1
|
Perez RE, Eckerdt F, Platanias LC. Schlafens: Emerging Therapeutic Targets. Cancers (Basel) 2024; 16:1805. [PMID: 38791884 PMCID: PMC11119473 DOI: 10.3390/cancers16101805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 05/02/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024] Open
Abstract
The interferon (IFN) family of immunomodulatory cytokines has been a focus of cancer research for over 50 years with direct and indirect implications in cancer therapy due to their properties to inhibit malignant cell proliferation and modulate immune responses. Among the transcriptional targets of the IFNs is a family of genes referred to as Schlafens. The products of these genes, Schlafen proteins, exert important roles in modulating cellular proliferation, differentiation, immune responses, viral replication, and chemosensitivity of malignant cells. Studies have demonstrated that abnormal expression of various Schlafens contributes to the pathophysiology of various cancers. Schlafens are now emerging as promising biomarkers and potentially attractive targets for drug development in cancer research. Here, we highlight research suggesting the use of Schlafens as cancer biomarkers and the rationale for the development of specific drugs targeting Schlafen proteins.
Collapse
Affiliation(s)
- Ricardo E. Perez
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL 60611, USA; (R.E.P.); (F.E.)
- Division of Hematology-Oncology, Department of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Frank Eckerdt
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL 60611, USA; (R.E.P.); (F.E.)
- Division of Hematology-Oncology, Department of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Leonidas C. Platanias
- Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL 60611, USA; (R.E.P.); (F.E.)
- Division of Hematology-Oncology, Department of Medicine, Northwestern University, Chicago, IL 60611, USA
- Department of Medicine, Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
| |
Collapse
|
2
|
Podvalnaya N, Bronkhorst AW, Lichtenberger R, Hellmann S, Nischwitz E, Falk T, Karaulanov E, Butter F, Falk S, Ketting RF. piRNA processing by a trimeric Schlafen-domain nuclease. Nature 2023; 622:402-409. [PMID: 37758951 PMCID: PMC10567574 DOI: 10.1038/s41586-023-06588-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023]
Abstract
Transposable elements are genomic parasites that expand within and spread between genomes1. PIWI proteins control transposon activity, notably in the germline2,3. These proteins recognize their targets through small RNA co-factors named PIWI-interacting RNAs (piRNAs), making piRNA biogenesis a key specificity-determining step in this crucial genome immunity system. Although the processing of piRNA precursors is an essential step in this process, many of the molecular details remain unclear. Here, we identify an endoribonuclease, precursor of 21U RNA 5'-end cleavage holoenzyme (PUCH), that initiates piRNA processing in the nematode Caenorhabditis elegans. Genetic and biochemical studies show that PUCH, a trimer of Schlafen-like-domain proteins (SLFL proteins), executes 5'-end piRNA precursor cleavage. PUCH-mediated processing strictly requires a 7-methyl-G cap (m7G-cap) and a uracil at position three. We also demonstrate how PUCH interacts with PETISCO, a complex that binds to piRNA precursors4, and that this interaction enhances piRNA production in vivo. The identification of PUCH concludes the search for the 5'-end piRNA biogenesis factor in C. elegans and uncovers a type of RNA endonuclease formed by three SLFL proteins. Mammalian Schlafen (SLFN) genes have been associated with immunity5, exposing a molecular link between immune responses in mammals and deeply conserved RNA-based mechanisms that control transposable elements.
Collapse
Affiliation(s)
- Nadezda Podvalnaya
- Biology of Non-coding RNA group, Institute of Molecular Biology, Mainz, Germany
- International PhD Programme on Gene Regulation, Epigenetics & Genome Stability, Mainz, Germany
| | - Alfred W Bronkhorst
- Biology of Non-coding RNA group, Institute of Molecular Biology, Mainz, Germany
| | - Raffael Lichtenberger
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Department of Structural and Computational Biology, Center for Molecular Biology, University of Vienna, Vienna, Austria
| | - Svenja Hellmann
- Biology of Non-coding RNA group, Institute of Molecular Biology, Mainz, Germany
| | - Emily Nischwitz
- International PhD Programme on Gene Regulation, Epigenetics & Genome Stability, Mainz, Germany
- Quantitative Proteomics group, Institute of Molecular Biology, Mainz, Germany
| | - Torben Falk
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria
- Department of Structural and Computational Biology, Center for Molecular Biology, University of Vienna, Vienna, Austria
| | - Emil Karaulanov
- Bioinformatics Core Facility, Institute of Molecular Biology, Mainz, Germany
| | - Falk Butter
- Department of Structural and Computational Biology, Center for Molecular Biology, University of Vienna, Vienna, Austria
- Institute of Molecular Virology and Cell Biology, Friedrich Loeffler Institute, Greifswald, Germany
| | - Sebastian Falk
- Max Perutz Labs, Vienna Biocenter Campus (VBC), Vienna, Austria.
- Department of Structural and Computational Biology, Center for Molecular Biology, University of Vienna, Vienna, Austria.
| | - René F Ketting
- Biology of Non-coding RNA group, Institute of Molecular Biology, Mainz, Germany.
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz, Germany.
| |
Collapse
|
3
|
Structural, molecular, and functional insights into Schlafen proteins. EXPERIMENTAL & MOLECULAR MEDICINE 2022; 54:730-738. [PMID: 35768579 PMCID: PMC9256597 DOI: 10.1038/s12276-022-00794-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 04/08/2022] [Accepted: 04/14/2022] [Indexed: 11/30/2022]
Abstract
Schlafen (SLFN) genes belong to a vertebrate gene family encoding proteins with high sequence homology. However, each SLFN is functionally divergent and differentially expressed in various tissues and species, showing a wide range of expression in cancer and normal cells. SLFNs are involved in various cellular and tissue-specific processes, including DNA replication, proliferation, immune and interferon responses, viral infections, and sensitivity to DNA-targeted anticancer agents. The fundamental molecular characteristics of SLFNs and their structures are beginning to be elucidated. Here, we review recent structural insights into the N-terminal, middle and C-terminal domains (N-, M-, and C-domains, respectively) of human SLFNs and discuss the current understanding of their biological roles. We review the distinct molecular activities of SLFN11, SLFN5, and SLFN12 and the relevance of SLFN11 as a predictive biomarker in oncology. The diverse roles that Schlafen family proteins play in cell proliferation, immune modulation, and other biological processes make them promising targets for treating and tracking diseases, especially cancer. Ukhyun Jo and Yves Pommier from the National Cancer Institute in Bethesda, USA, review the molecular characteristics and structural features of Schlafen proteins. These proteins take their name from the German word for “sleep”, as the first described Schlafen proteins caused cells to stop dividing, although later reports found that related members of the same protein family serve myriad cellular functions, including in the regulation of DNA replication. A better understanding of Schlafen proteins could open up new avenues in cancer management, for instance, diagnostics that monitor activity levels of one such protein, SLFN11, could help oncologists predict how well patients might respond to anti-cancer therapies.
Collapse
|
4
|
Schlafens Can Put Viruses to Sleep. Viruses 2022; 14:v14020442. [PMID: 35216035 PMCID: PMC8875196 DOI: 10.3390/v14020442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/11/2022] [Accepted: 02/15/2022] [Indexed: 12/21/2022] Open
Abstract
The Schlafen gene family encodes for proteins involved in various biological tasks, including cell proliferation, differentiation, and T cell development. Schlafens were initially discovered in mice, and have been studied in the context of cancer biology, as well as their role in protecting cells during viral infection. This protein family provides antiviral barriers via direct and indirect effects on virus infection. Schlafens can inhibit the replication of viruses with both RNA and DNA genomes. In this review, we summarize the cellular functions and the emerging relationship between Schlafens and innate immunity. We also discuss the functions and distinctions of this emerging family of proteins as host restriction factors against viral infection. Further research into Schlafen protein function will provide insight into their mechanisms that contribute to intrinsic and innate host immunity.
Collapse
|
5
|
Zheng Q, Duan L, Lou Y, Chao T, Guo G, Lu L, Zhang H, Zhao Y, Liang Y, Wang H. Slfn4 deficiency improves MAPK-mediated inflammation, oxidative stress, apoptosis and abates atherosclerosis progression in apolipoprotein E-deficient mice. Atherosclerosis 2021; 337:42-52. [PMID: 34757313 DOI: 10.1016/j.atherosclerosis.2021.10.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 10/12/2021] [Accepted: 10/15/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND AND AIMS Atherosclerosis, a progressive inflammatory disease characterized by elevated inflammation and lipid accumulation in the aortic endothelium, arises in part from the infiltration of inflammatory cells into the vascular wall. However, it is not fully defined how inflammatory cells, especially macrophages, affect the pathogenesis of atherosclerosis. Schlafen4 (Slfn4) mRNA is remarkably upregulated upon ox-LDL stimulation in macrophages. Nonetheless, the role of Slfn4 in foam cell formation remains unclear. METHODS To determine whether and how Slfn4 regulates lesion macrophage function during atherosclerosis,we engineered ApoE-/-Slfn4-/- double-deficient mice on an ApoE-/- background and evaluated the deficiency of Slfn4 expression in atherosclerotic lesion formation in vivo. RESULTS Our results demonstrate that total absence of SLFN4 and the bone marrow-restricted deletion of Slfn4 in ApoE-/- mice remarkably diminish inflammatory cell numbers within arterial plaques as well as limit development of atherosclerosis in moderate hypercholesterolemia condition. This is linked to a marked reduction in the expression of proinflammatory cytokines, the generation of the reactive oxygen species (ROS) and the apoptosis of cells. Furthermore, the activation of MAPKs and apoptosis signaling pathways is compromised in the absence of Slfn4. CONCLUSIONS These findings demonstrate a novel role of Slfn4 in modulating vascular inflammation and atherosclerosis, highlighting a new target for the related diseases.
Collapse
Affiliation(s)
- Qianqian Zheng
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Liangwei Duan
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Yunwei Lou
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Tianzhu Chao
- Laboratory of Mouse Genetics, Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Guo Guo
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Liaoxun Lu
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China; Laboratory of Mouse Genetics, Institute of Psychiatry and Neuroscience, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Hongxia Zhang
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Yucong Zhao
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Yinming Liang
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China.
| | - Hui Wang
- Henan Key Laboratory of Immunology and Targeted Drugs, Xinxiang Medical University, Xinxiang, People's Republic of China; Henan Collaborative Innovation Center of Molecular Diagnosis and Laboratory Medicine, School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, People's Republic of China.
| |
Collapse
|
6
|
Schlafens: Emerging Proteins in Cancer Cell Biology. Cells 2021; 10:cells10092238. [PMID: 34571887 PMCID: PMC8465726 DOI: 10.3390/cells10092238] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/23/2021] [Accepted: 08/25/2021] [Indexed: 12/29/2022] Open
Abstract
Schlafens (SLFN) are a family of genes widely expressed in mammals, including humans and rodents. These intriguing proteins play different roles in regulating cell proliferation, cell differentiation, immune cell growth and maturation, and inhibiting viral replication. The emerging evidence is implicating Schlafens in cancer biology and chemosensitivity. Although Schlafens share common domains and a high degree of homology, different Schlafens act differently. In particular, they show specific and occasionally opposing effects in some cancer types. This review will briefly summarize the history, structure, and non-malignant biological functions of Schlafens. The roles of human and mouse Schlafens in different cancer types will then be outlined. Finally, we will discuss the implication of Schlafens in the anti-tumor effect of interferons and the use of Schlafens as predictors of chemosensitivity.
Collapse
|
7
|
Affiliation(s)
- Carlos Maluquer de Motes
- Department of Microbial Sciences, School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
- * E-mail:
| |
Collapse
|
8
|
Chen J, Kuhn LA. Deciphering the three-domain architecture in schlafens and the structures and roles of human schlafen12 and serpinB12 in transcriptional regulation. J Mol Graph Model 2019; 90:59-76. [PMID: 31026779 PMCID: PMC6657700 DOI: 10.1016/j.jmgm.2019.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 04/03/2019] [Accepted: 04/05/2019] [Indexed: 12/22/2022]
Abstract
Schlafen proteins are important in cell differentiation and defense against viruses, and yet this family of vertebrate proteins is just beginning to be understood at the molecular level. Here, the three-dimensional architecture and molecular interfaces of human schlafen12 (hSLFN12), which promotes intestinal stem cell differentiation, are analyzed by sequence conservation and structural modeling in light of the functions of its homologs and binding partners. Our analysis shows that the schlafen or divergent AAA ATPase domain described in the N-terminal region of schlafens in databases and the literature is a misannotation. This N-terminal region is conclusively an AlbA_2 DNA/RNA binding domain, forming the conserved core of schlafens and their sequence homologs from bacteria through mammals. Group III schlafens additionally contain a AAA NTPase domain in their C-terminal helicase region. In hSLFN12, we have uncovered a domain matching rho GTPases, which directly follows the AlbA_2 domain in all group II-III schlafens. Potential roles for the GTPase-like domain include antiviral activity and cytoskeletal interactions that contribute to nucleocytoplasmic shuttling and cell polarization during differentiation. Based on features conserved with rSlfn13, the AlbA_2 region in hSLFN12 is likely to bind RNA, possibly as a ribonuclease. We hypothesize that RNA binding by hSLFN12 contributes to an RNA-induced transcriptional silencing/E3 ligase complex, given the functions of hSLFN12's partners, SUV39H1, JMJD6, and PDLIM7. hSLFN12's partner hSerpinB12 may contribute to heterochromatin formation, based on its homology to MENT, or directly regulate transcription via its binding to RNA polymerase II. The analysis presented here provides clear architectural and transcriptional regulation hypotheses to guide experimental design for hSLFN12 and the thousands of schlafens that share its motifs.
Collapse
Affiliation(s)
- Jiaxing Chen
- Protein Structural Analysis and Design Lab, Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI, 48824-1319, USA
| | - Leslie A Kuhn
- Protein Structural Analysis and Design Lab, Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI, 48824-1319, USA.
| |
Collapse
|
9
|
Chang HW, Yang CH, Luo YC, Su BG, Cheng HY, Tung SY, Carillo KJD, Liao YT, Tzou DLM, Wang HC, Chang W. Vaccinia viral A26 protein is a fusion suppressor of mature virus and triggers membrane fusion through conformational change at low pH. PLoS Pathog 2019; 15:e1007826. [PMID: 31220181 PMCID: PMC6605681 DOI: 10.1371/journal.ppat.1007826] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 07/02/2019] [Accepted: 05/07/2019] [Indexed: 11/24/2022] Open
Abstract
Vaccinia mature virus requires A26 envelope protein to mediate acid-dependent endocytosis into HeLa cells in which we hypothesized that A26 protein functions as an acid-sensitive membrane fusion suppressor. Here, we provide evidence showing that N-terminal domain (aa1-75) of A26 protein is an acid-sensitive region that regulates membrane fusion. Crystal structure of A26 protein revealed that His48 and His53 are in close contact with Lys47, Arg57, His314 and Arg312, suggesting that at low pH these His-cation pairs could initiate conformational changes through protonation of His48 and His53 and subsequent electrostatic repulsion. All the A26 mutant mature viruses that interrupted His-cation pair interactions of His48 and His 53 indeed have lost virion infectivity. Isolation of revertant viruses revealed that second site mutations caused frame shifts and premature termination of A26 protein such that reverent viruses regained cell entry through plasma membrane fusion. Together, we conclude that viral A26 protein functions as an acid-sensitive fusion suppressor during vaccinia mature virus endocytosis. Vaccinia virus is a complex large DNA virus with a large number of viral membrane proteins to facilitate cell entry. Although it is well established that vaccinia mature virus uses endocytosis to enter cells, it remains unclear how it triggers membrane fusion in the acidic environment of endosomes. Recently, we hypothesized that A26 protein in vaccinia mature virus functions as an acid-sensitive membrane fusion suppressor, which suggests a novel viral regulation not present in other enveloped viruses. We postulated that conformational changes of A26 protein at low pH result in de-repression of viral fusion complex activity to trigger viral and endosomal membrane fusion. Here, we provide structural, biochemical and biological evidence demonstrating that vaccinia A26 protein does indeed function as an acid-sensitive fusion suppressor protein to regulate vaccinia mature virus membrane fusion during endocytosis. Our data reveal an important and unique “checkpoint” for vaccinia mature virus endocytosis that has not been described for other viruses. Furthermore, by isolating adaptive vaccinia mutants that escaped endocytic blockage, we discovered that mutations within the A26L gene serve as an effective strategy for switching the viral infection route from endocytosis to plasma membrane fusion, expanding viral host range.
Collapse
Affiliation(s)
- Hung-Wei Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Cheng-Han Yang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Yu-Chun Luo
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Bo-Gang Su
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Huei-Yin Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Shu-Yun Tung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Kathleen Joyce D. Carillo
- Sustainable Chemical Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
| | - Yi-Ting Liao
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taiwan
| | - Der-Lii M. Tzou
- Sustainable Chemical Science and Technology Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Institute of Chemistry, Academia Sinica, Taipei, Taiwan
- Department of Applied Chemistry, National Chia-Yi University, Chia-Yi, Taiwan
| | - Hao-Ching Wang
- The Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan
- Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taiwan
- * E-mail: (HCW); (WC)
| | - Wen Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- * E-mail: (HCW); (WC)
| |
Collapse
|
10
|
Liu F, Zhou P, Wang Q, Zhang M, Li D. The Schlafen family: complex roles in different cell types and virus replication. Cell Biol Int 2017; 42:2-8. [PMID: 28460425 DOI: 10.1002/cbin.10778] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 04/23/2017] [Indexed: 12/28/2022]
Abstract
The Schlafen (slfn) gene family members express broadly, but the research has mainly focused on human slfn (h-slfn) and mouse slfn (m-slfn). The slfn members can be divided into three groups, and each group has its own characteristics and functions. Although the effects of slfns are still poorly understood, it has been confirmed that slfns are involved in the defense of immune system and regulate immune cells' proliferation and differentiation. In some malignant tumors, the slfn proteins can inhibit the growth and invasion of cancer cells, promote cancer cells sensibility to chemotherapeutics, and can be a promising new therapeutic target. In addition, the slfn proteins also disturb replication and virulence of viruses. In this review, we summarize the characteristics of the Schlafen family's structures and functions with the aim to achieve a more comprehensive understanding of slfns.
Collapse
Affiliation(s)
- Furao Liu
- Department of Oncology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Pingting Zhou
- Department of Oncology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Qian Wang
- Department of Oncology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Meichao Zhang
- Department of Oncology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Dong Li
- Department of Oncology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| |
Collapse
|
11
|
Tamošiūnaitė A, Hoffmann D, Franke A, Schluckebier J, Tauscher K, Tischer BK, Beer M, Klopfleisch R, Osterrieder N. Histopathological and Immunohistochemical Studies of Cowpox Virus Replication in a Three-Dimensional Skin Model. J Comp Pathol 2016; 155:55-61. [PMID: 27291992 DOI: 10.1016/j.jcpa.2016.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/18/2016] [Accepted: 05/04/2016] [Indexed: 11/26/2022]
Abstract
Human cowpox virus (CPXV) infections are rare, but can result in severe and sometimes fatal outcomes. The majority of recent cases were traced back to contacts with infected domestic cats or pet rats. The aim of the present study was to evaluate a three-dimensional (3D) skin model as a possible replacement for animal experiments. We monitored CPXV lesion formation, viral gene expression and cell cycle patterns after infection of 3D skin cultures with two CPXV strains of different pathogenic potential: a recent pet rat isolate (RatPox09) and the reference Brighton red strain. Infected 3D skin cultures exhibited histological alterations that were similar to those of mammal skin infections, but there were no differences in gene expression patterns and tissue damage between the two CPXV strains in the model system. In conclusion, 3D skin cultures reflect the development of pox lesions in the skin very well, but seem not to allow differentiation between more or less virulent virus strains, a distinction that is made possible by experimental infection in suitable animal models.
Collapse
Affiliation(s)
- A Tamošiūnaitė
- Institut für Virologie, Freie Universität Berlin, Zentrum für Infektionsmedizin, Berlin, Germany
| | - D Hoffmann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, Greifswald-Insel Riems, Germany
| | - A Franke
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, Greifswald-Insel Riems, Germany
| | - J Schluckebier
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, Greifswald-Insel Riems, Germany
| | - K Tauscher
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institute, Südufer 10, Greifswald-Insel Riems, Germany
| | - B K Tischer
- Institut für Virologie, Freie Universität Berlin, Zentrum für Infektionsmedizin, Berlin, Germany
| | - M Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Südufer 10, Greifswald-Insel Riems, Germany
| | - R Klopfleisch
- Institute for Veterinary Pathology, Freie Universität Berlin, Berlin, Germany
| | - N Osterrieder
- Institut für Virologie, Freie Universität Berlin, Zentrum für Infektionsmedizin, Berlin, Germany.
| |
Collapse
|
12
|
Dahiya SS, Kumar S, Mehta SC, Narnaware SD, Singh R, Tuteja FC. Camelpox: A brief review on its epidemiology, current status and challenges. Acta Trop 2016; 158:32-38. [PMID: 26902797 DOI: 10.1016/j.actatropica.2016.02.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 02/12/2016] [Accepted: 02/18/2016] [Indexed: 11/17/2022]
Abstract
Camelpox caused by a Camelpox virus (CMLV) is a very important host specific viral disease of camel. It is highly contagious in nature and causes serious impact on health even mortality of camels and economic losses to the camel owners. It manifests itself either in the local/mild or generalized/severe form. Various outbreaks of different pathogenicity have been reported from camel dwelling areas of the world. CMLV has been characterized in embryonated chicken eggs with the production of characteristic pock lesions and in various cell lines with the capacity to induce giant cells. Being of Poxviridae family, CMLV employs various strategies to impede host immune system and facilitates its own pathogenesis. Both live and attenuated vaccine has been found effective against CMLV infection. The present review gives a comprehensive overview of camelpox disease with respect to its transmission, epidemiology, virion characteristics, viral life cycle, host interaction and its immune modulation.
Collapse
Affiliation(s)
- Shyam Singh Dahiya
- National Research Center on Camel, Jorbeer, Bikaner, Rajasthan 334001, India.
| | - Sachin Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | | | - Shirish D Narnaware
- National Research Center on Camel, Jorbeer, Bikaner, Rajasthan 334001, India
| | - Raghvendar Singh
- National Research Center on Camel, Jorbeer, Bikaner, Rajasthan 334001, India
| | - Fateh Chand Tuteja
- National Research Center on Camel, Jorbeer, Bikaner, Rajasthan 334001, India
| |
Collapse
|
13
|
Puck A, Aigner R, Modak M, Cejka P, Blaas D, Stöckl J. Expression and regulation of Schlafen (SLFN) family members in primary human monocytes, monocyte-derived dendritic cells and T cells. RESULTS IN IMMUNOLOGY 2015; 5:23-32. [PMID: 26623250 PMCID: PMC4625362 DOI: 10.1016/j.rinim.2015.10.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/26/2015] [Accepted: 10/14/2015] [Indexed: 12/03/2022]
Abstract
Schlafen (SLFN/Slfn) family members have been investigated for their involvement in fundamental cellular processes including growth regulation, differentiation and control of viral replication. However, most research has been focused on the characterization of Slfns within the murine system or in human cell lines. Since little is known about SLFNs in primary human immune cells, we set out to analyze the expression and regulation of the six human SLFN genes in monocytes, monocyte-derived dendritic cells (moDCs) and T cells. Comparison of SLFN gene expression across these three cell types showed high mRNA expression of SLFN11 in monocytes and moDCs and high SLFN5 expression in T cells, indicating functional importance within these cell types. Differentiation of monocytes to moDCs leads to the gradual upregulation of SLFN12L and SLFN13 while SLFN12 levels were decreased by differentiation stimuli. Stimulation of moDCs via human rhinovirus, lipopolysaccharide, or IFN-α lead to strong upregulation of SLFN gene expression, while peptidoglycan poorly stimulated regulation of both SLFNs and the classical interferon-stimulated gene MxA. T cell activation was found to downregulate the expression of SLFN5, SLFN12 and SLFN12L, which was reversible upon addition of exogenous IFN-α. In conclusion, we demonstrate, that SLFN gene upregulation is mainly dependent on autocrine type I interferon signaling in primary human immune cells. Rapid decrease of SLFN expression levels following T cell receptor stimulation indicates a role of SLFNs in the regulation of human T cell quiescence.
Collapse
Affiliation(s)
- Alexander Puck
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Regina Aigner
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Madhura Modak
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Petra Cejka
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Dieter Blaas
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Vienna Biocenter, Medical University of Vienna, Vienna, Austria
| | - Johannes Stöckl
- Institute of Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
14
|
Genetic characterization and phylogenetic analysis of host-range genes of Camelpox virus isolates from India. Virusdisease 2015; 26:151-62. [PMID: 26396982 DOI: 10.1007/s13337-015-0266-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/07/2015] [Indexed: 10/23/2022] Open
Abstract
Camelpox virus (CMLV), a close variant of variola virus (VARV) infects camels worldwide. The zoonotic infections reported from India signify the need to study the host-range genes-responsible for host tropism. We report sequence and phylogenetic analysis of five host-range genes: cytokine response modifier B (crmB), chemokine binding protein (ckbp), viral schlafen-like (v-slfn), myxomavirus T4-like (M-T4-like) and b5r of CMLVs isolated from outbreaks in India. Comparative analysis revealed that these genes are conserved among CMLVs and shared 94.5-100 % identity at both nucleotide (nt) and amino acid (aa) levels. All genes showed identity (59.3-98.4 %) with cowpox virus (CPXV) while three genes-crmB, ckbp and b5r showed similarity (92-96.5 %) with VARVs at both nt and aa levels. Interestingly, three consecutive serine residue insertions were observed in CKBP protein of CMLV-Delhi09 isolate which was similar to CPXV-BR and VACVs, besides five point mutations (K53Q, N67I, F84S, A127T and E182G) were also similar to zoonotic OPXVs. Further, few inconsistent point mutation(s) were also observed in other gene(s) among Indian CMLVs. These indicate that different strains of CMLVs are circulating in India and these mutations could play an important role in adaptation of CMLVs in humans. The phylogeny revealed clustering of all CMLVs together except CMLV-Delhi09 which grouped separately due to the presence of specific point mutations. However, the topology of the concatenated phylogeny showed close evolutionary relationship of CMLV with VARV and TATV followed by CPXV-RatGer09/1 from Germany. The availability of this genetic information will be useful in unveiling new strategies to control emerging zoonotic poxvirus infections.
Collapse
|
15
|
Bhanuprakash V, Prabhu M, Venkatesan G, Balamurugan V, Hosamani M, Pathak KML, Singh RK. Camelpox: epidemiology, diagnosis and control measures. Expert Rev Anti Infect Ther 2014; 8:1187-201. [DOI: 10.1586/eri.10.105] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
16
|
Camelpox, an emerging orthopox viral disease. INDIAN JOURNAL OF VIROLOGY : AN OFFICIAL ORGAN OF INDIAN VIROLOGICAL SOCIETY 2013; 24:295-305. [PMID: 24426291 DOI: 10.1007/s13337-013-0145-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 06/25/2013] [Indexed: 10/26/2022]
Abstract
Camelpox is considered as emerging public health problem during this decade due to increased reported cases and outbreaks in camels. Camelpox is a contagious, often sporadic, and notifiable skin disease of camelids and is socio-economically significant as it incurs considerable loss in terms of morbidity, mortality, loss of weight and reduction in milk yield and confined to camel-rearing countries. The causative agent, camelpox virus (CMLV) is genetically closely related to variola virus and has gained much attention from researchers due to its recent emergence in human. The virus carrying genes responsible for host immune evasion mechanisms owing to the threat posed by potential bio-warfare agents. Although the disease can be diagnosed based on clinical features, the similar confounding skin lesions necessitate identification, detection and differentiation of the CMLV by molecular techniques. Vaccines are available in some countries and the available live attenuated vaccine provides long-lasting immunity. Further, novel highly sensitive and specific techniques would be useful in the identification of emerging and re-emerging virus, thereby therapeutic, prophylactic, preventive measures would be applied in time to curtail further spread of camelpox like other zoonotic diseases. This review provide overview of the camelpox particularly on its epidemiology, pathogenesis and biology of the disease, diagnostic approaches and control measures.
Collapse
|
17
|
Phylogenetic analysis of immunomodulatory protein genes of camelpoxvirus obtained from India. Comp Immunol Microbiol Infect Dis 2013; 36:415-24. [DOI: 10.1016/j.cimid.2013.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 03/04/2013] [Accepted: 03/07/2013] [Indexed: 10/27/2022]
|
18
|
Horizontal transfer and the evolution of host-pathogen interactions. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2012; 2012:679045. [PMID: 23227424 PMCID: PMC3513734 DOI: 10.1155/2012/679045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 10/26/2012] [Indexed: 12/16/2022]
Abstract
Horizontal gene transfer has been long known in viruses and prokaryotes, but its importance in eukaryotes has been only acknowledged recently. Close contact between organisms, as it occurs between pathogens and their hosts, facilitates the occurrence of DNA transfer events. Once inserted in a foreign genome, DNA sequences have sometimes been coopted by pathogens to improve their survival or infectivity, or by hosts to protect themselves against the harm of pathogens. Hence, horizontal transfer constitutes a source of novel sequences that can be adopted to change the host-pathogen interactions. Therefore, horizontal transfer can have an important impact on the coevolution of pathogens and their hosts.
Collapse
|
19
|
|
20
|
Duraffour S, Matthys P, van den Oord JJ, De Schutter T, Mitera T, Snoeck R, Andrei G. Study of camelpox virus pathogenesis in athymic nude mice. PLoS One 2011; 6:e21561. [PMID: 21738709 PMCID: PMC3125194 DOI: 10.1371/journal.pone.0021561] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 06/02/2011] [Indexed: 11/29/2022] Open
Abstract
Camelpox virus (CMLV) is the closest known orthopoxvirus genetically related to variola virus. So far, CMLV was restricted to camelids but, recently, three human cases of camelpox have been described in India, highlighting the need to pursue research on its pathogenesis, which has been hampered by the lack of small animal models. Here, we confirm that NMRI immunocompetent mice are resistant to intranasal (i.n.) CMLV infection. However, we demonstrate that CMLV induced a severe disease following i.n. challenge of athymic nude mice, which was accompanied with a failure in gaining weight, leading to euthanasia of the animals. On the other hand, intracutaneous (i.c.) infection resulted in disease development without impacting the body weight evolution. CMLV replication in tissues and body fluids was confirmed in the two models. We further analyzed innate immune and B cell responses induced in the spleen and draining lymph nodes after exposure to CMLV. In both models, strong increases in CD11b+F4/80+ macrophages were seen in the spleen, while neutrophils, NK and B cell responses varied between the routes of infection. In the lymph nodes, the magnitude of CD11c+CD8α+ lymphoid and CD11c+CD11b+ myeloid dendritic cell responses increased in i.n. challenged animals. Analysis of cytokine profiles revealed significant increases of interleukin (IL)-6 and IL-18 in the sera of infected animals, while those of other cytokines were similar to uninfected controls. The efficacy of two antivirals (cidofovir or HPMPC, and its 2, 6-diaminopurine analog) was evaluated in both models. HPMPC was the most effective molecule affording 100% protection from morbidity. It appeared that both treatments did not affect immune cell responses or cytokine expression. In conclusion, we demonstrated that immunodeficient mice are permissive for CMLV propagation. These results provide a basis for studying the pathogenesis of CMLV, as well as for evaluating potential antiviral therapies in an immunodeficiency context.
Collapse
Affiliation(s)
- Sophie Duraffour
- Rega Institute, Laboratory of Virology and Chemotherapy, K.U.L, Leuven, Belgium.
| | | | | | | | | | | | | |
Collapse
|
21
|
de la Casa-Esperón E. From mammals to viruses: the Schlafen genes in developmental, proliferative and immune processes. Biomol Concepts 2011; 2:159-69. [DOI: 10.1515/bmc.2011.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 04/29/2011] [Indexed: 11/15/2022] Open
Abstract
AbstractThe Schlafen genes have been associated with proliferation control and with several differentiation processes, as well as with disparate phenotypes such as immune response, embryonic lethality and meiotic drive. They constitute a gene family with widespread distribution in mammals, where they are expressed in several tissues, predominantly those of the immune system. Moreover, horizontal transfer of these genes to orthopoxviruses suggests a role of the viral Schlafens in evasion to the host immune response. The expression and functional studies of this gene family will be reviewed under the prism of their evolution and diversification, the challenges they pose and the future avenues of research.
Collapse
Affiliation(s)
- Elena de la Casa-Esperón
- 1Albacete Science and Technology Park, Regional Center for Biomedical Research (C.R.I.B.) at the University of Castilla-La Mancha, C/Almansa 14, 02006 Albacete, Spain
| |
Collapse
|
22
|
Macrophage activation and differentiation signals regulate schlafen-4 gene expression: evidence for Schlafen-4 as a modulator of myelopoiesis. PLoS One 2011; 6:e15723. [PMID: 21249125 PMCID: PMC3017543 DOI: 10.1371/journal.pone.0015723] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 11/28/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The ten mouse and six human members of the Schlafen (Slfn) gene family all contain an AAA domain. Little is known of their function, but previous studies suggest roles in immune cell development. In this report, we assessed Slfn regulation and function in macrophages, which are key cellular regulators of innate immunity. METHODOLOGY/PRINCIPAL FINDINGS Multiple members of the Slfn family were up-regulated in mouse bone marrow-derived macrophages (BMM) by the Toll-like Receptor (TLR)4 agonist lipopolysaccharide (LPS), the TLR3 agonist Poly(I∶C), and in disease-affected joints in the collagen-induced model of rheumatoid arthritis. Of these, the most inducible was Slfn4. TLR agonists that signal exclusively through the MyD88 adaptor protein had more modest effects on Slfn4 mRNA levels, thus implicating MyD88-independent signalling and autocrine interferon (IFN)-β in inducible expression. This was supported by the substantial reduction in basal and LPS-induced Slfn4 mRNA expression in IFNAR-1⁻/⁻ BMM. LPS causes growth arrest in macrophages, and other Slfn family genes have been implicated in growth control. Slfn4 mRNA levels were repressed during macrophage colony-stimulating factor (CSF-1)-mediated differentiation of bone marrow progenitors into BMM. To determine the role of Slfn4 in vivo, we over-expressed the gene specifically in macrophages in mice using a csf1r promoter-driven binary expression system. Transgenic over-expression of Slfn4 in myeloid cells did not alter macrophage colony formation or proliferation in vitro. Monocyte numbers, as well as inflammatory macrophages recruited to the peritoneal cavity, were reduced in transgenic mice that specifically over-expressed Slfn4, while macrophage numbers and hematopoietic activity were increased in the livers and spleens. CONCLUSIONS Slfn4 mRNA levels were up-regulated during macrophage activation but down-regulated during differentiation. Constitutive Slfn4 expression in the myeloid lineage in vivo perturbs myelopoiesis. We hypothesise that the down-regulation of Slfn4 gene expression during macrophage differentiation is a necessary step in development of this lineage.
Collapse
|
23
|
|
24
|
Berger M, Krebs P, Crozat K, Li X, Croker BA, Siggs OM, Popkin D, Du X, Lawson BR, Theofilopoulos AN, Xia Y, Khovananth K, Moresco EM, Satoh T, Takeuchi O, Akira S, Beutler B. An Slfn2 mutation causes lymphoid and myeloid immunodeficiency due to loss of immune cell quiescence. Nat Immunol 2010; 11:335-43. [PMID: 20190759 PMCID: PMC2861894 DOI: 10.1038/ni.1847] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 01/25/2010] [Indexed: 12/13/2022]
Abstract
We describe a new form of inherited immunodeficiency revealed by an N-ethyl-N-nitrosourea (ENU)-induced mutation called elektra. Homozygotes showed enhanced susceptibility to bacterial and viral infections, and diminished numbers of T cells and inflammatory monocytes that failed to proliferate upon infection and died via the intrinsic apoptotic pathway in response to diverse proliferative stimuli. Elektra mice exhibited an increased proportion of T cells poised to replicate DNA and their T cells expressed a subset of activation markers, suggestive of a semi-activated state. The elektra phenotype was positionally ascribed to a mutation in the gene encoding Schlafen-2 (Slfn2). Our findings reveal a physiological role for Slfn2 in the defense against pathogens through regulation of quiescence in T cells and monocytes.
Collapse
Affiliation(s)
- Michael Berger
- Department of Genetics, The Scripps Research Institute, La Jolla, California, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Bustos O, Naik S, Ayers G, Casola C, Perez-Lamigueiro MA, Chippindale PT, Pritham EJ, de la Casa-Esperón E. Evolution of the Schlafen genes, a gene family associated with embryonic lethality, meiotic drive, immune processes and orthopoxvirus virulence. Gene 2009; 447:1-11. [PMID: 19619625 PMCID: PMC9533870 DOI: 10.1016/j.gene.2009.07.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 06/26/2009] [Accepted: 07/04/2009] [Indexed: 12/30/2022]
Abstract
Genes of the Schlafen family, first discovered in mouse, are expressed in hematopoietic cells and are involved in immune processes. Previous results showed that they are candidate genes for two major phenomena: meiotic drive and embryonic lethality (DDK syndrome). However, these genes remain poorly understood, mostly due to the limitations imposed by their similarity, close location and the potential functional redundancy of the gene family members. Here we use genomic and phylogenetic studies to investigate the evolution and role of this family of genes. Our results show that the Schlafen family is widely distributed in mammals, where we recognize four major clades that experienced lineage-specific expansions or contractions in various orders, including primates and rodents. In addition, we identified members of the Schlafen family in Chondrichthyes and Amphibia, indicating an ancient origin of these genes. We find evidence that positive selection has acted on many Schlafen genes. Moreover, our analyses indicate that a member of the Schlafen family was horizontally transferred from murine rodents to orthopoxviruses, where it is hypothesized to play a role in allowing the virus to survive host immune defense mechanisms. The functional relevance of the viral Schlafen sequences is further underscored by our finding that they are evolving under purifying selection. This is of particular importance, since orthopoxviruses infect mammals and include variola, the causative agent of smallpox, and monkeypox, an emerging virus of great concern for human health.
Collapse
Affiliation(s)
- Olivia Bustos
- Department of Biology. The University of Texas Arlington, 501 S. Nedderman Dr. Arlington, TX 76019-0498, USA
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Hao L, Vassena R, Wu G, Han Z, Cheng Y, Latham KE, Sapienza C. The unfolded protein response contributes to preimplantation mouse embryo death in the DDK syndrome. Biol Reprod 2009; 80:944-53. [PMID: 19129515 DOI: 10.1095/biolreprod.108.072546] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
DDK syndrome is the polar-lethal embryonic death that occurs at the morula-blastocyst transition when female mice of the DDK strain are mated with males from many other inbred strains (so-called alien males). Embryonic death is caused by incompatibility between a DDK oocyte factor and an alien male gene, both of which map to the Om locus on mouse chromosome 11. We compared global transcription patterns of DDK x DDK embryos (high viability) and DDK x C57BL/6 embryos (low viability) at the morula stage, approximately 24 h before any morphological manifestations of DDK syndrome are observed. Of the transcripts that are differentially more abundant in the DDK x C57BL/6 embryos, many are the products of genes induced by the "unfolded protein response." We confirmed by quantitative RT-PCR that a number of genes in this pathway are upregulated in the DDK x C57BL/6 embryos. Immunostaining of the endoplasmic reticulum (ER) marker BIP/GRP78 (immunoglobin-binding protein/glucose-regulated protein of 78 kDa), official symbol HSPA5, heat shock protein 5 revealed an accompanying abnormal HSPA5 accumulation and ER structure in the DDK x C57BL/6 embryos. Immunostaining for HERPUD1 (homocysteine-inducible, ER stress-inducible, ubiquitin-like domain member 1) and ATF4 (activating transcription factor 4) also revealed accumulation of these stress-response products. Our results indicate that the unfolded protein response is induced in embryos destined to die of DDK syndrome and that the embryonic death observed is associated with inability to resolve the associated ER stress.
Collapse
Affiliation(s)
- Lanping Hao
- Fels Institute for Cancer Research and Molecular Biology, Temple University Medical School, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | | |
Collapse
|
27
|
Simón O, Williams T, Caballero P, Possee RD. Effects of Acp26 on in vitro and in vivo productivity, pathogenesis and virulence of Autographa californica multiple nucleopolyhedrovirus. Virus Res 2008; 136:202-5. [PMID: 18538883 DOI: 10.1016/j.virusres.2008.04.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 04/24/2008] [Accepted: 04/24/2008] [Indexed: 11/16/2022]
Affiliation(s)
- Oihane Simón
- Centre for Ecology and Hydrology, Mansfield Road, Oxford OX1 3SR, UK.
| | | | | | | |
Collapse
|
28
|
Subcellular localization of the Schlafen protein family. Biochem Biophys Res Commun 2008; 370:62-6. [PMID: 18355440 DOI: 10.1016/j.bbrc.2008.03.032] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Accepted: 03/05/2008] [Indexed: 11/23/2022]
Abstract
Although the first members of the Schlafen gene family were first described almost 10 years ago, the precise molecular/biochemical functions of the proteins they encode still remain largely unknown. Roles in cell growth, haematopoietic cell differentiation, and T cell development/maturation have, with some experimental support, been postulated, but none have been conclusively verified. Here, we have determined the subcellular localization of Schlafens 1, 2, 4, 5, 8, and 9, representing all three of the murine subgroups. We show that the proteins from subgroups I and II localize to the cytoplasm, while the longer forms in subgroup III localize exclusively to the nuclear compartment. We also demonstrate upregulation of Schlafen2 upon differentiation of haematopoietic cells and show this endogenous protein localizes to the cytoplasm. Thus, we propose the different subgroups of Schlafen proteins are likely to have functionally distinct roles, reflecting their differing localizations within the cell.
Collapse
|
29
|
Goenka S, Weaver RF. The p26 gene of the Autographa californica nucleopolyhedrovirus: Timing of transcription, and cellular localization and dimerization of product. Virus Res 2008; 131:136-44. [DOI: 10.1016/j.virusres.2007.08.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Revised: 08/30/2007] [Accepted: 08/30/2007] [Indexed: 11/15/2022]
|