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Lagunas-Rangel FA. Exploration of Giardia small nucleolar RNAs (snoRNAs) and their possible microRNA derivatives. Parasitology 2024:1-7. [PMID: 38767317 DOI: 10.1017/s003118202400060x] [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: 05/22/2024]
Abstract
Small nucleolar RNAs (snoRNAs) are short non-coding RNAs that are abundant in the nucleoli of eukaryotic cells and play a crucial role in various aspects of ribosomal RNA (rRNA) maturation, including modifications such as 2′-O-methylation or pseudouridylation. On the other hand, Giardia duodenalis is a microaerophilic, flagellated, binucleate protozoan responsible for causing giardiasis. Although numerous snoRNAs have been detected in Giardia, their investigation remains limited. Nevertheless, they have been found to play a crucial role in the rRNA precursor processing pathway and influence other cellular functions. In addition, it has been proposed that some microRNAs are generated from these snoRNAs through excision by the Giardia endoribonuclease Dicer. These microRNAs are believed to contribute to the regulation of antigenic variation, which allows the parasite to evade the host immune response. Specifically, they play a role in modulating variant-specific surface proteins (VSPs) and other cysteine-rich surface antigens (CSAs). The main objective of this study was to bring together the available data on snoRNAs in Giardia, uncovering their functions in various processes and their importance on a global scale. In addition, the research delved into potential microRNAs speculated to originate from snoRNAs, exploring their impact on cellular processes.
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Rojas-Pirela M, Andrade-Alviárez D, Medina L, Castillo C, Liempi A, Guerrero-Muñoz J, Ortega Y, Maya JD, Rojas V, Quiñones W, Michels PA, Kemmerling U. MicroRNAs: master regulators in host-parasitic protist interactions. Open Biol 2022; 12:210395. [PMID: 35702995 PMCID: PMC9198802 DOI: 10.1098/rsob.210395] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
MicroRNAs (miRNAs) are a group of small non-coding RNAs present in a wide diversity of organisms. MiRNAs regulate gene expression at a post-transcriptional level through their interaction with the 3' untranslated regions of target mRNAs, inducing translational inhibition or mRNA destabilization and degradation. Thus, miRNAs regulate key biological processes, such as cell death, signal transduction, development, cellular proliferation and differentiation. The dysregulation of miRNAs biogenesis and function is related to the pathogenesis of diseases, including parasite infection. Moreover, during host-parasite interactions, parasites and host miRNAs determine the probability of infection and progression of the disease. The present review is focused on the possible role of miRNAs in the pathogenesis of diseases of clinical interest caused by parasitic protists. In addition, the potential role of miRNAs as targets for the design of drugs and diagnostic and prognostic markers of parasitic diseases is also discussed.
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Affiliation(s)
- Maura Rojas-Pirela
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile,Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile,Facultad de Farmacia y Bioanálisis, Universidad de Los Andes, Mérida, Venezuela
| | - Diego Andrade-Alviárez
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | - Lisvaneth Medina
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
| | - Christian Castillo
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile,Núcleo de Investigación Aplicada en Ciencias Veterinarias y Agronómicas, Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Chile
| | - Ana Liempi
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
| | - Jesús Guerrero-Muñoz
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
| | - Yessica Ortega
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile,Facultad de Farmacia y Bioanálisis, Universidad de Los Andes, Mérida, Venezuela
| | - Juan Diego Maya
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
| | - Verónica Rojas
- Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile
| | - Wilfredo Quiñones
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | - Paul A. Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Ulrike Kemmerling
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago de Chile 8380453, Chile
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Abstract
Giardia duodenalis captured the attention of Leeuwenhoek in 1681 while he was examining his own diarrheal stool, but, ironically, it did not really gain attention as a human pathogen until the 1960s, when outbreaks were reported. Key technological advances, including in vitro cultivation, genomic and proteomic databases, and advances in microscopic and molecular approaches, have led to an understanding that this is a eukaryotic organism with a reduced genome rather than a truly premitochondriate eukaryote. This has included the discovery of mitosomes (vestiges of mitochondria), a transport system with many of the features of the Golgi apparatus, and even evidence for a sexual or parasexual cycle. Cell biology approaches have led to a better understanding of how Giardia survives with two nuclei and how it goes through its life cycle as a noninvasive organism in the hostile environment of the lumen of the host intestine. Studies of its immunology and pathogenesis have moved past the general understanding of the importance of the antibody response in controlling infection to determining the key role of the Th17 response. This work has led to understanding of the requirement for a balanced host immune response that avoids the extremes of an excessive response with collateral damage or one that is unable to clear the organism. This understanding is especially important in view of the remarkable ranges of early manifestations, which range from asymptomatic to persistent diarrhea and weight loss, and longer-term sequelae that include growth stunting in children who had no obvious symptoms and a high frequency of postinfectious irritable bowel syndrome (IBS).
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Meningher T, Boleslavsky D, Barshack I, Tabibian-Keissar H, Kohen R, Gur-Wahnon D, Ben-Dov IZ, Sidi Y, Avni D, Schwartz E. Giardia lamblia miRNAs as a new diagnostic tool for human giardiasis. PLoS Negl Trop Dis 2019; 13:e0007398. [PMID: 31206518 PMCID: PMC6597124 DOI: 10.1371/journal.pntd.0007398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 06/27/2019] [Accepted: 04/16/2019] [Indexed: 01/15/2023] Open
Abstract
Background Giardia lamblia is a very common cause of gastrointestinal symptoms worldwide. There are several methods for the diagnosis of Giardia infection, however none are ideal. We aim to find a new, microRNA-based method that will improve the currently available diagnostic methods for giardiasis. Methods Deep-sequence profiling of Giardia small-RNA revealed that miR5 and miR6 are highly expressed in Giardia. These miRNAs were tested by qRT-PCR in duodenal biopsies of patients with giardiasis who were positive by microscopic pathological evaluation. The gastric biopsies of the same patients served as negative control tissues. Additionally, these miRNAs were evaluated in stool samples of patients with proven giardiasis. Results All histologically proven duodenal biopsies of patients with Giardia infection were positive for Giardia miR5, with a mean threshold cycle (Ct) of 23.7, as well as for Giardia DNA qPCR (16S-like gene, mean Ct 26.3). Gastric biopsies which were tested as a control all were negative. Stool evaluation of miR6 in patients with giardiasis showed 90% specificity but only 66% sensitivity, and a lower accuracy rate was obtained with miR5. Conclusion Giardia miR5 testing in duodenal biopsies may be a new method for the diagnosis of giardiasis. It seems to be more sensitive when compared with testing for Giardia DNA by qPCR in duodenal biopsies. It will be important to investigate the contribution of routine Giardia miRNA testing in duodenal biopsies from patients with persistent abdominal symptoms Giardiasis is a major cause of diarrheal disease throughout the world. It is more common in areas with poor sanitation such as in many low-income countries, but it occurs in high-income countries as well. It is the most commonly identified intestinal parasite in the United States and it is endemic in other industrialized countries. The causative agent is the flagellate protozoan Giardia lamblia, and transmission is mainly by the fecal-oral route. The basic method of diagnosis is stool examination. It is usually found through stool microscopy examination which should be performed on fresh stool and repeated in 3 days. Despite some newer diagnostic methods, Giardia is still difficult to detect, often leading to misdiagnoses. In this study we show that using Giardia microRNA (miR5) as a marker for Giardia infection in duodenal biopsies may be a new method for diagnosis of giardiasis. It appears to be more sensitive than histological diagnosis and also more sensitive than Giardia DNA testing in duodenal biopsies. Interestingly, in our patients, duodenal biopsies were done for persistent abdominal symptoms and the finding of Giardia in their biopsy was unexpected. Thus, testing duodenal biopsies for Giardia miRNA in patients with persistent abdominal symptoms might contribute to diagnosis and prompt treatment for those with giardiasis.
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Affiliation(s)
- Tal Meningher
- Laboratory of Molecular Cell Biology, Sheba Medical Center, Ramat Gan, Israel
- Department of Medicine C, Sheba Medical Center, Ramat Gan, Israel
- Molecular Laboratory for the Study of Tropical Diseases, Sheba Medical Center, Ramat Gan, Israel
| | | | - Iris Barshack
- Department of Pathology, Sheba Medical Center, Ramat Gan, Israel
- Faculty of Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Hila Tabibian-Keissar
- Department of Pathology, Sheba Medical Center, Ramat Gan, Israel
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
| | - Refael Kohen
- Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Devorah Gur-Wahnon
- Laboratory of Medical Transcriptomics, Nephrology and Hypertension Services, Hadassah—Hebrew University Medical Center, Jerusalem, Israel
| | - Iddo Z. Ben-Dov
- Laboratory of Medical Transcriptomics, Nephrology and Hypertension Services, Hadassah—Hebrew University Medical Center, Jerusalem, Israel
| | - Yechezkel Sidi
- Laboratory of Molecular Cell Biology, Sheba Medical Center, Ramat Gan, Israel
- Department of Medicine C, Sheba Medical Center, Ramat Gan, Israel
- Faculty of Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Dror Avni
- Laboratory of Molecular Cell Biology, Sheba Medical Center, Ramat Gan, Israel
- Department of Medicine C, Sheba Medical Center, Ramat Gan, Israel
- Molecular Laboratory for the Study of Tropical Diseases, Sheba Medical Center, Ramat Gan, Israel
- * E-mail: , (DA); (ES)
| | - Eli Schwartz
- Molecular Laboratory for the Study of Tropical Diseases, Sheba Medical Center, Ramat Gan, Israel
- Faculty of Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Center for Geographic Medicine, Sheba Medical Center, Ramat Gan, Israel
- * E-mail: , (DA); (ES)
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Åsman AKM, Curtis BA, Archibald JM. Nucleomorph Small RNAs in Cryptophyte and Chlorarachniophyte Algae. Genome Biol Evol 2019; 11:1117-1134. [PMID: 30949682 PMCID: PMC6461891 DOI: 10.1093/gbe/evz064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2019] [Indexed: 12/27/2022] Open
Abstract
The regulation of gene expression and RNA maturation underlies fundamental processes such as cell homeostasis, development, and stress acclimation. The biogenesis and modification of RNA is tightly controlled by an array of regulatory RNAs and nucleic acid-binding proteins. While the role of small RNAs (sRNAs) in gene expression has been studied in-depth in select model organisms, little is known about sRNA biology across the eukaryotic tree of life. We used deep sequencing to explore the repertoires of sRNAs encoded by the miniaturized, endosymbiotically derived “nucleomorph” genomes of two single-celled algae, the cryptophyte Guillardia theta and the chlorarachniophyte Bigelowiella natans. A total of 32.3 and 35.3 million reads were generated from G. theta and B. natans, respectively. In G. theta, we identified nucleomorph U1, U2, and U4 spliceosomal small nuclear RNAs (snRNAs) as well as 11 C/D box small nucleolar RNAs (snoRNAs), five of which have potential plant and animal homologs. The snoRNAs are predicted to perform 2′-O methylation of rRNA (but not snRNA). In B. natans, we found the previously undetected 5S rRNA as well as six orphan sRNAs. Analysis of chlorarachniophyte snRNAs shed light on the removal of the miniature 18–21 nt introns found in B. natans nucleomorph genes. Neither of the nucleomorph genomes appears to encode RNA pseudouridylation machinery, and U5 snRNA cannot be found in the cryptophyte G. theta. Considering the central roles of U5 snRNA and RNA modifications in other organisms, cytoplasm-to-nucleomorph RNA shuttling in cryptophyte algae is a distinct possibility.
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Affiliation(s)
- Anna K M Åsman
- Department of Biochemistry and Molecular Biology, Dalhousie University, Nova Scotia, Canada.,Department of Molecular Sciences, Uppsala BioCenter, Swedish University of Agricultural Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Bruce A Curtis
- Department of Biochemistry and Molecular Biology, Dalhousie University, Nova Scotia, Canada
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Nova Scotia, Canada
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6
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Xu YF, Hannafon BN, Khatri U, Gin A, Ding WQ. The origin of exosomal miR-1246 in human cancer cells. RNA Biol 2019; 16:770-784. [PMID: 30806147 DOI: 10.1080/15476286.2019.1585738] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
miR-1246 is considered an oncomiR in various cancer types. However, the origin and biogenesis of miR-1246 remain controversial which often leads to misinterpretation of its detection and biological function, and inevitably masking its mechanisms of action. Using next generation small RNA sequencing, CRISPR-Cas9 knockout, siRNA knockdown and the poly-A tailing SYBR qRT-PCR, we examined the biogenesis of exosomal miR-1246 in human cancer cell model systems. We found that miR-1246 is highly enriched in exosomes derived from human cancer cells and that it originates from RNU2-1, a small nuclear RNA and essential component of the U2 complex of the spliceosome. Knockdown of Drosha and Dicer did not reduce exosomal miR-1246 levels, indicating that exosomal miR-1246 is generated in a Drosha- and Dicer-independent manner. Direct digestion of cellular lysate by RNase A and knockdown of the RNU2-1 binding protein SmB/B' demonstrated that exosomal miR-1246 is a RNU2-1 degradation product. Furthermore, the GCAG motif present in the RUN2-1 transcript was shown to mediate miR-1246 enrichment in cancer exosomes. We conclude that exosome miR-1246 is derived from RNU2-1 degradation through a non-canonical microRNA biogenesis process. These findings reveal the origin of an oncomiR in human cancer cells, providing guidance in understanding miR-1246 detection and biological function. Abbreviations: CRISPR, Clustered Regularly Interspaced Short Palindromic Repeats; miRNA, microRNA; PDAC, pancreatic ductal adenocarcinoma; RNU2-1, U2 small nuclear RNA; RT-PCR, Reverse transcription polymerase chain reaction; sgRNA, single-guide RNA.
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Affiliation(s)
- Yi-Fan Xu
- a Department of Pathology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| | - Bethany N Hannafon
- a Department of Pathology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| | - Ujjwol Khatri
- a Department of Pathology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| | - Amy Gin
- a Department of Pathology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
| | - Wei-Qun Ding
- a Department of Pathology , University of Oklahoma Health Sciences Center , Oklahoma City , OK , USA
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7
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Faso C, Hehl AB. A cytonaut's guide to protein trafficking in Giardia lamblia. ADVANCES IN PARASITOLOGY 2019; 106:105-127. [PMID: 31630756 DOI: 10.1016/bs.apar.2019.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Over the past years, the subcellular organization of the Excavata member Giardia lamblia (syn. duodenalis, intestinalis) has been investigated in considerable detail. There are several reasons for this endeavour which go beyond this parasite's medical importance and are mostly concerned with its reduced subcellular complexity and debated evolutionary status. One may say that simplification has emerged as a paradigm for the evolution of Giardia's subcellular architecture. However, a complete appreciation of the evolutionary and ecological significance of this phenomenon is far from complete. In this chapter, we present and discuss the most recent data on the main trafficking pathways in G. lamblia which include endo- and exo-cytosis, organellar import and function. We provide perspectives on open questions concerning organelle replication and inheritance and include a technical outlook on methods and approaches to genetic manipulations in G. lamblia. A better understanding of G. lamblia subcellular organization at the morphological and molecular level complements any effort aimed at elucidating this parasitic species' evolutionary status and could provide us with the basis for novel strategies to interfere with parasite transmission and/or pathogenesis.
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Affiliation(s)
- Carmen Faso
- Laboratory of Molecular Parasitology, Institute of Parasitology, University of Zurich (ZH), Zürich, Switzerland
| | - Adrian B Hehl
- Laboratory of Molecular Parasitology, Institute of Parasitology, University of Zurich (ZH), Zürich, Switzerland.
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8
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Zhang R, Jing Y, Zhang H, Niu Y, Liu C, Wang J, Zen K, Zhang CY, Li D. Comprehensive Evolutionary Analysis of the Major RNA-Induced Silencing Complex Members. Sci Rep 2018; 8:14189. [PMID: 30242207 PMCID: PMC6155107 DOI: 10.1038/s41598-018-32635-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 09/12/2018] [Indexed: 01/10/2023] Open
Abstract
RNA-induced silencing complex (RISC) plays a critical role in small interfering RNA (siRNA) and microRNAs (miRNA) pathways. Accumulating evidence has demonstrated that the major RISC members (AGO, DICER, TRBP, PACT and GW182) represent expression discrepancies or multiple orthologues/paralogues in different species. To elucidate their evolutionary characteristics, an integrated evolutionary analysis was performed. Here, animal and plant AGOs were divided into three classes (multifunctional AGOs, siRNA-associated AGOs and piRNA-associated AGOs for animal AGOs and multifunctional AGOs, siRNA-associated AGOs and complementary functioning AGOs for plant AGOs). Animal and plant DICERs were grouped into one class (multifunctional DICERs) and two classes (multifunctional DICERs and siRNA-associated DICERs), respectively. Protista/fungi AGOs or DICERs were specifically associated with the siRNA pathway. Additionally, TRBP/PACT/GW182 were identified only in animals, and all of them functioned in the miRNA pathway. Mammalian AGOs, animal DICERs and chordate TRBP/PACT were found to be monophyletic. A large number of gene duplications were identified in AGO and DICER groups. Taken together, we provide a comprehensive evolutionary analysis, describe a phylogenetic tree-based classification of the major RISC members and quantify their gene duplication events. These findings are potentially useful for classifying RISCs, optimizing species-specific RISCs and developing research model organisms.
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Affiliation(s)
- Rui Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Ying Jing
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Haiyang Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Yahan Niu
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Chang Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Jin Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Ke Zen
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Chen-Yu Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China
| | - Donghai Li
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences (NAILS), School of Life Sciences, Nanjing University, Nanjing, Jiangsu, 210023, P.R. China.
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9
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Stem-Loop RT-qPCR as an Efficient Tool for the Detection and Quantification of Small RNAs in Giardia lamblia. Genes (Basel) 2016; 7:genes7120131. [PMID: 27999395 PMCID: PMC5192507 DOI: 10.3390/genes7120131] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 11/26/2016] [Accepted: 11/26/2016] [Indexed: 11/16/2022] Open
Abstract
Stem-loop quantitative reverse transcription PCR (RT-qPCR) is a molecular technique used for identification and quantification of individual small RNAs in cells. In this work, we used a Universal ProbeLibrary (UPL)-based design to detect-in a rapid, sensitive, specific, and reproducible way-the small nucleolar RNA (snoRNA) GlsR17 and its derived miRNA (miR2) of Giardia lamblia using a stem-loop RT-qPCR approach. Both small RNAs could be isolated from both total RNA and small RNA samples. Identification of the two small RNAs was carried out by sequencing the PCR-amplified small RNA products upon ligation into the pJET1.2/blunt vector. GlsR17 is constitutively expressed during the 72 h cultures of trophozoites, while the mature miR2 is present in 2-fold higher abundance during the first 48 h than at 72 h. Because it has been suggested that miRNAs in G. lamblia have an important role in the regulation of gene expression, the use of the stem-loop RT-qPCR method could be valuable for the study of miRNAs of G. lamblia. This methodology will be a powerful tool for studying gene regulation in G. lamblia, and will help to better understand the features and functions of these regulatory molecules and how they work within the RNA interference (RNAi) pathway in G. lamblia.
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10
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Gargantini PR, Serradell MDC, Ríos DN, Tenaglia AH, Luján HD. Antigenic variation in the intestinal parasite Giardia lamblia. Curr Opin Microbiol 2016; 32:52-58. [DOI: 10.1016/j.mib.2016.04.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 01/25/2023]
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11
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Qu G, Kruszka K, Plewka P, Yang SY, Chiou TJ, Jarmolowski A, Szweykowska-Kulinska Z, Echeverria M, Karlowski WM. Promoter-based identification of novel non-coding RNAs reveals the presence of dicistronic snoRNA-miRNA genes in Arabidopsis thaliana. BMC Genomics 2015; 16:1009. [PMID: 26607788 PMCID: PMC4660826 DOI: 10.1186/s12864-015-2221-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 11/16/2015] [Indexed: 11/18/2022] Open
Abstract
Background In the past few decades, non-coding RNAs (ncRNAs) have emerged as important regulators of gene expression in eukaryotes. Most studies of ncRNAs in plants have focused on the identification of silencing microRNAs (miRNAs) and small interfering RNAs (siRNAs). Another important family of ncRNAs that has been well characterized in plants is the small nucleolar RNAs (snoRNAs) and the related small Cajal body-specific RNAs (scaRNAs). Both target chemical modifications of ribosomal RNAs (rRNAs) and small nuclear RNAs (snRNAs). In plants, the snoRNA genes are organized in clusters, transcribed by RNA Pol II from a common promoter and subsequently processed into mature molecules. The promoter regions of snoRNA polycistronic genes in plants are highly enriched in two conserved cis-regulatory elements (CREs), Telo-box and Site II, which coordinate the expression of snoRNAs and ribosomal protein coding genes throughout the cell cycle. Results In order to identify novel ncRNA genes, we have used the snoRNA Telo-box/Site II motifs combination as a functional promoter indicator to screen the Arabidopsis genome. The predictions generated by this process were tested by detailed exploration of available RNA-Seq and expression data sets and experimental validation. As a result, we have identified several snoRNAs, scaRNAs and 'orphan' snoRNAs. We also show evidence for 16 novel ncRNAs that lack similarity to any reported RNA family. Finally, we have identified two dicistronic genes encoding precursors that are processed to mature snoRNA and miRNA molecules. We discuss the evolutionary consequences of this result in the context of a tight link between snoRNAs and miRNAs in eukaryotes. Conclusions We present an alternative computational approach for non-coding RNA detection. Instead of depending on sequence or structure similarity in the whole genome screenings, we have explored the properties of promoter regions of well-characterized ncRNAs. Interestingly, besides expected ncRNAs predictions we were also able to recover single precursor arrangement for snoRNA-miRNA. Accompanied by analyses performed on rice sequences, we conclude that such arrangement might have interesting functional and evolutionary consequences and discuss this result in the context of a tight link between snoRNAs and miRNAs in eukaryotes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2221-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ge Qu
- Department of Computational Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznan, Umultowska 89, 61-614, Poznan, Poland.
| | - Katarzyna Kruszka
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznan, Umultowska 89, Poznan, 61-614, Poland.
| | - Patrycja Plewka
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznan, Umultowska 89, Poznan, 61-614, Poland.
| | - Shu-Yi Yang
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128 Academia Rd. Sec. 2, Taipei, 115, Taiwan.
| | - Tzyy-Jen Chiou
- Agricultural Biotechnology Research Center, Academia Sinica, No. 128 Academia Rd. Sec. 2, Taipei, 115, Taiwan.
| | - Artur Jarmolowski
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznan, Umultowska 89, Poznan, 61-614, Poland.
| | - Zofia Szweykowska-Kulinska
- Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznan, Umultowska 89, Poznan, 61-614, Poland.
| | - Manuel Echeverria
- Faculté des Sciences, Université de Perpignan via Domitia, 52, Av Paul Alduy, Perpignan, 66860, France.
| | - Wojciech M Karlowski
- Department of Computational Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznan, Umultowska 89, 61-614, Poznan, Poland.
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The generation gap: Proteome changes and strain variation during encystation in Giardia duodenalis. Mol Biochem Parasitol 2015; 201:47-56. [DOI: 10.1016/j.molbiopara.2015.05.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 05/26/2015] [Accepted: 05/28/2015] [Indexed: 12/26/2022]
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Thomson DW, Pillman KA, Anderson ML, Lawrence DM, Toubia J, Goodall GJ, Bracken CP. Assessing the gene regulatory properties of Argonaute-bound small RNAs of diverse genomic origin. Nucleic Acids Res 2015; 43:470-81. [PMID: 25452337 PMCID: PMC4288155 DOI: 10.1093/nar/gku1242] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 10/23/2014] [Accepted: 11/11/2014] [Indexed: 12/21/2022] Open
Abstract
High-throughput sequencing reveals an abundance of microRNA-sized fragments derived from larger non-coding RNAs. Roles for these small RNAs in gene silencing are suggested by their co-precipitation with Argonaute, the microRNA effector protein, though the extent to which they suppress gene expression endogenously remains unclear. To address this, we used luciferase reporters to determine the endogenous functionality of small RNAs from a diverse range of sources. We demonstrate small RNAs derived from snoRNAs have the capacity to act in a microRNA-like manner, though we note the vast majority of these are bound to Argonaute at levels below that required for detectable silencing activity. We show Argonaute exhibits a high degree of selectivity for the small RNAs with which it interacts and note that measuring Argonaute-associated levels is a better indicator of function than measuring total expression. Although binding to Argonaute at sufficient levels is necessary for demonstrating microRNA functionality in our reporter assay, this alone is not enough as some small RNAs derived from other non-coding RNAs (tRNAs, rRNAs, Y-RNAs) are associated with Argonaute at very high levels yet do not serve microRNA-like roles.
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Affiliation(s)
- Daniel W Thomson
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia Discipline of Medicine, University of Adelaide, Adelaide, SA 5005, Australia
| | - Katherine A Pillman
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia
| | - Matthew L Anderson
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia
| | - David M Lawrence
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia Australian Cancer Research Foundation (ACRF) Cancer Genomics Facility, Adelaide, SA 5005, Australia
| | - John Toubia
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia
| | - Gregory J Goodall
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia Discipline of Medicine, University of Adelaide, Adelaide, SA 5005, Australia School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
| | - Cameron P Bracken
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia Discipline of Medicine, University of Adelaide, Adelaide, SA 5005, Australia School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5005, Australia
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Emery SJ, van Sluyter S, Haynes PA. Proteomic analysis inGiardia duodenalisyields insights into strain virulence and antigenic variation. Proteomics 2014; 14:2523-34. [DOI: 10.1002/pmic.201400144] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 08/19/2014] [Accepted: 09/25/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Samantha J. Emery
- Department of Chemistry and Biomolecular Sciences; Macquarie University; North Ryde New South Wales Australia
| | - Steve van Sluyter
- Department of Chemistry and Biomolecular Sciences; Macquarie University; North Ryde New South Wales Australia
| | - Paul A. Haynes
- Department of Chemistry and Biomolecular Sciences; Macquarie University; North Ryde New South Wales Australia
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Both endo-siRNAs and tRNA-derived small RNAs are involved in the differentiation of primitive eukaryote Giardia lamblia. Proc Natl Acad Sci U S A 2014; 111:14159-64. [PMID: 25225396 DOI: 10.1073/pnas.1414394111] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Small RNAs (sRNAs), including microRNAs and endogenous siRNAs (endo-siRNAs), regulate most important biologic processes in eukaryotes, such as cell division and differentiation. Although sRNAs have been extensively studied in various eukaryotes, the role of sRNAs in the early emergence of eukaryotes is unclear. To address these questions, we deep sequenced the sRNA transcriptome of four different stages in the differentiation of Giardia lamblia, one of the most primitive eukaryotes. We identified a large number of endo-siRNAs in this fascinating parasitic protozoan and found that they were produced from live telomeric retrotransposons and three genomic regions (i.e., endo-siRNA generating regions [eSGRs]). eSGR-derived endo-siRNAs were proven to target mRNAs in trans. Gradual up-regulation of endo-siRNAs in the differentiation of Giardia suggested that they might be involved in the regulation of this process. This hypothesis was supported by the impairment of the differentiation ability of Giardia when GLDICER, essential for the biogenesis of endo-siRNAs, was knocked down. Endo-siRNAs are not the only sRNA regulators in Giardia differentiation, because a great number of tRNAs-derived sRNAs showed more dramatic expression changes than endo-siRNAs in this process. We totally identified five novel kinds of tRNAs-derived sRNAs and found that the biogenesis in four of them might be correlated with that of stress-induced tRNA-derived RNA (sitRNA), which was discovered in our previous studies. Our studies reveal an unexpected complex panorama of sRNA in G. lamblia and shed light on the origin and functional evolution of eukaryotic sRNAs.
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Saraiya AA, Li W, Wu J, Chang CH, Wang CC. The microRNAs in an ancient protist repress the variant-specific surface protein expression by targeting the entire coding sequence. PLoS Pathog 2014; 10:e1003791. [PMID: 24586143 PMCID: PMC3937270 DOI: 10.1371/journal.ppat.1003791] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 10/10/2013] [Indexed: 11/18/2022] Open
Abstract
microRNAs (miRNA) have been detected in the deeply branched protist, Giardia lamblia, and shown to repress expression of the family of variant-specific surface proteins (VSPs), only one of which is expressed in Giardia trophozoite at a given time. Three next-generation sequencing libraries of Giardia Argonaute-associated small RNAs were constructed and analyzed. Analysis of the libraries identified a total of 99 new putative miRNAs with a size primarily in the 26 nt range similar to the size previously predicted by the Giardia Dicer crystal structure and identified by our own studies. Bioinformatic analysis identified multiple putative miRNA target sites in the mRNAs of all 73 VSPs. The effect of miRNA target sites within a defined 3′-region were tested on two vsp mRNAs. All the miRNAs showed partial repression of the corresponding vsp expression and were additive when the targeting sites were separately located. But the combined repression still falls short of 100%. Two other relatively short vsp mRNAs with 15 and 11 putative miRNA target sites identified throughout their ORFs were tested with their corresponding miRNAs. The results indicate that; (1) near 100% repression of vsp mRNA expression can be achieved through the combined action of multiple miRNAs on target sites located throughout the ORF; (2) the miRNA machinery could be instrumental in repressing the expression of vsp genes in Giardia; (3) this is the first time that all the miRNA target sites in the entire ORF of a mRNA have been tested and shown to be functional. Giardia lamblia is a protozoan parasite causing the diarrheal disease giardiasis. Variant-specific surface proteins (VSP) in Giardia are likely involved in its evasion of host immune response. Their expression is regulated by microRNAs (miRNA). To determine the full complement of miRNAs in Giardia, three cDNA libraries of Giardia Argonaute associated small RNAs were constructed and analyzed to identify a total of 105 miRNAs. Bioinformatic target identification showed that 102 of the 105 miRNAs find their putative target sites in vsp mRNAs. When only the target sites within the 3′ region,100 nts upstream of the stop codon, were tested against their corresponding miRNAs, however, only partial repression of VSP expression was observed. When all the miRNA target sites in the open reading frames of vsp mRNAs were examined, however, they all turned out to be functional. A saturation of them with the corresponding miRNAs resulted in a full repression of VSP expression, suggesting that this is the mechanism of miRNA repression of VSP expression in Giardia. The ability of miRNAs to regulate target sites throughout the entire open reading frame also provides the first indication that all the miRNA target sites in an mRNA are functional.
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Affiliation(s)
- Ashesh A. Saraiya
- Department of Pharmaceutical Chemistry, University of California-San Francisco, San Francisco, California, United States of America
| | - Wei Li
- Department of Pharmaceutical Chemistry, University of California-San Francisco, San Francisco, California, United States of America
| | - Jesse Wu
- Institute for Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan
| | - Chuan H. Chang
- Institute for Biomedical Informatics, National Yang-Ming University, Taipei, Taiwan
| | - Ching C. Wang
- Department of Pharmaceutical Chemistry, University of California-San Francisco, San Francisco, California, United States of America
- * E-mail:
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Burroughs AM, Ando Y, Aravind L. New perspectives on the diversification of the RNA interference system: insights from comparative genomics and small RNA sequencing. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 5:141-81. [PMID: 24311560 DOI: 10.1002/wrna.1210] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 10/03/2013] [Accepted: 11/01/2013] [Indexed: 12/19/2022]
Abstract
Our understanding of the pervasive involvement of small RNAs in regulating diverse biological processes has been greatly augmented by recent application of deep-sequencing technologies to small RNA across diverse eukaryotes. We review the currently known small RNA classes and place them in context of the reconstructed evolutionary history of the RNA interference (RNAi) protein machinery. This synthesis indicates that the earliest versions of eukaryotic RNAi systems likely utilized small RNA processed from three types of precursors: (1) sense-antisense transcriptional products, (2) genome-encoded, imperfectly complementary hairpin sequences, and (3) larger noncoding RNA precursor sequences. Structural dissection of PIWI proteins along with recent discovery of novel families (including Med13 of the Mediator complex) suggest that emergence of a distinct architecture with the N-terminal domains (also occurring separately fused to endoDNases in prokaryotes) formed via duplication of an ancestral unit was key to their recruitment as primary RNAi effectors and use of small RNAs of certain preferred lengths. Prokaryotic PIWI proteins are typically components of several RNA-directed DNA restriction or CRISPR/Cas systems. However, eukaryotic versions appear to have emerged from a subset that evolved RNA-directed RNAi. They were recruited alongside RNaseIII domains and RNA-dependent RNA polymerase (RdRP) domains, also from prokaryotic systems, to form the core eukaryotic RNAi system. Like certain regulatory systems, RNAi diversified into two distinct but linked arms concomitant with eukaryotic nucleocytoplasmic compartmentalization. Subsequent elaboration of RNAi proceeded via diversification of the core protein machinery through lineage-specific expansions and recruitment of new components from prokaryotes (nucleases and small RNA-modifying enzymes), allowing for diversification of associating small RNAs.
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Affiliation(s)
- Alexander Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
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18
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Chen CJ, Heard E. Small RNAs derived from structural non-coding RNAs. Methods 2013; 63:76-84. [DOI: 10.1016/j.ymeth.2013.05.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Revised: 04/12/2013] [Accepted: 05/06/2013] [Indexed: 12/25/2022] Open
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Kishore S, Gruber AR, Jedlinski DJ, Syed AP, Jorjani H, Zavolan M. Insights into snoRNA biogenesis and processing from PAR-CLIP of snoRNA core proteins and small RNA sequencing. Genome Biol 2013; 14:R45. [PMID: 23706177 PMCID: PMC4053766 DOI: 10.1186/gb-2013-14-5-r45] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/15/2013] [Accepted: 05/26/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In recent years, a variety of small RNAs derived from other RNAs with well-known functions such as tRNAs and snoRNAs, have been identified. The functional relevance of these RNAs is largely unknown. To gain insight into the complexity of snoRNA processing and the functional relevance of snoRNA-derived small RNAs, we sequence long and short RNAs, small RNAs that co-precipitate with the Argonaute 2 protein and RNA fragments obtained in photoreactive nucleotide-enhanced crosslinking and immunoprecipitation (PAR-CLIP) of core snoRNA-associated proteins. RESULTS Analysis of these data sets reveals that many loci in the human genome reproducibly give rise to C/D box-like snoRNAs, whose expression and evolutionary conservation are typically less pronounced relative to the snoRNAs that are currently cataloged. We further find that virtually all C/D box snoRNAs are specifically processed inside the regions of terminal complementarity, retaining in the mature form only 4-5 nucleotides upstream of the C box and 2-5 nucleotides downstream of the D box. Sequencing of the total and Argonaute 2-associated populations of small RNAs reveals that despite their cellular abundance, C/D box-derived small RNAs are not efficiently incorporated into the Ago2 protein. CONCLUSIONS We conclude that the human genome encodes a large number of snoRNAs that are processed along the canonical pathway and expressed at relatively low levels. Generation of snoRNA-derived processing products with alternative, particularly miRNA-like, functions appears to be uncommon.
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Affiliation(s)
- Shivendra Kishore
- Computational and Systems Biology, Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
| | - Andreas R Gruber
- Computational and Systems Biology, Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
| | - Dominik J Jedlinski
- Computational and Systems Biology, Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
| | - Afzal P Syed
- Computational and Systems Biology, Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
| | - Hadi Jorjani
- Computational and Systems Biology, Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
| | - Mihaela Zavolan
- Computational and Systems Biology, Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056 Basel, Switzerland
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Experimental verification of the identity of variant-specific surface proteins in Giardia lamblia trophozoites. mBio 2013; 4:e00321-13. [PMID: 23695837 PMCID: PMC3656445 DOI: 10.1128/mbio.00321-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The cell membrane of a Giardia lamblia trophozoite is covered with a single species of variant-specific surface protein (VSP) that is replaced by another VSP every 6 to 13 generations of cell growth, possibly for an evasion of host immunity. Experimentally, only six VSP species have been verified to localize to the cell membrane thus far. By assuming that VSP contains multiple CXXC motifs, 219 vsp genes were annotated in GiardiaDB of the WB isolate. By further assuming that VSP possesses both CXXC motifs and a CRGKA tail at the C terminus, Adam et al. (BMC Genomics 11:424, 2010) identified a total of 303 potential vsp genes in Giardia WB. The discrepancies between these two assumed VSP identities have caused some confusion. Here, we used experimental approaches to further verify what is required of the structures of a VSP to localize to the surface of cell membrane. The data led to the following conclusions. (i) The C-terminal CRGKA sequence is not essential for localizing VSPs to the cell membrane. (ii) A “motif 1” of 45 residues, consisting of two CXXCs separated by 12 to 15 amino acid residues, located close to the C terminus and a hydrophobic “motif 2” of 38 residues at the C terminus are both essential and sufficient for localizing the protein to the cell membrane. (ii) An N-terminal sequence upstream from motif 1 is not required for targeting VSPs to the cell membrane. By these criteria, we are able to identify 73 open reading frames as the putative vsp genes in Giardia. The intestinal pathogen Giardia lamblia expresses only one variant-specific surface protein (VSP) on the cell membrane surface at a given time, but it changes spontaneously every 6 to 13 generations of growth, presumably for evading the host immunity. Only 6 VSPs have been empirically shown to localize to the cell membrane surface thus far. Here, we used mutations of VSPs and methods of identifying their locations in Giardia cells and found that a “motif 1” of 45 residues, consisting of two CXXCs separated by 12 to 15 amino acid residues, located close to the C terminus and a hydrophobic “motif 2” of 38 residues at the C terminus are the only essential and sufficient structural requirements for localizing a protein to the cell membrane. By these criteria, 73 genes are identified in the Giardia WB strain genome database as the putative repertoire of VSPs.
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DNA topoisomerase II is involved in regulation of cyst wall protein genes and differentiation in Giardia lamblia. PLoS Negl Trop Dis 2013; 7:e2218. [PMID: 23696909 PMCID: PMC3656124 DOI: 10.1371/journal.pntd.0002218] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 04/04/2013] [Indexed: 12/16/2022] Open
Abstract
The protozoan Giardia lamblia differentiates into infectious cysts within the human intestinal tract for disease transmission. Expression of the cyst wall protein (cwp) genes increases with similar kinetics during encystation. However, little is known how their gene regulation shares common mechanisms. DNA topoisomerases maintain normal topology of genomic DNA. They are necessary for cell proliferation and tissue development as they are involved in transcription, DNA replication, and chromosome condensation. A putative topoisomerase II (topo II) gene has been identified in the G. lamblia genome. We asked whether Topo II could regulate Giardia encystation. We found that Topo II was present in cell nuclei and its gene was up-regulated during encystation. Topo II has typical ATPase and DNA cleavage activity of type II topoisomerases. Mutation analysis revealed that the catalytic important Tyr residue and cleavage domain are important for Topo II function. We used etoposide-mediated topoisomerase immunoprecipitation assays to confirm the binding of Topo II to the cwp promoters in vivo. Interestingly, Topo II overexpression increased the levels of cwp gene expression and cyst formation. Microarray analysis identified up-regulation of cwp and specific vsp genes by Topo II. We also found that the type II topoisomerase inhibitor etoposide has growth inhibition effect on Giardia. Addition of etoposide significantly decreased the levels of cwp gene expression and cyst formation. Our results suggest that Topo II has been functionally conserved during evolution and that Topo II plays important roles in induction of the cwp genes, which is key to Giardia differentiation into cysts. Giardia lamblia becomes infective by differentiation into water-resistant cysts. During encystation, cyst wall proteins (CWPs) are highly synthesized and are targeted to the cyst wall. However, little is known about the regulation mechanisms of these genes. DNA topoisomerases can resolve the topological problems and are needed for a variety of key cellular functions, including cell proliferation, cell differentiation and organ development in higher eukaryotes. We found that giardial Topo II was highly expressed during encystation. Topo II is present in Giardia nuclei and is associated with the encystation-induced cwp gene promoters. Topo II has typical DNA cleavage activity of type II topoisomerases. Interestingly, overexpression of Topo II can induce cwp gene expression and cyst formation. Addition of a type II topoisomerase inhibitor, etoposide, significantly decreased the levels of cwp gene expression and cyst formation. Etoposide also has growth inhibition effect on Giardia. Our results suggest that Topo II plays an important role in induction of encystation by up-regulation of the cwp gene expression. Our results provide insights into the function of Topo II in parasite differentiation into cysts and help develop ways to interrupt the parasite life cycle.
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Possenti A, Fratini F, Fantozzi L, Pozio E, Dubey JP, Ponzi M, Pizzi E, Spano F. Global proteomic analysis of the oocyst/sporozoite of Toxoplasma gondii reveals commitment to a host-independent lifestyle. BMC Genomics 2013; 14:183. [PMID: 23496850 PMCID: PMC3616887 DOI: 10.1186/1471-2164-14-183] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 03/07/2013] [Indexed: 12/02/2022] Open
Abstract
Background Toxoplasmosis is caused by the apicomplexan parasite Toxoplasma gondii and can be acquired either congenitally or via the oral route. In the latter case, transmission is mediated by two distinct invasive stages, i.e., bradyzoites residing in tissue cysts or sporozoites contained in environmentally resistant oocysts shed by felids in their feces. The oocyst plays a central epidemiological role, yet this stage has been scarcely investigated at the molecular level and the knowledge of its expressed proteome is very limited. Results Using one-dimensional gel electrophoresis coupled to liquid chromatography-linked tandem mass spectrometry, we analysed total or fractionated protein extracts of partially sporulated T. gondii oocysts, producing a dataset of 1304 non reduntant proteins (~18% of the total predicted proteome), ~59% of which were classified according to the MIPS functional catalogue database. Notably, the comparison of the oocyst dataset with the extensively covered proteome of T. gondii tachyzoite, the invasive stage responsible for the clinical signs of toxoplasmosis, identified 154 putative oocyst/sporozoite-specific proteins, some of which were validated by Western blot. The analysis of this protein subset showed that, compared to tachyzoites, oocysts have a greater capability of de novo amino acid biosynthesis and are well equipped to fuel the Krebs cycle with the acetyl-CoA generated through fatty acid β-oxidation and the degradation of branched amino acids. Conclusions The study reported herein significantly expanded our knowledge of the proteome expressed by the oocyst/sporozoite of T. gondii, shedding light on a stage-specifc subset of proteins whose functional profile is consistent with the adaptation of T. gondii oocysts to the nutrient-poor and stressing extracellular environment.
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Affiliation(s)
- Alessia Possenti
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161, Italy
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Manzano-Román R, Siles-Lucas M. MicroRNAs in parasitic diseases: Potential for diagnosis and targeting. Mol Biochem Parasitol 2012; 186:81-6. [DOI: 10.1016/j.molbiopara.2012.10.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/01/2012] [Accepted: 10/05/2012] [Indexed: 12/12/2022]
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Falaleeva M, Stamm S. Processing of snoRNAs as a new source of regulatory non-coding RNAs: snoRNA fragments form a new class of functional RNAs. Bioessays 2012. [PMID: 23180440 DOI: 10.1002/bies.201200117] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recent experimental evidence suggests that most of the genome is transcribed into non-coding RNAs. The initial transcripts undergo further processing generating shorter, metabolically stable RNAs with diverse functions. Small nucleolar RNAs (snoRNAs) are non-coding RNAs that modify rRNAs, tRNAs, and snRNAs that were considered stable. We review evidence that snoRNAs undergo further processing. High-throughput sequencing and RNase protection experiments showed widespread expression of snoRNA fragments, known as snoRNA-derived RNAs (sdRNAs). Some sdRNAs resemble miRNAs, these can associate with argonaute proteins and influence translation. Other sdRNAs are longer, form complexes with hnRNPs and influence gene expression. C/D box snoRNA fragmentation patterns are conserved across multiple cell types, suggesting a processing event, rather than degradation. The loss of expression from genetic loci that generate canonical snoRNAs and processed snoRNAs results in diseases, such as Prader-Willi Syndrome, indicating possible physiological roles for processed snoRNAs. We propose that processed snoRNAs acquire new roles in gene expression and represent a new class of regulatory RNAs distinct from canonical snoRNAs.
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Affiliation(s)
- Marina Falaleeva
- Department of Molecular and Cellular Biochemistry, University of Kentucky, College of Medicine, Lexington, KY, USA
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25
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Saraiya AA, Li W, Wang CC. Multistage neoplastic transformation of Syrian hamster embryo cells cultured at pH 6.70. Cancer Res 1990; 8:e55672. [PMID: 23405193 PMCID: PMC3565978 DOI: 10.1371/journal.pone.0055672] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 12/29/2012] [Indexed: 12/26/2022]
Abstract
MicroRNAs are major post-transcriptional regulators of gene expression. Here we show in the ancient protozoan Giardia lamblia a snoRNA-derived 26-nucleotide microRNA, miR3, which represses the translation of histone H2A mRNA containing an imperfect target but enhances translation when the target is made fully complementary. A stepwise mutational analysis of the fully complementary target showed that the activating effect of miR3 was significantly reduced when a single nucleotide at the 5′-end of the target was altered. The effect of miR3 became repressive when 12 of the nucleotides lost their complementation to miR3 with maximum repression reached when only 8 base-pairs remained between the miR3 seed sequence and the target. A synthetic 8-nucleotide RNA oligomer of the miR3 seed sequence was found capable of exerting a similar Argonaute-dependent translational repression. This is the first report showing a correlation between the extent of base-pairing with the target and a change in miRNA function.
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Affiliation(s)
- Ashesh A. Saraiya
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
| | - Wei Li
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
| | - Ching C. Wang
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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