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AbuObead DA, Alhomsi TK, Zhra M, Alosaimi B, Hamza M, Awadalla M, Abdelhadi OE, Alsharif JA, Okdah L, AlKattan K, Turki SA, Fakhoury HMA, Aljada A. Development and Validation of ScriptTaq COVID PCR: An In-House Multiplex rRT-PCR for Low-Cost Detection. Curr Issues Mol Biol 2022; 44:6117-6131. [PMID: 36547078 PMCID: PMC9777119 DOI: 10.3390/cimb44120417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/06/2022] [Accepted: 12/02/2022] [Indexed: 12/09/2022] Open
Abstract
The COVID-19 pandemic necessitated an extensive testing for active SARS-CoV-2 infection. However, securing affordable diagnostic tests is a struggle for low-resource settings. We report herein the development and validation of an in-house multiplex real-time RT-PCR diagnostic test for the detection of active COVID-19 infection (ScriptTaq COVID PCR). Furthermore, we describe two methods for RNA extraction using either an in-house silica column or silica-coated magnetic beads to replace commercial RNA extraction kits. Different buffer formulations for silica column and silica-coated magnetic beads were tested and used for RNA isolation. Taq polymerase enzyme and thermostable reverse transcriptase enzyme were purified from bacterial clones. Primers/probes sequences published by the WHO and CDC were used for the qualitative detection of the RNA-dependent RNA polymerase (RdRp) and nucleocapsid (N) genes, respectively. ScriptTaq COVID PCR assay was able to detect up to 100 copies per reaction of the viral RdRP and N genes. The test demonstrated an overall agreement of 95.4%, a positive percent agreement (PPA) of 90.2%, and a negative percent agreement (NPA) of 100.0% when compared with two commercially available kits. ScriptTaq COVID PCR diagnostic test is a specific, sensitive, and low-cost alternative for low-resource settings.
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Affiliation(s)
| | | | - Mahmoud Zhra
- College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
| | - Bandar Alosaimi
- Research Center, King Fahad Medical City, Riyadh Second Health Cluster, Riyadh 11525, Saudi Arabia
| | - Muaawia Hamza
- Research Center, King Fahad Medical City, Riyadh Second Health Cluster, Riyadh 11525, Saudi Arabia
- Faculty of Medicine, King Fahad Medical City, Riyadh 11525, Saudi Arabia
| | - Maaweya Awadalla
- Research Center, King Fahad Medical City, Riyadh Second Health Cluster, Riyadh 11525, Saudi Arabia
| | | | | | - Liliane Okdah
- Infectious Disease Research Department, King Abdullah International Medical Research Center, Riyadh 11481, Saudi Arabia
| | - Khaled AlKattan
- College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
| | - Saeed Al Turki
- Anwa Medical Labs, King Saud University, Riyadh 11451, Saudi Arabia
| | - Hana M. A. Fakhoury
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
- Correspondence: (H.M.A.F.); (A.A.)
| | - Ahmad Aljada
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
- Correspondence: (H.M.A.F.); (A.A.)
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2
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Smardz P, Sieradzan AK, Krupa P. Mechanical Stability of Ribonuclease A Heavily Depends on the Redox Environment. J Phys Chem B 2022; 126:6240-6249. [PMID: 35975925 PMCID: PMC9421896 DOI: 10.1021/acs.jpcb.2c04718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Disulfide bonds are covalent bonds that connect nonlocal fragments of proteins, and they are unique post-translational modifications of proteins. They require the oxidizing environment to be stable, which occurs for example during oxidative stress; however, in a cell the reductive environment is maintained, lowering their stability. Despite many years of research on disulfide bonds, their role in the protein life cycle is not fully understood and seems to strictly depend on a system or process in which they are involved. In this article, coarse-grained UNited RESidue (UNRES), and all-atom Assisted Model Building with Energy Refinement (AMBER) force fields were applied to run a series of steered molecular dynamics (SMD) simulations of one of the most studied, but still not fully understood, proteins─ribonuclease A (RNase A). SMD simulations were performed to study the mechanical stability of RNase A in different oxidative-reductive environments. As disulfide bonds (and any other covalent bonds) cannot break/form in any classical all-atom force field, we applied additional restraints between sulfur atoms of reduced cysteines which were able to mimic the breaking of the disulfide bonds. On the other hand, the coarse-grained UNRES force field enables us to study the breaking/formation of the disulfide bonds and control the reducing/oxidizing environment owing to the presence of the designed distance/orientation-dependent potential. This study reveals that disulfide bonds have a strong influence on the mechanical stability of RNase A only in a highly oxidative environment. However, the local stability of the secondary structure seems to play a major factor in the overall stability of the protein. Both our thermal unfolding and mechanical stretching studies show that the most stable disulfide bond is Cys65-Cys72. The breaking of disulfide bonds Cys26-Cys84 and Cys58-Cys110 is associated with large force peaks. They are structural bridges, which are mostly responsible for stabilizing the RNase A conformation, while the presence of the remaining two bonds (Cys65-Cys72 and Cys40-Cys95) is most likely connected with the enzymatic activity rather than the structural stability of RNase A in the cytoplasm. Our results prove that disulfide bonds are indeed stabilizing fragments of the proteins, but their role is strongly redox environment-dependent.
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Affiliation(s)
- Pamela Smardz
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Adam K Sieradzan
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Paweł Krupa
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland
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Kashima M, Kamitani M, Nomura Y, Mori-Moriyama N, Betsuyaku S, Hirata H, Nagano AJ. DeLTa-Seq: direct-lysate targeted RNA-Seq from crude tissue lysate. PLANT METHODS 2022; 18:99. [PMID: 35933383 PMCID: PMC9356424 DOI: 10.1186/s13007-022-00930-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/24/2022] [Indexed: 06/09/2023]
Abstract
BACKGROUND Quantification of gene expression such as RNA-Seq is a popular approach to study various biological phenomena. Despite the development of RNA-Seq library preparation methods and sequencing platforms in the last decade, RNA extraction remains the most laborious and costly step in RNA-Seq of tissue samples of various organisms. Thus, it is still difficult to examine gene expression in thousands of samples. RESULTS Here, we developed Direct-RT buffer in which homogenization of tissue samples and direct-lysate reverse transcription can be conducted without RNA purification. The DTT concentration in Direct-RT buffer prevented RNA degradation but not RT in the lysates of several plant tissues, yeast, and zebrafish larvae. Direct reverse transcription on these lysates in Direct-RT buffer produced comparable amounts of cDNA to those synthesized from purified RNA. To maximize the advantage of the Direct-RT buffer, we integrated Direct-RT and targeted RNA-Seq to develop a cost-effective, high-throughput quantification method for the expressions of hundreds of genes: DeLTa-Seq (Direct-Lysate reverse transcription and Targeted RNA-Seq). The DeLTa-Seq method could drastically improve the efficiency and accuracy of gene expression analysis. DeLTa-Seq analysis of 1056 samples revealed the temperature-dependent effects of jasmonic acid and salicylic acid in Arabidopsis thaliana. CONCLUSIONS The DeLTa-Seq method can realize large-scale studies using thousands of animal, plant, and microorganism samples, such as chemical screening, field experiments, and studies focusing on individual variability. In addition, Direct-RT is also beneficial for gene expression analysis in small tissues from which it is difficult to purify enough RNA for the experiments.
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Affiliation(s)
- Makoto Kashima
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194 Japan
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Fuchinobe 5-10-1, Chuoku, , Sagamihara 252-5258 Japan
| | - Mari Kamitani
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194 Japan
- Center for Ecological Research, Kyoto University, Hirano 2-509-3, Otsu, Shiga 520-2113 Japan
| | - Yasuyuki Nomura
- Research Institute for Food and Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194 Japan
| | - Natsumi Mori-Moriyama
- Faculty of Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194 Japan
| | - Shigeyuki Betsuyaku
- Faculty of Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194 Japan
| | - Hiromi Hirata
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Fuchinobe 5-10-1, Chuoku, , Sagamihara 252-5258 Japan
| | - Atsushi J. Nagano
- Faculty of Agriculture, Ryukoku University, Yokotani 1-5, Seta Oe-cho, Otsu, Shiga 520-2194 Japan
- Institute for Advanced Biosciences, Keio University, 403-1 Nipponkoku, Daihouji, Tsuruoka, Yamagata 997-0017 Japan
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4
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Malcı K, Walls LE, Rios-Solis L. Rational Design of CRISPR/Cas12a-RPA Based One-Pot COVID-19 Detection with Design of Experiments. ACS Synth Biol 2022; 11:1555-1567. [PMID: 35363475 PMCID: PMC9016756 DOI: 10.1021/acssynbio.1c00617] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
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Simple
and effective molecular diagnostic methods have gained importance
due to the devastating effects of the COVID-19 pandemic. Various isothermal
one-pot COVID-19 detection methods have been proposed as favorable
alternatives to standard RT-qPCR methods as they do not require sophisticated
and/or expensive devices. However, as one-pot reactions are highly
complex with a large number of variables, determining the optimum
conditions to maximize sensitivity while minimizing diagnostic cost
can be cumbersome. Here, statistical design of experiments (DoE) was
employed to accelerate the development and optimization of a CRISPR/Cas12a-RPA-based
one-pot detection method for the first time. Using a definitive screening
design, factors with a significant effect on performance were elucidated
and optimized, facilitating the detection of two copies/μL of
full-length SARS-CoV-2 (COVID-19) genome using simple instrumentation.
The screening revealed that the addition of a reverse transcription
buffer and an RNase inhibitor, components generally omitted in one-pot
reactions, improved performance significantly, and optimization of
reverse transcription had a critical impact on the method’s
sensitivity. This strategic method was also applied in a second approach
involving a DNA sequence of the N gene from the COVID-19 genome. The
slight differences in optimal conditions for the methods using RNA
and DNA templates highlight the importance of reaction-specific optimization
in ensuring robust and efficient diagnostic performance. The proposed
detection method is automation-compatible, rendering it suitable for
high-throughput testing. This study demonstrated the benefits of DoE
for the optimization of complex one-pot molecular diagnostics methods
to increase detection sensitivity.
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Affiliation(s)
- Koray Malcı
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Kings Buildings, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology (SynthSys), University of Edinburgh, Kings Buildings, Edinburgh EH9 3BD, United Kingdom
| | - Laura E. Walls
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Kings Buildings, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology (SynthSys), University of Edinburgh, Kings Buildings, Edinburgh EH9 3BD, United Kingdom
| | - Leonardo Rios-Solis
- Institute for Bioengineering, School of Engineering, University of Edinburgh, Kings Buildings, Edinburgh EH9 3BF, United Kingdom
- Centre for Synthetic and Systems Biology (SynthSys), University of Edinburgh, Kings Buildings, Edinburgh EH9 3BD, United Kingdom
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
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Kumar GNM, Kannangara CG, Knowles NR. Nucleases are upregulated in potato tubers afflicted with zebra chip disease. PLANTA 2022; 255:54. [PMID: 35103848 DOI: 10.1007/s00425-022-03832-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 01/18/2022] [Indexed: 06/14/2023]
Abstract
The defense response of potato tubers afflicted with zebra chip disease involves oxidatively mediated upregulation of nucleases that likely modulate localized programmed cell death to restrict the phloem-mobile, CLso bacterial pathogen to the vasculature. Zebra chip (ZC) is a bacterial disease of potato (Solanum tuberosum L.) caused by Candidatus Liberibacter solanacearum (CLso). Tubers from infected plants develop characteristic brown discoloration of the vasculature, a result of localized programmed cell death (PCD). We examined the potential contribution of nucleases in the response of tubers to CLso infection. Specific activities of the major isozymes of dsDNase, ssDNase, and RNase were substantially upregulated in tubers from CLso-infected plants, despite their significantly lower soluble protein content. However, ZC disease had no effect on nuclease isozyme profiles. Activities of the predominant nuclease isoforms from healthy and CLso-infected tubers had similar pH optima, thermotolerance, and responses to metallic co-factors. Nuclease activities were heat stable to 60 °C and resistant to precipitation with 70% (v/v) isopropanol, which constitute effective techniques for partial purification. DNase and RNase isozyme activities were highest at pH 7.2-8.5 and 6.8-7.2, respectively, and profiles were similar for tubers from CLso-infected and non-infected plants. RNase activities were mostly insensitive to inhibition by EDTA, except at pH 8.5 and above. DNase activities were inhibited by EDTA but less sensitive to inhibition at high pH than the RNases. The EDTA-mediated inhibition of DNase (ds/ss) activities was restored with ZnSO4, but not Ca+2 or Mg+2. By contrast, ZnSO4 inhibited the activities of RNases. DTT and CuSO4 inhibited the activities of all three nucleases. These results suggest that activation of tuber nucleases is dependent on the oxidation of sulfhydryl groups to disulfide and/or oxidation of Zn to Zn+2. In light of previous published results that established extensive CLso-induced upregulation of oxidative stress metabolism in tubers, we propose a model to show how increased nuclease activity could result from a glutathione-mediated oxidation of nuclease sulfhydryl groups in diseased tubers. DNases and RNases are likely an integral part of the hypersensitive response and may modulate PCD to isolate the pathogen to the vascular tissues of tubers.
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Affiliation(s)
- G N Mohan Kumar
- Department of Horticulture, Washington State University, Pullman, WA, 99163, USA.
| | - C G Kannangara
- Department of Crop and Soils, Washington State University, Pullman, WA, 99163, USA
- , 335/4A, 2nd Cross Street, Kotte Road, Nugegoda, Sri Lanka
| | - N Richard Knowles
- Department of Horticulture, Washington State University, Pullman, WA, 99163, USA
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RABL6A Promotes Pancreatic Neuroendocrine Tumor Angiogenesis and Progression In Vivo. Biomedicines 2021; 9:biomedicines9060633. [PMID: 34199469 PMCID: PMC8228095 DOI: 10.3390/biomedicines9060633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/26/2021] [Accepted: 05/28/2021] [Indexed: 02/06/2023] Open
Abstract
Pancreatic neuroendocrine tumors (pNETs) are difficult-to-treat neoplasms whose incidence is rising. Greater understanding of pNET pathogenesis is needed to identify new biomarkers and targets for improved therapy. RABL6A, a novel oncogenic GTPase, is highly expressed in patient pNETs and required for pNET cell proliferation and survival in vitro. Here, we investigated the role of RABL6A in pNET progression in vivo using a well-established model of the disease. RIP-Tag2 (RT2) mice develop functional pNETs (insulinomas) due to SV40 large T-antigen expression in pancreatic islet β cells. RABL6A loss in RT2 mice significantly delayed pancreatic tumor formation, reduced tumor angiogenesis and mitoses, and extended survival. Those effects correlated with upregulation of anti-angiogenic p19ARF and downregulation of proangiogenic c-Myc in RABL6A-deficient islets and tumors. Our findings demonstrate that RABL6A is a bona fide oncogenic driver of pNET angiogenesis and development in vivo.
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7
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Bender AT, Sullivan BP, Lillis L, Posner JD. Enzymatic and Chemical-Based Methods to Inactivate Endogenous Blood Ribonucleases for Nucleic Acid Diagnostics. J Mol Diagn 2020; 22:1030-1040. [PMID: 32450280 DOI: 10.1016/j.jmoldx.2020.04.211] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/20/2020] [Accepted: 04/28/2020] [Indexed: 01/28/2023] Open
Abstract
There are ongoing research efforts into simple and low-cost point-of-care nucleic acid amplification tests (NATs) addressing widespread diagnostic needs in resource-limited clinical settings. Nucleic acid testing for RNA targets in blood specimens typically requires sample preparation that inactivates robust blood ribonucleases (RNases) that can rapidly degrade exogenous RNA. Most NATs rely on decades-old methods that lyse pathogens and inactivate RNases with high concentrations of guanidinium salts. Herein, we investigate alternatives to standard guanidinium-based methods for RNase inactivation using an activity assay with an RNA substrate that fluoresces when cleaved. The effects of proteinase K, nonionic surfactants, SDS, dithiothreitol, and other additives on RNase activity in human serum are reported. Although proteinase K has been widely used in protocols for nuclease inactivation, it was found that high concentrations of proteinase K are unable to eliminate RNase activity in serum, unless used in concert with denaturing concentrations of SDS. It was observed that SDS must be combined with proteinase K, dithiothreitol, or both for irreversible and complete RNase inactivation in serum. This work provides an alternative chemistry for inactivating endogenous RNases for use in simple, low-cost point-of-care NATs for blood-borne pathogens.
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Affiliation(s)
- Andrew T Bender
- Department of Mechanical Engineering, University of Washington, Seattle, Washington
| | - Benjamin P Sullivan
- Department of Mechanical Engineering, University of Washington, Seattle, Washington
| | | | - Jonathan D Posner
- Department of Mechanical Engineering, University of Washington, Seattle, Washington; Department of Chemical Engineering, University of Washington, Seattle, Washington; Department of Family Medicine, University of Washington, Seattle, Washington.
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8
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Multiple Patterns of Regulation and Overexpression of a Ribonuclease-Like Pathogenesis-Related Protein Gene, OsPR10a, Conferring Disease Resistance in Rice and Arabidopsis. PLoS One 2016; 11:e0156414. [PMID: 27258121 PMCID: PMC4892481 DOI: 10.1371/journal.pone.0156414] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 05/13/2016] [Indexed: 12/13/2022] Open
Abstract
An abundant 17 kDa RNase, encoded by OsPR10a (also known as PBZ1), was purified from Pi-starved rice suspension-cultured cells. Biochemical analysis showed that the range of optimal temperature for its RNase activity was 40–70°C and the optimum pH was 5.0. Disulfide bond formation and divalent metal ion Mg2+ were required for the RNase activity. The expression of OsPR10a::GUS in transgenic rice was induced upon phosphate (Pi) starvation, wounding, infection by the pathogen Xanthomonas oryzae pv. oryzae (Xoo), leaf senescence, anther, style, the style-ovary junction, germinating embryo and shoot. We also provide first evidence in whole-plant system, demonstrated that OsPR10a-overexpressing in rice and Arabidopsis conferred significant level of enhanced resistance to infection by the pathogen Xoo and Xanthomona campestris pv. campestris (Xcc), respectively. Transgenic rice and Arabidopsis overexpressing OsPR10a significantly increased the length of primary root under phosphate deficiency (-Pi) condition. These results showed that OsPR10a might play multiple roles in phosphate recycling in phosphate-starved cells and senescing leaves, and could improve resistance to pathogen infection and/or against chewing insect pests. It is possible that Pi acquisition or homeostasis is associated with plant disease resistance. Our findings suggest that gene regulation of OsPR10a could act as a good model system to unravel the mechanisms behind the correlation between Pi starvation and plant-pathogen interactions, and also provides a potential application in crops disease resistance.
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9
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Groher F, Suess B. In vitro selection of antibiotic-binding aptamers. Methods 2016; 106:42-50. [PMID: 27223401 DOI: 10.1016/j.ymeth.2016.05.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/10/2016] [Accepted: 05/15/2016] [Indexed: 01/06/2023] Open
Abstract
Despite its wide applicability the selection of small molecule-binding RNA aptamers with high affinity binding and specificity is still challenging. We will present here a protocol which allows the in vitro selection of antibiotic-binding aptamers which turned out to be important building blocks for the design process of synthetic riboswitches. The presented methods will be compared with alternative in vitro selection protocols. A detailed note section will point out useful tips and pitfalls.
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Affiliation(s)
- Florian Groher
- Department of Biology, Technical University Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technical University Darmstadt, Schnittspahnstr. 10, 64287 Darmstadt, Germany.
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10
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Simultaneous isolation of mRNA and native protein from minute samples of cells. Biotechniques 2014; 56:229-37. [PMID: 24806223 DOI: 10.2144/000114165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 03/04/2014] [Indexed: 11/23/2022] Open
Abstract
Precious biological samples often lack a sufficient number of cells for multiple procedures, such as extraction of mRNA while maintaining protein in a non-denatured state suitable for subsequent characterization. Here we present a new method for the simultaneous purification of mRNA and native proteins from samples containing small numbers of cells. Our approach utilizes oligodeoxythymidylate [oligo(dT)25]-coated paramagnetic beads in an optimized reaction buffer to isolate mRNA comparable in quantity and quality to mRNA isolated with existing methods, while maintaining the proteins in their native state for traditional protein assays. We validated the procedure using neonatal rat ovaries and small numbers of human granulosa cells, demonstrating the extraction of mRNA suitable for gene expression analysis with simultaneous isolation of native proteins suitable for downstream characterization using different protein assays.
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11
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Kiritsi MN, Fragoulis EG, Sideris DC. Essential cysteine residues for human RNase κ catalytic activity. FEBS J 2012; 279:1318-26. [DOI: 10.1111/j.1742-4658.2012.08526.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Redox and heavy metal effects on the biochemical activities of an Arabidopsis polyadenylation factor subunit. Arch Biochem Biophys 2008; 473:88-95. [PMID: 18331819 DOI: 10.1016/j.abb.2008.02.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 02/08/2008] [Accepted: 02/16/2008] [Indexed: 11/20/2022]
Abstract
The Arabidopsis CPSF30 ortholog (AtCPSF30) is an RNA-binding endonuclease that is part of the plant polyadenylation complex. Previous work (B. Addepalli, A.G. Hunt, Nucleic Acids Res. 35 (2007) 4453-4463) demonstrated that different zinc finger motifs in the protein were responsible for RNA-binding and nuclease activity, respectively. In this study, a more detailed functional map of AtCPSF30 is presented, a map that includes descriptions of novel biochemical activities. Elevated temperatures, the specific zinc chelator 1,10-phenanthroline, and the sulfhydryl reagent dithiothreitol all had differential inhibitory effects on the RNA-binding and nuclease activities. The endonuclease activity of AtCPSF30 was inhibited by relatively high (>100muM) concentrations of zinc, and this inhibition required a plant-specific N-terminal domain apart from the zinc finger core of the protein. ATP stimulated the nuclease activity in the presence of zinc, and this stimulation required a plant-specific C-terminal domain, again apart from the zinc finger core. These studies reveal a subtle and unexpected complexity to AtCPSF30, and raise the possibility that multiple avenues of regulation may impinge on this protein through different functional domains.
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13
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Kim ST, Yu S, Kang YH, Kim SG, Kim JY, Kim SH, Kang KY. The rice pathogen-related protein 10 (JIOsPR10) is induced by abiotic and biotic stresses and exhibits ribonuclease activity. PLANT CELL REPORTS 2008; 27:593-603. [PMID: 18074138 DOI: 10.1007/s00299-007-0485-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 10/16/2007] [Accepted: 11/15/2007] [Indexed: 05/20/2023]
Abstract
We previously reported that rice blast fungus or jasmonic acid induced the expression of rice pathogenesis-related class 10 (JIOsPR10) proteins (Kim et al. 2003, 2004). However, no further studies have been carried out to examine the expression, localization, and enzymatic activity of this protein in either developmental tissues or in tissues under abiotic stress conditions. In this study, rice JIOsPR10 was examined by Western blot analysis, immunolocalization, and biochemical assays. Western blots revealed that the JIOsPR10 protein was expressed in developmental tissues, including in flower and root. The protein was also expressed under abiotic stresses, such as occurs during senescence and wounding. Using immunohistochemical techniques, we determined that expression of JIOsPR10 was localized to the palea of flower, in the exodermis, and inner part of the endodermis of the root. In senescencing tissues of leaf and coleoptiles, its expression was localized in vascular bundles. The RNase activity using JIOsPR10 recombinant protein was determined and abolished after treatment with DTT in a native in-gel assay. To test this, we created JIOsPR10 mutant proteins containing serine substitutions of amino acids C81S, C83S, or both and examined their RNase activities. The activity of the C83S mutant was decreased in the agarose gel assay compared to the wild type. Taken together, we hypothesize that the JIOsPR10 protein possesses RNase activity that is sensitive to DTT, suggesting the importance of the disulfide bonding between cysteine residues and that it might play a role in constitutive self-defense mechanisms in plants against biotic and abiotic stresses.
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Affiliation(s)
- Sun Tae Kim
- Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju, Korea
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14
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Sabar M, Balk J, Leaver CJ. Histochemical staining and quantification of plant mitochondrial respiratory chain complexes using blue-native polyacrylamide gel electrophoresis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 44:893-901. [PMID: 16297078 DOI: 10.1111/j.1365-313x.2005.02577.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Our knowledge of the respiratory chain and associated defects depends on the study of the multisubunit protein complexes in the inner mitochondrial membrane. Functional analysis of the plant mitochondrial respiratory chain has been successfully achieved by a combination of blue-native polyacrylamide gel electrophoresis (BN-PAGE) for separation of the protein complexes, and in-gel histochemical staining of the enzyme activities. We have optimized this powerful technique by determining linear ranges of amount of protein and enzyme activity for each respiratory complex. Time courses of the in-gel enzyme activities were also performed to determine optimal reaction times. Using the in-gel activity staining method we have previously shown decreased activity of complex V (F(1)F(0)-ATPase) in male-sterile sunflowers (Sabar et al., 2003). Here we have identified unique supercomplexes comprising complex IV (cytochrome c oxidase) in sunflower mitochondria. This method therefore represents a reliable tool for the diagnosis of respiratory dysfunction. In addition, the wider application of BN-PAGE in combination with enzyme activity staining is discussed.
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