1
|
Osborne M, Fubara A, Ó Cinnéide E, Coughlan AY, Wolfe KH. WHO elements - A new category of selfish genetic elements at the borderline between homing elements and transposable elements. Semin Cell Dev Biol 2024; 163:2-13. [PMID: 38664119 DOI: 10.1016/j.semcdb.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 05/26/2024]
Abstract
Homing genetic elements are a form of selfish DNA that inserts into a specific target site in the genome and spreads through the population by a process of biased inheritance. Two well-known types of homing element, called inteins and homing introns, were discovered decades ago. In this review we describe WHO elements, a newly discovered type of homing element that constitutes a distinct third category but is rare, having been found only in a few yeast species so far. WHO elements are inferred to spread using the same molecular homing mechanism as inteins and introns: they encode a site-specific endonuclease that cleaves the genome at the target site, making a DNA break that is subsequently repaired by copying the element. For most WHO elements, the target site is in the glycolytic gene FBA1. WHO elements differ from inteins and homing introns in two fundamental ways: they do not interrupt their host gene (FBA1), and they occur in clusters. The clusters were formed by successive integrations of different WHO elements into the FBA1 locus, the result of an 'arms race' between the endonuclease and its target site. We also describe one family of WHO elements (WHO10) that is no longer specifically associated with the FBA1 locus and instead appears to have become transposable, inserting at random genomic sites in Torulaspora globosa with up to 26 copies per strain. The WHO family of elements is therefore at the borderline between homing genetic elements and transposable elements.
Collapse
Affiliation(s)
- Matthieu Osborne
- Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Athaliah Fubara
- Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Eoin Ó Cinnéide
- Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Aisling Y Coughlan
- Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Kenneth H Wolfe
- Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland.
| |
Collapse
|
2
|
Lei B, Wang S, Zhang X, Chen T, Lin Y. Novel protein ligase based on dual split intein. Biochem Biophys Res Commun 2024; 720:150097. [PMID: 38754162 DOI: 10.1016/j.bbrc.2024.150097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 05/08/2024] [Indexed: 05/18/2024]
Abstract
Inteins are unique single-turnover enzymes that can excise themselves from the precursor protein without the aid of any external cofactors or energy. In most cases, inteins are covalently linked with the extein sequences and protein splicing happens spontaneously. In this study, a novel protein ligation system was developed based on two atypical split inteins without cross reaction, in which the large segments of one S1 and one S11 split intein fusion protein acted as a protein ligase, the small segments (only several amino acids long) was fused to the N-extein and C-extein, respectively. The splicing activity was demonstrated in E. coli and in vitro with different extein sequences, which showed ∼15% splicing efficiency in vitro. The protein trans-splicing in vitro was further optimized, and possible reaction explanations were explored. As a proof of concept, we expect this approach to expand the scope of trans-splicing-based protein engineering and provide new clues for intein based protein ligase.
Collapse
Affiliation(s)
- Bing Lei
- College of Biological Science and Medical Engineering, Donghua University, Shanghai, 201620, PR China
| | - Suyang Wang
- College of Biological Science and Medical Engineering, Donghua University, Shanghai, 201620, PR China
| | - Xiaomeng Zhang
- College of Biological Science and Medical Engineering, Donghua University, Shanghai, 201620, PR China
| | - Tianqi Chen
- College of Biological Science and Medical Engineering, Donghua University, Shanghai, 201620, PR China
| | - Ying Lin
- College of Biological Science and Medical Engineering, Donghua University, Shanghai, 201620, PR China.
| |
Collapse
|
3
|
Mikina W, Hałakuc P, Milanowski R. Transposon-derived introns as an element shaping the structure of eukaryotic genomes. Mob DNA 2024; 15:15. [PMID: 39068498 PMCID: PMC11282704 DOI: 10.1186/s13100-024-00325-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 07/23/2024] [Indexed: 07/30/2024] Open
Abstract
The widely accepted hypothesis postulates that the first spliceosomal introns originated from group II self-splicing introns. However, it is evident that not all spliceosomal introns in the nuclear genes of modern eukaryotes are inherited through vertical transfer of intronic sequences. Several phenomena contribute to the formation of new introns but their most common origin seems to be the insertion of transposable elements. Recent analyses have highlighted instances of mass gains of new introns from transposable elements. These events often coincide with an increase or change in the spliceosome's tolerance to splicing signals, including the acceptance of noncanonical borders. Widespread acquisitions of transposon-derived introns occur across diverse evolutionary lineages, indicating convergent processes. These events, though independent, likely require a similar set of conditions. These conditions include the presence of transposon elements with features enabling their removal at the RNA level as introns and/or the existence of a splicing mechanism capable of excising unusual sequences that would otherwise not be recognized as introns by standard splicing machinery. Herein we summarize those mechanisms across different eukaryotic lineages.
Collapse
Affiliation(s)
- Weronika Mikina
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, Warsaw, 02‑089, Poland
| | - Paweł Hałakuc
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, Warsaw, 02‑089, Poland
| | - Rafał Milanowski
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, Warsaw, 02‑089, Poland.
| |
Collapse
|
4
|
Gallot-Lavallée L, Jerlström-Hultqvist J, Zegarra-Vidarte P, Salas-Leiva DE, Stairs CW, Čepička I, Roger AJ, Archibald JM. Massive intein content in Anaeramoeba reveals aspects of intein mobility in eukaryotes. Proc Natl Acad Sci U S A 2023; 120:e2306381120. [PMID: 38019867 PMCID: PMC10710043 DOI: 10.1073/pnas.2306381120] [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: 04/19/2023] [Accepted: 10/20/2023] [Indexed: 12/01/2023] Open
Abstract
Inteins are self-splicing protein elements found in viruses and all three domains of life. How the DNA encoding these selfish elements spreads within and between genomes is poorly understood, particularly in eukaryotes where inteins are scarce. Here, we show that the nuclear genomes of three strains of Anaeramoeba encode between 45 and 103 inteins, in stark contrast to four found in the most intein-rich eukaryotic genome described previously. The Anaeramoeba inteins reside in a wide range of proteins, only some of which correspond to intein-containing proteins in other eukaryotes, prokaryotes, and viruses. Our data also suggest that viruses have contributed to the spread of inteins in Anaeramoeba and the colonization of new alleles. The persistence of Anaeramoeba inteins might be partly explained by intragenomic movement of intein-encoding regions from gene to gene. Our intein dataset greatly expands the spectrum of intein-containing proteins and provides insights into the evolution of inteins in eukaryotes.
Collapse
Affiliation(s)
- Lucie Gallot-Lavallée
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
- Institute for Comparative Genomics, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
| | - Jon Jerlström-Hultqvist
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
- Institute for Comparative Genomics, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
- Microbiology and Immunology, Department of Cell and Molecular Biology, Biomedical Centre, Uppsala University, Uppsala751 24, Sweden
| | - Paula Zegarra-Vidarte
- Microbiology and Immunology, Department of Cell and Molecular Biology, Biomedical Centre, Uppsala University, Uppsala751 24, Sweden
| | - Dayana E. Salas-Leiva
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
- Institute for Comparative Genomics, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
| | - Courtney W. Stairs
- Microbiology Group, Department of Biology, Lund University, Lund223 62, Sweden
| | - Ivan Čepička
- Department of Zoology, Charles University, Prague128 00, Czech Republic
| | - Andrew J. Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
- Institute for Comparative Genomics, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
| | - John M. Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
- Institute for Comparative Genomics, Dalhousie University, Halifax, Nova ScotiaB3H 4R2, Canada
| |
Collapse
|
5
|
Turgeman-Grott I, Arsenault D, Yahav D, Feng Y, Miezner G, Naki D, Peri O, Papke RT, Gogarten JP, Gophna U. Neighboring inteins interfere with one another's homing capacity. PNAS NEXUS 2023; 2:pgad354. [PMID: 38024399 PMCID: PMC10643990 DOI: 10.1093/pnasnexus/pgad354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 10/16/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023]
Abstract
Inteins are mobile genetic elements that invade conserved genes across all domains of life and viruses. In some instances, a single gene will have several intein insertion sites. In Haloarchaea, the minichromosome maintenance (MCM) protein at the core of replicative DNA helicase contains four intein insertion sites within close proximity, where two of these sites (MCM-a and MCM-d) are more likely to be invaded. A haloarchaeon that harbors both MCM-a and MCM-d inteins, Haloferax mediterranei, was studied in vivo to determine intein invasion dynamics and the interactions between neighboring inteins. Additionally, invasion frequencies and the conservation of insertion site sequences in 129 Haloferacales mcm homologs were analyzed to assess intein distribution across the order. We show that the inteins at MCM-a and MCM-d recognize and cleave their respective target sites and, in the event that only one empty intein invasion site is present, readily initiate homing (i.e. single homing). However, when two inteins are present co-homing into an intein-free target sequence is much less effective. The two inteins are more effective when invading alleles that already contain an intein at one of the two sites. Our in vivo and computational studies also support that having a proline in place of a serine as the first C-terminal extein residue of the MCM-d insertion site prevents successful intein splicing, but does not stop recognition of the insertion site by the intein's homing endonuclease.
Collapse
Affiliation(s)
- Israela Turgeman-Grott
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, P.O. Box 39040, 6997801 Tel Aviv, Israel
| | - Danielle Arsenault
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Storrs, CT 06268-3125, USA
| | - Dekel Yahav
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, P.O. Box 39040, 6997801 Tel Aviv, Israel
| | - Yutian Feng
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Storrs, CT 06268-3125, USA
| | - Guy Miezner
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, P.O. Box 39040, 6997801 Tel Aviv, Israel
| | - Doron Naki
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, P.O. Box 39040, 6997801 Tel Aviv, Israel
| | - Omri Peri
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, P.O. Box 39040, 6997801 Tel Aviv, Israel
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Storrs, CT 06268-3125, USA
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Storrs, CT 06268-3125, USA
- Institute for Systems Genomics, University of Connecticut, 67 North Eagleville Road, Storrs, CT 06268-3003, USA
| | - Uri Gophna
- The Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences, Tel Aviv University, P.O. Box 39040, 6997801 Tel Aviv, Israel
| |
Collapse
|
6
|
Hoffman JR, Karol KG, Ohmura Y, Pogoda CS, Keepers KG, McMullin RT, Lendemer JC. Mitochondrial genomes in the iconic reindeer lichens: Architecture, variation, and synteny across multiple evolutionary scales. Mycologia 2023; 115:187-205. [PMID: 36736327 DOI: 10.1080/00275514.2022.2157665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Variation in mitochondrial genome composition across intraspecific, interspecific, and higher taxonomic scales has been little studied in lichen obligate symbioses. Cladonia is one of the most diverse and ecologically important lichen genera, with over 500 species representing an array of unique morphologies and chemical profiles. Here, we assess mitochondrial genome diversity and variation in this flagship genus, with focused sampling of two clades of the "true" reindeer lichens, Cladonia subgenus Cladina, and additional genomes from nine outgroup taxa. We describe composition and architecture at the gene and the genome scale, examining patterns in organellar genome size in larger taxonomic groups in Ascomycota. Mitochondrial genomes of Cladonia, Pilophorus, and Stereocaulon were consistently larger than those of Lepraria and contained more introns, suggesting a selective pressure in asexual morphology in Lepraria driving it toward genomic simplification. Collectively, lichen mitochondrial genomes were larger than most other fungal life strategies, reaffirming the notion that coevolutionary streamlining does not correlate to genome size reductions. Genomes from Cladonia ravenelii and Stereocaulon pileatum exhibited ATP9 duplication, bearing paralogs that may still be functional. Homing endonuclease genes (HEGs), though scarce in Lepraria, were diverse and abundant in Cladonia, exhibiting variable evolutionary histories that were sometimes independent of the mitochondrial evolutionary history. Intraspecific HEG diversity was also high, with C. rangiferina especially bearing a range of HEGs with one unique to the species. This study reveals a rich history of events that have transformed mitochondrial genomes of Cladonia and related genera, allowing future study alongside a wealth of assembled genomes.
Collapse
Affiliation(s)
- Jordan R Hoffman
- Department of Biology, The City University of New York Graduate Center, 365 5th Avenue, New York, New York 10016
- Institute of Systemic Botany, The New York Botanical Garden, Bronx, New York 10458-5126
| | - Kenneth G Karol
- Institute of Systemic Botany, The New York Botanical Garden, Bronx, New York 10458-5126
| | - Yoshihito Ohmura
- Department of Botany, National Museum of Nature and Science, 4-1-1 Amakubo, Tsukuba 305-0005, Japan
| | - Cloe S Pogoda
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309
| | - Kyle G Keepers
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309
| | - Richard T McMullin
- Research and Collections, Canadian Museum of Nature, PO Box 3443, Station D, Ottawa, Ontario K1P 6P4, Canada
| | - James C Lendemer
- Institute of Systemic Botany, The New York Botanical Garden, Bronx, New York 10458-5126
| |
Collapse
|
7
|
Sahu PK, Sao R, Choudhary DK, Thada A, Kumar V, Mondal S, Das BK, Jankuloski L, Sharma D. Advancement in the Breeding, Biotechnological and Genomic Tools towards Development of Durable Genetic Resistance against the Rice Blast Disease. PLANTS 2022; 11:plants11182386. [PMID: 36145787 PMCID: PMC9504543 DOI: 10.3390/plants11182386] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/31/2022] [Accepted: 09/03/2022] [Indexed: 01/02/2023]
Abstract
Rice production needs to be sustained in the coming decades, as the changeable climatic conditions are becoming more conducive to disease outbreaks. The majority of rice diseases cause enormous economic damage and yield instability. Among them, rice blast caused by Magnaportheoryzae is a serious fungal disease and is considered one of the major threats to world rice production. This pathogen can infect the above-ground tissues of rice plants at any growth stage and causes complete crop failure under favorable conditions. Therefore, management of blast disease is essentially required to sustain global food production. When looking at the drawback of chemical management strategy, the development of durable, resistant varieties is one of the most sustainable, economic, and environment-friendly approaches to counter the outbreaks of rice blasts. Interestingly, several blast-resistant rice cultivars have been developed with the help of breeding and biotechnological methods. In addition, 146 R genes have been identified, and 37 among them have been molecularly characterized to date. Further, more than 500 loci have been identified for blast resistance which enhances the resources for developing blast resistance through marker-assisted selection (MAS), marker-assisted backcross breeding (MABB), and genome editing tools. Apart from these, a better understanding of rice blast pathogens, the infection process of the pathogen, and the genetics of the immune response of the host plant are very important for the effective management of the blast disease. Further, high throughput phenotyping and disease screening protocols have played significant roles in easy comprehension of the mechanism of disease spread. The present review critically emphasizes the pathogenesis, pathogenomics, screening techniques, traditional and molecular breeding approaches, and transgenic and genome editing tools to develop a broad spectrum and durable resistance against blast disease in rice. The updated and comprehensive information presented in this review would be definitely helpful for the researchers, breeders, and students in the planning and execution of a resistance breeding program in rice against this pathogen.
Collapse
Affiliation(s)
- Parmeshwar K. Sahu
- Department of Genetics and Plant Breeding, Indira Gandhi Krishi Vishwavidyalaya, Raipur 492012, Chhattisgarh, India
| | - Richa Sao
- Department of Genetics and Plant Breeding, Indira Gandhi Krishi Vishwavidyalaya, Raipur 492012, Chhattisgarh, India
| | | | - Antra Thada
- Department of Genetics and Plant Breeding, Indira Gandhi Krishi Vishwavidyalaya, Raipur 492012, Chhattisgarh, India
| | - Vinay Kumar
- ICAR-National Institute of Biotic Stress Management, Baronda, Raipur 493225, Chhattisgarh, India
| | - Suvendu Mondal
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Bikram K. Das
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Ljupcho Jankuloski
- Plant Breeding and Genetics Section, Joint FAO/IAEA Centre, International Atomic Energy Agency, 1400 Vienna, Austria
- Correspondence: (L.J.); (D.S.); Tel.: +91-7000591137 (D.S.)
| | - Deepak Sharma
- Department of Genetics and Plant Breeding, Indira Gandhi Krishi Vishwavidyalaya, Raipur 492012, Chhattisgarh, India
- Correspondence: (L.J.); (D.S.); Tel.: +91-7000591137 (D.S.)
| |
Collapse
|
8
|
Intraspecific comparison of mitochondrial genomes reveals the evolution in medicinal fungus Ganoderma lingzhi. J Biosci Bioeng 2022; 134:374-383. [PMID: 36075811 DOI: 10.1016/j.jbiosc.2022.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 06/28/2022] [Accepted: 07/05/2022] [Indexed: 11/21/2022]
Abstract
Several mitogenomes of the genus Ganoderma have been assembled, but intraspecific comparisons of mitogenomes in Ganoderma lingzhi have not been reported. In this study, 19 G. lingzhi mitogenomes were assembled and analyzed combined with three mitogenomes of G. lingzhi from GenBank in term of the characteristics, evolution, and phylogeny. The results showed that the mitogenomes of the G. lingzhi strains are closed circular ranging from 49.23 kb to 68.37 kb. The genetic distance, selective pressure, and base variation indicate that the 14 common protein coding genes were highly conserved. The differences in introns, open reading frames, and repetitive sequences in the mitogenome were the main factors leaded to the variations in mitogenome. The introns were horizontally transferred in mitogenomes, and the differences between introns in the same insertion, which were primarily caused by the repetitive sequence, showed that the introns may be under degeneration. Besides, the frequent insertion and deletion of introns showed an evolutionary rate faster than protein coding genes. Phylogenetic analysis showed that the G. lingzhi strains gathered with high support, and those with the same intron distribution law had closer clustering relationships.
Collapse
|
9
|
Lan T, Que H, Luo M, Zhao X, Wei X. Genome editing via non-viral delivery platforms: current progress in personalized cancer therapy. Mol Cancer 2022; 21:71. [PMID: 35277177 PMCID: PMC8915502 DOI: 10.1186/s12943-022-01550-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/24/2022] [Indexed: 02/08/2023] Open
Abstract
Cancer is a severe disease that substantially jeopardizes global health. Although considerable efforts have been made to discover effective anti-cancer therapeutics, the cancer incidence and mortality are still growing. The personalized anti-cancer therapies present themselves as a promising solution for the dilemma because they could precisely destroy or fix the cancer targets based on the comprehensive genomic analyses. In addition, genome editing is an ideal way to implement personalized anti-cancer therapy because it allows the direct modification of pro-tumor genes as well as the generation of personalized anti-tumor immune cells. Furthermore, non-viral delivery system could effectively transport genome editing tools (GETs) into the cell nucleus with an appreciable safety profile. In this manuscript, the important attributes and recent progress of GETs will be discussed. Besides, the laboratory and clinical investigations that seek for the possibility of combining non-viral delivery systems with GETs for the treatment of cancer will be assessed in the scope of personalized therapy.
Collapse
Affiliation(s)
- Tianxia Lan
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Sichuan, 610041, Chengdu, China
| | - Haiying Que
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Sichuan, 610041, Chengdu, China
| | - Min Luo
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Sichuan, 610041, Chengdu, China
| | - Xia Zhao
- Department of Gynecology and Obstetrics, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second Hospital, Sichuan University, Sichuan, 610041, Chengdu, China.
| | - Xiawei Wei
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Sichuan, 610041, Chengdu, China.
| |
Collapse
|
10
|
Abstract
Intervening proteins, or inteins, are mobile genetic elements that are translated within host polypeptides and removed at the protein level by splicing. In protein splicing, a self-mediated reaction removes the intein, leaving a peptide bond in place. While protein splicing can proceed in the absence of external cofactors, several examples of conditional protein splicing (CPS) have emerged. In CPS, the rate and accuracy of splicing are highly dependent on environmental conditions. Because the activity of the intein-containing host protein is compromised prior to splicing and inteins are highly abundant in the microbial world, CPS represents an emerging form of posttranslational regulation that is potentially widespread in microbes. Reactive chlorine species (RCS) are highly potent oxidants encountered by bacteria in a variety of natural environments, including within cells of the mammalian innate immune system. Here, we demonstrate that two naturally occurring RCS, namely, hypochlorous acid (the active compound in bleach) and N-chlorotaurine, can reversibly block splicing of DnaB inteins from Mycobacterium leprae and Mycobacterium smegmatis in vitro. Further, using a reporter that monitors DnaB intein activity within M. smegmatis, we show that DnaB protein splicing is inhibited by RCS in the native host. DnaB, an essential replicative helicase, is the most common intein-housing protein in bacteria. These results add to the growing list of environmental conditions that are relevant to the survival of the intein-containing host and influence protein splicing, as well as suggesting a novel mycobacterial response to RCS. We propose a model in which DnaB splicing, and therefore replication, is paused when these mycobacteria encounter RCS. IMPORTANCE Inteins are both widespread and abundant in microbes, including within several bacterial and fungal pathogens. Inteins are domains translated within host proteins and removed at the protein level by splicing. Traditionally considered molecular parasites, some inteins have emerged in recent years as adaptive posttranslational regulatory elements. Several studies have demonstrated CPS, in which the rate and accuracy of protein splicing, and thus host protein functions, are responsive to environmental conditions relevant to the intein-containing organism. In this work, we demonstrate that two naturally occurring RCS, including the active compound in household bleach, reversibly inhibit protein splicing of Mycobacterium leprae and Mycobacterium smegmatis DnaB inteins. In addition to describing a new physiologically relevant condition that can temporarily inhibit protein splicing, this study suggests a novel stress response in Mycobacterium, a bacterial genus of tremendous importance to humans.
Collapse
|
11
|
Wall DA, Tarrant SP, Wang C, Mills KV, Lennon CW. Intein Inhibitors as Novel Antimicrobials: Protein Splicing in Human Pathogens, Screening Methods, and Off-Target Considerations. Front Mol Biosci 2021; 8:752824. [PMID: 34692773 PMCID: PMC8529194 DOI: 10.3389/fmolb.2021.752824] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/24/2021] [Indexed: 01/20/2023] Open
Abstract
Protein splicing is a post-translational process by which an intervening polypeptide, or intein, catalyzes its own removal from the flanking polypeptides, or exteins, concomitant with extein ligation. Although inteins are highly abundant in the microbial world, including within several human pathogens, they are absent in the genomes of metazoans. As protein splicing is required to permit function of essential proteins within pathogens, inteins represent attractive antimicrobial targets. Here we review key proteins interrupted by inteins in pathogenic mycobacteria and fungi, exciting discoveries that provide proof of concept that intein activity can be inhibited and that this inhibition has an effect on the host organism's fitness, and bioanalytical methods that have been used to screen for intein activity. We also consider potential off-target inhibition of hedgehog signaling, given the similarity in structure and function of inteins and hedgehog autoprocessing domains.
Collapse
Affiliation(s)
- Diana A Wall
- Department of Chemistry, College of the Holy Cross, Worcester, MA, United States
| | - Seanan P Tarrant
- Department of Chemistry, College of the Holy Cross, Worcester, MA, United States
| | - Chunyu Wang
- Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States.,Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, Worcester, MA, United States
| | - Christopher W Lennon
- Department of Biological Sciences, Murray State University, Murray, KY, United States
| |
Collapse
|
12
|
Mukhopadhyay J, Hausner G. Organellar Introns in Fungi, Algae, and Plants. Cells 2021; 10:cells10082001. [PMID: 34440770 PMCID: PMC8393795 DOI: 10.3390/cells10082001] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/31/2021] [Accepted: 08/05/2021] [Indexed: 12/16/2022] Open
Abstract
Introns are ubiquitous in eukaryotic genomes and have long been considered as ‘junk RNA’ but the huge energy expenditure in their transcription, removal, and degradation indicate that they may have functional significance and can offer evolutionary advantages. In fungi, plants and algae introns make a significant contribution to the size of the organellar genomes. Organellar introns are classified as catalytic self-splicing introns that can be categorized as either Group I or Group II introns. There are some biases, with Group I introns being more frequently encountered in fungal mitochondrial genomes, whereas among plants Group II introns dominate within the mitochondrial and chloroplast genomes. Organellar introns can encode a variety of proteins, such as maturases, homing endonucleases, reverse transcriptases, and, in some cases, ribosomal proteins, along with other novel open reading frames. Although organellar introns are viewed to be ribozymes, they do interact with various intron- or nuclear genome-encoded protein factors that assist in the intron RNA to fold into competent splicing structures, or facilitate the turn-over of intron RNAs to prevent reverse splicing. Organellar introns are also known to be involved in non-canonical splicing, such as backsplicing and trans-splicing which can result in novel splicing products or, in some instances, compensate for the fragmentation of genes by recombination events. In organellar genomes, Group I and II introns may exist in nested intronic arrangements, such as introns within introns, referred to as twintrons, where splicing of the external intron may be dependent on splicing of the internal intron. These nested or complex introns, with two or three-component intron modules, are being explored as platforms for alternative splicing and their possible function as molecular switches for modulating gene expression which could be potentially applied towards heterologous gene expression. This review explores recent findings on organellar Group I and II introns, focusing on splicing and mobility mechanisms aided by associated intron/nuclear encoded proteins and their potential roles in organellar gene expression and cross talk between nuclear and organellar genomes. Potential application for these types of elements in biotechnology are also discussed.
Collapse
MESH Headings
- Evolution, Molecular
- Gene Expression Regulation, Fungal
- Gene Expression Regulation, Plant
- Genome, Fungal
- Genome, Plant
- Introns
- Organelles/genetics
- Organelles/metabolism
- RNA Splicing
- RNA Stability
- RNA, Algal/genetics
- RNA, Algal/metabolism
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Untranslated/genetics
- RNA, Untranslated/metabolism
- Transcription, Genetic
Collapse
|
13
|
Boyd CM, Angermeyer A, Hays SG, Barth ZK, Patel KM, Seed KD. Bacteriophage ICP1: A Persistent Predator of Vibrio cholerae. Annu Rev Virol 2021; 8:285-304. [PMID: 34314595 PMCID: PMC9040626 DOI: 10.1146/annurev-virology-091919-072020] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bacteriophages or phages—viruses of bacteria—are abundant and considered to be highly diverse. Interestingly, a particular group of lytic Vibrio cholerae–specific phages (vibriophages) of the International Centre for Diarrheal Disease Research, Bangladesh cholera phage 1 (ICP1) lineage show high levels of genome conservation over large spans of time and geography, despite a constant coevolutionary arms race with their host. From a collection of 67 sequenced ICP1 isolates, mostly from clinical samples, we find these phages have mosaic genomes consisting of large, conserved modules disrupted by variable sequences that likely evolve mostly through mobile endonuclease-mediated recombination during coinfection. Several variable regions have been associated with adaptations against antiphage elements in V. cholerae; notably, this includes ICP1’s CRISPR-Cas system. The ongoing association of ICP1 and V. cholerae in cholera-endemic regions makes this system a rich source for discovery of novel defense and counterdefense strategies in bacteria-phage conflicts in nature.
Collapse
Affiliation(s)
- Caroline M Boyd
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Angus Angermeyer
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Stephanie G Hays
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Zachary K Barth
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Kishen M Patel
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA; .,Chan Zuckerberg Biohub, San Francisco, California 94158, USA
| |
Collapse
|
14
|
Megarioti AH, Kouvelis VN. The Coevolution of Fungal Mitochondrial Introns and Their Homing Endonucleases (GIY-YIG and LAGLIDADG). Genome Biol Evol 2021; 12:1337-1354. [PMID: 32585032 PMCID: PMC7487136 DOI: 10.1093/gbe/evaa126] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/17/2020] [Indexed: 12/21/2022] Open
Abstract
Fungal mitochondrial (mt) genomes exhibit great diversity in size which is partially attributed to their variable intergenic regions and most importantly to the inclusion of introns within their genes. These introns belong to group I or II, and both of them are self-splicing. The majority of them carry genes encoding homing endonucleases, either LAGLIDADG or GIY-YIG. In this study, it was found that these intronic homing endonucleases genes (HEGs) may originate from mt free-standing open reading frames which can be found nowadays in species belonging to Early Diverging Fungi as “living fossils.” A total of 487 introns carrying HEGs which were located in the publicly available mt genomes of representative species belonging to orders from all fungal phyla was analyzed. Their distribution in the mt genes, their insertion target sequence, and the phylogenetic analyses of the HEGs showed that these introns along with their HEGs form a composite structure in which both selfish elements coevolved. The invasion of the ancestral free-standing HEGs in the introns occurred through a perpetual mechanism, called in this study as “aenaon” hypothesis. It is based on recombination, transpositions, and horizontal gene transfer events throughout evolution. HEGs phylogenetically clustered primarily according to their intron hosts and secondarily to the mt genes carrying the introns and their HEGs. The evolutionary models created revealed an “intron-early” evolution which was enriched by “intron-late” events through many different independent recombinational events which resulted from both vertical and horizontal gene transfers.
Collapse
Affiliation(s)
- Amalia H Megarioti
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Greece
| | - Vassili N Kouvelis
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Greece
| |
Collapse
|
15
|
Barth ZK, Nguyen MH, Seed KD. A chimeric nuclease substitutes a phage CRISPR-Cas system to provide sequence-specific immunity against subviral parasites. eLife 2021; 10:68339. [PMID: 34232860 PMCID: PMC8263062 DOI: 10.7554/elife.68339] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/27/2021] [Indexed: 02/06/2023] Open
Abstract
Mobile genetic elements, elements that can move horizontally between genomes, have profound effects on their host's fitness. The phage-inducible chromosomal island-like element (PLE) is a mobile element that integrates into the chromosome of Vibrio cholerae and parasitizes the bacteriophage ICP1 to move between cells. This parasitism by PLE is such that it abolishes the production of ICP1 progeny and provides a defensive boon to the host cell population. In response to the severe parasitism imposed by PLE, ICP1 has acquired an adaptive CRISPR-Cas system that targets the PLE genome during infection. However, ICP1 isolates that naturally lack CRISPR-Cas are still able to overcome certain PLE variants, and the mechanism of this immunity against PLE has thus far remained unknown. Here, we show that ICP1 isolates that lack CRISPR-Cas encode an endonuclease in the same locus, and that the endonuclease provides ICP1 with immunity to a subset of PLEs. Further analysis shows that this endonuclease is of chimeric origin, incorporating a DNA-binding domain that is highly similar to some PLE replication origin-binding proteins. This similarity allows the endonuclease to bind and cleave PLE origins of replication. The endonuclease appears to exert considerable selective pressure on PLEs and may drive PLE replication module swapping and origin restructuring as mechanisms of escape. This work demonstrates that new genome defense systems can arise through domain shuffling and provides a greater understanding of the evolutionary forces driving genome modularity and temporal succession in mobile elements.
Collapse
Affiliation(s)
- Zachary K Barth
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States
| | - Maria Ht Nguyen
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, United States.,Chan Zuckerberg Biohub, San Francisco, United States
| |
Collapse
|
16
|
Mini-Intein Structures from Extremophiles Suggest a Strategy for Finding Novel Robust Inteins. Microorganisms 2021; 9:microorganisms9061226. [PMID: 34198729 PMCID: PMC8229266 DOI: 10.3390/microorganisms9061226] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/26/2021] [Accepted: 06/02/2021] [Indexed: 11/28/2022] Open
Abstract
Inteins are prevalent among extremophiles. Mini-inteins with robust splicing properties are of particular interest for biotechnological applications due to their small size. However, biochemical and structural characterization has still been limited to a small number of inteins, and only a few serve as widely used tools in protein engineering. We determined the crystal structure of a naturally occurring Pol-II mini-intein from Pyrococcus horikoshii and compared all three mini-inteins found in the genome of P. horikoshii. Despite their similar sizes, the comparison revealed distinct differences in the insertions and deletions, implying specific evolutionary pathways from distinct ancestral origins. Our studies suggest that sporadically distributed mini-inteins might be more promising for further protein engineering applications than highly conserved mini-inteins. Structural investigations of additional inteins could guide the shortest path to finding novel robust mini-inteins suitable for various protein engineering purposes.
Collapse
|
17
|
Woods D, LeSassier DS, Egbunam I, Lennon CW. Construction and Quantitation of a Selectable Protein Splicing Sensor Using Gibson Assembly and Spot Titers. Curr Protoc 2021; 1:e82. [PMID: 33739627 DOI: 10.1002/cpz1.82] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Inteins (intervening proteins) are translated within host proteins and removed through protein splicing. Conditional protein splicing (CPS), where the rate and accuracy of splicing are highly dependent on environmental cues, has emerged as a novel form of post-translational regulation. While CPS has been demonstrated for several inteins in vitro, a comprehensive understanding of inteins requires tools to quantitatively monitor their activity within the cellular context. Here, we describe a method for construction of a splicing-dependent system that can be used to quantitatively assay for conditions that modulate protein splicing. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Construction of an intein-containing KanR2 library using Gibson assembly Basic Protocol 2: Phenotype determination using quantitative spot titers Support Protocol 1: Preparation of LB agar plates for spot titers Support Protocol 2: Preparation and transformation of competent M. smegmatis cells.
Collapse
Affiliation(s)
- Daniel Woods
- Wadsworth Center, New York State Department of Health, Albany, New York
| | | | | | | |
Collapse
|
18
|
Analysis of small and large subunit rDNA introns from several ectomycorrhizal fungi species. PLoS One 2021; 16:e0245714. [PMID: 33720962 PMCID: PMC7959364 DOI: 10.1371/journal.pone.0245714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 01/06/2021] [Indexed: 11/19/2022] Open
Abstract
The small (18S) and large (28S) nuclear ribosomal DNA (rDNA) introns have been researched and sequenced in a variety of ectomycorrhizal fungal taxa in this study, it is found that both 18S and 28S rDNA would contain introns and display some degree variation in size, nucleotide sequences and insertion positions within the same fungi species (Meliniomyces). Under investigations among the tested isolates, 18S rDNA has four sites for intron insertions, 28S rDNA has two sites for intron insertions. Both 18S and 28S rDNA introns among the tested isolates belong to group I introns with a set of secondary structure elements designated P1-P10 helics and loops. We found a 12 nt nucleotide sequences TACCACAGGGAT at site 2 in the 3'-end of 28S rDNA, site 2 introns just insert the upstream or the downstream of the12 nt nucleotide sequences. Afters sequence analysis of all 18S and 28S rDNA introns from tested isolates, three high conserved regions around 30 nt nucleotides (conserved 1, conserved 2, conserved 3) and identical nucleotides can be found. Conserved 1, conserved 2 and conserved 3 regions have high GC content, GC percentage is almost more than 60%. From our results, it seems that the more convenient host sites, intron sequences and secondary structures, or isolates for 18S and 28S rDNA intron insertion and deletion, the more popular they are. No matter 18S rDNA introns or 18S rDNA introns among tested isolates, complementary base pairing at the splicing sites in P1-IGS-P10 tertiary helix around 5'-end introns and exons were weak.
Collapse
|
19
|
Panda S, Nanda A, Nasker SS, Sen D, Mehra A, Nayak S. Metal effect on intein splicing: A review. Biochimie 2021; 185:53-67. [PMID: 33727137 DOI: 10.1016/j.biochi.2021.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/04/2021] [Accepted: 03/06/2021] [Indexed: 02/08/2023]
Abstract
Inteins are intervening polypeptides that interrupt the functional domains of several important proteins across the three domains of life. Inteins excise themselves from the precursor protein, ligating concomitant extein residues in a process called protein splicing. Post-translational auto-removal of inteins remain critical for the generation of active proteins. The perspective of inteins in science is a robust field of research, however fundamental studies centralized upon splicing regulatory mechanism are imperative for addressing more intricate issues. Controlled engineering of intein splicing has many applications; intein inhibition can facilitate novel drug design, while activation of intein splicing is exploited in protein purification. This paper provides a comprehensive review of the past and recent advances in the splicing regulation via metal-intein interaction. We compare the behavior of different metal ions on diverse intein systems. Though metals such as Zn, Cu, Pt, Cd, Co, Ni exhibit intein inhibitory effect heterogeneously on different inteins, divalent metal ions such as Ca and Mg fail to do so. The observed diversity in the metal-intein interaction arises mostly due to intein polymorphism and variations in atomic structure of metals. A mechanistic understanding of intein regulation by metals in native as well as synthetically engineered intein systems may yield potent intein inhibitors via direct or indirect approach.
Collapse
Affiliation(s)
- Sunita Panda
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Ananya Nanda
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Sourya Subhra Nasker
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Debjani Sen
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Ashwaria Mehra
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India
| | - Sasmita Nayak
- School of Biotechnology, Kalinga Institute of Industrial Technology, Bhubaneswar, Odisha, 751024, India.
| |
Collapse
|
20
|
Inteins in Science: Evolution to Application. Microorganisms 2020; 8:microorganisms8122004. [PMID: 33339089 PMCID: PMC7765530 DOI: 10.3390/microorganisms8122004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 12/20/2022] Open
Abstract
Inteins are mobile genetic elements that apply standard enzymatic strategies to excise themselves post-translationally from the precursor protein via protein splicing. Since their discovery in the 1990s, recent advances in intein technology allow for them to be implemented as a modern biotechnological contrivance. Radical improvement in the structure and catalytic framework of cis- and trans-splicing inteins devised the development of engineered inteins that contribute to various efficient downstream techniques. Previous literature indicates that implementation of intein-mediated splicing has been extended to in vivo systems. Besides, the homing endonuclease domain also acts as a versatile biotechnological tool involving genetic manipulation and control of monogenic diseases. This review orients the understanding of inteins by sequentially studying the distribution and evolution pattern of intein, thereby highlighting a role in genetic mobility. Further, we include an in-depth summary of specific applications branching from protein purification using self-cleaving tags to protein modification, post-translational processing and labelling, followed by the development of intein-based biosensors. These engineered inteins offer a disruptive approach towards research avenues like biomaterial construction, metabolic engineering and synthetic biology. Therefore, this linear perspective allows for a more comprehensive understanding of intein function and its diverse applications.
Collapse
|
21
|
Dutheil JY, Münch K, Schotanus K, Stukenbrock EH, Kahmann R. The insertion of a mitochondrial selfish element into the nuclear genome and its consequences. Ecol Evol 2020; 10:11117-11132. [PMID: 33144953 PMCID: PMC7593156 DOI: 10.1002/ece3.6749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 08/12/2020] [Indexed: 12/15/2022] Open
Abstract
Homing endonucleases (HE) are enzymes capable of cutting DNA at highly specific target sequences, the repair of the generated double-strand break resulting in the insertion of the HE-encoding gene ("homing" mechanism). HEs are present in all three domains of life and viruses; in eukaryotes, they are mostly found in the genomes of mitochondria and chloroplasts, as well as nuclear ribosomal RNAs. We here report the case of a HE that accidentally integrated into a telomeric region of the nuclear genome of the fungal maize pathogen Ustilago maydis. We show that the gene has a mitochondrial origin, but its original copy is absent from the U. maydis mitochondrial genome, suggesting a subsequent loss or a horizontal transfer from a different species. The telomeric HE underwent mutations in its active site and lost its original start codon. A potential other start codon was retained downstream, but we did not detect any significant transcription of the newly created open reading frame, suggesting that the inserted gene is not functional. Besides, the insertion site is located in a putative RecQ helicase gene, truncating the C-terminal domain of the protein. The truncated helicase is expressed during infection of the host, together with other homologous telomeric helicases. This unusual mutational event altered two genes: The integrated HE gene subsequently lost its homing activity, while its insertion created a truncated version of an existing gene, possibly altering its function. As the insertion is absent in other field isolates, suggesting that it is recent, the U. maydis 521 reference strain offers a snapshot of this singular mutational event.
Collapse
Affiliation(s)
- Julien Y. Dutheil
- Max Planck Institute for Evolutionary BiologyPlönGermany
- Max Planck Institute for Terrestrial MicrobiologyMarburgGermany
- Institute of Evolutionary SciencesCNRS – University of Montpellier – IRD – EPHEMontpellierFrance
| | - Karin Münch
- Max Planck Institute for Terrestrial MicrobiologyMarburgGermany
| | - Klaas Schotanus
- Max Planck Institute for Terrestrial MicrobiologyMarburgGermany
- Christian Albrechts University of KielKielGermany
- Present address:
Department of Molecular Genetics and Microbiology (MGM)Duke University Medical CenterDurhamNCUSA
| | - Eva H. Stukenbrock
- Max Planck Institute for Evolutionary BiologyPlönGermany
- Max Planck Institute for Terrestrial MicrobiologyMarburgGermany
- Christian Albrechts University of KielKielGermany
| | - Regine Kahmann
- Max Planck Institute for Terrestrial MicrobiologyMarburgGermany
| |
Collapse
|
22
|
Robinzon S, Cawood AR, Ruiz MA, Gophna U, Altman-Price N, Mills KV. Protein Splicing Activity of the Haloferax volcanii PolB-c Intein Is Sensitive to Homing Endonuclease Domain Mutations. Biochemistry 2020; 59:3359-3367. [PMID: 32822531 DOI: 10.1021/acs.biochem.0c00512] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Inteins are selfish genetic elements residing in open reading frames that can splice post-translationally, resulting in the ligation of an uninterrupted, functional protein. Like other inteins, the DNA polymerase B (PolB) intein of the halophilic archaeon Haloferax volcanii has an active homing endonuclease (HEN) domain, facilitating its horizontal transmission. Previous work has shown that the presence of the PolB intein exerts a significant fitness cost on the organism compared to an intein-free isogenic H. volcanii. Here, we show that mutation of a conserved residue in the HEN domain not only reduces intein homing but also slows growth. Surprisingly, although this mutation is far from the protein splicing active site, it also significantly reduces in vitro protein splicing. Moreover, two additional HEN domain mutations, which could not be introduced to H. volcanii, presumably due to lethality, also eliminate protein splicing activity in vitro. These results suggest an interplay between HEN residues and the protein splicing domain, despite an over 35 Å separation in a PolB intein homology model. The combination of in vivo and in vitro evidence strongly supports a model of codependence between the self-splicing domain and the HEN domain that has been alluded to by previous in vitro studies of protein splicing with HEN domain-containing inteins.
Collapse
Affiliation(s)
- Shachar Robinzon
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Alexandra R Cawood
- Department of Chemistry, College of the Holy Cross, Worcester, Massachusetts 01610, United States
| | - Mercedes A Ruiz
- Department of Chemistry, College of the Holy Cross, Worcester, Massachusetts 01610, United States
| | - Uri Gophna
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Neta Altman-Price
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.,The Open University, Raanana 43107, Israel
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, Worcester, Massachusetts 01610, United States
| |
Collapse
|
23
|
Cinget B, Bélanger RR. Discovery of new group I-D introns leads to creation of subtypes and link to an adaptive response of the mitochondrial genome in fungi. RNA Biol 2020; 17:1252-1260. [PMID: 32449459 PMCID: PMC7595605 DOI: 10.1080/15476286.2020.1763024] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/27/2020] [Accepted: 04/24/2020] [Indexed: 01/02/2023] Open
Abstract
Group I catalytic introns are widespread in bacterial, archaeal, viral, organellar, and some eukaryotic genomes, where they are reported to provide regulatory functions. The group I introns are currently divided into five types (A-E), which are themselves distributed into several subtypes, with the exception of group I type D intron (GI-D). GI-D introns belong to the rarest group with only 17 described to date, including only one with a putative role reported in fungi, where it would interfere with an adaptive response in the cytochrome b (COB) gene to quinone outside inhibitor (QoI) fungicide resistance. Using homology search methods taking into account both conserved sequences and RNA secondary structures, we analysed the mitochondrial genomes or COB genes of 169 fungal species, including some frequently under QoI selection pressure. These analyses have led to the identification of 216 novel GI-D introns, and the definition of three distinct subtypes, one of which being linked with a functional activity. We have further uncovered a homing site for this GI-D intron type, which helps refine the accepted model of quinone outside inhibitor resistance, whereby mobility of the intron across fungal mitochondrial genomes, would influence a fungus ability to develop resistance to QoIs.
Collapse
Affiliation(s)
- Benjamin Cinget
- Département de Phytologie, Faculty of Agriculture and Food Sciences, Centre de Recherche en Innovation des Végétaux (CRIV), Université Laval, Québec, Québec, Canada
| | - Richard R. Bélanger
- Département de Phytologie, Faculty of Agriculture and Food Sciences, Centre de Recherche en Innovation des Végétaux (CRIV), Université Laval, Québec, Québec, Canada
| |
Collapse
|
24
|
Mazo N, Navo CD, Peregrina JM, Busto JH, Jiménez-Osés G. Selective modification of sulfamidate-containing peptides. Org Biomol Chem 2020; 18:6265-6275. [PMID: 32618321 DOI: 10.1039/d0ob01061h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hybrid peptides whose N-terminal residues are activated in the form of α-methylisoserine-derived cyclic sulfamidates exhibit rich reactivity as electrophiles, allowing site- and stereoselective modifications at different backbone and side chain positions. The unique properties of this scaffold allow the stereocontrolled late-stage functionalization of the peptide backbone by nucleophilic ring opening with fluorescent probes, thiocarbohydrates and tags for strain-promoted azide-alkyne cycloaddition as well as by installing labile N-terminal affinity tags (biotin) and cytotoxic drugs (chlorambucil) for pH-controlled release. Finally, an unexpected base-promoted acyl group migration from the sulfamidate N-terminus allows fast and quantitative intramolecular modification of nucleophilic side chains on the fully unprotected peptides.
Collapse
Affiliation(s)
- Nuria Mazo
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, E-26006 Logroño, Spain
| | - Claudio D Navo
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain.
| | - Jesús M Peregrina
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, E-26006 Logroño, Spain
| | - Jesús H Busto
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, E-26006 Logroño, Spain
| | - Gonzalo Jiménez-Osés
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain.
| |
Collapse
|
25
|
Ponts N, Gautier C, Gouzy J, Pinson-Gadais L, Foulongne-Oriol M, Ducos C, Richard-Forget F, Savoie JM, Zhao C, Barroso G. Evolution of Fusarium tricinctum and Fusarium avenaceum mitochondrial genomes is driven by mobility of introns and of a new type of palindromic microsatellite repeats. BMC Genomics 2020; 21:358. [PMID: 32397981 PMCID: PMC7218506 DOI: 10.1186/s12864-020-6770-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/04/2020] [Indexed: 12/13/2022] Open
Abstract
Background Increased contamination of European and Asian wheat and barley crops with “emerging” mycotoxins such as enniatins or beauvericin, produced by Fusarium avenaceum and Fusarium tricinctum, suggest that these phylogenetically close species could be involved in future food-safety crises. Results The mitochondrial genomes of F. tricinctum strain INRA104 and F. avenaceum strain FaLH27 have been annotated. A comparative analysis was carried out then extended to a set of 25 wild strains. Results show that they constitute two distinct species, easily distinguished by their mitochondrial sequences. The mitochondrial genetic variability is mainly located within the intergenic regions. Marks of variations show they have evolved (i) by Single Nucleotide Polymorphisms (SNPs), (ii) by length variations mediated by insertion/deletion sequences (Indels), and (iii) by length mutations generated by DNA sliding events occurring in mononucleotide (A)n or (T)n microsatellite type sequences arranged in a peculiar palindromic organization. The optionality of these palindromes between both species argues for their mobility. The presence of Indels and SNPs in palindrome neighbouring regions suggests their involvement in these observed variations. Moreover, the intraspecific and interspecific variations in the presence/absence of group I introns suggest a high mobility, resulting from several events of gain and loss during short evolution periods. Phylogenetic analyses of intron orthologous sequences suggest that most introns could have originated from lateral transfers from phylogenetically close or distant species belonging to various Ascomycota genera and even to the Basidiomycota fungal division. Conclusions Mitochondrial genome evolution between F. tricinctum and F. avenaceum is mostly driven by two types of mobile genetic elements, implicated in genome polymorphism. The first one is represented by group I introns. Indeed, both genomes harbour optional (inter- or intra-specifically) group I introns, all carrying putatively functional hegs, arguing for a high mobility of these introns during short evolution periods. The gain events were shown to involve, for most of them, lateral transfers between phylogenetically distant species. This study has also revealed a new type of mobile genetic element constituted by a palindromic arrangement of (A) n and (T) n microsatellite sequences whose presence was related to occurrence of SNPs and Indels in the neighbouring regions.
Collapse
Affiliation(s)
- Nadia Ponts
- INRAE, MycSA, F-33882, Villenave d'Ornon, France
| | | | - Jérôme Gouzy
- LIPM, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | | | | | | | | | | | - Chen Zhao
- Academy of National Food and Strategic Reserves Administration, Beijing, China
| | - Gérard Barroso
- INRAE, MycSA, F-33882, Villenave d'Ornon, France. .,University of Bordeaux, INRAE, MycSA, F-33882, Villenave d'Ornon, France.
| |
Collapse
|
26
|
Zubaer A, Wai A, Hausner G. The fungal mitochondrial Nad5 pan-genic intron landscape. Mitochondrial DNA A DNA Mapp Seq Anal 2019; 30:835-842. [PMID: 31698975 DOI: 10.1080/24701394.2019.1687691] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
An intron landscape was prepared for the fungal mitochondrial nad5 gene. A hundred and eighty-eight fungal species were examined and a total of 265 introns were noted to be located in 29 intron insertion sites within the examined nad5 genes. Two hundred and sixty-three introns could be classified as group I types and two group II introns were noted. One additional group II intron module was identified nested within a composite group I intron. Based on features related to RNA secondary structures, introns can be classified into different subtypes and it was observed that intron insertion-sites are biased towards phase 0 and they appear to be specific to an intron type. Intron landscapes could be used as a guide map to predict the location of fungal mtDNA mobile introns, which are composite elements that include a ribozyme component and in some instances open reading frames encoding homing endonucleases or reverse transcriptases and all of these have applications in biotechnology.
Collapse
Affiliation(s)
- Abdullah Zubaer
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | - Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| |
Collapse
|
27
|
Crystal structures of CDC21-1 inteins from hyperthermophilic archaea reveal the selection mechanism for the highly conserved homing endonuclease insertion site. Extremophiles 2019; 23:669-679. [PMID: 31363851 PMCID: PMC6801210 DOI: 10.1007/s00792-019-01117-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/09/2019] [Indexed: 11/27/2022]
Abstract
Self-splicing inteins are mobile genetic elements invading host genes via nested homing endonuclease (HEN) domains. All HEN domains residing within inteins are inserted at a highly conserved insertion site. A purifying selection mechanism directing the location of the HEN insertion site has not yet been identified. In this work, we solved the three-dimensional crystal structures of two inteins inserted in the cell division control protein 21 of the hyperthermophilic archaea Pyrococcus abyssi and Pyrococcus horikoshii. A comparison between the structures provides the structural basis for the thermo-stabilization mechanism of inteins that have lost the HEN domain during evolution. The presence of an entire extein domain in the intein structure from Pyrococcus horikoshii suggests the selection mechanism for the highly conserved HEN insertion point.
Collapse
|
28
|
Behra PRK, Pettersson BMF, Das S, Dasgupta S, Kirsebom LA. Comparative genomics of Mycobacterium mucogenicum and Mycobacterium neoaurum clade members emphasizing tRNA and non-coding RNA. BMC Evol Biol 2019; 19:124. [PMID: 31215393 PMCID: PMC6582537 DOI: 10.1186/s12862-019-1447-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 05/27/2019] [Indexed: 02/07/2023] Open
Abstract
Background Mycobacteria occupy various ecological niches and can be isolated from soil, tap water and ground water. Several cause diseases in humans and animals. To get deeper insight into our understanding of mycobacterial evolution focusing on tRNA and non-coding (nc)RNA, we conducted a comparative genome analysis of Mycobacterium mucogenicum (Mmuc) and Mycobacterium neoaurum (Mneo) clade members. Results Genome sizes for Mmuc- and Mneo-clade members vary between 5.4 and 6.5 Mbps with the complete MmucT (type strain) genome encompassing 6.1 Mbp. The number of tRNA genes range between 46 and 79 (including one pseudo tRNA gene) with 39 tRNA genes common among the members of these clades, while additional tRNA genes were probably acquired through horizontal gene transfer. Selected tRNAs and ncRNAs (RNase P RNA, tmRNA, 4.5S RNA, Ms1 RNA and 6C RNA) are expressed, and the levels for several of these are higher in stationary phase compared to exponentially growing cells. The rare tRNAIleTAT isoacceptor and two for mycobacteria novel ncRNAs: the Lactobacillales-derived GOLLD RNA and a homolog to the antisense Salmonella typhimurium phage Sar RNA, were shown to be present and expressed in certain Mmuc-clade members. Conclusions Phages, IS elements, horizontally transferred tRNA gene clusters, and phage-derived ncRNAs appears to have influenced the evolution of the Mmuc- and Mneo-clades. While the number of predicted coding sequences correlates with genome size, the number of tRNA coding genes does not. The majority of the tRNA genes in mycobacteria are transcribed mainly from single genes and the levels of certain ncRNAs, including RNase P RNA (essential for the processing of tRNAs), are higher at stationary phase compared to exponentially growing cells. We provide supporting evidence that Ms1 RNA represents a mycobacterial 6S RNA variant. The evolutionary routes for the ncRNAs RNase P RNA, tmRNA and Ms1 RNA are different from that of the core genes. Electronic supplementary material The online version of this article (10.1186/s12862-019-1447-7) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Phani Rama Krishna Behra
- Department of Cell and Molecular Biology, Biomedical Centre, Box 596, SE-751 24, Uppsala, Sweden
| | - B M Fredrik Pettersson
- Department of Cell and Molecular Biology, Biomedical Centre, Box 596, SE-751 24, Uppsala, Sweden
| | - Sarbashis Das
- Department of Cell and Molecular Biology, Biomedical Centre, Box 596, SE-751 24, Uppsala, Sweden
| | - Santanu Dasgupta
- Department of Cell and Molecular Biology, Biomedical Centre, Box 596, SE-751 24, Uppsala, Sweden
| | - Leif A Kirsebom
- Department of Cell and Molecular Biology, Biomedical Centre, Box 596, SE-751 24, Uppsala, Sweden.
| |
Collapse
|
29
|
Fan WW, Zhang S, Zhang YJ. The complete mitochondrial genome of the Chan-hua fungus Isaria cicadae: a tale of intron evolution in Cordycipitaceae. Environ Microbiol 2019; 21:864-879. [PMID: 30623556 DOI: 10.1111/1462-2920.14522] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/04/2019] [Accepted: 01/05/2019] [Indexed: 11/30/2022]
Abstract
Isaria cicadae is an entomogenous fungus of great medicinal value. Its nuclear genome has been reported, while its mitogenome remains unknown. Herein, we first described its mitogenome and then inferred intron evolution from both intraspecific and interspecific perspectives. The fungus represented the largest mitogenome (56.6 kb in strain CCAD02) known in Cordycipitaceae due to the presence of 25 introns interrupting nine genes. Comparison of three I. cicadae strains revealed intron presence/absence dynamics at six intron loci plus a few indels and single nucleotide polymorphisms. Phylogenetic analyses confirmed the placement of I. cicadae in Cordycipitaceae. Comparison of 10 Cordycipitaceae species revealed a high degree of synteny and conserved genetic content. They, however, varied in intron numbers (1-25 per species) with overall 34 intron loci identified, which resulted in more than twofold variations in mitogenome sizes (24.5-56.6 kb). An rnl intron encoding ribosomal protein S3 was present in all species, suggesting its early invasion in Cordycipitaceae, while further divergence occurred for this intron. The other introns identified in this study were present in some, but not all of the species and have undergone multiple gains and losses in Cordycipitaceae. This study greatly enhanced our understanding of intron evolution in Cordycipitaceae.
Collapse
Affiliation(s)
- Wen-Wen Fan
- School of Life Science, Shanxi University, Taiyuan 030006, China.,Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Shu Zhang
- Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, China
| | - Yong-Jie Zhang
- School of Life Science, Shanxi University, Taiyuan 030006, China
| |
Collapse
|
30
|
Zubaer A, Wai A, Hausner G. The mitochondrial genome of Endoconidiophora resinifera is intron rich. Sci Rep 2018; 8:17591. [PMID: 30514960 PMCID: PMC6279837 DOI: 10.1038/s41598-018-35926-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 11/08/2018] [Indexed: 02/07/2023] Open
Abstract
Endoconidiophora resinifera (=Ceratocystis resinifera) is a blue-stain fungus that occurs on conifers. The data showed that the Endoconidiophora resinifera mitochondrial genome is one of the largest mitochondrial genomes (>220 kb) so far reported among members of the Ascomycota. An exceptional large number of introns (81) were noted and differences among the four strains were restricted to minor variations in intron numbers and a few indels and single nucleotide polymorphisms. The major differences among the four strains examined are due to size polymorphisms generated by the absence or presence of mitochondrial introns. Also, these mitochondrial genomes encode the largest cytochrome oxidase subunit 1 gene (47.5 kb) reported so far among the fungi. The large size for this gene again can be attributed to the large number of intron insertions. This study reports the first mitochondrial genome for the genus Endoconidiophora, previously members of this genus were assigned to Ceratocystis. The latter genus has recently undergone extensive taxonomic revisions and the mitochondrial genome might provide loci that could be applied as molecular markers assisting in the identification of taxa within this group of economically important fungi. The large mitochondrial genome also may provide some insight on mechanisms that can lead to mitochondrial genome expansion.
Collapse
Affiliation(s)
- Abdullah Zubaer
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
| |
Collapse
|
31
|
Deng Y, Hsiang T, Li S, Lin L, Wang Q, Chen Q, Xie B, Ming R. Comparison of the Mitochondrial Genome Sequences of Six Annulohypoxylon stygium Isolates Suggests Short Fragment Insertions as a Potential Factor Leading to Larger Genomic Size. Front Microbiol 2018; 9:2079. [PMID: 30250455 PMCID: PMC6140425 DOI: 10.3389/fmicb.2018.02079] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 08/14/2018] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial DNA (mtDNA) is a core non-nuclear genetic material found in all eukaryotic organisms, the size of which varies extensively in the eumycota, even within species. In this study, mitochondrial genomes of six isolates of Annulohypoxylon stygium (Lév.) were assembled from raw reads from PacBio and Illumina sequencing. The diversity of genomic structures, conserved genes, intergenic regions and introns were analyzed and compared. Genome sizes ranged from 132 to 147 kb and contained the same sets of conserved protein-coding, tRNA and rRNA genes and shared the same gene arrangements and orientation. In addition, most intergenic regions were homogeneous and had similar sizes except for the region between cytochrome b (cob) and cytochrome c oxidase I (cox1) genes which ranged from 2,998 to 8,039 bp among the six isolates. Sixty-five intron insertion sites and 99 different introns were detected in these genomes. Each genome contained 45 or more introns, which varied in distribution and content. Introns from homologous insertion sites also showed high diversity in size, type and content. Comparison of introns at the same loci showed some complex introns, such as twintrons and ORF-less introns. There were 44 short fragment insertions detected within introns, intergenic regions, or as introns, some of them located at conserved domain regions of homing endonuclease genes. Insertions of short fragments such as small inverted repeats might affect or hinder the movement of introns, and these allowed for intron accumulation in the mitochondrial genomes analyzed, and enlarged their size. This study showed that the evolution of fungal mitochondrial introns is complex, and the results suggest short fragment insertions as a potential factor leading to larger mitochondrial genomes in A. stygium.
Collapse
Affiliation(s)
- Youjin Deng
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Tom Hsiang
- Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Shuxian Li
- USDA-Agricultural Research Service, Crop Genetics Research Unit, Stoneville, MS, United States
| | - Longji Lin
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qingfu Wang
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qinghe Chen
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Baogui Xie
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ray Ming
- Center for Genomics and Biotechnology, Haixia Institute of Science and Technology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| |
Collapse
|
32
|
Garcia Garces H, Cordeiro RT, Bagagli E. PRP8 intein in dermatophytes: Evolution and species identification. Med Mycol 2018; 56:746-758. [PMID: 29228309 DOI: 10.1093/mmy/myx102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/27/2017] [Indexed: 11/14/2022] Open
Abstract
Dermatophytes are keratinophilic fungi belonging to the family Arthrodermataceae. Despite having a monophyletic origin, its systematics has always been complex and controversial. Sequencing of nuclear ribosomal ITS and D1/D2 rDNA has been proposed as an efficient tool for identifying species in this group of fungi, while multilocus analyses have been used for phylogenetic species recognition. However, the search for new markers, with sequence and size variation, which enable species identification in only one polymerase chain reaction (PCR) step, is very attractive. Inteins seems to fulfill these characteristics. They are self-splicing genetic elements present within housekeeping coding genes, such as PRP8, that codify the most important protein of the spliceosome. The PRP8 intein has been described for Microsporum canis in databases but has not been studied in dermatophytes in any other published work. Thus, our aim was to determine the potential of this intervening element for establishing phylogenetic relationships among dermatophytes and for identifying species. It was found that all studied species have a full-length PRP8 intein with a Homing Endonuclease belonging to the family LAGLIDADG. Phylogenetic analyses were consistent with other previous phylogenies, confirming Epidermophyton floccosum in the same clade of the Arthroderma gypseum complex, Microsporum audouinii close to M. canis, differentiating A. gypseum from Arthroderma incurvatum, and in addition, better defining the Trichophyton interdigitale and Trichophyton rubrum species grouping. Length polymorphism in the HE region enables identification of the most relevant Microsporum species by a simple PCR-electrophoresis assay. Intein PRP8 within dermatophytes is a powerful additional tool for identifying and systematizing dermatophytes.
Collapse
Affiliation(s)
- Hans Garcia Garces
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual de São Paulo. São Paulo. Brasil
| | - Raquel Theodoro Cordeiro
- Instituto de Medicina Tropical do RN, Universidade Federal de Rio Grande do Norte. Rio Grande do Norte. Brasil
| | - E Bagagli
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual de São Paulo. São Paulo. Brasil
| |
Collapse
|
33
|
Ajuebor J, Buttimer C, Arroyo-Moreno S, Chanishvili N, Gabriel EM, O'Mahony J, McAuliffe O, Neve H, Franz C, Coffey A. Comparison of Staphylococcus Phage K with Close Phage Relatives Commonly Employed in Phage Therapeutics. Antibiotics (Basel) 2018; 7:E37. [PMID: 29693603 PMCID: PMC6022877 DOI: 10.3390/antibiotics7020037] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/12/2018] [Accepted: 04/19/2018] [Indexed: 01/20/2023] Open
Abstract
The increase in antibiotic resistance in pathogenic bacteria is a public health danger requiring alternative treatment options, and this has led to renewed interest in phage therapy. In this respect, we describe the distinct host ranges of Staphylococcus phage K, and two other K-like phages against 23 isolates, including 21 methicillin-resistant S. aureus (MRSA) representative sequence types representing the Irish National MRSA Reference Laboratory collection. The two K-like phages were isolated from the Fersisi therapeutic phage mix from the Tbilisi Eliava Institute, and were designated B1 (vB_SauM_B1) and JA1 (vB_SauM_JA1). The sequence relatedness of B1 and JA1 to phage K was observed to be 95% and 94% respectively. In terms of host range on the 23 Staphylococcus isolates, B1 and JA1 infected 73.9% and 78.2% respectively, whereas K infected only 43.5%. Eleven open reading frames (ORFs) present in both phages B1 and JA1 but absent in phage K were identified by comparative genomic analysis. These ORFs were also found to be present in the genomes of phages (Team 1, vB_SauM-fRuSau02, Sb_1 and ISP) that are components of several commercial phage mixtures with reported wide host ranges. This is the first comparative study of therapeutic staphylococcal phages within the recently described genus Kayvirus.
Collapse
Affiliation(s)
- Jude Ajuebor
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork T12 P928, UK.
| | - Colin Buttimer
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork T12 P928, UK.
| | - Sara Arroyo-Moreno
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork T12 P928, UK.
| | - Nina Chanishvili
- Eliava Institute of Bacteriophages, Microbiology and Virology, Tbilisi 0160, Georgia.
| | - Emma M Gabriel
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork T12 P928, UK.
| | - Jim O'Mahony
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork T12 P928, UK.
| | - Olivia McAuliffe
- Teagasc, Moorepark Food Research Centre, Fermoy, Cork P61 C996, UK.
| | - Horst Neve
- Department of Microbiology and Biotechnology, Max Rubner-Institut, DE-24103 Kiel, Germany.
| | - Charles Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institut, DE-24103 Kiel, Germany.
| | - Aidan Coffey
- Department of Biological Sciences, Cork Institute of Technology, Bishopstown, Cork T12 P928, UK.
- Alimentary Pharmabiotic Centre, University College, Cork T12 YT20, UK.
| |
Collapse
|
34
|
Iwaï H, Mikula KM, Oeemig JS, Zhou D, Li M, Wlodawer A. Structural Basis for the Persistence of Homing Endonucleases in Transcription Factor IIB Inteins. J Mol Biol 2017; 429:3942-3956. [PMID: 29055778 PMCID: PMC6309676 DOI: 10.1016/j.jmb.2017.10.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/29/2017] [Accepted: 10/12/2017] [Indexed: 11/19/2022]
Abstract
Inteins are mobile genetic elements that are spliced out of proteins after translation. Some inteins contain a homing endonuclease (HEN) responsible for their propagation. Hedgehog/INTein (HINT) domains catalyzing protein splicing and their nested HEN domains are thought to be functionally independent because of the existence of functional mini-inteins without HEN domains. Despite the lack of obvious mutualism between HEN and HINT domains, HEN domains are persistently found at one specific site in inteins, indicating their potential functional role in protein splicing. Here we report crystal structures of inactive and active mini-inteins derived from inteins residing in the transcription factor IIB of Methanococcus jannaschii and Methanocaldococcus vulcanius, revealing a novel modified HINT fold that might provide new insights into the mutualism between the HEN and HINT domains. We propose an evolutionary model of inteins and a functional role of HEN domains in inteins.
Collapse
Affiliation(s)
- Hideo Iwaï
- Research Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, P.O. Box 65, Helsinki FIN-00014, Finland.
| | - Kornelia M Mikula
- Research Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, P.O. Box 65, Helsinki FIN-00014, Finland
| | - Jesper S Oeemig
- Research Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki, P.O. Box 65, Helsinki FIN-00014, Finland
| | - Dongwen Zhou
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Mi Li
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA; Basic Science Program, Leidos Biomedical Research, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Alexander Wlodawer
- Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA.
| |
Collapse
|
35
|
Amgarten D, Martins LF, Lombardi KC, Antunes LP, de Souza APS, Nicastro GG, Kitajima EW, Quaggio RB, Upton C, Setubal JC, da Silva AM. Three novel Pseudomonas phages isolated from composting provide insights into the evolution and diversity of tailed phages. BMC Genomics 2017; 18:346. [PMID: 28472930 PMCID: PMC5418858 DOI: 10.1186/s12864-017-3729-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 04/26/2017] [Indexed: 12/18/2022] Open
Abstract
Background Among viruses, bacteriophages are a group of special interest due to their capacity of infecting bacteria that are important for biotechnology and human health. Composting is a microbial-driven process in which complex organic matter is converted into humus-like substances. In thermophilic composting, the degradation activity is carried out primarily by bacteria and little is known about the presence and role of bacteriophages in this process. Results Using Pseudomonas aeruginosa as host, we isolated three new phages from a composting operation at the Sao Paulo Zoo Park (Brazil). One of the isolated phages is similar to Pseudomonas phage Ab18 and belongs to the Siphoviridae YuA-like viral genus. The other two isolated phages are similar to each other and present genomes sharing low similarity with phage genomes in public databases; we therefore hypothesize that they belong to a new genus in the Podoviridae family. Detailed genomic descriptions and comparisons of the three phages are presented, as well as two new clusters of phage genomes in the Viral Orthologous Clusters database of large DNA viruses. We found sequences encoding homing endonucleases that disrupt a putative ribonucleotide reductase gene and an RNA polymerase subunit 2 gene in two of the phages. These findings provide insights about the evolution of two-subunits RNA polymerases and the possible role of homing endonucleases in this process. Infection tests on 30 different strains of bacteria reveal a narrow host range for the three phages, restricted to P. aeruginosa PA14 and three other P. aeruginosa clinical isolates. Biofilm dissolution assays suggest that these phages could be promising antimicrobial agents against P. aeruginosa PA14 infections. Analyses on composting metagenomic and metatranscriptomic data indicate association between abundance variations in both phage and host populations in the environment. Conclusion The results about the newly discovered and described phages contribute to the understanding of tailed bacteriophage diversity, evolution, and role in the complex composting environment. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3729-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Deyvid Amgarten
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.,Programa de Pós-Graduação Interunidades em Bioinformática, Universidade de São Paulo, São Paulo, Brazil
| | - Layla Farage Martins
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Karen Cristina Lombardi
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | | | | | - Elliott Watanabe Kitajima
- Departamento de Fitopatologia e Nematologia, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, Brazil
| | - Ronaldo Bento Quaggio
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Chris Upton
- Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - João Carlos Setubal
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil. .,Biocomplexity Institute of Virginia Tech, Blacksburg, VA, USA.
| | - Aline Maria da Silva
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.
| |
Collapse
|
36
|
Loss and Gain of Group I Introns in the Mitochondrial Cox1 Gene of the Scleractinia (Cnidaria; Anthozoa). Zool Stud 2017; 56:e9. [PMID: 31966208 DOI: 10.6620/zs.2017.56-09] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 04/12/2017] [Indexed: 01/21/2023]
Abstract
Yaoyang Chuang, Marcelo Kitahara, Hironobu Fukami, Dianne Tracey, David J. Miller, and Chaolun Allen Chen (2017) Group I introns encoding a homing endonuclease gene (HEG) that is potentially capable of sponsoring mobility are present in the cytochrome oxidase subunit 1 (cox1) gene of some Hexacorallia, including a number of scleractinians assigned to the "robust" coral clade. In an e ort to infer the evolutionary history of this cox1 group I intron, DNA sequences were determined for 12 representative "basal" and "complex" corals and for 11 members of the Corallimorpharia, a sister order of the Scleractinia. Comparisons of insertion sites, secondary structures, and amino acid sequences of the HEG implied a common origin for cox1 introns of corallimorpharians, and basal and complex corals, but cox1 introns of robust corals were highly divergent, most likely reflecting independent acquisition. Phylogenetic analyses with a calibrated molecular clock suggested that cox1 introns of scleractinians and corallimorpharians have persisted at the same insertion site as that in the common ancestor 552 million years ago (mya). This ancestral intron was probably lost in complex corals around 213 to 190 mya at the junction between the Trassic and Jurassic. The coral cox1 gene remained intronless until new introns, probably from sponges or fungi, reinvaded different positions of the cox1 gene in robust corals around 135 mya in the Cretaceous, and then it subsequently began to lose them around 65.5 mya in some robust coral lineages coincident with the later Maastrichtian extinction at the Cretaceous-Tertiary boundary.
Collapse
|
37
|
Genome editing approaches: manipulating of lovastatin and taxol synthesis of filamentous fungi by CRISPR/Cas9 system. Appl Microbiol Biotechnol 2017; 101:3953-3976. [PMID: 28389711 DOI: 10.1007/s00253-017-8263-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 12/28/2022]
Abstract
Filamentous fungi are prolific repertoire of structurally diverse secondary metabolites of remarkable biological activities such as lovastatin and paclitaxel that have been approved by FDA as drugs for hypercholesterolemia and cancer treatment. The clusters of genes encoding lovastatin and paclitaxel are cryptic at standard laboratory cultural conditions (Kennedy et al. Science 284:1368-1372, 1999; Bergmann et al. Nature Chem Biol 3:213-217, 2007). The expression of these genes might be triggered in response to nutritional and physical conditions; nevertheless, the overall yield of these metabolites does not match the global need. Consequently, overexpression of the downstream limiting enzymes and/or blocking the competing metabolic pathways of these metabolites could be the most successful technologies to enhance their yield. This is the first review summarizing the different strategies implemented for fungal genome editing, molecular regulatory mechanisms, and prospective of clustered regulatory interspaced short palindromic repeat/Cas9 system in metabolic engineering of fungi to improve their yield of lovastatin and taxol to industrial scale. Thus, elucidating the putative metabolic pathways in fungi for overproduction of lovastatin and taxol was the ultimate objective of this review.
Collapse
|
38
|
Hamada Y. Recent progress in prodrug design strategies based on generally applicable modifications. Bioorg Med Chem Lett 2017; 27:1627-1632. [PMID: 28285913 DOI: 10.1016/j.bmcl.2017.02.075] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 11/15/2022]
Abstract
The development of prodrugs has progressed with the aim of improving drug bioavailability by overcoming various barriers that reduce drug benefits in clinical use, such as stability, duration, water solubility, side effect profile, and taste. Many conventional drugs act as the precursors of an active agent in vivo; for example, the anti-HIV agent azidothymidine (AZT) is converted into its corresponding active triphosphate ester in the body, meaning that AZT is a prodrug in the broadest sense. However prodrug design is generally difficult owing to the lack of general versatility. Thus, these prodrugs, broadly defined, are often discovered by chance or trial-and-error. Recently, many prodrugs that could release the corresponding parent drugs with or without enzymatic action under physiological conditions have been reported. These prodrugs can be easily designed and synthesized because of their generally applicable modifications. This digest paper provides an overview of recent development in prodrug strategies for drugs with a carboxylic acid or hydroxyl/amino group on the basis of a generally applicable modification strategy, such as esterification, amidation, or benzylation.
Collapse
Affiliation(s)
- Yoshio Hamada
- Faculty of Frontiers of Innovative Research in Science and Technology, Konan University, Minatojima-minamimachi, Chuo, Kobe 650-0043, Japan; Faculty of Pharmaceutical Sciences, Kobe Pharmaceutical University, Motoyamakita, Higashinada, Kobe 658-8558, Japan.
| |
Collapse
|
39
|
Fernandes JAL, Prandini THR, Castro MDCA, Arantes TD, Giacobino J, Bagagli E, Theodoro RC. Evolution and Application of Inteins in Candida species: A Review. Front Microbiol 2016; 7:1585. [PMID: 27777569 PMCID: PMC5056185 DOI: 10.3389/fmicb.2016.01585] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 09/21/2016] [Indexed: 11/13/2022] Open
Abstract
Inteins are invasive intervening sequences that perform an autocatalytic splicing from their host proteins. Among eukaryotes, these elements are present in many fungal species, including those considered opportunistic or primary pathogens, such as Candida spp. Here we reviewed and updated the list of Candida species containing inteins in the genes VMA, THRRS and GLT1 and pointed out the importance of these elements as molecular markers for molecular epidemiological researches and species-specific diagnosis, since the presence, as well as the size of these inteins, is polymorphic among the different species. Although absent in Candida albicans, these elements are present in different sizes, in some environmental Candida spp. and also in most of the non-albicans Candida spp. considered emergent opportunistic pathogens. Besides, the possible role of these inteins in yeast physiology was also discussed in the light of the recent findings on the importance of these elements as post-translational modulators of gene expression, reinforcing their relevance as alternative therapeutic targets for the treatment of non-albicans Candida infections, because, once the splicing of an intein is inhibited, its host protein, which is usually a housekeeping protein, becomes non-functional.
Collapse
Affiliation(s)
- José A L Fernandes
- Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte Natal, Brazil
| | - Tâmara H R Prandini
- Department of Microbiology and Immunology, Institute of Biosciences, Universidade Estadual Paulista Julio de Mesquita Filho Botucatu, Brazil
| | - Maria da Conceiçao A Castro
- Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte Natal, Brazil
| | - Thales D Arantes
- Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do NorteNatal, Brazil; Post-graduation Program in Biochemistry, Universidade Federal do Rio Grande do NorteNatal, Brazil
| | - Juliana Giacobino
- Department of Microbiology and Immunology, Institute of Biosciences, Universidade Estadual Paulista Julio de Mesquita Filho Botucatu, Brazil
| | - Eduardo Bagagli
- Department of Microbiology and Immunology, Institute of Biosciences, Universidade Estadual Paulista Julio de Mesquita Filho Botucatu, Brazil
| | - Raquel C Theodoro
- Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte Natal, Brazil
| |
Collapse
|
40
|
Impact of a homing intein on recombination frequency and organismal fitness. Proc Natl Acad Sci U S A 2016; 113:E4654-61. [PMID: 27462108 DOI: 10.1073/pnas.1606416113] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inteins are parasitic genetic elements that excise themselves at the protein level by self-splicing, allowing the formation of functional, nondisrupted proteins. Many inteins contain a homing endonuclease (HEN) domain and rely on its activity for horizontal propagation. However, successful invasion of an entire population will make this activity redundant, and the HEN domain is expected to degenerate quickly under these conditions. Several theories have been proposed for the continued existence of the both active HEN and noninvaded alleles within a population. However, to date, these models were not directly tested experimentally. Using the natural cell fusion ability of the halophilic archaeon Haloferax volcanii we were able to examine this question in vivo, by mating polB intein-positive [insertion site c in the gene encoding DNA polymerase B (polB-c)] and intein-negative cells and examining the dispersal efficiency of this intein in a natural, polyploid population. Through competition between otherwise isogenic intein-positive and intein-negative strains we determined a surprisingly high fitness cost of over 7% for the polB-c intein. Our laboratory culture experiments and samples taken from Israel's Mediterranean coastline show that the polB-c inteins do not efficiently take over an inteinless population through mating, even under ideal conditions. The presence of the HEN/intein promoted recombination when intein-positive and intein-negative cells were mated. Increased recombination due to HEN activity contributes not only to intein dissemination but also to variation at the population level because recombination tracts during repair extend substantially from the homing site.
Collapse
|
41
|
Hamada Y. A novel N-terminal degradation reaction of peptides via N-amidination. Bioorg Med Chem Lett 2016; 26:1690-5. [PMID: 26916439 DOI: 10.1016/j.bmcl.2016.02.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 02/05/2016] [Accepted: 02/19/2016] [Indexed: 10/22/2022]
Abstract
The cleavage of amide bonds requires considerable energy. It is difficult to cleave the amide bonds in peptides at room temperature, whereas ester bonds are cleaved easily. If peptide bonds can be selectively cleaved at room temperature, it will become a powerful tool for life science research, peptide prodrug, and tissue-targeting drug delivery systems. To cleave a specific amide bond at room temperature, the decomposition reaction of arginine methyl ester was investigated. Arginine methyl ester forms a dimer; the dimer releases a heterocyclic compound and ornithine methyl ester at room temperature. We designed and synthesized N-amidinopeptides based on the decomposition reaction of arginine methyl ester. Alanyl-alanine anilide was used as the model peptide and could be converted into N-degraded peptide, alanine anilide, via an N-amidination reaction at close to room temperature. Although the cleavage rate in pH 7.4 phosphate buffered saline (PBS) at 37°C was slow (t1/2=35.7h), a rapid cleavage rate was observed in 2% NaOH aq (t1/2=1.5min). To evaluate the versatility of this reaction, a series of peptides with Lys, Glu, Ser, Cys, Tyr, Val, and Pro residue at the N-terminal were synthesized; they showed rapid cleavage rates of t1/2 values from 1min to 10min.
Collapse
Affiliation(s)
- Yoshio Hamada
- Medicinal Chemistry Laboratory, Kobe Pharmaceutical University, Motoyamakita, Higashinada, Kobe 658-8558, Japan.
| |
Collapse
|
42
|
Kamikawa R, Shiratori T, Ishida KI, Miyashita H, Roger AJ. Group II Intron-Mediated Trans-Splicing in the Gene-Rich Mitochondrial Genome of an Enigmatic Eukaryote, Diphylleia rotans. Genome Biol Evol 2016; 8:458-66. [PMID: 26833505 PMCID: PMC4779616 DOI: 10.1093/gbe/evw011] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Although mitochondria have evolved from a single endosymbiotic event, present day mitochondria of diverse eukaryotes display a great range of genome structures, content and features. Group I and group II introns are two features that are distributed broadly but patchily in mitochondrial genomes across branches of the tree of eukaryotes. While group I intron-mediated trans-splicing has been reported from some lineages distantly related to each other, findings of group II intron-mediated trans-splicing has been restricted to members of the Chloroplastida. In this study, we found the mitochondrial genome of the unicellular eukaryote Diphylleia rotans possesses currently the second largest gene repertoire. On the basis of a probable phylogenetic position of Diphylleia, which is located within Amorphea, current mosaic gene distribution in Amorphea must invoke parallel gene losses from mitochondrial genomes during evolution. Most notably, although the cytochrome c oxidase subunit (cox) 1 gene was split into four pieces which located at a distance to each other, we confirmed that a single mature mRNA that covered the entire coding region could be generated by group II intron-mediated trans-splicing. This is the first example of group II intron-mediated trans-splicing outside Chloroplastida. Similar trans-splicing mechanisms likely work for bipartitely split cox2 and nad3 genes to generate single mature mRNAs. We finally discuss origin and evolution of this type of trans-splicing in D. rotans as well as in eukaryotes.
Collapse
Affiliation(s)
- Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Japan Graduate School of Global Environmental Studies, Kyoto University, Japan
| | - Takashi Shiratori
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | - Ken-Ichiro Ishida
- Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | - Hideaki Miyashita
- Graduate School of Human and Environmental Studies, Kyoto University, Japan Graduate School of Global Environmental Studies, Kyoto University, Japan
| | - Andrew J Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada Program in Integrated Microbial Biodiversity, Canadian Institute for Advanced Research, Halifax, Nova Scotia, Canada
| |
Collapse
|
43
|
Induced Pluripotency and Gene Editing in Disease Modelling: Perspectives and Challenges. Int J Mol Sci 2015; 16:28614-34. [PMID: 26633382 PMCID: PMC4691066 DOI: 10.3390/ijms161226119] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/13/2015] [Accepted: 11/24/2015] [Indexed: 02/07/2023] Open
Abstract
Embryonic stem cells (ESCs) are chiefly characterized by their ability to self-renew and to differentiate into any cell type derived from the three main germ layers. It was demonstrated that somatic cells could be reprogrammed to form induced pluripotent stem cells (iPSCs) via various strategies. Gene editing is a technique that can be used to make targeted changes in the genome, and the efficiency of this process has been significantly enhanced by recent advancements. The use of engineered endonucleases, such as homing endonucleases, zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and Cas9 of the CRISPR system, has significantly enhanced the efficiency of gene editing. The combination of somatic cell reprogramming with gene editing enables us to model human diseases in vitro, in a manner considered superior to animal disease models. In this review, we discuss the various strategies of reprogramming and gene targeting with an emphasis on the current advancements and challenges of using these techniques to model human diseases.
Collapse
|
44
|
Novikova O, Jayachandran P, Kelley DS, Morton Z, Merwin S, Topilina NI, Belfort M. Intein Clustering Suggests Functional Importance in Different Domains of Life. Mol Biol Evol 2015; 33:783-99. [PMID: 26609079 PMCID: PMC4760082 DOI: 10.1093/molbev/msv271] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Inteins, also called protein introns, are self-splicing mobile elements found in all domains of life. A bioinformatic survey of genomic data highlights a biased distribution of inteins among functional categories of proteins in both bacteria and archaea, with a strong preference for a single network of functions containing replisome proteins. Many nonorthologous, functionally equivalent replicative proteins in bacteria and archaea carry inteins, suggesting a selective retention of inteins in proteins of particular functions across domains of life. Inteins cluster not only in proteins with related roles but also in specific functional units of those proteins, like ATPase domains. This peculiar bias does not fully fit the models describing inteins exclusively as parasitic elements. In such models, evolutionary dynamics of inteins is viewed primarily through their mobility with the intein homing endonuclease (HEN) as the major factor of intein acquisition and loss. Although the HEN is essential for intein invasion and spread in populations, HEN dynamics does not explain the observed biased distribution of inteins among proteins in specific functional categories. We propose that the protein splicing domain of the intein can act as an environmental sensor that adapts to a particular niche and could increase the chance of the intein becoming fixed in a population. We argue that selective retention of some inteins might be beneficial under certain environmental stresses, to act as panic buttons that reversibly inhibit specific networks, consistent with the observed intein distribution.
Collapse
Affiliation(s)
- Olga Novikova
- Department of Biological Sciences and RNA Institute, University at Albany
| | | | - Danielle S Kelley
- Department of Biomedical Sciences, School of Public Health, University at Albany
| | - Zachary Morton
- Department of Biological Sciences and RNA Institute, University at Albany
| | | | - Natalya I Topilina
- Department of Biological Sciences and RNA Institute, University at Albany
| | - Marlene Belfort
- Department of Biological Sciences and RNA Institute, University at Albany Department of Biomedical Sciences, School of Public Health, University at Albany
| |
Collapse
|
45
|
Sex or no sex? Group I introns and independent marker genes reveal the existence of three sexual but reproductively isolated biospecies in Trichia varia (Myxomycetes). ORG DIVERS EVOL 2015. [DOI: 10.1007/s13127-015-0230-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
46
|
Piégu B, Bire S, Arensburger P, Bigot Y. A survey of transposable element classification systems--a call for a fundamental update to meet the challenge of their diversity and complexity. Mol Phylogenet Evol 2015; 86:90-109. [PMID: 25797922 DOI: 10.1016/j.ympev.2015.03.009] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 03/11/2015] [Accepted: 03/12/2015] [Indexed: 10/25/2022]
Abstract
The increase of publicly available sequencing data has allowed for rapid progress in our understanding of genome composition. As new information becomes available we should constantly be updating and reanalyzing existing and newly acquired data. In this report we focus on transposable elements (TEs) which make up a significant portion of nearly all sequenced genomes. Our ability to accurately identify and classify these sequences is critical to understanding their impact on host genomes. At the same time, as we demonstrate in this report, problems with existing classification schemes have led to significant misunderstandings of the evolution of both TE sequences and their host genomes. In a pioneering publication Finnegan (1989) proposed classifying all TE sequences into two classes based on transposition mechanisms and structural features: the retrotransposons (class I) and the DNA transposons (class II). We have retraced how ideas regarding TE classification and annotation in both prokaryotic and eukaryotic scientific communities have changed over time. This has led us to observe that: (1) a number of TEs have convergent structural features and/or transposition mechanisms that have led to misleading conclusions regarding their classification, (2) the evolution of TEs is similar to that of viruses by having several unrelated origins, (3) there might be at least 8 classes and 12 orders of TEs including 10 novel orders. In an effort to address these classification issues we propose: (1) the outline of a universal TE classification, (2) a set of methods and classification rules that could be used by all scientific communities involved in the study of TEs, and (3) a 5-year schedule for the establishment of an International Committee for Taxonomy of Transposable Elements (ICTTE).
Collapse
Affiliation(s)
- Benoît Piégu
- UMR INRA-CNRS 7247, PRC, Centre INRA de Nouzilly, 37380 Nouzilly, France
| | - Solenne Bire
- UMR INRA-CNRS 7247, PRC, Centre INRA de Nouzilly, 37380 Nouzilly, France; Institute of Biotechnology, University of Lausanne, Center for Biotechnology UNIL-EPFL, 1015 Lausanne, Switzerland
| | - Peter Arensburger
- UMR INRA-CNRS 7247, PRC, Centre INRA de Nouzilly, 37380 Nouzilly, France; Biological Sciences Department, California State Polytechnic University, Pomona, CA 91768, United States.
| | - Yves Bigot
- UMR INRA-CNRS 7247, PRC, Centre INRA de Nouzilly, 37380 Nouzilly, France.
| |
Collapse
|
47
|
Uversky VN. The intrinsic disorder alphabet. III. Dual personality of serine. INTRINSICALLY DISORDERED PROTEINS 2015; 3:e1027032. [PMID: 28232888 DOI: 10.1080/21690707.2015.1027032] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Revised: 02/16/2015] [Accepted: 03/02/2015] [Indexed: 12/23/2022]
Abstract
Proteins are natural polypeptides consisting of 20 major amino acid residues, content and order of which in a given amino acid sequence defines the ability of a related protein to fold into unique functional state or to stay intrinsically disordered. Amino acid sequences code for both foldable (ordered) proteins/domains and for intrinsically disordered proteins (IDPs) and IDP regions (IDPRs), but these sequence codes are dramatically different. This difference starts with a very general property of the corresponding amino acid sequences, namely, their compositions. IDPs/IDPRs are enriched in specific disorder-promoting residues, whereas amino acid sequences of ordered proteins/domains typically contain more order-promoting residues. Therefore, the relative abundances of various amino acids in ordered and disordered proteins can be used to scale amino acids according to their disorder promoting potentials. This review continues a series of publications on the roles of different amino acids in defining the phenomenon of protein intrinsic disorder and represents serine, which is the third most disorder-promoting residue. Similar to previous publications, this review represents some physico-chemical properties of serine and the roles of this residue in structures and functions of ordered proteins, describes major posttranslational modifications tailored to serine, and finally gives an overview of roles of serine in structure and functions of intrinsically disordered proteins.
Collapse
Affiliation(s)
- Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer Research Institute; Morsani College of Medicine, University of South Florida; Tampa, FL USA; Biology Department; Faculty of Science, King Abdulaziz University; Jeddah, Kingdom of Saudi Arabia; Institute for Biological Instrumentation, Russian Academy of Sciences; Pushchino, Moscow Region, Russia; Laboratory of Structural Dynamics, Stability and Folding of Proteins; Institute of Cytology, Russian Academy of Sciences; St. Petersburg, Russia
| |
Collapse
|
48
|
The intraspecific variability of mitochondrial genes of Agaricus bisporus reveals an extensive group I intron mobility combined with low nucleotide substitution rates. Curr Genet 2014; 61:87-102. [DOI: 10.1007/s00294-014-0448-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 08/12/2014] [Accepted: 08/18/2014] [Indexed: 12/16/2022]
|
49
|
Intronic and plasmid-derived regions contribute to the large mitochondrial genome sizes of Agaricomycetes. Curr Genet 2014; 60:303-13. [PMID: 25011705 PMCID: PMC4201751 DOI: 10.1007/s00294-014-0436-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 05/30/2014] [Accepted: 06/21/2014] [Indexed: 01/13/2023]
Abstract
Sizes of mitochondrial genomes vary extensively between fungal species although they typically contain a conserved set of core genes. We have characterised the mitochondrial genome of the conifer root rot pathogen Heterobasidion irregulare and compared the size, gene content and structure of 20 Basidiomycete mitochondrial genomes. The mitochondrial genome of H. irregulare was 114, 193 bp and contained a core set of 15 protein coding genes, two rRNA genes and 26 tRNA genes. In addition, we found six non-conserved open reading frames (ORFs) and four putative plasmid genes clustered in three separate regions together with 24 introns and 14 intronic homing endonuclease genes, unequally spread across seven of the core genes. The size differences among the 20 Basidiomycetes can largely be explained by length variation of intergenic regions and introns. The Agaricomycetes contained the nine largest mitochondrial genomes in the Basidiomycete group and Agaricomycete genomes are significantly (p < 0.001) larger than the other Basidiomycetes. A feature of the Agaricomycete mitochondrial genomes in this study was the simultaneous occurrence of putative plasmid genes and non-conserved ORFs, with Cantharellus cibarius as only exception, where no non-conserved ORF was identified. This indicates a mitochondrial plasmid origin of the non-conserved ORFs or increased mitochondrial genome dynamics of species harbouring mitochondrial plasmids. We hypothesise that two independent factors are the driving forces for large mitochondrial genomes: the homing endonuclease genes in introns and integration of plasmid DNA.
Collapse
|
50
|
Soucy SM, Fullmer MS, Papke RT, Gogarten JP. Inteins as indicators of gene flow in the halobacteria. Front Microbiol 2014; 5:299. [PMID: 25018750 PMCID: PMC4071816 DOI: 10.3389/fmicb.2014.00299] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 05/30/2014] [Indexed: 12/21/2022] Open
Abstract
This research uses inteins, a type of mobile genetic element, to infer patterns of gene transfer within the Halobacteria. We surveyed 118 genomes representing 26 genera of Halobacteria for intein sequences. We then used the presence-absence profile, sequence similarity and phylogenies from the inteins recovered to explore how intein distribution can provide insight on the dynamics of gene flow between closely related and divergent organisms. We identified 24 proteins in the Halobacteria that have been invaded by inteins at some point in their evolutionary history, including two proteins not previously reported to contain an intein. Furthermore, the size of an intein is used as a heuristic for the phase of the intein's life cycle. Larger size inteins are assumed to be the canonical two domain inteins, consisting of self-splicing and homing endonuclease domains (HEN); smaller sizes are assumed to have lost the HEN domain. For many halobacterial groups the consensus phylogenetic signal derived from intein sequences is compatible with vertical inheritance or with a strong gene transfer bias creating these clusters. Regardless, the coexistence of intein-free and intein-containing alleles reveal ongoing transfer and loss of inteins within these groups. Inteins were frequently shared with other Euryarchaeota and among the Bacteria, with members of the Cyanobacteria (Cyanothece, Anabaena), Bacteriodetes (Salinibacter), Betaproteobacteria (Delftia, Acidovorax), Firmicutes (Halanaerobium), Actinobacteria (Longispora), and Deinococcus-Thermus-group.
Collapse
Affiliation(s)
- Shannon M Soucy
- Department of Molecular and Cell Biology, University of Connecticut Storrs, CT, USA
| | - Matthew S Fullmer
- Department of Molecular and Cell Biology, University of Connecticut Storrs, CT, USA
| | - R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut Storrs, CT, USA
| | | |
Collapse
|