(s)
- Ivan R Moraes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Hamine C de Oliveira
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil
| | - Marcos R M Fontes
- Departamento de Biofísica e Farmacologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Botucatu, SP, Brazil; Instituto de Estudos Avançados do Mar (IEAMar), Universidade Estadual Paulista (UNESP), São Vicente, SP, Brazil.
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3
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Lee J, Kwon YE, Edwards SD, Guim H, Jae Jeong K. Improved biocompatibility of dendrimer-based gene delivery by histidine-modified nuclear localization signals. Int J Pharm 2023; 644:123299. [PMID: 37558147 DOI: 10.1016/j.ijpharm.2023.123299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/29/2023] [Accepted: 08/06/2023] [Indexed: 08/11/2023]
Abstract
Polyamidoamine (PAMAM) dendrimers have been explored as an alternative to polyethylenimine (PEI) as a gene delivery carrier because of their relatively low cytotoxicity and excellent biocompatibility. The transfection efficiency of PAMAM dendrimers can be improved by the addition of nuclear localization signal (NLS), a positively charged peptide sequence recognized by cargo proteins in the cytoplasm for nuclear transport. However, increased positive charges from NLS can cause damage to the cytoplasmic and mitochondrial membranes and lead to reactive oxygen species (ROS)-induced cytotoxicity. This negative effect of NLS can be negated without a significant reduction in transfection efficiency by adding histidine, an essential amino acid known as a natural antioxidant, to NLS. However, little is known about the exact mechanism by which histidine reduces cytotoxicity of NLS-modified dendrimers. In this study, we selected cystamine core PAMAM dendrimer generation 2 (cPG2) and conjugated it with NLS derived from Merkel cell polyomavirus large T antigen and histidine (n = 0-3) to improve transfection efficiency and reduce cytoxicity. NLS-modified cPG2 derivatives showed similar or higher transfection efficiency than PEI 25 kDa in NIH3T3 and human mesenchymal stem cells (hMSC). The cytotoxicity of NLS-modified cPG2 derivatives was substantially lower than PEI 25 kDa and was further reduced as the number of histidine in NLS increased. To understand the mechanism of cytoprotective effect of histidine-conjugated NLS, we examined ROS scavenging, hydroxyl radical generation and mitochondrial membrane potential as a function of the number of histidine in NLS. As the number of hisidine increased, cPG2 scavenged ROS more effectively as evidenced by the hydroxyl radical antioxidant capacity (HORAC) assay. This was consistent with the reduced intracellular hydroxyl radical concentration measured by 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) assay in NIH3T3. Finally, fluorescence imaging with JC-1 confirmed that the mitochondrial membranes of NIH 3T3 were well-protected during the transfection when NLS contained histidine. These experimental results confirm the hypothesis that histidine residues scavenge ROS that is generated during the transfection process, preventing the excessive damage to mitochondrial membranes, leading to reduced cytotoxicity.
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Affiliation(s)
- Jeil Lee
- Department of Chemical Engineering, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Yong-Eun Kwon
- Center for Scientific Instrumentation, Korea Basic Science Institute, 169-148 Gwahak-ro, Yuseong-gu, Daejeon 34133, Republic of Korea
| | - Seth D Edwards
- Department of Chemical Engineering, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Hwanuk Guim
- Research Center for Materials Analysis, Korea Basic Science Institute, 169-148 Gwahak-ro, Yuseong-gu, Daejeon 34133, Republic of Korea
| | - Kyung Jae Jeong
- Department of Chemical Engineering, University of New Hampshire, Durham, New Hampshire 03824, United States.
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4
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Hisaoka S, Osawa J, Kobashi R, Ishida A, Kameshita I, Sueyoshi N. Subcellular distribution of bone morphogenetic protein 2-inducible kinase (BMP2K): Regulation by liquid-liquid phase separation and nucleocytoplasmic shuttling. Biochem Biophys Res Commun 2023; 649:16-24. [PMID: 36739695 DOI: 10.1016/j.bbrc.2023.01.076] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/12/2023] [Accepted: 01/23/2023] [Indexed: 01/26/2023]
Abstract
Bone morphogenetic protein 2 (BMP2)-inducible kinase (BMP2K) is induced by the cytokine BMP2, which is also implicated in the production of bone differentiation. In addition to regulating bone differentiation, BMP2K is implicated in a variety of cancers. Therefore, understanding the variables that determine where in the cell this kinase functions may help in understanding malignancies linked to BMP2K. However, the mechanisms regulating the subcellular localization of BMP2K are mainly unknown. By liquid-liquid phase separation (LLPS), BMP2K forms droplets in the cytoplasm, but how the droplets are regulated remains unclear. The reason why BMP2K localizes to the cytoplasm irrespective of having a nuclear localization signal (NLS) is also unknown. Here we show the element that controls BMP2K's LLPS and cytoplasmic localization. A glutamine-rich area is necessary for BMP2K phase separation, and droplet formation is controlled by hyperosmolarity. Cytoplasmic localization of BMP2K is managed by inhibition of NLS function through phosphorylation of Ser-1010 and by a newly found cytoplasmic localization region that antagonizes the NLS. These results will provide an important biochemical foundation for the advancement of BMP2K-related cell biology, structural biology, and pathophysiology.
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Affiliation(s)
- Shiho Hisaoka
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Jin Osawa
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Riku Kobashi
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Atsuhiko Ishida
- Laboratory of Molecular Brain Science, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, 739-8521, Japan.
| | - Isamu Kameshita
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Noriyuki Sueyoshi
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan.
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5
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Panagiotopoulos AA, Kalyvianaki K, Tsodoulou PK, Darivianaki MN, Dellis D, Notas G, Daskalakis V, Theodoropoulos PA, Panagiotidis CΑ, Castanas E, Kampa M. Recognition motifs for importin 4 [(L)PPRS(G/P)P] and importin 5 [KP(K/Y)LV] binding, identified by bio-informatic simulation and experimental in vitro validation. Comput Struct Biotechnol J 2022; 20:5952-5961. [PMID: 36382187 PMCID: PMC9646746 DOI: 10.1016/j.csbj.2022.10.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 01/21/2023] Open
Abstract
Nuclear translocation of large proteins is mediated through karyopherins, carrier proteins recognizing specific motifs of cargo proteins, known as nuclear localization signals (NLS). However, only few NLS signals have been reported until now. In the present work, NLS signals for Importins 4 and 5 were identified through an unsupervised in silico approach, followed by experimental in vitro validation. The sequences LPPRS(G/P)P and KP(K/Y)LV were identified and are proposed as recognition motifs for Importins 4 and 5 binding, respectively. They are involved in the trafficking of important proteins into the nucleus. These sequences were validated in the breast cancer cell line T47D, which expresses both Importins 4 and 5. Elucidating the complex relationships of the nuclear transporters and their cargo proteins is very important in better understanding the mechanism of nuclear transport of proteins and laying the foundation for the development of novel therapeutics, targeting specific importins.
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Affiliation(s)
| | - Konstantina Kalyvianaki
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, 71013, Greece
| | - Paraskevi K. Tsodoulou
- Laboratory of Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Maria N. Darivianaki
- Laboratory of Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Dimitris Dellis
- National Infrastructures for Research and Technology, Athens 11523, Greece
| | - George Notas
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, 71013, Greece
| | - Vangelis Daskalakis
- Department of Chemical Engineering, Cyprus University of Technology, Limassol, Cyprus
| | | | - Christos Α. Panagiotidis
- Laboratory of Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Elias Castanas
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, 71013, Greece,Corresponding authors.
| | - Marilena Kampa
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, 71013, Greece,Corresponding authors.
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6
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Kashyap J, Tyagi RK. Mitotic genome bookmarking by nuclear receptor VDR advocates transmission of cellular transcriptional memory to progeny cells. Exp Cell Res 2022; 417:113193. [PMID: 35523304 DOI: 10.1016/j.yexcr.2022.113193] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 04/26/2022] [Accepted: 04/30/2022] [Indexed: 11/04/2022]
Abstract
Mitosis is an essential process for the self-renewal of cells that is accompanied by dynamic changes in nuclear architecture and chromatin organization. Despite all the changes, the cell manages to re-establish all the parental epigenetic marks, post-mitotically. Recent reports suggest that some sequence-specific transcription factors remain attached to mitotic chromatin during cell division to ensure timely reactivation of a subset of transcription factors necessary to maintain cell identity. These mitotically associated factors are suggested to act as 'genome bookmarking factors' and the phenomenon is termed 'genome bookmarking'. Here, we studied this phenomenon with Vitamin D Receptor (VDR), a key regulator of calcium and phosphate homeostasis and a member of the nuclear receptor superfamily. This study, for the first time, has confirmed VDR as a mitotic bookmarking factor that may be playing a crucial role in the maintenance of cell identity and genome bookmarking. Full 'DNA binding domain (DBD)' present in VDR was identified as essential for enrichment of VDR on mitotic chromatin. Furthermore, the study also demonstrates that VDR evokes mitotic chromatin binding behaviour in its heterodimeric partner Retinoid X receptor (RXR). Interestingly, for promoting bookmarking behaviour in RXR, both DBD and/or ligand-binding domain (LBD) in conjunction with hinge region of VDR were required. Additionally, ChIP analysis showed that VDR remains associated with DR3 (direct repeat 3) region of its specific target gene promoter CYP24A1(Cytochrome P450 family 24 subfamily A member1), during mitosis. Altogether, our study illustrates a novel function of VDR in the epigenetic transmission and control of expression of target proteome for maintenance of cell identity and traits in progeny cells.
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Affiliation(s)
- Jyoti Kashyap
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Rakesh K Tyagi
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India.
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7
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Wang C, Meng L, Wang J, Zhang K, Duan S, Ren P, Wei Y, Fu X, Yu B, Wu J, Yu X. Role of Intracellular Distribution of Feline and Bovine SAMHD1 Proteins in Lentiviral Restriction. Virol Sin 2021; 36:981-996. [PMID: 33751400 DOI: 10.1007/s12250-021-00351-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 12/28/2020] [Indexed: 11/28/2022] Open
Abstract
Human SAMHD1 (hSAM) restricts lentiviruses at the reverse transcription step through its dNTP triphosphohydrolase (dNTPase) activity. Besides humans, several mammalian species such as cats and cows that carry their own lentiviruses also express SAMHD1. However, the intracellular distribution of feline and bovine SAMHD1 (fSAM and bSAM) and its significance in their lentiviral restriction function is not known. Here, we demonstrated that fSAM and bSAM were both predominantly localized to the nucleus and nuclear localization signal (11KRPR14)-deleted fSAM and bSAM relocalized to the cytoplasm. Both cytoplasmic fSAM and bSAM retained the antiviral function against different lentiviruses and cytoplasmic fSAM could restrict Vpx-encoding SIV and HIV-2 more efficiently than its wild-type (WT) protein as cytoplasmic hSAM. Further investigation revealed that cytoplasmic fSAM was resistant to Vpx-induced degradation like cytoplasmic hSAM, while cytoplasmic bSAM was not, but they all demonstrated the same in vitro dNTPase activity and all could interact with Vpx as their WT proteins, indicating that cytoplasmic hSAM and fSAM can suppress more SIV and HIV-2 by being less sensitive to Vpx-mediated degradation. Our results suggested that fSAM- and bSAM-mediated lentiviral restriction does not require their nuclear localization and that fSAM shares more common features with hSAM. These findings may provide insights for the establishment of alternative animal models to study SAMHD1 in vivo.
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Affiliation(s)
- Chu Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China.,The First Hospital and Institute of Immunology, Jilin University, Changchun, 130012, China
| | - Lina Meng
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Jialin Wang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Kaikai Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Sizhu Duan
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Pengyu Ren
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Yingzhe Wei
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Xinyu Fu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Bin Yu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China.,Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Jiaxin Wu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China. .,Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun, 130012, China.
| | - Xianghui Yu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, 130012, China. .,Key Laboratory for Molecular Enzymology and Engineering, the Ministry of Education, School of Life Sciences, Jilin University, Changchun, 130012, China.
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Panagiotopoulos AA, Polioudaki C, Ntallis SG, Dellis D, Notas G, Panagiotidis CA, Theodoropoulos PA, Castanas E, Kampa M. The sequence [EKRKI(E/R)(K/L/R/S/T)] is a nuclear localization signal for importin 7 binding (NLS7). Biochim Biophys Acta Gen Subj 2021; 1865:129851. [PMID: 33482249 DOI: 10.1016/j.bbagen.2021.129851] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 01/14/2021] [Accepted: 01/14/2021] [Indexed: 12/22/2022]
Abstract
BACKGROUND Nuclear translocation of large proteins is mediated through specific protein carriers, collectively named karyopherins (importins, exportins and adaptor proteins). Cargo proteins are recognized by importins through specific motifs, known as nuclear localization signals (NLS). However, only the NLS recognized by importin α and transportin (M9 NLS) have been identified so far METHODS: An unsupervised in silico approach was used, followed by experimental validation. RESULTS We identified the sequence EKRKI(E/R)(K/L/R/S/T) as an NLS signal for importin 7 recognition. This sequence was validated in the breast cancer cell line T47D, which expresses importin 7. Finally, we verified that importin 7-mediated nuclear protein transport is affected by cargo protein phosphorylation. CONCLUSIONS The NLS sequence for importin 7 was identified and we propose this approach as an identification method of novel specific NLS sequences for β-karyopherin family members. GENERAL SIGNIFICANCE Elucidating the complex relationships of the nuclear transporters and their cargo proteins may help in laying the foundation for the development of novel therapeutics, targeting specific importins, with an immediate translational impact.
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Affiliation(s)
| | - Chara Polioudaki
- Laboratory of Biochemistry, School of Medicine, University of Crete, 71013, Greece
| | - Sotirios G Ntallis
- Laboratory of Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | | | - George Notas
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, 71013, Greece
| | - Christos A Panagiotidis
- Laboratory of Pharmacology, School of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | | | - Elias Castanas
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, 71013, Greece.
| | - Marilena Kampa
- Laboratory of Experimental Endocrinology, School of Medicine, University of Crete, 71013, Greece.
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9
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Yao M, Dong Y, Wang Y, Liu H, Ma H, Zhang H, Zhang L, Cheng L, Lv X, Xu Z, Zhang F, Lei Y, Ye W. N 6-methyladenosine modifications enhance enterovirus 71 ORF translation through METTL3 cytoplasmic distribution. Biochem Biophys Res Commun 2020; 527:297-304. [PMID: 32446384 DOI: 10.1016/j.bbrc.2020.04.088] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 04/16/2020] [Indexed: 01/10/2023]
Abstract
During replication, numerous viral RNAs are modified by N6-methyladenosine (m6A), the most abundant internal RNA modification. m6A is believed to regulate elements of RNA metabolism, such as splicing, stability, translation, secondary structure formation, and viral replication. In this study, we assessed the occurrence of m6A modification of the EV71 genome in human cells and revealed a preferred, conserved modification site across diverse viral strains. A single m6A modification at the 5' UTR-VP4 junction was shown to perform a protranslational function. Depletion of the METTL3 methyltransferase or treatment with 3-deazaadenosine significantly reduced EV71 replication. Specifically, METTL3 colocalized with the viral dsRNA replication intermediate in the cytoplasm during EV71 infection. As a nuclear resident protein, METTL3 relies on the binding of the nuclear import protein karyopherin to its nuclear localization signal (NLS) for nuclear translocation. We observed that EV71 2A and METTL3 share nuclear import proteins. The results of this study revealed an inner mechanism by which EV71 2A regulates the subcellular location of METTL3 to amplify its own gene expression, providing an increased understanding of RNA epitranscriptomics during the EV71 replication cycle.
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Affiliation(s)
- Min Yao
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Yangchao Dong
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Yuan Wang
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - He Liu
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Hongwei Ma
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Hui Zhang
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Liang Zhang
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Linfeng Cheng
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Xin Lv
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Zhikai Xu
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China
| | - Fanglin Zhang
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China.
| | - Yingfeng Lei
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China.
| | - Wei Ye
- Department of Microbiology, School of Preclinical Medicine, Fourth Military Medical University, Xi'an, 710032, China.
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10
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Li M, Chen T, Zou X, Xu Z, Wang Y, Wang P, Ou X, Li Y, Chen D, Peng T, Wang Y, Cai M. Characterization of the Nucleocytoplasmic Transport Mechanisms of Epstein-Barr Virus BFLF2. Cell Physiol Biochem 2018; 51:1500-1517. [PMID: 30497081 DOI: 10.1159/000495641] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 11/21/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Epstein-Barr virus (EBV) BFLF2, the homologue of herpes simplex virus 1 (HSV-1) UL31, is crucial for the efficient viral DNA packaging and primary egress across the nuclear membrane. However, we still do not know its subcellular transport mechanisms. METHODS Interspecies heterokaryon assays were utilized to detect the nucleocytoplasmic shuttling of BFLF2, and mutation analysis, plasmid transfection and fluorescence microscopy assays were performed to identify the functional nuclear localization sequence (NLS) and nuclear export sequence (NES) of BFLF2 in live cells. Furthermore, the nuclear import and export of BFLF2 were assessed by confocal microscopy, co-immunoprecipitation and immunoblot assays. RESULTS BFLF2 was confirmed to shuttle between the nucleus and cytoplasm. Two predicted NESs were shown to be nonfunctional, yet we proved that the nuclear export of BFLF2 was mediated through transporter associated with antigen processing (TAP), but not chromosomal region maintenance 1 (CRM1) dependent pathway. Furthermore, one functional NLS, 22RRLMHPHHRNYTASKASAH40, was identified, and the aa22-23, aa22-25, aa28-30 and aa37-40 had an important role in the nuclear localization of BFLF2. Besides, the nuclear import of BFLF2 was demonstrated through Ran-, importin α7-, importin β1- and transportin-1-dependent mechanism that does not require importin α1, α3 and α5. CONCLUSION These works are of significance for the further study of the functions of BFLF2 during EBV infection, as well as for further insights into the design of new antiviral drug target and vaccine development against EBV.
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Affiliation(s)
- Meili Li
- Guangdong Provincial Key Laboratory of Allergy and Clinical Immunology, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.,Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Tao Chen
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Xingmei Zou
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Zuo Xu
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Yuanfang Wang
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Ping Wang
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Xiaowen Ou
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Yiwen Li
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Daixiong Chen
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China
| | - Tao Peng
- State Key Laboratory of Respiratory Diseases, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town, China.,South China Vaccine Corporation Limited, Guangzhou Science Park, Guangzhou, China
| | - Yao Wang
- GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Xinzao Town, China
| | - Mingsheng Cai
- Department of Pathogenic Biology and Immunology, Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Xinzao Town,
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11
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Ferri G, Storti B, Bizzarri R. Nucleocytoplasmic transport in cells with progerin-induced defective nuclear lamina. Biophys Chem 2017; 229:77-83. [PMID: 28712764 DOI: 10.1016/j.bpc.2017.06.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 06/14/2017] [Accepted: 06/14/2017] [Indexed: 10/19/2022]
Abstract
Recent data indicate that nuclear lamina (NL) plays a relevant role in many fundamental cellular functions. The peculiar role of NL in cells is dramatically demonstrated by the Hutchinson-Gilford progeria syndrome (HGPS), an inherited laminopathy that causes premature, rapid aging shortly after birth. In HGPS, a mutant form of Lamin A (progeria) leads to a dysmorphic NL structure, but how this perturbation is transduced into cellular changes is still largely unknown. Owing to the close structural relationship between NL and the Nuclear Pore Complex (NPC), in this work we test whether HGPS affects passive and active nucleo-cytoplasmic shuttling of cargoes by means of an established model based of fluorescence recovery after photobleaching. Our findings clearly demonstrate that dysmorphic NL is decoupled from the dynamic characteristics of passive and active transport towards and from the nucleus, as well as from the binding affinity of transport protein mediators.
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Affiliation(s)
- Gianmarco Ferri
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy; Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Barbara Storti
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - Ranieri Bizzarri
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa, Italy.
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12
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Cai M, Jiang S, Zeng Z, Li X, Mo C, Yang Y, Chen C, Xie P, Bian Y, Wang J, Huang J, Chen D, Peng T, Li M. Probing the nuclear import signal and nuclear transport molecular determinants of PRV ICP22. Cell Biosci 2016; 6:3. [PMID: 26816613 PMCID: PMC4727382 DOI: 10.1186/s13578-016-0069-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 01/10/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Herpes simplex virus 1 (HSV-1) ICP22 is a multifunctional protein and important for HSV-1 replication. Pseudorabies virus (PRV) ICP22 (P-ICP22) is a homologue of HSV-1 ICP22 and is reported to be able to selectively modify the transcription of different kinetic classes of PRV genes, however, the subcellular localization, localization signal and molecular determinants for its transport to execute this function is less well understood. RESULTS In this study, by utilizing live cells fluorescent microscopy, P-ICP22 fused to enhanced yellow fluorescent protein (EYFP) gene was transient expressed in live cells and shown to exhibit a predominantly nucleus localization in the absence of other viral proteins. By transfection of a series of P-ICP22 deletion mutants fused to EYFP, a bona fide nuclear localization signal (NLS) and its key amino acids (aa) of P-ICP22 was, for the first time, determined and mapped to aa 41-60 (PASTPTPPKRGRYVVEHPEY) and aa 49-50 (KR), respectively. Besides, the P-ICP22 was demonstrated to be targeted to the nucleus via Ran-, importin α1-, and α7-mediated pathway. CONCLUSIONS Our findings reported herein disclose the NLS and molecular mechanism for nuclear transport of P-ICP22, these results will uncover new avenues for depicting the biological roles of P-ICP22 during PRV infection.
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Affiliation(s)
- Mingsheng Cai
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China ; Guangzhou Hoffmann Institute of Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Si Jiang
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China ; Guangzhou Hoffmann Institute of Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Zhancheng Zeng
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Xiaowei Li
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Chuncong Mo
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Yanjia Yang
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Chunke Chen
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Peiping Xie
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Yun Bian
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Jinlin Wang
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Jinlu Huang
- Guangdong Haid Group Co., Ltd., Guangzhou, 511400 People's Republic of China
| | - Daixiong Chen
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China ; Guangzhou Hoffmann Institute of Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Tao Peng
- Guangzhou Hoffmann Institute of Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
| | - Meili Li
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China ; Guangzhou Hoffmann Institute of Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436 People's Republic of China
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13
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Li M, Jiang S, Wang J, Mo C, Zeng Z, Yang Y, Chen C, Li X, Cui W, Huang J, Peng T, Cai M. Characterization of the nuclear import and export signals of pseudorabies virus UL31. Arch Virol 2015. [PMID: 26195191 DOI: 10.1007/s00705-015-2527-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The pseudorabies virus (PRV) UL31 protein (pUL31) is a homologue of the herpes simplex virus 1 pUL31, which is a multifunctional protein that is important for HSV-1 infection. However, little is known concerning the subcellular localization signal of PRV UL31. Here, by transfection with a series of PRV UL31 deletion mutants fused to an enhanced yellow fluorescent protein (EYFP) gene, a bipartite nuclear localization signal (NLS) and a PY motif NLS of UL31 were identified and mapped to amino acids (aa) 4 to 20 (RRRLLRRKSSAARRKTL) and aa 21 to 34 (TRAARDRYAPYFAY), respectively. Additionally, the predicted nuclear export signal (NES) was shown to be nonfunctional. Taken together, this information opens up new avenues for investigating the biological functions of UL31 during PRV infection.
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Affiliation(s)
- Meili Li
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
- Guangzhou Hoffmann Institute of Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436, People's Republic of China
| | - Si Jiang
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
| | - Jinlin Wang
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
| | - Chuncong Mo
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
| | - Zhancheng Zeng
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
| | - Yanjia Yang
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
| | - Chunke Chen
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
| | - Xiaowei Li
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
| | - Wei Cui
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China
| | - Jinlu Huang
- Guangdong Haid Group Co., Ltd., Guangzhou, 511400, People's Republic of China
| | - Tao Peng
- Guangzhou Hoffmann Institute of Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436, People's Republic of China
| | - Mingsheng Cai
- Department of Pathogenic Biology and Immunology, School of Basic Science, Guangzhou Medical University, Xinzao Town, Panyu, Guangzhou, 511436, Guangdong, People's Republic of China.
- Guangzhou Hoffmann Institute of Immunology, School of Basic Science, Guangzhou Medical University, Guangzhou, 511436, People's Republic of China.
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14
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Shinmura K, Kato H, Kawanishi Y, Goto M, Tao H, Inoue Y, Nakamura S, Sugimura H. NEIL1 p.Gln282Stop variant is predominantly localized in the cytoplasm and exhibits reduced activity in suppressing mutations. Gene 2015; 571:33-42. [PMID: 26095805 DOI: 10.1016/j.gene.2015.06.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 04/21/2015] [Accepted: 06/16/2015] [Indexed: 01/04/2023]
Abstract
Human NEIL1 protein is a DNA glycosylase known to be involved in the repair of oxidized DNA lesions. A c.C844T germline variant of the NEIL1 gene has recently been identified in the Japanese population, however, the p.Q282Stop-type protein produced from this variant gene has not yet been characterized. In this study to determine whether the NEIL1 c.C844T variant might be a defective allele, we investigated the subcellular localization of the p.Q282Stop-type protein and its ability to suppress the development of mutations in mammalian cells. In contrast to the nuclear localization of wild-type (WT) NEIL1, the p.Q282Stop-type protein tagged with GFP or FLAG was localized predominantly in the cytoplasm of human H1299 cells. Mutant forms of the putative nuclear localization signal (NLS, amino acid sequences 359 to 378) of NEIL1-GFP resulted in predominant cytoplasmic localization of the mutants, suggesting that the abnormal localization of p.Q282Stop-type NEIL1 may also be caused by a loss of the putative NLS in the protein. Next, V79 mammalian cell lines inducibly expressing WT NEIL1 or p.Q282Stop-type NEIL1 were established using the piggyBac transposon vector system, and the mutation frequency was compared between the cell lines by HPRT assay. The frequency of mutations induced by glucose oxidase, an oxidative stress inducer, was higher in the p.Q282Stop-type NEIL1-transposed cells than that in the WT NEIL1-transposed cells. Finally, the Cancer Genome Atlas (TCGA) data showed an increased number of somatic mutations in primary carcinomas containing a truncating NEIL1 mutation. These results suggest that p.Q282Stop-type NEIL1 is predominantly localized in the cytoplasm, possibly due to a loss of the NLS, and possesses a reduced ability to suppress the onset of mutations, both findings suggesting that NEIL1 c.C844T is a defective allele.
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Affiliation(s)
- Kazuya Shinmura
- Department of Tumor Pathology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
| | - Hisami Kato
- Department of Tumor Pathology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yuichi Kawanishi
- Research Equipment Center, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Masanori Goto
- Division of Carcinogenesis and Prevention, National Cancer Center Research Institute, Tokyo, Japan
| | - Hong Tao
- Department of Tumor Pathology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Yusuke Inoue
- Department of Tumor Pathology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Satoki Nakamura
- Department of Tumor Pathology, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Haruhiko Sugimura
- Department of Tumor Pathology, Hamamatsu University School of Medicine, Hamamatsu, Japan
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15
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Ma Q, Tan J, Cui X, Luo D, Yu M, Liang C, Qiao W. Residues R(199)H(200) of prototype foamy virus transactivator Bel1 contribute to its binding with LTR and IP promoters but not its nuclear localization. Virology 2013; 449:215-23. [PMID: 24418555 DOI: 10.1016/j.virol.2013.11.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 11/14/2013] [Accepted: 11/20/2013] [Indexed: 10/25/2022]
Abstract
Prototype foamy virus encodes a transactivator called Bel1 that enhances viral gene transcription and is essential for PFV replication. Nuclear localization of Bel1 has been reported to rely on two proximal basic motifs R(199)H(200) and R(221)R(222)R(223) that likely function together as a bipartite nuclear localization signal. In this study, we report that mutating R(221)R(222)R(223), but not R(199)H(200), relocates Bel1 from the nucleus to the cytoplasm, suggesting an essential role for R(221)R(222)R(223) in the nuclear localization of Bel1. Although not affecting the nuclear localization of Bel1, mutating R(199)H(200) disables Bel1 from transactivating PFV promoters. Results of EMSA reveal that the R(199)H(200) residues are vital for the binding of Bel1 to viral promoter DNA. Moreover, mutating R(199)H(200) in Bel1 impairs PFV replication to a much greater extent than mutating R(221)R(222)R(223). Collectively, our findings suggest that R(199)H(200) directly participate in Bel1 binding to viral promoter DNA and are indispensible for Bel1 transactivation activity.
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Affiliation(s)
- Qinglin Ma
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Juan Tan
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xiaoxu Cui
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin 300071, China; Centre Laboratory, TianJin 4th Centre Hospital, Tianjin 300140, China
| | - Di Luo
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Miao Yu
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Chen Liang
- Lady Davis Institute, Jewish General Hospital, Montreal, QC, Canada H3T 1E2; Departments of Medicine McGill University, Montreal, QC, Canada; Microbiology and Immunology, McGill University, Montreal, QC, Canada
| | - Wentao Qiao
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin 300071, China.
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