1
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Kim K, Shi AB, Kelley K, Chen XS. Unraveling the Enzyme-Substrate Properties for APOBEC3A-Mediated RNA Editing. J Mol Biol 2023; 435:168198. [PMID: 37442413 PMCID: PMC10528890 DOI: 10.1016/j.jmb.2023.168198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/29/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023]
Abstract
The APOBEC3 family of human cytidine deaminases is involved in various cellular processes, including the innate and acquired immune system, mostly through inducing C-to-U in single-stranded DNA and/or RNA mutations. Although recent studies have examined RNA editing by APOBEC3A (A3A), its intracellular target specificity are not fully characterized. To address this gap, we performed in-depth analysis of cellular RNA editing using our recently developed sensitive cell-based fluorescence assay. Our findings demonstrate that A3A and an A3A-loop1-containing APOBEC3B (A3B) chimera are capable of RNA editing. We observed that A3A prefers to edit specific RNA substrates which are not efficiently deaminated by other APOBEC members. The editing efficiency of A3A is influenced by the RNA sequence contexts and distinct stem-loop secondary structures. Based on the identified RNA specificity features, we predicted potential A3A-editing targets in the encoding region of cellular mRNAs and discovered novel RNA transcripts that are extensively edited by A3A. Furthermore, we found a trend of increased synonymous mutations at the sites for more efficient A3A-editing, indicating evolutionary adaptation to the higher editing rate by A3A. Our results shed light on the intracellular RNA editing properties of A3A and provide insights into new RNA targets and potential impact of A3A-mediated RNA editing.
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Affiliation(s)
- Kyumin Kim
- Molecular and Computational Biology Program, Departments of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA. https://twitter.com/KYUMINK1324
| | - Alan B Shi
- Molecular and Computational Biology Program, Departments of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Kori Kelley
- Molecular and Computational Biology Program, Departments of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiaojiang S Chen
- Molecular and Computational Biology Program, Departments of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA; Genetic, Molecular and Cellular Biology Program, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA; Center of Excellence in NanoBiophysics, University of Southern California, Los Angeles, CA 90089, USA; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA.
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2
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Lactobacillus for ribosome peptide editing cancer. Clin Transl Oncol 2023; 25:1522-1544. [PMID: 36694080 PMCID: PMC9873400 DOI: 10.1007/s12094-022-03066-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/24/2022] [Indexed: 01/25/2023]
Abstract
This study reviews newly discovered insect peptide point mutations as new possible cancer research targets. To interpret newly discovered peptide point mutations in insects as new possible cancer research targets, we focused on the numerous peptide changes found in the 'CSP' family on the sex pheromone gland of the female silkworm moth Bombyx mori. We predict that the Bombyx peptide modifications will have a significant effect on cancer CUP (cancers of unknown primary) therapy and that bacterial peptide editing techniques, specifically Lactobacillus combined to CRISPR, will be used to regulate ribosomes and treat cancer in humans.
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3
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C-to-U RNA Editing: A Site Directed RNA Editing Tool for Restoration of Genetic Code. Genes (Basel) 2022; 13:genes13091636. [PMID: 36140804 PMCID: PMC9498875 DOI: 10.3390/genes13091636] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 11/18/2022] Open
Abstract
The restoration of genetic code by editing mutated genes is a potential method for the treatment of genetic diseases/disorders. Genetic disorders are caused by the point mutations of thymine (T) to cytidine (C) or guanosine (G) to adenine (A), for which gene editing (editing of mutated genes) is a promising therapeutic technique. In C-to-Uridine (U) RNA editing, it converts the base C-to-U in RNA molecules and leads to nonsynonymous changes when occurring in coding regions; however, for G-to-A mutations, A-to-I editing occurs. Editing of C-to-U is not as physiologically common as that of A-to-I editing. Although hundreds to thousands of coding sites have been found to be C-to-U edited or editable in humans, the biological significance of this phenomenon remains elusive. In this review, we have tried to provide detailed information on physiological and artificial approaches for C-to-U RNA editing.
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4
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Wu J, Li N, Zhu L, Zhen D, Li M, Chen H, Ye M, Wei Y, Shao G. Multiple roles of apolipoprotein B mRNA editing enzyme catalytic subunit 3B (APOBEC3B) in human tumors: a pan-cancer analysis. BMC Bioinformatics 2022; 23:312. [PMID: 35918642 PMCID: PMC9344753 DOI: 10.1186/s12859-022-04862-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/25/2022] [Indexed: 11/14/2022] Open
Abstract
Although there have been some recent cell and animal experiments indicating that expression of the gene encoding apolipoprotein B mRNA editing enzyme catalytic subunit 3B (APOBEC3B) is closely related to cancer, it still lacks pan-cancer analysis. Here we analyzed the potential carcinogenic role of APOBEC3B in 33 tumors based on The Cancer Genome Atlas (TCGA). APOBEC3B was highly expressed in most tumors and weakly expressed in a few. Differences in expression level were significantly correlated with the pathological tumor stage and prognosis of affected patients. The high-frequency APOBEC3B changes were principally mutations and amplifications in some tumors, such as uterine corpus endometrial carcinomas or cutaneous melanomas. In testicular germ cell tumors and invasive breast carcinomas, APOBEC3B expression and CD8+ T lymphocyte counts were correlated. In other cancers, such as human papilloma virus (HPV)-related head and neck squamous cell carcinomas or esophageal adenocarcinomas, there was also cancer-associated fibroblast infiltration. The APOBEC3B enzyme acts in the mitochondrial respiratory electron transport chain and in oxidative phosphorylation. This first pan-cancer study provides a comprehensive understanding of the multiple roles of APOBEC3B in different tumor types.
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Affiliation(s)
- Jiacheng Wu
- Medical College, Ningbo University, Ningbo, Zhejiang, People's Republic of China.,Department of Cardiothoracic Surgery, Lihuili Hospital Affiliated to Ningbo University, Ningbo, 315000, Zhejiang, People's Republic of China
| | - Ni Li
- Department of Cardiothoracic Surgery, Lihuili Hospital Affiliated to Ningbo University, Ningbo, 315000, Zhejiang, People's Republic of China
| | - Linwen Zhu
- Department of Cardiothoracic Surgery, Lihuili Hospital Affiliated to Ningbo University, Ningbo, 315000, Zhejiang, People's Republic of China
| | - Dawei Zhen
- Department of Cardiothoracic Surgery, Lihuili Hospital Affiliated to Ningbo University, Ningbo, 315000, Zhejiang, People's Republic of China
| | - Mengqi Li
- Department of Geriatrics, Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Shaoxing, Zhejiang, People's Republic of China
| | - Hang Chen
- Medical College, Ningbo University, Ningbo, Zhejiang, People's Republic of China.,Department of Cardiothoracic Surgery, Lihuili Hospital Affiliated to Ningbo University, Ningbo, 315000, Zhejiang, People's Republic of China
| | - Mengmeng Ye
- Medical College, Ningbo University, Ningbo, Zhejiang, People's Republic of China.,Department of Cardiothoracic Surgery, Lihuili Hospital Affiliated to Ningbo University, Ningbo, 315000, Zhejiang, People's Republic of China
| | - Yiqin Wei
- Medical College, Ningbo University, Ningbo, Zhejiang, People's Republic of China.,Department of Cardiothoracic Surgery, Lihuili Hospital Affiliated to Ningbo University, Ningbo, 315000, Zhejiang, People's Republic of China
| | - Guofeng Shao
- Department of Cardiothoracic Surgery, Lihuili Hospital Affiliated to Ningbo University, Ningbo, 315000, Zhejiang, People's Republic of China.
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5
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Destefanis E, Avşar G, Groza P, Romitelli A, Torrini S, Pir P, Conticello SG, Aguilo F, Dassi E. A mark of disease: how mRNA modifications shape genetic and acquired pathologies. RNA (NEW YORK, N.Y.) 2021; 27:367-389. [PMID: 33376192 PMCID: PMC7962492 DOI: 10.1261/rna.077271.120] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
RNA modifications have recently emerged as a widespread and complex facet of gene expression regulation. Counting more than 170 distinct chemical modifications with far-reaching implications for RNA fate, they are collectively referred to as the epitranscriptome. These modifications can occur in all RNA species, including messenger RNAs (mRNAs) and noncoding RNAs (ncRNAs). In mRNAs the deposition, removal, and recognition of chemical marks by writers, erasers and readers influence their structure, localization, stability, and translation. In turn, this modulates key molecular and cellular processes such as RNA metabolism, cell cycle, apoptosis, and others. Unsurprisingly, given their relevance for cellular and organismal functions, alterations of epitranscriptomic marks have been observed in a broad range of human diseases, including cancer, neurological and metabolic disorders. Here, we will review the major types of mRNA modifications and editing processes in conjunction with the enzymes involved in their metabolism and describe their impact on human diseases. We present the current knowledge in an updated catalog. We will also discuss the emerging evidence on the crosstalk of epitranscriptomic marks and what this interplay could imply for the dynamics of mRNA modifications. Understanding how this complex regulatory layer can affect the course of human pathologies will ultimately lead to its exploitation toward novel epitranscriptomic therapeutic strategies.
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Affiliation(s)
- Eliana Destefanis
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
- The EPITRAN COST Action Consortium, COST Action CA16120
| | - Gülben Avşar
- The EPITRAN COST Action Consortium, COST Action CA16120
- Department of Bioengineering, Gebze Technical University, 41400 Kocaeli, Turkey
| | - Paula Groza
- The EPITRAN COST Action Consortium, COST Action CA16120
- Department of Medical Biosciences, Umeå University, 901 87 Umeå, Sweden
- Wallenberg Center for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Antonia Romitelli
- The EPITRAN COST Action Consortium, COST Action CA16120
- Core Research Laboratory, ISPRO-Institute for Cancer Research, Prevention and Clinical Network, 50139 Firenze, Italy
- Department of Medical Biotechnologies, Università di Siena, 53100 Siena, Italy
| | - Serena Torrini
- The EPITRAN COST Action Consortium, COST Action CA16120
- Core Research Laboratory, ISPRO-Institute for Cancer Research, Prevention and Clinical Network, 50139 Firenze, Italy
- Department of Medical Biotechnologies, Università di Siena, 53100 Siena, Italy
| | - Pınar Pir
- The EPITRAN COST Action Consortium, COST Action CA16120
- Department of Bioengineering, Gebze Technical University, 41400 Kocaeli, Turkey
| | - Silvestro G Conticello
- The EPITRAN COST Action Consortium, COST Action CA16120
- Core Research Laboratory, ISPRO-Institute for Cancer Research, Prevention and Clinical Network, 50139 Firenze, Italy
- Institute of Clinical Physiology, National Research Council, 56124 Pisa, Italy
| | - Francesca Aguilo
- The EPITRAN COST Action Consortium, COST Action CA16120
- Department of Medical Biosciences, Umeå University, 901 87 Umeå, Sweden
- Wallenberg Center for Molecular Medicine, Umeå University, 901 87 Umeå, Sweden
| | - Erik Dassi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, 38123 Trento, Italy
- The EPITRAN COST Action Consortium, COST Action CA16120
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6
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Kurkowiak M, Arcimowicz Ł, Chruściel E, Urban-Wójciuk Z, Papak I, Keegan L, O'Connell M, Kowalski J, Hupp T, Marek-Trzonkowska N. The effects of RNA editing in cancer tissue at different stages in carcinogenesis. RNA Biol 2021; 18:1524-1539. [PMID: 33593231 PMCID: PMC8582992 DOI: 10.1080/15476286.2021.1877024] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
RNA editing is one of the most prevalent and abundant forms of post-transcriptional RNA modification observed in normal physiological processes and often aberrant in diseases including cancer. RNA editing changes the sequences of mRNAs, making them different from the source DNA sequence. Edited mRNAs can produce editing-recoded protein isoforms that are functionally different from the corresponding genome-encoded protein isoforms. The major type of RNA editing in mammals occurs by enzymatic deamination of adenosine to inosine (A-to-I) within double-stranded RNAs (dsRNAs) or hairpins in pre-mRNA transcripts. Enzymes that catalyse these processes belong to the adenosine deaminase acting on RNA (ADAR) family. The vast majority of knowledge on the RNA editing landscape relevant to human disease has been acquired using in vitro cancer cell culture models. The limitation of such in vitro models, however, is that the physiological or disease relevance of results obtained is not necessarily obvious. In this review we focus on discussing in vivo occurring RNA editing events that have been identified in human cancer tissue using samples surgically resected or clinically retrieved from patients. We discuss how RNA editing events occurring in tumours in vivo can identify pathological signalling mechanisms relevant to human cancer physiology which is linked to the different stages of cancer progression including initiation, promotion, survival, proliferation, immune escape and metastasis.
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Affiliation(s)
- Małgorzata Kurkowiak
- International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Gdańsk, Poland
| | - Łukasz Arcimowicz
- International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Gdańsk, Poland
| | - Elżbieta Chruściel
- International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Gdańsk, Poland
| | - Zuzanna Urban-Wójciuk
- International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Gdańsk, Poland
| | - Ines Papak
- International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Gdańsk, Poland
| | - Liam Keegan
- CEITEC Masaryk University, Brno, CZ, Czech Republic
| | | | - Jacek Kowalski
- International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Gdańsk, Poland.,Department of Pathomorphology, Medical University of Gdańsk, Gdańsk, Poland
| | - Ted Hupp
- International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Gdańsk, Poland.,University of Edinburgh, Edinburgh Cancer Research Centre, Edinburgh, Scotland, UK
| | - Natalia Marek-Trzonkowska
- International Centre for Cancer Vaccine Science (ICCVS), University of Gdańsk, Gdańsk, Poland.,Laboratory of Immunoregulation and Cellular Therapies, Department of Family Medicine, Medical University of Gdańsk, Gdańsk, Poland
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7
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Barzak FM, Ryan TM, Kvach MV, Kurup HM, Aihara H, Harris RS, Filichev VV, Harjes E, Jameson GB. Small-Angle X-ray Scattering Models of APOBEC3B Catalytic Domain in a Complex with a Single-Stranded DNA Inhibitor. Viruses 2021; 13:290. [PMID: 33673243 PMCID: PMC7918907 DOI: 10.3390/v13020290] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 02/02/2021] [Accepted: 02/05/2021] [Indexed: 12/12/2022] Open
Abstract
In normal cells APOBEC3 (A3A-A3H) enzymes as part of the innate immune system deaminate cytosine to uracil on single-stranded DNA (ssDNA) to scramble DNA in order to give protection against a range of exogenous retroviruses, DNA-based parasites, and endogenous retroelements. However, some viruses and cancer cells use these enzymes, especially A3A and A3B, to escape the adaptive immune response and thereby lead to the evolution of drug resistance. We have synthesized first-in-class inhibitors featuring modified ssDNA. We present models based on small-angle X-ray scattering (SAXS) data that (1) confirm that the mode of binding of inhibitor to an active A3B C-terminal domain construct in the solution state is the same as the mode of binding substrate to inactive mutants of A3A and A3B revealed in X-ray crystal structures and (2) give insight into the disulfide-linked inactive dimer formed under the oxidizing conditions of purification.
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Affiliation(s)
- Fareeda M. Barzak
- School of Fundamental Sciences, Massey University, Private Bag 11 222, New Zealand; (F.M.B.); (M.V.K.); (H.M.K.)
| | - Timothy M. Ryan
- SAXS/WAXS, Australian Synchrotron/ANSTO, 800 Blackburn Road, Clayton, VIC 3168, Australia;
| | - Maksim V. Kvach
- School of Fundamental Sciences, Massey University, Private Bag 11 222, New Zealand; (F.M.B.); (M.V.K.); (H.M.K.)
| | - Harikrishnan M. Kurup
- School of Fundamental Sciences, Massey University, Private Bag 11 222, New Zealand; (F.M.B.); (M.V.K.); (H.M.K.)
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; (H.A.); (R.S.H.)
| | - Reuben S. Harris
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; (H.A.); (R.S.H.)
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, MN 55455, USA
| | - Vyacheslav V. Filichev
- School of Fundamental Sciences, Massey University, Private Bag 11 222, New Zealand; (F.M.B.); (M.V.K.); (H.M.K.)
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland 1142, New Zealand
| | - Elena Harjes
- School of Fundamental Sciences, Massey University, Private Bag 11 222, New Zealand; (F.M.B.); (M.V.K.); (H.M.K.)
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland 1142, New Zealand
| | - Geoffrey B. Jameson
- School of Fundamental Sciences, Massey University, Private Bag 11 222, New Zealand; (F.M.B.); (M.V.K.); (H.M.K.)
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland 1142, New Zealand
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8
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Lerner T, Kluesner M, Tasakis RN, Moriarity BS, Papavasiliou FN, Pecori R. C-to-U RNA Editing: From Computational Detection to Experimental Validation. Methods Mol Biol 2021; 2181:51-67. [PMID: 32729074 DOI: 10.1007/978-1-0716-0787-9_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The AID/APOBEC family of enzymes are cytidine deaminases that act upon DNA and RNA. Among APOBECs, the best characterized family member to act on RNA is the enzyme APOBEC1. APOBEC1-mediated RNA editing plays a key role in lipid metabolism and in maintenance of brain homeostasis. Editing can be easily detected in RNA-seq data as a cytosine to thymine (C-to-T) change with regard to the reference. However, there are many other sources of base conversions relative to reference, such as PCR errors, SNPs, and even DNA editing by mutator APOBECs. Furthermore, APOBEC1 exhibits disparate activity in different cell types, with respect to which transcripts are edited and the level to which they are edited. When considering these potential sources of error and variability, an RNA-seq comparison between wild-type APOBEC1 sample and a matched control with an APOBEC1 knockout is a reliable method for the discrimination of true sites edited by APOBEC1. Here we present a detailed description of a method for studying APOBEC1 RNA editing, specifically in the murine macrophage cell line RAW 264.7. Our method covers the production of an APOBEC1 knockout cell line using the CRISPR/Cas9 system, through to experimental validation and quantification of editing sites (where we discuss a recently published algorithm (termed MultiEditR) which allows for the detection and quantification of RNA editing from Sanger sequencing). Importantly, this same protocol can be adapted to any RNA modification detectable by RNA-seq analysis for which the responsible protein is known.
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Affiliation(s)
- Taga Lerner
- Division of Immune Diversity, Program in Cancer Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Mitchell Kluesner
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - Rafail Nikolaos Tasakis
- Division of Immune Diversity, Program in Cancer Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, Heidelberg, Germany
| | - Branden S Moriarity
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA.,Center for Genome Engineering, University of Minnesota, Minneapolis, MN, USA.,Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
| | - F Nina Papavasiliou
- Division of Immune Diversity, Program in Cancer Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Riccardo Pecori
- Division of Immune Diversity, Program in Cancer Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.
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9
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Yang H, Ito F, Wolfe AD, Li S, Mohammadzadeh N, Love RP, Yan M, Zirkle B, Gaba A, Chelico L, Chen XS. Understanding the structural basis of HIV-1 restriction by the full length double-domain APOBEC3G. Nat Commun 2020; 11:632. [PMID: 32005813 PMCID: PMC6994475 DOI: 10.1038/s41467-020-14377-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 12/18/2019] [Indexed: 12/17/2022] Open
Abstract
APOBEC3G, a member of the double-domain cytidine deaminase (CD) APOBEC, binds RNA to package into virions and restrict HIV-1 through deamination-dependent or deamination-independent inhibition. Mainly due to lack of a full-length double-domain APOBEC structure, it is unknown how CD1/CD2 domains connect and how dimerization/multimerization is linked to RNA binding and virion packaging for HIV-1 restriction. We report rhesus macaque A3G structures that show different inter-domain packing through a short linker and refolding of CD2. The A3G dimer structure has a hydrophobic dimer-interface matching with that of the previously reported CD1 structure. A3G dimerization generates a surface with intensified positive electrostatic potentials (PEP) for RNA binding and dimer stabilization. Unexpectedly, mutating the PEP surface and the hydrophobic interface of A3G does not abolish virion packaging and HIV-1 restriction. The data support a model in which only one RNA-binding mode is critical for virion packaging and restriction of HIV-1 by A3G. APOBEC3G (A3G) belongs to the DNA/RNA cytosine deaminase family that plays important roles in innate immunity against HIV and internal retroelements. Here the authors report the structures of two full-length A3G variants that provides insight into domain organization, multimerization, RNA binding, and viral restriction.
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Affiliation(s)
- Hanjing Yang
- Molecular and Computational Biology, Departments of Biological Sciences, Chemistry, University of Southern California, Los Angeles, CA, 90089, USA
| | - Fumiaki Ito
- Molecular and Computational Biology, Departments of Biological Sciences, Chemistry, University of Southern California, Los Angeles, CA, 90089, USA
| | - Aaron D Wolfe
- Molecular and Computational Biology, Departments of Biological Sciences, Chemistry, University of Southern California, Los Angeles, CA, 90089, USA.,Genetic, Molecular and Cellular Biology Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.,Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, 90033, USA
| | - Shuxing Li
- Molecular and Computational Biology, Departments of Biological Sciences, Chemistry, University of Southern California, Los Angeles, CA, 90089, USA.,Center of Excellence in NanoBiophysics, University of Southern California, Los Angeles, CA, 90089, USA
| | - Nazanin Mohammadzadeh
- Department of Biochemistry, Microbiology, and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Robin P Love
- Department of Biochemistry, Microbiology, and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Maocai Yan
- Molecular and Computational Biology, Departments of Biological Sciences, Chemistry, University of Southern California, Los Angeles, CA, 90089, USA.,School of Pharmacy, Jining Medical University, 276800, Rizhao, Shandong, China
| | - Brett Zirkle
- Molecular and Computational Biology, Departments of Biological Sciences, Chemistry, University of Southern California, Los Angeles, CA, 90089, USA.,Genetic, Molecular and Cellular Biology Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Amit Gaba
- Department of Biochemistry, Microbiology, and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Linda Chelico
- Department of Biochemistry, Microbiology, and Immunology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Xiaojiang S Chen
- Molecular and Computational Biology, Departments of Biological Sciences, Chemistry, University of Southern California, Los Angeles, CA, 90089, USA. .,Genetic, Molecular and Cellular Biology Program, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA. .,Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, 90033, USA. .,Center of Excellence in NanoBiophysics, University of Southern California, Los Angeles, CA, 90089, USA.
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10
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Zhang XL, Luo MT, Song JH, Pang W, Zheng YT. An Alu Element Insertion in Intron 1 Results in Aberrant Alternative Splicing of APOBEC3G Pre-mRNA in Northern Pig-Tailed Macaques ( Macaca leonina) That May Reduce APOBEC3G-Mediated Hypermutation Pressure on HIV-1. J Virol 2020; 94:e01722-19. [PMID: 31776266 PMCID: PMC6997765 DOI: 10.1128/jvi.01722-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 11/14/2019] [Indexed: 11/20/2022] Open
Abstract
APOBEC3 family members, particularly APOBEC3F and APOBEC3G, inhibit the replication and spread of various retroviruses by inducing hypermutation in newly synthesized viral DNA. Viral hypermutation by APOBEC3 is associated with viral evolution, viral transmission, and disease progression. In recent years, increasing attention has been paid to targeting APOBEC3G for AIDS therapy. Thus, a controllable model system using species such as macaques, which provide a relatively ideal in vivo system, is needed for the study of APOBEC3-related issues. To appropriately utilize this animal model for biomedical research, important differences between human and macaque APOBEC3s must be considered. In this study, we found that the ratio of APOBEC3G-mediated/APOBEC3-mediated HIV-1 hypermutation footprints was much lower in peripheral blood mononuclear cells (PBMCs) from northern pig-tailed macaques than in PBMCs from humans. Next, we identified a novel and conserved APOBEC3G pre-mRNA alternative splicing pattern in macaques, which differed from that in humans and resulted from an Alu element insertion into macaque APOBEC3G gene intron 1. This alternative splicing pattern generating an aberrant APOBEC3G mRNA isoform may significantly dilute full-length APOBEC3G and reduce APOBEC3G-mediated hypermutation pressure on HIV-1 in northern pig-tailed macaques, which was supported by the elimination of other possibilities accounting for this hypermutation difference between the two hosts.IMPORTANCE APOBEC3 family members, particularly APOBEC3F and APOBEC3G, are important cellular antiviral factors. Recently, more attention has been paid to targeting APOBEC3G for AIDS therapy. To appropriately utilize macaque animal models for the study of APOBEC3-related issues, it is important that the differences between human and macaque APOBEC3s are clarified. In this study, we identified a novel and conserved APOBEC3G pre-mRNA alternative splicing pattern in macaques, which differed from that in humans and which may reduce the APOBEC3G-mediated hypermutation pressure on HIV-1 in northern pig-tailed macaques (NPMs). Our work provides important information for the proper application of macaque animal models for APOBEC3-related issues in AIDS research and a better understanding of the biological functions of APOBEC3 proteins.
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Affiliation(s)
- Xiao-Liang Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Meng-Ting Luo
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Jia-Hao Song
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Institute of Health Sciences, Anhui University, Hefei, Anhui, China
| | - Wei Pang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yong-Tang Zheng
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Center for Biosafety Mega-Science, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China
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11
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Asaoka M, Ishikawa T, Takabe K, Patnaik SK. APOBEC3-Mediated RNA Editing in Breast Cancer is Associated with Heightened Immune Activity and Improved Survival. Int J Mol Sci 2019; 20:E5621. [PMID: 31717692 PMCID: PMC6888598 DOI: 10.3390/ijms20225621] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 12/15/2022] Open
Abstract
APOBEC3 enzymes contribute significantly to DNA mutagenesis in cancer. These enzymes are also capable of converting C bases at specific positions of RNAs to U. However, the prevalence and significance of this C-to-U RNA editing in any cancer is currently unknown. We developed a bioinformatics workflow to determine RNA editing levels at known APOBEC3-mediated RNA editing sites using exome and mRNA sequencing data of 1040 breast cancer tumors. Although reliable editing determinations were limited due to sequencing depth, editing was observed in both tumor and adjacent normal tissues. For 440 sites (411 genes), editing was determinable for ≥5 tumors, with editing occurring in 0.6%-100% of tumors (mean 20%, SD 14%) at an average level of 0.6%-20% (mean 7%, SD 4%). Compared to tumors with low RNA editing, editing-high tumors had enriched expression of immune-related gene sets, and higher T cell and M1 macrophage infiltration, B and T cell receptor diversity, and immune cytolytic activity. Concordant with this, patients with increased RNA editing in tumors had better disease- and progression-free survivals (hazard ratio = 1.67-1.75, p < 0.05). Our study identifies that APOBEC3-mediated RNA editing occurs in breast cancer tumors and is positively associated with elevated immune activity and improved survival.
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Affiliation(s)
- Mariko Asaoka
- Department of Breast Surgery, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA
- Department of Breast Surgery and Oncology, Tokyo Medical University, Tokyo 160-8402, Japan
| | - Takashi Ishikawa
- Department of Breast Surgery and Oncology, Tokyo Medical University, Tokyo 160-8402, Japan
| | - Kazuaki Takabe
- Department of Breast Surgery, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA
- Department of Breast Surgery and Oncology, Tokyo Medical University, Tokyo 160-8402, Japan
- Department of Surgery, Jacobs School of Medicine and Biomedical Sciences, State University of New York, Buffalo, NY 14263, USA
- Department of Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan
- Department of Surgery, Yokohama City University, Yokohama 236-0004, Japan
| | - Santosh K. Patnaik
- Department of Surgery, Jacobs School of Medicine and Biomedical Sciences, State University of New York, Buffalo, NY 14263, USA
- Department of Thoracic Surgery, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA
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12
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Perelygina L, Chen MH, Suppiah S, Adebayo A, Abernathy E, Dorsey M, Bercovitch L, Paris K, White KP, Krol A, Dhossche J, Torshin IY, Saini N, Klimczak LJ, Gordenin DA, Zharkikh A, Plotkin S, Sullivan KE, Icenogle J. Infectious vaccine-derived rubella viruses emerge, persist, and evolve in cutaneous granulomas of children with primary immunodeficiencies. PLoS Pathog 2019; 15:e1008080. [PMID: 31658304 PMCID: PMC6837625 DOI: 10.1371/journal.ppat.1008080] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 11/07/2019] [Accepted: 09/13/2019] [Indexed: 12/18/2022] Open
Abstract
Rubella viruses (RV) have been found in an association with granulomas in children with primary immune deficiencies (PID). Here, we report the recovery and characterization of infectious immunodeficiency-related vaccine-derived rubella viruses (iVDRV) from diagnostic skin biopsies of four patients. Sequence evolution within PID hosts was studied by comparison of the complete genomic sequences of the iVDRVs with the genome of the vaccine virus RA27/3. The degree of divergence of each iVDRV correlated with the duration of persistence indicating continuous intrahost evolution. The evolution rates for synonymous and nonsynonymous substitutions were estimated to be 5.7 x 10-3 subs/site/year and 8.9 x 10-4 subs/site/year, respectively. Mutational spectra and signatures indicated a major role for APOBEC cytidine deaminases and a secondary role for ADAR adenosine deaminases in generating diversity of iVDRVs. The distributions of mutations across the genes and 3D hotspots for amino acid substitutions in the E1 glycoprotein identified regions that may be under positive selective pressure. Quasispecies diversity was higher in granulomas than in recovered infectious iVDRVs. Growth properties of iVDRVs were assessed in WI-38 fibroblast cultures. None of the iVDRV isolates showed complete reversion to wild type phenotype but the replicative and persistence characteristics of iVDRVs were different from those of the RA27/3 vaccine strain, making predictions of iVDRV transmissibility and teratogenicity difficult. However, detection of iVDRV RNA in nasopharyngeal specimen and poor neutralization of some iVDRV strains by sera from vaccinated persons suggests possible public health risks associated with iVDRV carriers. Detection of IgM antibody to RV in sera of two out of three patients may be a marker of virus persistence, potentially useful for identifying patients with iVDRV before development of lesions. Studies of the evolutionary dynamics of iVDRV during persistence will contribute to development of infection control strategies and antiviral therapies.
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Affiliation(s)
- Ludmila Perelygina
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Min-hsin Chen
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Suganthi Suppiah
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Adebola Adebayo
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Emily Abernathy
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Morna Dorsey
- Department of Pediatrics, University of California, San Francisco, San Francisco, California, United States of America
| | - Lionel Bercovitch
- Department of Dermatology, Hasbro Children's Hospital and Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America
| | - Kenneth Paris
- Division of Allergy and Immunology, Children's Hospital New Orleans, New Orleans, Louisiana, United States of America
| | - Kevin P. White
- Department of Dermatology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Alfons Krol
- Department of Dermatology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Julie Dhossche
- Department of Dermatology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Ivan Y. Torshin
- Institute of Pharmacoinformatics, Federal Research Center “Computer Science and Control” of Russian Academy of Sciences, Dorodnicyn Computing Center, Moscow, Russian Federation
| | - Natalie Saini
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, US National Institutes of Health, Research Triangle Park, North Carolina, United States of America
| | - Leszek J. Klimczak
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences, US National Institutes of Health, Research Triangle Park, North Carolina, United States of America
| | - Dmitry A. Gordenin
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, US National Institutes of Health, Research Triangle Park, North Carolina, United States of America
| | - Andrey Zharkikh
- Myriad Genetics, Inc., Salt Lake City, Utah, United States of America
| | - Stanley Plotkin
- University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Kathleen E. Sullivan
- Division of Allergy and Immunology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Joseph Icenogle
- Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
- * E-mail:
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13
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Contribution of Cytidine Deaminase to Thymidylate Biosynthesis in Trypanosoma brucei: Intracellular Localization and Properties of the Enzyme. mSphere 2019; 4:4/4/e00374-19. [PMID: 31391279 PMCID: PMC6686228 DOI: 10.1128/msphere.00374-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Cytidine deaminase (CDA) is a pyrimidine salvage enzyme that catalyzes cytidine and deoxycytidine hydrolytic deamination to yield uridine and deoxyuridine. Here we report the biochemical characterization of Trypanosoma brucei CDA as an enzyme within the tetrameric class of the CDA family that efficiently deaminates cytidine, deoxycytidine, and the nucleoside analogue 5-methyl-2'-deoxycytidine. In line with previous studies, we show that RNA interference (RNAi)-mediated CDA depletion impairs T. brucei proliferation when grown in pyrimidine-deficient medium, while supplementation with thymidine or deoxyuridine restores growth, further underscoring the role of this enzyme in providing deoxyuridine for dUMP formation via thymidine kinase, the substrate required for de novo thymidylate biosynthesis. This observation contrasts with the existence in T. brucei of a dimeric deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase), an essential enzyme that can produce dUMP via the hydrolysis of dUTP/dUDP. Thus, T. brucei dUTPase-null mutants are thymidine auxotrophs, suggesting that dUTPase might have a role in providing dUMP for thymidylate biosynthesis. We show that overexpression of human dCMP deaminase (DCTD), an enzyme that provides directly dUMP through dCMP deamination, does not reverse the lethal phenotype of dUTPase knockout cells, which further supports the notion that in T. brucei, CDA is uniquely involved in providing dUMP, while the main role of dUTPase would be the withdrawal of the excess of dUTP to avoid its incorporation into DNA. Furthermore, we report the mitochondrial localization of CDA, highlighting the importance of this organelle in pyrimidine metabolism.IMPORTANCE Cytidine deaminases (CDAs) catalyze the hydrolytic deamination of cytidine and deoxycytidine in the pyrimidine salvage pathway. In kinetoplastids, pyrimidine metabolism has been extensively studied as a source of potential drug targets, given the fact that many of the enzymes of the pathway are essential. Thymidylate (dTMP) synthesis in Trypanosoma brucei exhibits unique characteristics. Thus, it has been suggested that the production of dUMP, the substrate for dTMP formation, is solely dependent on cytidine deaminase and thymidine kinase. Here we characterize recombinant T. brucei CDA (TbCDA) and present evidence that indeed the alternative route for dUMP formation via deoxyuridine 5'-triphosphate nucleotidohydrolase does not have a prominent role in de novo dTMP formation. Furthermore, we provide a scheme for the compartmentalization of dTMP biosynthesis, taking into account the observation that CDA is located in the mitochondrion, together with available information on the intracellular localization of other enzymes involved in the dTTP biosynthetic pathway.
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14
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Yan X, Lan W, Wang C, Cao C. Structural Investigations on the Interactions between Cytidine Deaminase Human APOBEC3G and DNA. Chem Asian J 2019; 14:2235-2241. [PMID: 31116511 DOI: 10.1002/asia.201900480] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/20/2019] [Indexed: 02/05/2023]
Abstract
Human APOBEC3G (A3G) inhibits the replication of human immunodeficiency virus-1 by deaminating cytidine at the 3'-end in the target motif 5'-CCC-3' in viral cDNA during reverse transcription. It in vitro deaminates two consecutive cytidines in a 3'->5' order. Although a crystal structure of the A3G catalytic domain (A3G-CD2) with DNA was reported, it is unknown why residues involved in enzymatic reaction are distributed widely. Here, we introduced an iodine atom into the C-5 position of cytidine (dC6 I ) in DNA 5'-ATTC4 C5 C6 I A7 ATT-3' (TCCC6 I ). It switches the deamination sequence preference from CCC to TCC, although small dC6 I deamination was observed. Solution structures of A3G-CD2 in complexes with products DNA TCUC6 I and TCUU6 I indicate that the substrate DNA binds A3G-CD2 in TCC and CCC modes. The dC6 deamination correlates with the 4th base type. The CCC mode favours dC6 deamination, while the TCC mode results in dC5 deamination. These studies present an extensive basis to design inhibitors to impede viral evolvability.
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Affiliation(s)
- Xiaoxuan Yan
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai, 200032, China.,University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing, 100049, China
| | - Wenxian Lan
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai, 200032, China
| | - Chunxi Wang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai, 200032, China
| | - Chunyang Cao
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Science, 345 Lingling Road, Shanghai, 200032, China.,University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing, 100049, China
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15
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Lerner T, Papavasiliou FN, Pecori R. RNA Editors, Cofactors, and mRNA Targets: An Overview of the C-to-U RNA Editing Machinery and Its Implication in Human Disease. Genes (Basel) 2018; 10:E13. [PMID: 30591678 PMCID: PMC6356216 DOI: 10.3390/genes10010013] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 12/10/2018] [Accepted: 12/20/2018] [Indexed: 12/22/2022] Open
Abstract
One of the most prevalent epitranscriptomic modifications is RNA editing. In higher eukaryotes, RNA editing is catalyzed by one of two classes of deaminases: ADAR family enzymes that catalyze A-to-I (read as G) editing, and AID/APOBEC family enzymes that catalyze C-to-U. ADAR-catalyzed deamination has been studied extensively. Here we focus on AID/APOBEC-catalyzed editing, and review the emergent knowledge regarding C-to-U editing consequences in the context of human disease.
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Affiliation(s)
- Taga Lerner
- Division of Immune Diversity, Program in Cancer Immunology, German Cancer Research Centre, 69120 Heidelberg, Germany.
- Division of Biosciences, Uni Heidelberg, 69120 Heidelberg, Germany.
| | - F Nina Papavasiliou
- Division of Immune Diversity, Program in Cancer Immunology, German Cancer Research Centre, 69120 Heidelberg, Germany.
| | - Riccardo Pecori
- Division of Immune Diversity, Program in Cancer Immunology, German Cancer Research Centre, 69120 Heidelberg, Germany.
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16
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Salter JD, Smith HC. Modeling the Embrace of a Mutator: APOBEC Selection of Nucleic Acid Ligands. Trends Biochem Sci 2018; 43:606-622. [PMID: 29803538 PMCID: PMC6073885 DOI: 10.1016/j.tibs.2018.04.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 04/25/2018] [Accepted: 04/30/2018] [Indexed: 12/17/2022]
Abstract
The 11-member APOBEC (apolipoprotein B mRNA editing catalytic polypeptide-like) family of zinc-dependent cytidine deaminases bind to RNA and single-stranded DNA (ssDNA) and, in specific contexts, modify select (deoxy)cytidines to (deoxy)uridines. In this review, we describe advances made through high-resolution co-crystal structures of APOBECs bound to mono- or oligonucleotides that reveal potential substrate-specific binding sites at the active site and non-sequence-specific nucleic acid binding sites distal to the active site. We also discuss the effect of APOBEC oligomerization on functionality. Future structural studies will need to address how ssDNA binding away from the active site may enhance catalysis and the mechanism by which RNA binding may modulate catalytic activity on ssDNA. APOBEC proteins catalyze deamination of cytidine or deoxycytidine in either a sequence-specific or semi-specific manner on either DNA or RNA. APOBECs each possess the cytidine deaminase core fold, but sequence and structural differences among loops surrounding the zinc-dependent active site impart differences in sequence-dependent target preferences, binding affinity, catalytic rate, and regulation of substrate access to the active site among the 11 family members. APOBECs also regulate the deamination reaction through additional nucleic acid substrate binding sites located within surface grooves or patches of positive electrostatic potential that are distal to the active site but may do so nonspecifically. Binding of nonsubstrate RNA and RNA-mediated oligomerization by APOBECs that deaminate ssDNA downregulates catalytic activity but also controls APOBEC subcellular or virion localization. The presence of a second, though noncatalytic, cytidine deaminase domain for some APOBECs and the ability of some APOBECs to oligomerize add additional molecular surfaces for positive or negative regulation of catalysis through nucleic acid binding.
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Affiliation(s)
- Jason D Salter
- OyaGen, Inc., 77 Ridgeland Road, Rochester, NY 14623, USA.
| | - Harold C Smith
- OyaGen, Inc., 77 Ridgeland Road, Rochester, NY 14623, USA; University of Rochester, School of Medicine and Dentistry, Department of Biochemistry and Biophysics, 601 Elmwood Avenue, Rochester, NY 14642, USA.
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17
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Leighton LJ, Ke K, Zajaczkowski EL, Edmunds J, Spitale RC, Bredy TW. Experience-dependent neural plasticity, learning, and memory in the era of epitranscriptomics. GENES, BRAIN, AND BEHAVIOR 2018; 17:e12426. [PMID: 28926184 PMCID: PMC5858957 DOI: 10.1111/gbb.12426] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/15/2017] [Accepted: 09/15/2017] [Indexed: 12/23/2022]
Abstract
In this short review, we highlight recent findings in the emerging field of epitranscriptomic mechanisms and discuss their potential role in neural plasticity, learning and memory. These include the influence of RNA modifications on activity-induced RNA structure states, RNA editing and RNA localization, and how qualitative state changes in RNA increase the functional diversity and information-carrying capacity of RNA molecules. We predict that RNA modifications may be just as important for synaptic plasticity and memory as quantitative changes in transcript and protein abundance, but with the added advantage of not being required to signal back to the nucleus, and therefore better suited to be coordinated with the temporal dynamics of learning.
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Affiliation(s)
- Laura J. Leighton
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia 4072
| | - Ke Ke
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, CA, USA 92697
| | - Esmi L. Zajaczkowski
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia 4072
| | - Jordan Edmunds
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia 4072
| | - Robert C. Spitale
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, CA, USA 92697
| | - Timothy W. Bredy
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia 4072
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18
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Orecchini E, Frassinelli L, Galardi S, Ciafrè SA, Michienzi A. Post-transcriptional regulation of LINE-1 retrotransposition by AID/APOBEC and ADAR deaminases. Chromosome Res 2018; 26:45-59. [PMID: 29396793 DOI: 10.1007/s10577-018-9572-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 01/07/2018] [Indexed: 02/05/2023]
Abstract
Long interspersed element-1 (LINE-1 or L1) retrotransposons represent the only functional family of autonomous transposable elements in humans and formed 17% of our genome. Even though most of the human L1 sequences are inactive, a limited number of copies per individual retain the ability to mobilize by a process termed retrotransposition. The ongoing L1 retrotransposition may result in insertional mutagenesis that could lead to negative consequences such as genetic disease and cancer. For this reason, cells have evolved several mechanisms of defense to restrict L1 activity. Among them, a critical role for cellular deaminases [activation-induced deaminase (AID)/apolipoprotein B mRNA-editing catalytic polypeptide-like (APOBEC) and adenosine deaminases that act on RNA (ADAR) enzymes] has emerged. The majority of the AID/APOBEC family of proteins are responsible for the deamination of cytosine to uracil (C-to-U editing) within DNA and RNA targets. The ADARs convert adenosine bases to inosines (A-to-I editing) within double-stranded RNA (dsRNA) targets. This review will discuss the current understanding of the regulation of LINE-1 retrotransposition mediated by these enzymes.
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Affiliation(s)
- Elisa Orecchini
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Loredana Frassinelli
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Silvia Galardi
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Silvia Anna Ciafrè
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Alessandro Michienzi
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.
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19
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Rayon-Estrada V, Harjanto D, Hamilton CE, Berchiche YA, Gantman EC, Sakmar TP, Bulloch K, Gagnidze K, Harroch S, McEwen BS, Papavasiliou FN. Epitranscriptomic profiling across cell types reveals associations between APOBEC1-mediated RNA editing, gene expression outcomes, and cellular function. Proc Natl Acad Sci U S A 2017; 114:13296-13301. [PMID: 29167373 PMCID: PMC5740640 DOI: 10.1073/pnas.1714227114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Epitranscriptomics refers to posttranscriptional alterations on an mRNA sequence that are dynamic and reproducible, and affect gene expression in a similar way to epigenetic modifications. However, the functional relevance of those modifications for the transcript, the cell, and the organism remain poorly understood. Here, we focus on RNA editing and show that Apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-1 (APOBEC1), together with its cofactor RBM47, mediates robust editing in different tissues. The majority of editing events alter the sequence of the 3'UTR of targeted transcripts, and we focus on one cell type (monocytes) and on a small set of highly edited transcripts within it to show that editing alters gene expression by modulating translation (but not RNA stability or localization). We further show that specific cellular processes (phagocytosis and transendothelial migration) are enriched for transcripts that are targets of editing and that editing alters their function. Finally, we survey bone marrow progenitors and demonstrate that common monocyte progenitor cells express high levels of APOBEC1 and are susceptible to loss of the editing enzyme. Overall, APOBEC1-mediated transcriptome diversification is required for the fine-tuning of protein expression in monocytes, suggesting an epitranscriptomic mechanism for the proper maintenance of homeostasis in innate immune cells.
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Affiliation(s)
- Violeta Rayon-Estrada
- Laboratory of Lymphocyte Biology, The Rockefeller University, New York, NY 10065
- The Rockefeller Graduate Program, The Rockefeller University, New York, NY 10065
| | - Dewi Harjanto
- Laboratory of Lymphocyte Biology, The Rockefeller University, New York, NY 10065
| | - Claire E Hamilton
- Laboratory of Lymphocyte Biology, The Rockefeller University, New York, NY 10065
- The Rockefeller Graduate Program, The Rockefeller University, New York, NY 10065
- The Tri-Institutional MD-PhD Program, The Rockefeller University, New York, NY 10065
| | - Yamina A Berchiche
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, NY 10065
| | - Emily Conn Gantman
- The Rockefeller Graduate Program, The Rockefeller University, New York, NY 10065
- Laboratory of Molecular Neuro-Oncology, The Rockefeller University, New York, NY 10065
| | - Thomas P Sakmar
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, NY 10065
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, 141 57 Huddinge, Sweden
| | - Karen Bulloch
- The Neuroimmunology and Inflammation Program, The Rockefeller University, New York, NY 10065
| | - Khatuna Gagnidze
- The Neuroimmunology and Inflammation Program, The Rockefeller University, New York, NY 10065
| | - Sheila Harroch
- Division of Immune Diversity, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Bruce S McEwen
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065
| | - F Nina Papavasiliou
- Laboratory of Lymphocyte Biology, The Rockefeller University, New York, NY 10065;
- Division of Immune Diversity, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
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20
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Sharma S, Baysal BE. Stem-loop structure preference for site-specific RNA editing by APOBEC3A and APOBEC3G. PeerJ 2017; 5:e4136. [PMID: 29230368 PMCID: PMC5723131 DOI: 10.7717/peerj.4136] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 11/15/2017] [Indexed: 01/12/2023] Open
Abstract
APOBEC3A and APOBEC3G cytidine deaminases inhibit viruses and endogenous retrotransposons. We recently demonstrated the novel cellular C-to-U RNA editing function of APOBEC3A and APOBEC3G. Both enzymes deaminate single-stranded DNAs at multiple TC or CC nucleotide sequences, but edit only a select set of RNAs, often at a single TC or CC nucleotide sequence. To examine the specific site preference for APOBEC3A and -3G-mediated RNA editing, we performed mutagenesis studies of the endogenous cellular RNA substrates of both proteins. We demonstrate that both enzymes prefer RNA substrates that have a predicted stem-loop with the reactive C at the 3′-end of the loop. The size of the loop, the nucleotides immediately 5′ to the target cytosine and stability of the stem have a major impact on the level of RNA editing. Our findings show that both sequence and secondary structure are preferred for RNA editing by APOBEC3A and -3G, and suggest an explanation for substrate and site-specificity of RNA editing by APOBEC3A and -3G enzymes.
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Affiliation(s)
- Shraddha Sharma
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, NY, United States of America
| | - Bora E Baysal
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, NY, United States of America
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21
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Xiao X, Yang H, Arutiunian V, Fang Y, Besse G, Morimoto C, Zirkle B, Chen XS. Structural determinants of APOBEC3B non-catalytic domain for molecular assembly and catalytic regulation. Nucleic Acids Res 2017; 45:7494-7506. [PMID: 28575276 PMCID: PMC5499559 DOI: 10.1093/nar/gkx362] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 05/27/2017] [Indexed: 12/26/2022] Open
Abstract
The catalytic activity of human cytidine deaminase APOBEC3B (A3B) has been correlated with kataegic mutational patterns within multiple cancer types. The molecular basis of how the N-terminal non-catalytic CD1 regulates the catalytic activity and consequently, biological function of A3B remains relatively unknown. Here, we report the crystal structure of a soluble human A3B-CD1 variant and delineate several structural elements of CD1 involved in molecular assembly, nucleic acid interactions and catalytic regulation of A3B. We show that (i) A3B expressed in human cells exists in hypoactive high-molecular-weight (HMW) complexes, which can be activated without apparent dissociation into low-molecular-weight (LMW) species after RNase A treatment. (ii) Multiple surface hydrophobic residues of CD1 mediate the HMW complex assembly and affect the catalytic activity, including one tryptophan residue W127 that likely acts through regulating nucleic acid binding. (iii) One of the highly positively charged surfaces on CD1 is involved in RNA-dependent attenuation of A3B catalysis. (iv) Surface hydrophobic residues of CD1 are involved in heterogeneous nuclear ribonucleoproteins (hnRNPs) binding to A3B. The structural and biochemical insights described here suggest that unique structural features on CD1 regulate the molecular assembly and catalytic activity of A3B through distinct mechanisms.
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Affiliation(s)
- Xiao Xiao
- Genetic, Molecular and Cellular Biology Program, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Molecular and Computational Biology, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
- These authors contributed equally to this work as first authors
| | - Hanjing Yang
- Molecular and Computational Biology, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
- These authors contributed equally to this work as first authors
| | - Vagan Arutiunian
- Molecular and Computational Biology, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Yao Fang
- Molecular and Computational Biology, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
- Department of Clinical Microbiology and Immunology of Southwest Hospital, Third Military Medical University, Chongqing 400038, China
- 161 Hospital, Wuhan 430012, China
| | - Guillaume Besse
- Molecular and Computational Biology, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
- Polytech' Clermont-Ferrand, Université Blaise Pascal, Clermont-Ferrand, France
| | - Cherie Morimoto
- Molecular and Computational Biology, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Brett Zirkle
- Genetic, Molecular and Cellular Biology Program, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Molecular and Computational Biology, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Xiaojiang S. Chen
- Genetic, Molecular and Cellular Biology Program, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
- Molecular and Computational Biology, Departments of Biological Sciences and Chemistry, University of Southern California, Los Angeles, CA 90089, USA
- Center of Excellence in NanoBiophysics, University of Southern California, Los Angeles, CA 90089, USA
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA
- To whom correspondence should be addressed. Tel: +1 213 740 5487; Fax: +1 213 740 4340;
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22
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Opossum APOBEC1 is a DNA mutator with retrovirus and retroelement restriction activity. Sci Rep 2017; 7:46719. [PMID: 28429755 PMCID: PMC5399452 DOI: 10.1038/srep46719] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 03/23/2017] [Indexed: 01/12/2023] Open
Abstract
APOBEC3s (A3s) are single-stranded DNA cytosine deaminases that provide innate immune defences against retroviruses and mobile elements. A3s are specific to eutherian mammals because no direct homologs exist at the syntenic genomic locus in metatherian (marsupial) or prototherian (monotreme) mammals. However, the A3s in these species have the likely evolutionary precursors, the antibody gene deaminase AID and the RNA/DNA editing enzyme APOBEC1 (A1). Here, we used cell culture-based assays to determine whether opossum A1 restricts the infectivity of retroviruses including human immunodeficiency virus type 1 (HIV-1) and the mobility of LTR/non-LTR retrotransposons. Opossum A1 partially inhibited HIV-1, as well as simian immunodeficiency virus (SIV), murine leukemia virus (MLV), and the retrotransposon MusD. The mechanism of inhibition required catalytic activity, except for human LINE1 (L1) restriction, which was deamination-independent. These results indicate that opossum A1 functions as an innate barrier to infection by retroviruses such as HIV-1, and controls LTR/non-LTR retrotransposition in marsupials.
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23
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Zhang XL, Song JH, Pang W, Zheng YT. Molecular cloning and anti-HIV-1 activities of APOBEC3s from northern pig-tailed macaques (Macaca leonina). DONG WU XUE YAN JIU = ZOOLOGICAL RESEARCH 2017; 37:246-51. [PMID: 27469256 DOI: 10.13918/j.issn.2095-8137.2016.4.246] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Northern pig-tailed macaques (NPMs, Macaca leonina) are susceptible to HIV-1 infection largely due to the loss of HIV-1-restricting factor TRIM5α. However, great impediments still exist in the persistent replication of HIV-1 in vivo, suggesting some viral restriction factors are reserved in this host. The APOBEC3 proteins have demonstrated a capacity to restrict HIV-1 replication, but their inhibitory effects in NPMs remain elusive. In this study, we cloned the NPM A3A-A3H genes, and determined by BLAST searching that their coding sequences (CDSs) showed 99% identity to the corresponding counterparts from rhesus and southern pig-tailed macaques. We further analyzed the anti-HIV-1 activities of the A3A-A3H genes, and found that A3G and A3F had the greatest anti-HIV-1 activity compared with that of other members. The results of this study indicate that A3G and A3F might play critical roles in limiting HIV-1 replication in NPMs in vivo. Furthermore, this research provides valuable information for the optimization of monkey models of HIV-1 infection.
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Affiliation(s)
- Xiao-Liang Zhang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China;Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming Yunnan 650500, China
| | - Jia-Hao Song
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China;Institute of Health Sciences, Anhui University, Hefei Anhui 230601, China
| | - Wei Pang
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China
| | - Yong-Tang Zheng
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China;Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming Yunnan 650500, China;Kunming Primate Research Center of the Chinese Academy of Sciences, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming Yunnan 650223, China.
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24
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Pan Y, Sun Z, Maiti A, Kanai T, Matsuo H, Li M, Harris RS, Shlyakhtenko LS, Lyubchenko YL. Nanoscale Characterization of Interaction of APOBEC3G with RNA. Biochemistry 2017; 56:1473-1481. [PMID: 28029777 DOI: 10.1021/acs.biochem.6b01189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The human cytidine deaminase APOBEC3G (A3G) is a potent inhibitor of the HIV-1 virus in the absence of viral infectivity factor (Vif). The molecular mechanism of A3G antiviral activity is primarily attributed to deamination of single-stranded DNA (ssDNA); however, the nondeamination mechanism also contributes to HIV-1 restriction. The interaction of A3G with ssDNA and RNA is required for its antiviral activity. Here we used atomic force microscopy to directly visualize A3G-RNA and A3G-ssDNA complexes and compare them to each other. Our results showed that A3G in A3G-RNA complexes exists primarily in monomeric-dimeric states, similar to its stoichiometry in complexes with ssDNA. New A3G-RNA complexes in which A3G binds to two RNA molecules were identified. These data suggest the existence of two separate RNA binding sites on A3G. Such complexes were not observed with ssDNA substrates. Time-lapse high-speed atomic force microscopy was applied to characterize the dynamics of the complexes. The data revealed that the two RNA binding sites have different affinities for A3G. On the basis of the obtained results, a model for the interaction of A3G with RNA is proposed.
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Affiliation(s)
- Yangang Pan
- Department of Pharmaceutical Sciences, College of Pharmacy, WSH, University of Nebraska Medical Center , 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Zhiqiang Sun
- Department of Pharmaceutical Sciences, College of Pharmacy, WSH, University of Nebraska Medical Center , 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Atanu Maiti
- Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc. , Advanced Technology Research Facility, 8560 Progress Drive, Frederick, Maryland 21702, United States
| | - Tapan Kanai
- Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc. , Advanced Technology Research Facility, 8560 Progress Drive, Frederick, Maryland 21702, United States
| | - Hiroshi Matsuo
- Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc. , Advanced Technology Research Facility, 8560 Progress Drive, Frederick, Maryland 21702, United States
| | - Ming Li
- Department of Biochemistry, Molecular Biology and Biophysics, Institute for Molecular Virology, Center for Genome Engineering, Masonic Cancer Center, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Reuben S Harris
- Department of Biochemistry, Molecular Biology and Biophysics, Institute for Molecular Virology, Center for Genome Engineering, Masonic Cancer Center, University of Minnesota , Minneapolis, Minnesota 55455, United States.,Howard Hughes Medical Institute, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Luda S Shlyakhtenko
- Department of Pharmaceutical Sciences, College of Pharmacy, WSH, University of Nebraska Medical Center , 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
| | - Yuri L Lyubchenko
- Department of Pharmaceutical Sciences, College of Pharmacy, WSH, University of Nebraska Medical Center , 986025 Nebraska Medical Center, Omaha, Nebraska 68198-6025, United States
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25
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Sharma S, Patnaik SK, Taggart RT, Baysal BE. The double-domain cytidine deaminase APOBEC3G is a cellular site-specific RNA editing enzyme. Sci Rep 2016; 6:39100. [PMID: 27974822 PMCID: PMC5156925 DOI: 10.1038/srep39100] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 11/16/2016] [Indexed: 11/10/2022] Open
Abstract
APOBEC3G is a cytidine deaminase with two homologous domains and restricts retroelements and HIV-1. APOBEC3G deaminates single-stranded DNAs via its C-terminal domain, whereas the N-terminal domain is considered non-catalytic. Although APOBEC3G is known to bind RNAs, APOBEC3G-mediated RNA editing has not been observed. We recently discovered RNA editing by the single-domain enzyme APOBEC3A in innate immune cells. To determine if APOBEC3G is capable of RNA editing, we transiently expressed APOBEC3G in the HEK293T cell line and performed transcriptome-wide RNA sequencing. We show that APOBEC3G causes site-specific C-to-U editing of mRNAs from over 600 genes. The edited cytidines are often flanked by inverted repeats, but are largely distinct from those deaminated by APOBEC3A. We verified protein-recoding RNA editing of selected genes including several that are known to be involved in HIV-1 infectivity. APOBEC3G co-purifies with highly edited mRNA substrates. We find that conserved catalytic residues in both cytidine deaminase domains are required for RNA editing. Our findings demonstrate the novel RNA editing function of APOBEC3G and suggest a role for the N-terminal domain in RNA editing.
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Affiliation(s)
- Shraddha Sharma
- Departments of Pathology and Thoracic Surgery, Roswell Park Cancer Institute, Elm and Carlton Streets Buffalo, NY, 14263, USA
| | - Santosh K. Patnaik
- Departments of Pathology and Thoracic Surgery, Roswell Park Cancer Institute, Elm and Carlton Streets Buffalo, NY, 14263, USA
| | - Robert T. Taggart
- Departments of Pathology and Thoracic Surgery, Roswell Park Cancer Institute, Elm and Carlton Streets Buffalo, NY, 14263, USA
| | - Bora E. Baysal
- Departments of Pathology and Thoracic Surgery, Roswell Park Cancer Institute, Elm and Carlton Streets Buffalo, NY, 14263, USA
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26
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Meier JC, Kankowski S, Krestel H, Hetsch F. RNA Editing-Systemic Relevance and Clue to Disease Mechanisms? Front Mol Neurosci 2016; 9:124. [PMID: 27932948 PMCID: PMC5120146 DOI: 10.3389/fnmol.2016.00124] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 11/04/2016] [Indexed: 11/13/2022] Open
Abstract
Recent advances in sequencing technologies led to the identification of a plethora of different genes and several hundreds of amino acid recoding edited positions. Changes in editing rates of some of these positions were associated with diseases such as atherosclerosis, myopathy, epilepsy, major depression disorder, schizophrenia and other mental disorders as well as cancer and brain tumors. This review article summarizes our current knowledge on that front and presents glycine receptor C-to-U RNA editing as a first example of disease-associated increased RNA editing that includes assessment of disease mechanisms of the corresponding gene product in an animal model.
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Affiliation(s)
- Jochen C Meier
- Cell Physiology, Technische Universität Braunschweig Braunschweig, Germany
| | - Svenja Kankowski
- Cell Physiology, Technische Universität Braunschweig Braunschweig, Germany
| | - Heinz Krestel
- Neurology, Universitätsspital und Universität Bern Bern, Switzerland
| | - Florian Hetsch
- Cell Physiology, Technische Universität Braunschweig Braunschweig, Germany
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27
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Abstract
Apolipoprotein B mRNA Editing Catalytic Polypeptide-like 1 or APOBEC1 was discovered in 1993 as the zinc-dependent cytidine deaminase responsible for the production of an in frame stop codon in apoB mRNA through modification of cytidine at nucleotide position 6666 to uridine. At the time of this discovery there was much speculation concerning the mechanism of base modification RNA editing which has been rekindled by the discovery of multiple C to U RNA editing events in the 3′ UTRs of mRNAs and the finding that other members of the APOBEC family while able to bind RNA, have the biological function of being DNA mutating enzymes. Current research is addressing the mechanism for these nucleotide modification events that appear not to adhere to the mooring sequence-dependent model for APOBEC1 involving the assembly of a multi protein containing editosome. This review will summarize our current understanding of the structure and function of APOBEC proteins and examine how RNA binding to them may be a regulatory mechanism.
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Affiliation(s)
- Harold C Smith
- a University of Rochester, School of Medicine and Dentistry , Department of Biochemistry and Biophysics , Rochester , NY , USA
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28
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Hoernes TP, Erlacher MD. Translating the epitranscriptome. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27345446 PMCID: PMC5215311 DOI: 10.1002/wrna.1375] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/25/2016] [Accepted: 05/31/2016] [Indexed: 12/14/2022]
Abstract
RNA modifications are indispensable for the translation machinery to provide accurate and efficient protein synthesis. Whereas the importance of transfer RNA (tRNA) and ribosomal RNA (rRNA) modifications has been well described and is unquestioned for decades, the significance of internal messenger RNA (mRNA) modifications has only recently been revealed. Novel experimental methods have enabled the identification of thousands of modified sites within the untranslated and translated regions of mRNAs. Thus far, N6‐methyladenosine (m6A), pseudouridine (Ψ), 5‐methylcytosine (m5C) and N1‐methyladenosine (m1A) were identified in eukaryal, and to some extent in prokaryal mRNAs. Several of the functions of these mRNA modifications have previously been reported, but many aspects remain elusive. Modifications can be important factors for the direct regulation of protein synthesis. The potential diversification of genomic information and regulation of RNA expression through editing and modifying mRNAs is versatile and many questions need to be addressed to completely elucidate the role of mRNA modifications. Herein, we summarize and highlight some recent findings on various co‐ and post‐transcriptional modifications, describing the impact of these processes on gene expression, with emphasis on protein synthesis. WIREs RNA 2017, 8:e1375. doi: 10.1002/wrna.1375 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Thomas Philipp Hoernes
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Matthias David Erlacher
- Division of Genomics and RNomics, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
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29
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The APOBEC Protein Family: United by Structure, Divergent in Function. Trends Biochem Sci 2016; 41:578-594. [PMID: 27283515 DOI: 10.1016/j.tibs.2016.05.001] [Citation(s) in RCA: 235] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 04/28/2016] [Accepted: 05/03/2016] [Indexed: 12/13/2022]
Abstract
The APOBEC (apolipoprotein B mRNA editing catalytic polypeptide-like) family of proteins have diverse and important functions in human health and disease. These proteins have an intrinsic ability to bind to both RNA and single-stranded (ss) DNA. Both function and tissue-specific expression varies widely for each APOBEC protein. We are beginning to understand that the activity of APOBEC proteins is regulated through genetic alterations, changes in their transcription and mRNA processing, and through their interactions with other macromolecules in the cell. Loss of cellular control of APOBEC activities leads to DNA hypermutation and promiscuous RNA editing associated with the development of cancer or viral drug resistance, underscoring the importance of understanding how APOBEC proteins are regulated.
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30
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Marino D, Perković M, Hain A, Jaguva Vasudevan AA, Hofmann H, Hanschmann KM, Mühlebach MD, Schumann GG, König R, Cichutek K, Häussinger D, Münk C. APOBEC4 Enhances the Replication of HIV-1. PLoS One 2016; 11:e0155422. [PMID: 27249646 PMCID: PMC4889046 DOI: 10.1371/journal.pone.0155422] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 04/28/2016] [Indexed: 12/24/2022] Open
Abstract
APOBEC4 (A4) is a member of the AID/APOBEC family of cytidine deaminases. In this study we found a high mRNA expression of A4 in human testis. In contrast, there were only low levels of A4 mRNA detectable in 293T, HeLa, Jurkat or A3.01 cells. Ectopic expression of A4 in HeLa cells resulted in mostly cytoplasmic localization of the protein. To test whether A4 has antiviral activity similar to that of proteins of the APOBEC3 (A3) subfamily, A4 was co-expressed in 293T cells with wild type HIV-1 and HIV-1 luciferase reporter viruses. We found that A4 did not inhibit the replication of HIV-1 but instead enhanced the production of HIV-1 in a dose-dependent manner and seemed to act on the viral LTR. A4 did not show detectable cytidine deamination activity in vitro and weakly interacted with single-stranded DNA. The presence of A4 in virus producer cells enhanced HIV-1 replication by transiently transfected A4 or stably expressed A4 in HIV-susceptible cells. APOBEC4 was capable of similarly enhancing transcription from a broad spectrum of promoters, regardless of whether they were viral or mammalian. We hypothesize that A4 may have a natural role in modulating host promoters or endogenous LTR promoters.
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Affiliation(s)
- Daniela Marino
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Mario Perković
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Anika Hain
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Ananda A. Jaguva Vasudevan
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Henning Hofmann
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | | | - Michael D. Mühlebach
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
- Product Testing of Immunological Medicinal Products for Veterinary Uses, Paul-Ehrlich-Institute, Langen, Germany
| | - Gerald G. Schumann
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Renate König
- Host-Pathogen Interactions, Paul-Ehrlich-Institute, Langen, Germany
- Sanford Burnham Prebys Medical Discovery Institute, Immunity and Pathogenesis Program, La Jolla, California, United States of America
| | - Klaus Cichutek
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Division of Medical Biotechnology, Paul-Ehrlich-Institute, Langen, Germany
- * E-mail:
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31
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Licht K, Jantsch MF. Rapid and dynamic transcriptome regulation by RNA editing and RNA modifications. J Cell Biol 2016; 213:15-22. [PMID: 27044895 PMCID: PMC4828693 DOI: 10.1083/jcb.201511041] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 03/07/2016] [Indexed: 12/14/2022] Open
Abstract
Advances in next-generation sequencing and mass spectrometry have revealed widespread messenger RNA modifications and RNA editing, with dramatic effects on mammalian transcriptomes. Factors introducing, deleting, or interpreting specific modifications have been identified, and analogous with epigenetic terminology, have been designated "writers," "erasers," and "readers." Such modifications in the transcriptome are referred to as epitranscriptomic changes and represent a fascinating new layer of gene expression regulation that has only recently been appreciated. Here, we outline how RNA editing and RNA modification can rapidly affect gene expression, making both processes as well suited to respond to cellular stress and to regulate the transcriptome during development or circadian periods.
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Affiliation(s)
- Konstantin Licht
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Michael F Jantsch
- Department of Cell and Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, A-1090 Vienna, Austria Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, A-1030 Vienna, Austria
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32
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Yan S, He F, Gao B, Wu H, Li M, Huang L, Liang J, Wu Q, Li Y. Increased APOBEC3B Predicts Worse Outcomes in Lung Cancer: A Comprehensive Retrospective Study. J Cancer 2016; 7:618-25. [PMID: 27076842 PMCID: PMC4829547 DOI: 10.7150/jca.14030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/26/2016] [Indexed: 12/28/2022] Open
Abstract
Lung cancer ranks as the most common and lethal malignancy in America and worldwide. APOBEC3B is a newly identified DNA cytosine deaminase, which is supposed to function as a major source of DNA mutation in many different tumors. In this study, we combine the data of online databases and two hundred and twenty-one primary non-small-cell lung carcinoma (NSCLC) specimens from Sun Yat-sen University Cancer Center to investigate, for the first time, the clinical role of APOBEC3B in lung cancer. We found that the APOBEC3 expression was commonly elevated in NSCLC tissues and overexpression of APOBEC3B was correlated with unfavorable prognosis of the patients with NSCLC. Furthermore, APOBEC3B expression was associated with nodal status, TNM staging and adjuvant chemotherapy of the patients with NSCLC. Further research is warranted.
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Affiliation(s)
- Shumei Yan
- 1. State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine, Guangzhou City, Guangdong Province, P.R. China;; 2. Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou City, Guangdong Province, P.R. China
| | - Fan He
- 3. Department of Molecular Oncology, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL 33612, USA
| | - Bei Gao
- 4. State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou City, Guangdong Province, P.R. China
| | - Huini Wu
- 5. Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois 60607, USA
| | - Mei Li
- 1. State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine, Guangzhou City, Guangdong Province, P.R. China;; 2. Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou City, Guangdong Province, P.R. China
| | - Liyun Huang
- 1. State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine, Guangzhou City, Guangdong Province, P.R. China;; 2. Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou City, Guangdong Province, P.R. China
| | - Jianzhong Liang
- 1. State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine, Guangzhou City, Guangdong Province, P.R. China;; 2. Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou City, Guangdong Province, P.R. China
| | - Qiuliang Wu
- 1. State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine, Guangzhou City, Guangdong Province, P.R. China;; 2. Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou City, Guangdong Province, P.R. China
| | - Yong Li
- 1. State Key Laboratory of Oncology in South China and Collaborative Innovation Center for Cancer Medicine, Guangzhou City, Guangdong Province, P.R. China;; 2. Department of Pathology, Sun Yat-sen University Cancer Center, Guangzhou City, Guangdong Province, P.R. China
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Polevoda B, McDougall WM, Bennett RP, Salter JD, Smith HC. Structural and functional assessment of APOBEC3G macromolecular complexes. Methods 2016; 107:10-22. [PMID: 26988126 DOI: 10.1016/j.ymeth.2016.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 03/10/2016] [Accepted: 03/11/2016] [Indexed: 12/20/2022] Open
Abstract
There are eleven members in the human APOBEC family of proteins that are evolutionarily related through their zinc-dependent cytidine deaminase domains. The human APOBEC gene clusters arose on chromosome 6 and 22 through gene duplication and divergence to where current day APOBEC proteins are functionally diverse and broadly expressed in tissues. APOBEC serve enzymatic and non enzymatic functions in cells. In both cases, formation of higher-order structures driven by APOBEC protein-protein interactions and binding to RNA and/or single stranded DNA are integral to their function. In some circumstances, these interactions are regulatory and modulate APOBEC activities. We are just beginning to understand how macromolecular interactions drive processes such as APOBEC subcellular compartmentalization, formation of holoenzyme complexes, gene targeting, foreign DNA restriction, anti-retroviral activity, formation of ribonucleoprotein particles and APOBEC degradation. Protein-protein and protein-nucleic acid cross-linking methods coupled with mass spectrometry, electrophoretic mobility shift assays, glycerol gradient sedimentation, fluorescence anisotropy and APOBEC deaminase assays are enabling mapping of interacting surfaces that are essential for these functions. The goal of this methods review is through example of our research on APOBEC3G, describe the application of cross-linking methods to characterize and quantify macromolecular interactions and their functional implications. Given the homology in structure and function, it is proposed that these methods will be generally applicable to the discovery process for other APOBEC and RNA and DNA editing and modifying proteins.
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Affiliation(s)
- Bogdan Polevoda
- Department of Biochemistry and Biophysics, University of Rochester, School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - William M McDougall
- Department of Biochemistry and Biophysics, University of Rochester, School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Ryan P Bennett
- OyaGen, Inc, Rochester BioVenture Center, 77 Ridgeland Road, Rochester, NY 14623, USA
| | - Jason D Salter
- OyaGen, Inc, Rochester BioVenture Center, 77 Ridgeland Road, Rochester, NY 14623, USA
| | - Harold C Smith
- Department of Biochemistry and Biophysics, University of Rochester, School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA; Wilmot Cancer Institute, 601 Elmwood Avenue, Rochester, NY 14642, USA; Center for RNA Biology, 601 Elmwood Avenue, Rochester, NY 14642, USA; OyaGen, Inc, Rochester BioVenture Center, 77 Ridgeland Road, Rochester, NY 14623, USA; Center for AIDS Research, 601 Elmwood Avenue, Rochester, NY 14642, USA.
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Functional requirements of AID's higher order structures and their interaction with RNA-binding proteins. Proc Natl Acad Sci U S A 2016; 113:E1545-54. [PMID: 26929374 DOI: 10.1073/pnas.1601678113] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Activation-induced cytidine deaminase (AID) is essential for the somatic hypermutation (SHM) and class-switch recombination (CSR) of Ig genes. Although both the N and C termini of AID have unique functions in DNA cleavage and recombination, respectively, during SHM and CSR, their molecular mechanisms are poorly understood. Using a bimolecular fluorescence complementation (BiFC) assay combined with glycerol gradient fractionation, we revealed that the AID C terminus is required for a stable dimer formation. Furthermore, AID monomers and dimers form complexes with distinct heterogeneous nuclear ribonucleoproteins (hnRNPs). AID monomers associate with DNA cleavage cofactor hnRNP K whereas AID dimers associate with recombination cofactors hnRNP L, hnRNP U, and Serpine mRNA-binding protein 1. All of these AID/ribonucleoprotein associations are RNA-dependent. We propose that AID's structure-specific cofactor complex formations differentially contribute to its DNA-cleavage and recombination functions.
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Severi F, Conticello SG. Flow-cytometric visualization of C>U mRNA editing reveals the dynamics of the process in live cells. RNA Biol 2016; 12:389-97. [PMID: 25806564 PMCID: PMC4615904 DOI: 10.1080/15476286.2015.1026033] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
APOBEC1 is the catalytic subunit of the complex that edits ApolipoproteinB (ApoB) mRNA, which specifically deaminates cytidine 6666 to uracil in the human transcript. The editing leads to the generation of a stop codon, resulting in the synthesis of a truncated form of ApoB. We have developed a method to quantitatively assay ApoB RNA editing in live cells by using a double fluorescent mCherry-EGFP chimera containing a ∼300bp fragment encompassing the region of ApoB subject to RNA editing. Coexpression of APOBEC1 together with this chimera causes specific RNA editing of the ApoB fragment. The insertion of a stop codon between the mCherry and EGFP thus induces the loss of EGFP fluorescence. Using this method we analyze the dynamics of APOBEC1-dependent RNA editing under various conditions. Namely we show the interplay of APOBEC1 with known interactors (ACF, hnRNP-C1, GRY-RBP) in cells that are RNA editing-proficient (HuH-7) or -deficient (HEK-293T), and the effects of restricted cellular localization of APOBEC1 on the efficiency of the editing. Furthermore, our approach is effective in assaying the induction of RNA editing in Caco-2, a cellular model physiologically capable of ApoB RNA editing.
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Key Words
- ACF, APOBEC1 Complementation Factor
- ADAR, Adenosine Deaminase, RNA-specific
- ADAT, Adenosine Deaminase, tRNA-specific
- AID/APOBECs
- APOBEC1, Apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1
- ApoB, Apolipoprotein B
- EGFP, Enhanced Green Fluorescent Protein
- FACS, Fluorescence activated cell sorting
- FBS, Fetal bovine serum
- GRY-RBP, Glycine-Arginine-Tyrosine-rich RNA-binding protein
- RBM47, RNA binding motif protein 47
- RNA editing
- cds, coding sequence
- cytosine deaminase
- hnRNP-C1, heterogeneous nuclear ribonucleoprotein C1
- lipid metabolism
- mRNA
- post-transcriptional modification
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Affiliation(s)
- Francesco Severi
- a Core Research Laboratory; Istituto Toscano Tumori ; Firenze , Italy
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Knisbacher BA, Levanon EY. DNA Editing of LTR Retrotransposons Reveals the Impact of APOBECs on Vertebrate Genomes. Mol Biol Evol 2015; 33:554-67. [PMID: 26541172 PMCID: PMC4866542 DOI: 10.1093/molbev/msv239] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Long terminal repeat retrotransposons (LTR) are widespread in vertebrates and their dynamism facilitates genome evolution. However, these endogenous retroviruses (ERVs) must be restricted to maintain genomic stability. The APOBECs, a protein family that can edit C-to-U in DNA, do so by interfering with reverse transcription and hypermutating retrotransposon DNA. In some cases, a retrotransposon may integrate into the genome despite being hypermutated. Such an event introduces a unique sequence into the genome, increasing retrotransposon diversity and the probability of developing new function at the locus of insertion. The prevalence of this phenomenon and its effects on vertebrate genomes are still unclear. In this study, we screened ERV sequences in the genomes of 123 diverse species and identified hundreds of thousands of edited sites in multiple vertebrate lineages, including placental mammals, marsupials, and birds. Numerous edited ERVs carry high mutation loads, some with greater than 350 edited sites, profoundly damaging their open-reading frames. For many of the species studied, this is the first evidence that APOBECs are active players in their innate immune system. Unexpectedly, some birds and especially zebra finch and medium ground-finch (one of Darwin’s finches) are exceptionally enriched in DNA editing. We demonstrate that edited retrotransposons may be preferentially retained in active genomic regions, as reflected from their enrichment in genes, exons, promoters, and transcription start sites, thereby raising the probability of their exaptation for novel function. In conclusion, DNA editing of retrotransposons by APOBECs has a substantial role in vertebrate innate immunity and may boost genome evolution.
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Affiliation(s)
- Binyamin A Knisbacher
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, 52900, Israel
| | - Erez Y Levanon
- The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, 52900, Israel
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Polevoda B, McDougall WM, Tun BN, Cheung M, Salter JD, Friedman AE, Smith HC. RNA binding to APOBEC3G induces the disassembly of functional deaminase complexes by displacing single-stranded DNA substrates. Nucleic Acids Res 2015; 43:9434-45. [PMID: 26424853 PMCID: PMC4627094 DOI: 10.1093/nar/gkv970] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/14/2015] [Accepted: 09/15/2015] [Indexed: 11/14/2022] Open
Abstract
APOBEC3G (A3G) DNA deaminase activity requires a holoenzyme complex whose assembly on nascent viral reverse transcripts initiates with A3G dimers binding to ssDNA followed by formation of higher-order A3G homo oligomers. Catalytic activity is inhibited when A3G binds to RNA. Our prior studies suggested that RNA inhibited A3G binding to ssDNA. In this report, near equilibrium binding and gel shift analyses showed that A3G assembly and disassembly on ssDNA was an ordered process involving A3G dimers and multimers thereof. Although, fluorescence anisotropy showed that A3G had similar nanomolar affinity for RNA and ssDNA, RNA stochastically dissociated A3G dimers and higher-order oligomers from ssDNA, suggesting a different modality for RNA binding. Mass spectrometry mapping of A3G peptides cross-linked to nucleic acid suggested ssDNA only bound to three peptides, amino acids (aa) 181-194 in the N-terminus and aa 314-320 and 345-374 in the C-terminus that were part of a continuous exposed surface. RNA bound to these peptides and uniquely associated with three additional peptides in the N- terminus, aa 15-29, 41-52 and 83-99, that formed a continuous surface area adjacent to the ssDNA binding surface. The data predict a mechanistic model of RNA inhibition of ssDNA binding to A3G in which competitive and allosteric interactions determine RNA-bound versus ssDNA-bound conformational states.
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Affiliation(s)
- Bogdan Polevoda
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - William M McDougall
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Bradley N Tun
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Michael Cheung
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Jason D Salter
- OyaGen, Inc, Rochester BioVenture Center, 77 Ridgeland Road, Rochester, NY 14623, USA
| | - Alan E Friedman
- Environmental Health Sciences Center, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | - Harold C Smith
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA Center for RNA Biology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA OyaGen, Inc, Rochester BioVenture Center, 77 Ridgeland Road, Rochester, NY 14623, USA Environmental Health Sciences Center, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA Center for AIDS Research, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642, USA
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Abstract
Cytidine (C) to Uridine (U) RNA editing is a post-trancriptional modification that until recently was known to only affect Apolipoprotein b (Apob) RNA and minimally require 2 components of the C to U editosome, the deaminase APOBEC1 and the RNA-binding protein A1CF. Our latest work has identified a novel RNA-binding protein, RBM47, as a core component of the editosome, which can substitute A1CF for the editing of ApoB mRNA. In addition, new RNA species that are subjected to C to U editing have been identified. Here, we highlight these recent discoveries and discuss how they change our view of the composition of the C to U editing machinery and expand our knowledge of the functional attributes of C to U RNA editing.
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Affiliation(s)
- Nicolas Fossat
- a Embryology Unit; Children's Medical Research Institute ; Westmead , Australia
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Sharma S, Patnaik SK, Taggart RT, Kannisto ED, Enriquez SM, Gollnick P, Baysal BE. APOBEC3A cytidine deaminase induces RNA editing in monocytes and macrophages. Nat Commun 2015; 6:6881. [PMID: 25898173 PMCID: PMC4411297 DOI: 10.1038/ncomms7881] [Citation(s) in RCA: 163] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/10/2015] [Indexed: 01/01/2023] Open
Abstract
The extent, regulation and enzymatic basis of RNA editing by cytidine deamination are incompletely understood. Here we show that transcripts of hundreds of genes undergo site-specific C>U RNA editing in macrophages during M1 polarization and in monocytes in response to hypoxia and interferons. This editing alters the amino acid sequences for scores of proteins, including many that are involved in pathogenesis of viral diseases. APOBEC3A, which is known to deaminate cytidines of single-stranded DNA and to inhibit viruses and retrotransposons, mediates this RNA editing. Amino acid residues of APOBEC3A that are known to be required for its DNA deamination and anti-retrotransposition activities were also found to affect its RNA deamination activity. Our study demonstrates the cellular RNA editing activity of a member of the APOBEC3 family of innate restriction factors and expands the understanding of C>U RNA editing in mammals. Aberrant RNA editing is linked to a range of neuropsychiatric and chronic diseases. Here Sharma et al. show that APOBEC3A can function as an RNA editing protein in response to physiological stimuli, significantly expanding our understanding of RNA editing and the role this may play in diseases.
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Affiliation(s)
- Shraddha Sharma
- Department of Pathology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York 14203, USA
| | - Santosh K Patnaik
- Department of Thoracic Surgery, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York 14203, USA
| | - R Thomas Taggart
- Department of Pathology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York 14203, USA
| | - Eric D Kannisto
- Department of Thoracic Surgery, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York 14203, USA
| | - Sally M Enriquez
- Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - Paul Gollnick
- Department of Biological Sciences, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - Bora E Baysal
- Department of Pathology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, New York 14203, USA
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40
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Identification of DNA cleavage- and recombination-specific hnRNP cofactors for activation-induced cytidine deaminase. Proc Natl Acad Sci U S A 2015; 112:5791-6. [PMID: 25902538 DOI: 10.1073/pnas.1506167112] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Activation-induced cytidine deaminase (AID) is essential for antibody class switch recombination (CSR) and somatic hypermutation (SHM). AID originally was postulated to function as an RNA-editing enzyme, based on its strong homology with apolipoprotein B mRNA-editing enzyme, catalytic polypeptide 1 (APOBEC1), the enzyme that edits apolipoprotein B-100 mRNA in the presence of the APOBEC cofactor APOBEC1 complementation factor/APOBEC complementation factor (A1CF/ACF). Because A1CF is structurally similar to heterogeneous nuclear ribonucleoproteins (hnRNPs), we investigated the involvement of several well-known hnRNPs in AID function by using siRNA knockdown and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9-mediated disruption. We found that hnRNP K deficiency inhibited DNA cleavage and thereby induced both CSR and SHM, whereas hnRNP L deficiency inhibited only CSR and somewhat enhanced SHM. Interestingly, both hnRNPs exhibited RNA-dependent interactions with AID, and mutant forms of these proteins containing deletions in the RNA-recognition motif failed to rescue CSR. Thus, our study suggests that hnRNP K and hnRNP L may serve as A1CF-like cofactors in AID-mediated CSR and SHM.
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Xu J, Deng Y, Li Q, Zhu X, He Z. STRIPE2 encodes a putative dCMP deaminase that plays an important role in chloroplast development in rice. J Genet Genomics 2014; 41:539-48. [PMID: 25438698 DOI: 10.1016/j.jgg.2014.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 05/08/2014] [Accepted: 05/09/2014] [Indexed: 12/20/2022]
Abstract
Mutants with abnormal leaf coloration are good genetic materials for understanding the mechanism of chloroplast development and chlorophyll biosynthesis. In this study, a rice mutant st2 (stripe2) with stripe leaves was identified from the γ-ray irradiated mutant pool. The st2 mutant exhibited decreased accumulation of chlorophyll and aberrant chloroplasts. Genetic analysis indicated that the st2 mutant was controlled by a single recessive locus. The ST2 gene was finely confined to a 27-kb region on chromosome 1 by the map-based cloning strategy and a 5-bp deletion in Os01g0765000 was identified by sequence analysis. The deletion happened in the joint of exon 3 and intron 3 and led to new spliced products of mRNA. Genetic complementation confirmed that Os01g0765000 is the ST2 gene. We found that the ST2 gene was expressed ubiquitously. Subcellular localization assay showed that the ST2 protein was located in mitochondria. ST2 belongs to the cytidine deaminase-like family and possibly functions as the dCMP deaminase, which catalyzes the formation of dUMP from dCMP by deamination. Additionally, exogenous application of dUMP could partially rescue the st2 phenotype. Therefore, our study identified a putative dCMP deaminase as a novel regulator in chloroplast development for the first time.
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Affiliation(s)
- Jing Xu
- National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yiwen Deng
- National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Qun Li
- National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xudong Zhu
- China National Rice Research Institute, Hangzhou 31006, China.
| | - Zuhua He
- National Key Laboratory of Plant Molecular Genetics and National Center of Plant Gene Research, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
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Mouse knockout models for HIV-1 restriction factors. Cell Mol Life Sci 2014; 71:3749-66. [PMID: 24854580 PMCID: PMC4160573 DOI: 10.1007/s00018-014-1646-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/24/2014] [Accepted: 05/05/2014] [Indexed: 12/21/2022]
Abstract
Infection of cells with human immunodeficiency virus 1 (HIV-1) is controlled by restriction factors, host proteins that counteract a variety of steps in the life cycle of this lentivirus. These include SAMHD1, APOBEC3G and tetherin, which block reverse transcription, hypermutate viral DNA and prevent progeny virus release, respectively. These and other HIV-1 restriction factors are conserved and have clear orthologues in the mouse. This review summarises studies in knockout mice lacking HIV-1 restriction factors. In vivo experiments in such animals have not only validated in vitro data obtained from cultured cells, but have also revealed new findings about the biology of these proteins. Indeed, genetic ablation of HIV-1 restriction factors in the mouse has provided evidence that restriction factors control retroviruses and other viruses in vivo and has led to new insights into the mechanisms by which these proteins counteract infection. For example, in vivo experiments in knockout mice demonstrate that virus control exerted by restriction factors can shape adaptive immune responses. Moreover, the availability of animals lacking restriction factors opens the possibility to study the function of these proteins in other contexts such as autoimmunity and cancer. Further in vivo studies of more recently identified HIV-1 restriction factors in gene targeted mice are, therefore, justified.
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