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Kipkorir T, Polgar P, Barker D, D’Halluin A, Patel Z, Arnvig K. A novel regulatory interplay between atypical B12 riboswitches and uORF translation in Mycobacterium tuberculosis. Nucleic Acids Res 2024; 52:7876-7892. [PMID: 38709884 PMCID: PMC11260477 DOI: 10.1093/nar/gkae338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 04/10/2024] [Accepted: 04/17/2024] [Indexed: 05/08/2024] Open
Abstract
Vitamin B12 is an essential cofactor in all domains of life and B12-sensing riboswitches are some of the most widely distributed riboswitches. Mycobacterium tuberculosis, the causative agent of tuberculosis, harbours two B12-sensing riboswitches. One controls expression of metE, encoding a B12-independent methionine synthase, the other controls expression of ppe2 of uncertain function. Here, we analysed ligand sensing, secondary structure and gene expression control of the metE and ppe2 riboswitches. Our results provide the first evidence of B12 binding by these riboswitches and show that they exhibit different preferences for individual isoforms of B12, use distinct regulatory and structural elements and act as translational OFF switches. Based on our results, we propose that the ppe2 switch represents a new variant of Class IIb B12-sensing riboswitches. Moreover, we have identified short translated open reading frames (uORFs) upstream of metE and ppe2, which modulate the expression of their downstream genes. Translation of the metE uORF suppresses MetE expression, while translation of the ppe2 uORF is essential for PPE2 expression. Our findings reveal an unexpected regulatory interplay between B12-sensing riboswitches and the translational machinery, highlighting a new level of cis-regulatory complexity in M. tuberculosis. Attention to such mechanisms will be critical in designing next-level intervention strategies.
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Affiliation(s)
- Terry Kipkorir
- Institute for Structural and Molecular Biology, University College London, Gower Street, WC1E 6BT London, UK
| | - Peter Polgar
- Institute for Structural and Molecular Biology, University College London, Gower Street, WC1E 6BT London, UK
| | - Declan Barker
- Institute for Structural and Molecular Biology, University College London, Gower Street, WC1E 6BT London, UK
| | - Alexandre D’Halluin
- Institute for Structural and Molecular Biology, University College London, Gower Street, WC1E 6BT London, UK
| | - Zaynah Patel
- Institute for Structural and Molecular Biology, University College London, Gower Street, WC1E 6BT London, UK
| | - Kristine B Arnvig
- Institute for Structural and Molecular Biology, University College London, Gower Street, WC1E 6BT London, UK
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2
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Singh RN, Sani RK. Genome-Wide Computational Prediction and Analysis of Noncoding RNAs in Oleidesulfovibrio alaskensis G20. Microorganisms 2024; 12:960. [PMID: 38792789 PMCID: PMC11124144 DOI: 10.3390/microorganisms12050960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/03/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Noncoding RNAs (ncRNAs) play key roles in the regulation of important pathways, including cellular growth, stress management, signaling, and biofilm formation. Sulfate-reducing bacteria (SRB) contribute to huge economic losses causing microbial-induced corrosion through biofilms on metal surfaces. To effectively combat the challenges posed by SRB, it is essential to understand their molecular mechanisms of biofilm formation. This study aimed to identify ncRNAs in the genome of a model SRB, Oleidesulfovibrio alaskensis G20 (OA G20). Three in silico approaches revealed genome-wide distribution of 37 ncRNAs excluding tRNAs in the OA G20. These ncRNAs belonged to 18 different Rfam families. This study identified riboswitches, sRNAs, RNP, and SRP. The analysis revealed that these ncRNAs could play key roles in the regulation of several pathways of biosynthesis and transport involved in biofilm formation by OA G20. Three sRNAs, Pseudomonas P10, Hammerhead type II, and sX4, which were found in OA G20, are rare and their roles have not been determined in SRB. These results suggest that applying various computational methods could enrich the results and lead to the discovery of additional novel ncRNAs, which could lead to understanding the "rules of life of OA G20" during biofilm formation.
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Affiliation(s)
- Ram Nageena Singh
- Department of Chemical and Biological Engineering, South Dakota Mines, Rapid City, SD 57701, USA;
- 2-Dimensional Materials for Biofilm Engineering, Science and Technology, South Dakota Mines, Rapid City, SD 57701, USA
| | - Rajesh K. Sani
- Department of Chemical and Biological Engineering, South Dakota Mines, Rapid City, SD 57701, USA;
- 2-Dimensional Materials for Biofilm Engineering, Science and Technology, South Dakota Mines, Rapid City, SD 57701, USA
- Data Driven Material Discovery Center for Bioengineering Innovation, South Dakota Mines, Rapid City, SD 57701, USA
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3
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Wu Y, Zhu L, Zhang Y, Xu W. Multidimensional Applications and Challenges of Riboswitches in Biosensing and Biotherapy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2304852. [PMID: 37658499 DOI: 10.1002/smll.202304852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/15/2023] [Indexed: 09/03/2023]
Abstract
Riboswitches have received significant attention over the last two decades for their multiple functionalities and great potential for applications in various fields. This article highlights and reviews the recent advances in biosensing and biotherapy. These fields involve a wide range of applications, such as food safety detection, environmental monitoring, metabolic engineering, live cell imaging, wearable biosensors, antibacterial drug targets, and gene therapy. The discovery, origin, and optimization of riboswitches are summarized to help readers better understand their multidimensional applications. Finally, this review discusses the multidimensional challenges and development of riboswitches in order to further expand their potential for novel applications.
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Affiliation(s)
- Yifan Wu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Longjiao Zhu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Yangzi Zhang
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Wentao Xu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
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Wu Y, Zhu L, Li S, Chu H, Wang X, Xu W. High content design of riboswitch biosensors: All-around rational module-by-module design. Biosens Bioelectron 2022; 220:114887. [DOI: 10.1016/j.bios.2022.114887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/27/2022] [Accepted: 11/03/2022] [Indexed: 11/11/2022]
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5
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Chee WKD, Yeoh JW, Dao VL, Poh CL. Thermogenetics: Applications come of age. Biotechnol Adv 2022; 55:107907. [PMID: 35041863 DOI: 10.1016/j.biotechadv.2022.107907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/13/2021] [Accepted: 01/09/2022] [Indexed: 12/20/2022]
Abstract
Temperature is a ubiquitous physical cue that is non-invasive, penetrative and easy to apply. In the growing field of thermogenetics, through beneficial repurposing of natural thermosensing mechanisms, synthetic biology is bringing new opportunities to design and build robust temperature-sensitive (TS) sensors which forms a thermogenetic toolbox of well characterised biological parts. Recent advancements in technological platforms available have expedited the discovery of novel or de novo thermosensors which are increasingly deployed in many practical temperature-dependent biomedical, industrial and biosafety applications. In all, the review aims to convey both the exhilarating recent technological developments underlying the advancement of thermosensors and the exciting opportunities the nascent thermogenetic field holds for biomedical and biotechnology applications.
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Affiliation(s)
- Wai Kit David Chee
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Jing Wui Yeoh
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Viet Linh Dao
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Chueh Loo Poh
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
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6
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Timsit Y, Grégoire SP. Towards the Idea of Molecular Brains. Int J Mol Sci 2021; 22:ijms222111868. [PMID: 34769300 PMCID: PMC8584932 DOI: 10.3390/ijms222111868] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/24/2021] [Accepted: 10/28/2021] [Indexed: 02/06/2023] Open
Abstract
How can single cells without nervous systems perform complex behaviours such as habituation, associative learning and decision making, which are considered the hallmark of animals with a brain? Are there molecular systems that underlie cognitive properties equivalent to those of the brain? This review follows the development of the idea of molecular brains from Darwin’s “root brain hypothesis”, through bacterial chemotaxis, to the recent discovery of neuron-like r-protein networks in the ribosome. By combining a structural biology view with a Bayesian brain approach, this review explores the evolutionary labyrinth of information processing systems across scales. Ribosomal protein networks open a window into what were probably the earliest signalling systems to emerge before the radiation of the three kingdoms. While ribosomal networks are characterised by long-lasting interactions between their protein nodes, cell signalling networks are essentially based on transient interactions. As a corollary, while signals propagated in persistent networks may be ephemeral, networks whose interactions are transient constrain signals diffusing into the cytoplasm to be durable in time, such as post-translational modifications of proteins or second messenger synthesis. The duration and nature of the signals, in turn, implies different mechanisms for the integration of multiple signals and decision making. Evolution then reinvented networks with persistent interactions with the development of nervous systems in metazoans. Ribosomal protein networks and simple nervous systems display architectural and functional analogies whose comparison could suggest scale invariance in information processing. At the molecular level, the significant complexification of eukaryotic ribosomal protein networks is associated with a burst in the acquisition of new conserved aromatic amino acids. Knowing that aromatic residues play a critical role in allosteric receptors and channels, this observation suggests a general role of π systems and their interactions with charged amino acids in multiple signal integration and information processing. We think that these findings may provide the molecular basis for designing future computers with organic processors.
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Affiliation(s)
- Youri Timsit
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO UM110, 13288 Marseille, France
- Research Federation for the Study of Global Ocean Systems Ecology and Evolution, FR2022/Tara GOSEE, 3 rue Michel-Ange, 75016 Paris, France
- Correspondence:
| | - Sergeant-Perthuis Grégoire
- Institut de Mathématiques de Jussieu—Paris Rive Gauche (IMJ-PRG), UMR 7586, CNRS-Université Paris Diderot, 75013 Paris, France;
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Chan CW, Mondragón A. Crystal structure of an atypical cobalamin riboswitch reveals RNA structural adaptability as basis for promiscuous ligand binding. Nucleic Acids Res 2020; 48:7569-7583. [PMID: 32544228 PMCID: PMC7367189 DOI: 10.1093/nar/gkaa507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/15/2020] [Accepted: 06/11/2020] [Indexed: 11/25/2022] Open
Abstract
Cobalamin riboswitches encompass a structurally diverse group of cis-acting, gene regulatory elements found mostly in bacterial messenger RNA and are classified into subtypes based on secondary and tertiary characteristics. An unusual variant of the cobalamin riboswitch with predicted structural features was identified in Bacillus subtilis over a decade ago, but its structure and mechanisms of cobalamin selectivity and translational control have remained unsolved. We present the crystal structure of the aptamer domain of this atypical cobalamin riboswitch and a model for the complete riboswitch, including its expression platform domain. We demonstrate that this riboswitch binds to multiple cobalamin derivatives and correlate its promiscuous behavior to its structure and unique arrangement of peripheral elements. Comparative structural analyses between conventional cobalamin riboswitches and the B. subtilis cobalamin riboswitch reveal that the likely basis for this promiscuous ligand binding is intrinsic structural adaptability encoded in the RNA structure. It suggests that cobalamin selectivity might ultimately be viewed as existing on a spectrum of affinity for each derivative rather than as belonging to distinct types based on ligand specificities. Our work provides an interesting and notable example of functional coupling of ligand-sensing and adaptive folding by a structured RNA molecule.
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Affiliation(s)
- Clarence W Chan
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Drive, Evanston, IL 60208-3500, USA
| | - Alfonso Mondragón
- Department of Molecular Biosciences, Northwestern University, 2205 Tech Drive, Evanston, IL 60208-3500, USA
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8
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Antunes D, Jorge NAN, Caffarena ER, Passetti F. Using RNA Sequence and Structure for the Prediction of Riboswitch Aptamer: A Comprehensive Review of Available Software and Tools. Front Genet 2018; 8:231. [PMID: 29403526 PMCID: PMC5780412 DOI: 10.3389/fgene.2017.00231] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/21/2017] [Indexed: 12/14/2022] Open
Abstract
RNA molecules are essential players in many fundamental biological processes. Prokaryotes and eukaryotes have distinct RNA classes with specific structural features and functional roles. Computational prediction of protein structures is a research field in which high confidence three-dimensional protein models can be proposed based on the sequence alignment between target and templates. However, to date, only a few approaches have been developed for the computational prediction of RNA structures. Similar to proteins, RNA structures may be altered due to the interaction with various ligands, including proteins, other RNAs, and metabolites. A riboswitch is a molecular mechanism, found in the three kingdoms of life, in which the RNA structure is modified by the binding of a metabolite. It can regulate multiple gene expression mechanisms, such as transcription, translation initiation, and mRNA splicing and processing. Due to their nature, these entities also act on the regulation of gene expression and detection of small metabolites and have the potential to helping in the discovery of new classes of antimicrobial agents. In this review, we describe software and web servers currently available for riboswitch aptamer identification and secondary and tertiary structure prediction, including applications.
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Affiliation(s)
- Deborah Antunes
- Scientific Computing Program (PROCC), Computational Biophysics and Molecular Modeling Group, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Natasha A N Jorge
- Laboratory of Functional Genomics and Bioinformatics, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Laboratory of Gene Expression Regulation, Carlos Chagas Institute, Fundação Oswaldo Cruz, Curitiba, Brazil
| | - Ernesto R Caffarena
- Scientific Computing Program (PROCC), Computational Biophysics and Molecular Modeling Group, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Fabio Passetti
- Laboratory of Functional Genomics and Bioinformatics, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.,Laboratory of Gene Expression Regulation, Carlos Chagas Institute, Fundação Oswaldo Cruz, Curitiba, Brazil
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9
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Lukoszek R, Feist P, Ignatova Z. Insights into the adaptive response of Arabidopsis thaliana to prolonged thermal stress by ribosomal profiling and RNA-Seq. BMC PLANT BIOLOGY 2016; 16:221. [PMID: 27724872 PMCID: PMC5057212 DOI: 10.1186/s12870-016-0915-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 10/05/2016] [Indexed: 05/19/2023]
Abstract
BACKGROUND Environmental stress puts organisms at risk and requires specific stress-tailored responses to maximize survival. Long-term exposure to stress necessitates a global reprogramming of the cellular activities at different levels of gene expression. RESULTS Here, we use ribosome profiling and RNA sequencing to globally profile the adaptive response of Arabidopsis thaliana to prolonged heat stress. To adapt to long heat exposure, the expression of many genes is modulated in a coordinated manner at a transcriptional and translational level. However, a significant group of genes opposes this trend and shows mainly translational regulation. Different secondary structure elements are likely candidates to play a role in regulating translation of those genes. CONCLUSIONS Our data also uncover on how the subunit stoichiometry of multimeric protein complexes in plastids is maintained upon heat exposure.
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Affiliation(s)
- Radoslaw Lukoszek
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Present Address: Division of Plant Sciences/Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH UK
| | - Peter Feist
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Zoya Ignatova
- Biochemistry, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
- Biochemistry and Molecular Biology, Department of Chemistry, University of Hamburg, Hamburg, Germany
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10
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Kim D, Thairu MW, Hansen AK. Novel Insights into Insect-Microbe Interactions-Role of Epigenomics and Small RNAs. FRONTIERS IN PLANT SCIENCE 2016; 7:1164. [PMID: 27540386 PMCID: PMC4972996 DOI: 10.3389/fpls.2016.01164] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 07/20/2016] [Indexed: 05/23/2023]
Abstract
It has become increasingly clear that microbes form close associations with the vast majority of animal species, especially insects. In fact, an array of diverse microbes is known to form shared metabolic pathways with their insect hosts. A growing area of research in insect-microbe interactions, notably for hemipteran insects and their mutualistic symbionts, is to elucidate the regulation of this inter-domain metabolism. This review examines two new emerging mechanisms of gene regulation and their importance in host-microbe interactions. Specifically, we highlight how the incipient areas of research on regulatory "dark matter" such as epigenomics and small RNAs, can play a pivotal role in the evolution of both insect and microbe gene regulation. We then propose specific models of how these dynamic forms of gene regulation can influence insect-symbiont-plant interactions. Future studies in this area of research will give us a systematic understanding of how these symbiotic microbes and animals reciprocally respond to and regulate their shared metabolic processes.
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11
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Fürtig B, Reining A, Sochor F, Oberhauser EM, Heckel A, Schwalbe H. Characterization of conformational dynamics of bistable RNA by equilibrium and non-equilibrium NMR. CURRENT PROTOCOLS IN NUCLEIC ACID CHEMISTRY 2014; 55:11.13.1-16. [PMID: 25631532 DOI: 10.1002/0471142700.nc1113s55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Unlike proteins, a given RNA sequence can adopt more than a single conformation. The two (or more) conformations are long-lived and have similar stabilities, but interconvert only slowly. Such bi- or multistability is often linked to the biological functions of the RNA. This unit describes how nuclear magnetic resonance (NMR) spectroscopy can be used to characterize the conformational dynamics of bistable RNAs.
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Affiliation(s)
- Boris Fürtig
- Institute of Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe University, Frankfurt, Germany; Institute of Organic Chemistry and Chemical Biology, Cluster of Excellence Macromolecular Complexes, Johann Wolfgang Goethe University, Frankfurt, Germany
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12
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González-Calvo L, Joy M, Alberti C, Ripoll G, Molino F, Serrano M, Calvo JH. Effect of finishing period length with α-tocopherol supplementation on the expression of vitamin E-related genes in the muscle and subcutaneous fat of light lambs. Gene 2014; 552:225-33. [PMID: 25241385 DOI: 10.1016/j.gene.2014.09.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 07/11/2014] [Accepted: 09/17/2014] [Indexed: 01/19/2023]
Abstract
The aim of this study was to investigate how different finishing period lengths with α-tocopherol supplementation or alfalfa grazing affect mRNA expression levels of genes related to vitamin E metabolism in L. thoracis (LT) muscle and subcutaneous fat (SF) from lambs of the Rasa Aragonesa breed. Indoors, concentrate-fed light lambs (n=48) were supplemented with 500 dl-α-tocopheryl acetate/kg concentrate for an average finishing period length of 0 (C), 10.7 (VE10d), 21.2 (VE20d) and, 32.3 (VE30d) days before slaughtering. Simultaneously, 8 lambs with their dams were alfalfa-grazed. The α-tocopherol affected in a short-term the expression of genes in LT muscle (ABCA1, LPL, APOE, and SREBP1) and SF (ABCA1, SCARB1, LPL, and PPARG). On the contrary, PPARA gene expression showed a long-term α-tocopherol effect because the highest levels of PPARA mRNA were found in the VE30d.
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Affiliation(s)
- L González-Calvo
- Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Unidad de Tecnología en Producción Animal, Avda. Montañana, 930, 50059 Zaragoza, Spain
| | - M Joy
- Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Unidad de Tecnología en Producción Animal, Avda. Montañana, 930, 50059 Zaragoza, Spain
| | - C Alberti
- Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Unidad de Tecnología en Producción Animal, Avda. Montañana, 930, 50059 Zaragoza, Spain
| | - G Ripoll
- Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Unidad de Tecnología en Producción Animal, Avda. Montañana, 930, 50059 Zaragoza, Spain
| | - F Molino
- Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Unidad de Tecnología en Producción Animal, Avda. Montañana, 930, 50059 Zaragoza, Spain
| | - M Serrano
- Departamento de Mejora Genética animal, INIA, 28040 Madrid, Spain
| | - J H Calvo
- Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Unidad de Tecnología en Producción Animal, Avda. Montañana, 930, 50059 Zaragoza, Spain; ARAID, C/ María de Luna, n° 11, 1ª planta, Edificio CEEI Aragón, 50018 Zaragoza, Spain.
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13
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Chandrasekaran NC, Weir C, Alfraji S, Grice J, Roberts MS, Barnard RT. Effects of magnesium deficiency--more than skin deep. Exp Biol Med (Maywood) 2014; 239:1280-91. [PMID: 24928863 DOI: 10.1177/1535370214537745] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Dead Sea and magnesium salt therapy are two of the oldest forms of treatment for skin disease and several other disorders, supported by a body of largely anecdotal evidence. In this paper we review possible pathways for penetration of magnesium ions through the epidermis to reach the circulation, in turn replenishing cellular magnesium levels. We also discuss mechanisms for intercellular movement of magnesium ions and possible mechanisms for the interaction between magnesium ions and inflammatory mediators. Upon addition of magnesium ions in vitro, the expression of inflammatory mediators such as tumour necrosis factor α (TNFα) and nuclear factor κβ (NFκβ) is down regulated. Dysregulation of these and other inflammatory mediators has been linked to several inflammatory disorders, including asthma, arthritis, atherosclerosis and neuroinflammation.
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Affiliation(s)
- Navin Chandrakanth Chandrasekaran
- School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, Queensland 4072, Australia School of Medicine, Translational Research Institute, The University of Queensland, Wooloongabba, Queensland 4102, Australia
| | - Christopher Weir
- Walter and Eliza Hall Institute of Medical Research and Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Sumaya Alfraji
- School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, Queensland 4072, Australia
| | - Jeff Grice
- School of Medicine, Translational Research Institute, The University of Queensland, Wooloongabba, Queensland 4102, Australia
| | - Michael S Roberts
- School of Medicine, Translational Research Institute, The University of Queensland, Wooloongabba, Queensland 4102, Australia
| | - Ross T Barnard
- School of Chemistry and Molecular Biosciences, Australian Infectious Diseases Research Centre, The University of Queensland, Queensland 4072, Australia
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14
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Dinan AM, Loftus BJ. (Non-)translational medicine: targeting bacterial RNA. Front Genet 2013; 4:230. [PMID: 24265632 PMCID: PMC3821060 DOI: 10.3389/fgene.2013.00230] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 10/18/2013] [Indexed: 11/26/2022] Open
Abstract
The rise and spread of antibiotic resistance is among the most severe challenges facing modern medicine. Despite this fact, attempts to develop novel classes of antibiotic have been largely unsuccessful. The traditional mechanisms by which antibiotics work are subject to relatively rapid bacterial resistance via mutation, and hence have a limited period of efficacy. One promising strategy to ameliorate this problem is to shift from the use of chemical compounds targeting protein structures and processes to a new era of RNA-based therapeutics. RNA-mediated regulation (riboregulation) has evolved naturally in bacteria and is therefore a highly efficient means by which gene expression can be manipulated. Here, we describe recent advances toward the development of effective anti-bacterial therapies, which operate through various strategies centered on RNA.
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Affiliation(s)
- Adam M Dinan
- School of Medicine and Medical Science, Conway Institute of Biomolecular and Biomedical Research, University College Dublin Dublin, Ireland
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15
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NMR spectroscopy on domain dynamics in biomacromolecules. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2013; 112:58-117. [DOI: 10.1016/j.pbiomolbio.2013.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 12/22/2022]
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16
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Vandivier LE, Li F, Zheng Q, Willmann MR, Chen Y, Gregory BD. Arabidopsis mRNA secondary structure correlates with protein function and domains. PLANT SIGNALING & BEHAVIOR 2013; 8:e24301. [PMID: 23603972 PMCID: PMC3908981 DOI: 10.4161/psb.24301] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Accepted: 03/14/2013] [Indexed: 05/19/2023]
Abstract
RNAs fold into intricate structures that are determined by specific base pairing interactions encoded within their primary sequences. Recently, a number of transcriptome-wide studies have suggested that RNA secondary structure is a potent cis-acting regulator of numerous post-transcriptional processes in viruses and eukaryotes. However, the need for experimentally-based structure determination methods has not been well addressed. Here, we show that the regulatory significance of Arabidopsis RNA secondary structure is revealed specifically through high-throughput, sequencing-based, structure mapping data, not by computational prediction. Additionally, we find that transcripts with similar levels of secondary structure in their UTRs (5' or 3') or CDS tend to encode proteins with coherent functions. Finally, we reveal that portions of mRNAs encoding predicted protein domains are significantly more structured than those specifying inter-domain regions. In total, our findings show the utility of high-throughput, sequencing-based, structure-mapping approaches and suggest that mRNA folding regulates protein maturation and function.
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Affiliation(s)
- Lee E. Vandivier
- Department of Biology; PENN Genome Frontiers Institute; University of Pennsylvania; Philadelphia, PA USA
- Cell and Molecular Biology Graduate Program; University of Pennsylvania; Philadelphia, PA USA
| | - Fan Li
- Department of Biology; PENN Genome Frontiers Institute; University of Pennsylvania; Philadelphia, PA USA
- Genomics and Computational Biology Graduate Program; University of Pennsylvania; Philadelphia, PA USA
| | - Qi Zheng
- Department of Biology; PENN Genome Frontiers Institute; University of Pennsylvania; Philadelphia, PA USA
| | - Matthew R. Willmann
- Department of Biology; PENN Genome Frontiers Institute; University of Pennsylvania; Philadelphia, PA USA
| | - Ying Chen
- Department of Biology; PENN Genome Frontiers Institute; University of Pennsylvania; Philadelphia, PA USA
- Genomics and Computational Biology Graduate Program; University of Pennsylvania; Philadelphia, PA USA
| | - Brian D. Gregory
- Department of Biology; PENN Genome Frontiers Institute; University of Pennsylvania; Philadelphia, PA USA
- Cell and Molecular Biology Graduate Program; University of Pennsylvania; Philadelphia, PA USA
- Genomics and Computational Biology Graduate Program; University of Pennsylvania; Philadelphia, PA USA
- Correspondence to: Brian D. Gregory,
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Kritsky MS, Telegina TA, Vechtomova YL, Buglak AA. Why flavins are not competitors of chlorophyll in the evolution of biological converters of solar energy. Int J Mol Sci 2012; 14:575-93. [PMID: 23271372 PMCID: PMC3565283 DOI: 10.3390/ijms14010575] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 12/10/2012] [Accepted: 12/13/2012] [Indexed: 12/17/2022] Open
Abstract
Excited flavin molecules can photocatalyze reactions, leading to the accumulation of free energy in the products, and the data accumulated through biochemical experiments and by modeling prebiological processes suggest that flavins were available in the earliest stages of evolution. Furthermore, model experiments have shown that abiogenic flavin conjugated with a polyamino acid matrix, a pigment that photocatalyzes the phosphorylation of ADP to form ATP, could have been present in the prebiotic environment. Indeed, excited flavin molecules play key roles in many photoenzymes and regulatory photoreceptors, and the substantial structural differences between photoreceptor families indicate that evolution has repeatedly used flavins as chromophores for photoreceptor proteins. Some of these photoreceptors are equipped with a light-harvesting antenna, which transfers excitation energy to chemically reactive flavins in the reaction center. The sum of the available data suggests that evolution could have led to the formation of a flavin-based biological converter to convert light energy into energy in the form of ATP.
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Affiliation(s)
- Mikhail S. Kritsky
- A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, House 33, Building 2, Leninsky Prospekt, Moscow 119071, Russia; E-Mails: (T.A.T.); (Y.L.V.); (A.A.B.)
| | - Taisiya A. Telegina
- A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, House 33, Building 2, Leninsky Prospekt, Moscow 119071, Russia; E-Mails: (T.A.T.); (Y.L.V.); (A.A.B.)
| | - Yulia L. Vechtomova
- A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, House 33, Building 2, Leninsky Prospekt, Moscow 119071, Russia; E-Mails: (T.A.T.); (Y.L.V.); (A.A.B.)
| | - Andrey A. Buglak
- A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, House 33, Building 2, Leninsky Prospekt, Moscow 119071, Russia; E-Mails: (T.A.T.); (Y.L.V.); (A.A.B.)
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18
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Bateman A, Agrawal S, Birney E, Bruford EA, Bujnicki JM, Cochrane G, Cole JR, Dinger ME, Enright AJ, Gardner PP, Gautheret D, Griffiths-Jones S, Harrow J, Herrero J, Holmes IH, Huang HD, Kelly KA, Kersey P, Kozomara A, Lowe TM, Marz M, Moxon S, Pruitt KD, Samuelsson T, Stadler PF, Vilella AJ, Vogel JH, Williams KP, Wright MW, Zwieb C. RNAcentral: A vision for an international database of RNA sequences. RNA (NEW YORK, N.Y.) 2011; 17:1941-6. [PMID: 21940779 PMCID: PMC3198587 DOI: 10.1261/rna.2750811] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
During the last decade there has been a great increase in the number of noncoding RNA genes identified, including new classes such as microRNAs and piRNAs. There is also a large growth in the amount of experimental characterization of these RNA components. Despite this growth in information, it is still difficult for researchers to access RNA data, because key data resources for noncoding RNAs have not yet been created. The most pressing omission is the lack of a comprehensive RNA sequence database, much like UniProt, which provides a comprehensive set of protein knowledge. In this article we propose the creation of a new open public resource that we term RNAcentral, which will contain a comprehensive collection of RNA sequences and fill an important gap in the provision of biomedical databases. We envision RNA researchers from all over the world joining a federated RNAcentral network, contributing specialized knowledge and databases. RNAcentral would centralize key data that are currently held across a variety of databases, allowing researchers instant access to a single, unified resource. This resource would facilitate the next generation of RNA research and help drive further discoveries, including those that improve food production and human and animal health. We encourage additional RNA database resources and research groups to join this effort. We aim to obtain international network funding to further this endeavor.
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Affiliation(s)
- Alex Bateman
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SA, United Kingdom
- Corresponding author.E-mail .
| | - Shipra Agrawal
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bangalore 560 100, India
- BioCOS Life Sciences Private Limited, Bangalore 560 100, India
| | - Ewan Birney
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, United Kingdom
| | - Elspeth A. Bruford
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, United Kingdom
| | - Janusz M. Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Trojdena 4, 02-109 Warsaw, Poland
- Laboratory of Bioinformatics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Umultowska 89, 61-614 Poznan, Poland
| | - Guy Cochrane
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, United Kingdom
| | - James R. Cole
- Microbial Ecology Center, Michigan State University, East Lansing, Michigan 48824-1319, USA
| | - Marcel E. Dinger
- Institute for Molecular Bioscience, The University of Queensland, St Lucia QLD 4072, Australia
| | - Anton J. Enright
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, United Kingdom
| | - Paul P. Gardner
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SA, United Kingdom
| | - Daniel Gautheret
- Institut de Génétique et Microbiologie–UMR CNRS 8621, Université Paris-Sud–Bâtiment 400, 91405 Orsay Cedex, France
| | - Sam Griffiths-Jones
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester, M13 9PT, United Kingdom
| | - Jen Harrow
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SA, United Kingdom
| | - Javier Herrero
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, United Kingdom
| | - Ian H. Holmes
- Department of Bioengineering, University of California, Berkeley, California 94720-1762, USA
| | - Hsien-Da Huang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, HsinChu, 30050, Taiwan
| | - Krystyna A. Kelly
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
| | - Paul Kersey
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, United Kingdom
| | - Ana Kozomara
- Faculty of Life Sciences, University of Manchester, Michael Smith Building, Manchester, M13 9PT, United Kingdom
| | - Todd M. Lowe
- Department of Biomolecular Engineering, University of California, Santa Cruz, California 95064, USA
| | - Manja Marz
- RNA Bioinformatics Group, Institute of Pharmaceutical Chemistry, Marbacher Weg 6, 35037 Marburg, Germany
| | - Simon Moxon
- University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - Kim D. Pruitt
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland 20894, USA
| | - Tore Samuelsson
- Department of Medical Biochemistry, University of Goteborg, Medicinareg. 9A, S-405 30 Goteborg, Sweden
| | - Peter F. Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, 04009 Leipzig, Germany
| | - Albert J. Vilella
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, United Kingdom
| | - Jan-Hinnerk Vogel
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SA, United Kingdom
| | - Kelly P. Williams
- Sandia National Laboratories, MS 9291, Livermore, California 94551-0969, USA
| | - Mathew W. Wright
- European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, CB10 1SD, United Kingdom
| | - Christian Zwieb
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3901, USA
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Ham YW, Humphreys DJ, Choi S, Dayton DL. Rational design of SAM analogues targeting SAM-II riboswitch aptamer. Bioorg Med Chem Lett 2011; 21:5071-4. [DOI: 10.1016/j.bmcl.2011.04.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 03/31/2011] [Accepted: 04/07/2011] [Indexed: 12/23/2022]
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Bardaro MF, Varani G. Examining the relationship between RNA function and motion using nuclear magnetic resonance. WILEY INTERDISCIPLINARY REVIEWS-RNA 2011; 3:122-32. [PMID: 22180312 DOI: 10.1002/wrna.108] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The biological function of proteins and nucleic acids relies on their complex structures, yet dynamics provides an additional layer of functional adaptability. Numerous studies have demonstrated that RNA is only able to perform the multitude of functions for which it is responsible by readily changing its conformation in response to binding of proteins or small molecules. Examination of RNA dynamics is therefore essential to understanding its biological function. Nuclear magnetic resonance (NMR) has emerged as a leading technique for the examination of RNA motion and conformational transitions. It can examine domain motions as well as motion with atomic level resolution over a wide range of time scales. This review examines how NMR spectroscopy can be applied to examine the relationship between function and dynamics in RNA.
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Abstract
LOV (light, oxygen or voltage) domains are protein photosensors that are conserved in bacteria, archaea, plants and fungi, and detect blue light via a flavin cofactor. LOV domains are present in both chemotrophic and phototrophic bacterial species, in which they are found amino-terminally of signalling and regulatory domains such as sensor histidine kinases, diguanylate cyclases-phosphodiesterases, DNA-binding domains and regulators of RNA polymerase σ-factors. In this Review, we describe the current state of knowledge about the function of bacterial LOV proteins, the structural basis of LOV domain-mediated signal transduction, and the use of LOV domains as genetically encoded photoswitches in synthetic biology.
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22
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Carrasco MA, Tan JC, Duman JG. A cross-species compendium of proteins/gene products related to cold stress identified by bioinformatic approaches. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:1127-1135. [PMID: 21565197 DOI: 10.1016/j.jinsphys.2011.04.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2011] [Revised: 04/26/2011] [Accepted: 04/27/2011] [Indexed: 05/30/2023]
Abstract
The purpose of this investigation was to construct a compendium of low temperature responsive proteins/gene products across species as identified by bioinformatics based approaches, thus allowing low temperature researchers a searchable database. Another purpose was to identify specific low temperature responsive proteins/gene products across at least two different species. We generated a database containing 2030 low temperature responsive protein/gene product entries, of which 1353 were up-regulated and 549 were down-regulated in response to various cold exposures across 34 different species; including bacteria (9 species), yeast (1 species), animals (including nematodes (1 species), collembola (2 species), insects (5 species), fish (1 species), amphibians (1 species), reptiles (1 species), mammals (2 species)), and plants (moss (1 species), gymnosperms (1 species) and angiosperms (9 species)). There were 39 studies using 12 different cold treatments; 20 used proteomics and 18 used transcriptomics. Concerning our purpose of identifying specific temperature responsive proteins/gene products across species, we found 113 shared proteins/gene products groups, each of which was found in at least two species. Of these shared proteins/gene products groups, 58 proteins/gene products (including protein/gene product families) that were consistently regulated, meaning always either up- or down-regulated, across species. Another 23 proteins/gene products were inconsistently regulated, meaning that the proteins/gene products were up-regulated in some species and treatments while being down-regulated in other species and treatments. An additional 32 proteins/gene products that are part of larger family headings and are difficult to separate from related member proteins (such the ribosomal proteins, 30S, 50S, and others) were inconsistently regulated. This work is an attempt to create a centralized database and repository for low temperature responsive proteins/gene products in all species.
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Affiliation(s)
- Martin A Carrasco
- University of Notre Dame, Galvin Life Sciences, Notre Dame, IN 46556, USA.
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23
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Krivoruchko A, Siewers V, Nielsen J. Opportunities for yeast metabolic engineering: Lessons from synthetic biology. Biotechnol J 2011; 6:262-76. [DOI: 10.1002/biot.201000308] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Revised: 01/06/2011] [Accepted: 01/13/2011] [Indexed: 11/08/2022]
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24
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Shu W, Liu M, Chen H, Bo X, Wang S. ARDesigner: A web-based system for allosteric RNA design. J Biotechnol 2010; 150:466-73. [DOI: 10.1016/j.jbiotec.2010.10.067] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 10/11/2010] [Accepted: 10/12/2010] [Indexed: 12/19/2022]
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25
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Kritsky MS, Telegina TA, Vechtomova YL, Kolesnikov MP, Lyudnikova TA, Golub OA. Excited flavin and pterin coenzyme molecules in evolution. BIOCHEMISTRY (MOSCOW) 2010; 75:1200-16. [DOI: 10.1134/s0006297910100020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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26
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How do bacteria sense and respond to low temperature? Arch Microbiol 2010; 192:85-95. [DOI: 10.1007/s00203-009-0539-y] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 11/19/2009] [Accepted: 12/21/2009] [Indexed: 11/30/2022]
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A combinatorial interplay among the 1-aminocyclopropane-1-carboxylate isoforms regulates ethylene biosynthesis in Arabidopsis thaliana. Genetics 2009; 183:979-1003. [PMID: 19752216 DOI: 10.1534/genetics.109.107102] [Citation(s) in RCA: 212] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Ethylene (C(2)H(4)) is a unique plant-signaling molecule that regulates numerous developmental processes. The key enzyme in the two-step biosynthetic pathway of ethylene is 1-aminocyclopropane-1-carboxylate synthase (ACS), which catalyzes the conversion of S-adenosylmethionine (AdoMet) to ACC, the precursor of ethylene. To understand the function of this important enzyme, we analyzed the entire family of nine ACS isoforms (ACS1, ACS2, ACS4-9, and ACS11) encoded in the Arabidopsis genome. Our analysis reveals that members of this protein family share an essential function, because individual ACS genes are not essential for Arabidopsis viability, whereas elimination of the entire gene family results in embryonic lethality. Phenotypic characterization of single and multiple mutants unmasks unique but overlapping functions of the various ACS members in plant developmental events, including multiple growth characteristics, flowering time, response to gravity, disease resistance, and ethylene production. Ethylene acts as a repressor of flowering by regulating the transcription of the FLOWERING LOCUS C. Each single and high order mutant has a characteristic molecular phenotype with unique and overlapping gene expression patterns. The expression of several genes involved in light perception and signaling is altered in the high order mutants. These results, together with the in planta ACS interaction map, suggest that ethylene-mediated processes are orchestrated by a combinatorial interplay among ACS isoforms that determines the relative ratio of homo- and heterodimers (active or inactive) in a spatial and temporal manner. These subunit isoforms comprise a combinatorial code that is a central regulator of ethylene production during plant development. The lethality of the null ACS mutant contrasts with the viability of null mutations in key components of the ethylene signaling apparatus, strongly supporting the view that ACC, the precursor of ethylene, is a primary regulator of plant growth and development.
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Win MN, Liang JC, Smolke CD. Frameworks for programming biological function through RNA parts and devices. ACTA ACUST UNITED AC 2009; 16:298-310. [PMID: 19318211 DOI: 10.1016/j.chembiol.2009.02.011] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 02/09/2009] [Accepted: 02/24/2009] [Indexed: 12/30/2022]
Abstract
One of the long-term goals of synthetic biology is to reliably engineer biological systems that perform human-defined functions. Currently, researchers face several scientific and technical challenges in designing and building biological systems, one of which is associated with our limited ability to access, transmit, and control molecular information through the design of functional biomolecules exhibiting novel properties. The fields of RNA biology and nucleic acid engineering, along with the tremendous interdisciplinary growth of synthetic biology, are fueling advances in the emerging field of RNA programming in living systems. Researchers are designing functional RNA molecules that exhibit increasingly complex functions and integrating these molecules into cellular circuits to program higher-level biological functions. The continued integration and growth of RNA design and synthetic biology presents exciting potential to transform how we interact with and program biology.
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Affiliation(s)
- Maung Nyan Win
- Division of Chemistry and Chemical Engineering, 1200 E. California Boulevard, MC 210-41, California Institute of Technology, Pasadena, CA 91125, USA
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29
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Blouin S, Mulhbacher J, Penedo JC, Lafontaine DA. Riboswitches: ancient and promising genetic regulators. Chembiochem 2009; 10:400-16. [PMID: 19101979 DOI: 10.1002/cbic.200800593] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BAIT AND SWITCH: Metabolite-sensing riboswitches make use of RNA structural modulation to regulate gene expression, as illustrated in the scheme, in response to subtle changes in metabolite concentrations. This review describes the current knowledge about naturally occurring riboswitches and their growing potential as antibacterial cellular targets and as molecular biosensors. Newly discovered metabolite-sensing riboswitches have revealed that cellular processes extensively make use of RNA structural modulation to regulate gene expression in response to subtle changes in metabolite concentrations. Riboswitches are involved at various regulation levels of gene expression, such as transcription attenuation, translation initiation, mRNA splicing and mRNA processing. Riboswitches are found in the three kingdoms of life, and in various cases, are involved in the regulation of essential genes, which makes their regulation an essential part of cell survival. Because riboswitches operate without the assistance of accessory proteins, they are believed to be remnants of an ancient time, when gene regulation was strictly based on RNA, from which are left numerous "living molecular fossils", as exemplified by ribozymes, and more spectacularly, by the ribosome. Due to their nature, riboswitches hold high expectations for the manipulation of gene expression and the detection of small metabolites, and also offer an unprecedented potential for the discovery of novel classes of antimicrobial agents.
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Affiliation(s)
- Simon Blouin
- Département de biologie, Université de Sherbrooke, Sherbrooke, Canada
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Abstract
Thiamine (vitamin B(1)) is an essential compound for organisms. It contains a pyrimidine ring structure and a thiazole ring structure. These two moieties of thiamine are synthesized independently and then coupled together. Here we report the molecular characterization of AtTHIC, which is involved in thiamine biosynthesis in Arabidopsis. AtTHIC is similar to Escherichia coli ThiC, which is involved in pyrimidine biosynthesis in prokaryotes. Heterologous expression of AtTHIC could functionally complement the thiC knock-out mutant of E. coli. Downregulation of AtTHIC expression by T-DNA insertion at its promoter region resulted in a drastic reduction of thiamine content in plants and the knock-down mutant thic1 showed albino (white leaves) and lethal phenotypes under the normal culture conditions. The thic1 mutant could be rescued by supplementation of thiamine and its defect functions could be complemented by expression of AtTHIC cDNA. Transient expression analysis revealed that the AtTHIC protein targets plastids and chloroplasts. AtTHIC was strongly expressed in leaves, flowers and siliques and the transcription of AtTHIC was downregulated by extrinsic thiamine. In conclusion, AtTHIC is a gene involved in pyrimidine synthesis in the thiamine biosynthesis pathway of Arabidopsis, and our results provide some new clues for elucidating the pathway of thiamine biosynthesis in plants.
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The genes and enzymes involved in the biosynthesis of thiamin and thiamin diphosphate in yeasts. Cell Mol Biol Lett 2008; 13:271-82. [PMID: 18161008 PMCID: PMC6275658 DOI: 10.2478/s11658-007-0055-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 10/03/2007] [Indexed: 11/20/2022] Open
Abstract
Thiamin (vitamin B1) is an essential molecule for all living organisms. Its major biologically active derivative is thiamin diphosphate, which serves as a cofactor for several enzymes involved in carbohydrate and amino acid metabolism. Important new functions for thiamin and its phosphate esters have recently been suggested, e.g. in gene expression regulation by influencing mRNA structure, in DNA repair after UV illumination, and in the protection of some organelles against reactive oxygen species. Unlike higher animals, which rely on nutritional thiamin intake, yeasts can synthesize thiamin de novo. The biosynthesis pathways include the separate synthesis of two precursors, 4-amino-5-hydroxymethyl-2-methylpyrimidine diphosphate and 5-(2-hydroxyethyl)-4-methylthiazole phosphate, which are then condensed into thiamin monophosphate. Additionally, yeasts evolved salvage mechanisms to utilize thiamin and its dephosphorylated late precursors, 4-amino-5-hydroxymethyl-2-methylpyrimidine and 5-(2-hydroxyethyl)-4-methylthiazole, from the environment. The current state of knowledge on the discrete steps of thiamin biosynthesis in yeasts is far from satisfactory; many intermediates are postulated only by analogy to the much better understood biosynthesis process in bacteria. On the other hand, the genetic mechanisms regulating thiamin biosynthesis in yeasts are currently under extensive exploration. Only recently, the structures of some of the yeast enzymes involved in thiamin biosynthesis, such as thiamin diphosphokinase and thiazole synthase, were determined at the atomic resolution, and mechanistic proposals for the catalysis of particular biosynthetic steps started to emerge.
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Kulbachinskiy AV. Methods for selection of aptamers to protein targets. BIOCHEMISTRY (MOSCOW) 2008; 72:1505-18. [PMID: 18282139 DOI: 10.1134/s000629790713007x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Aptamers are synthetic single-stranded RNA or DNA molecules capable of specific binding to other target molecules. In this review, the main aptamer properties are considered and methods for selection of aptamers against various protein targets are described. Special attention is given to the methods for directed selection of aptamers, which allow one to obtain ligands with specified properties.
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Affiliation(s)
- A V Kulbachinskiy
- Institute of Molecular Genetics, Russian Academy of Sciences, pl. Kurchatova 2, 123182 Moscow, Russia.
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33
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Win MN, Smolke CD. RNA as a versatile and powerful platform for engineering genetic regulatory tools. Biotechnol Genet Eng Rev 2008; 24:311-46. [PMID: 18059640 DOI: 10.1080/02648725.2007.10648106] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Maung Nyan Win
- Department of Chemical Engineering, MC 210-41, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125, USA
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34
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Ruiz-Roldán C, Puerto-Galán L, Roa J, Castro A, Di Pietro A, Roncero MIG, Hera C. The Fusarium oxysporum sti35 gene functions in thiamine biosynthesis and oxidative stress response. Fungal Genet Biol 2008; 45:6-16. [DOI: 10.1016/j.fgb.2007.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 06/27/2007] [Accepted: 09/12/2007] [Indexed: 01/07/2023]
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35
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Natural variability in S-adenosylmethionine (SAM)-dependent riboswitches: S-box elements in bacillus subtilis exhibit differential sensitivity to SAM In vivo and in vitro. J Bacteriol 2007; 190:823-33. [PMID: 18039762 DOI: 10.1128/jb.01034-07] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Riboswitches are regulatory systems in which changes in structural elements in the 5' region of the nascent RNA transcript (the "leader region") control expression of the downstream coding sequence in response to a regulatory signal in the absence of a trans-acting protein factor. The S-box riboswitch, found primarily in low-G+C gram-positive bacteria, is the paradigm for riboswitches that sense S-adenosylmethionine (SAM). Genes in the S-box family are involved in methionine metabolism, and their expression is induced in response to starvation for methionine. S-box genes exhibit conserved primary sequence and secondary structural elements in their leader regions. We previously demonstrated that SAM binds directly to S-box leader RNA, causing a structural rearrangement that results in premature termination of transcription at S-box leader region terminators. S-box genes have a variety of physiological roles, and natural variability in S-box structure and regulatory response could provide additional insight into the role of conserved S-box leader elements in SAM-directed transcription termination. In the current study, in vivo and in vitro assays were employed to analyze the differential regulation of S-box genes in response to SAM. A wide range of responses to SAM were observed for the 11 S-box-regulated transcriptional units in Bacillus subtilis, demonstrating that S-box riboswitches can be calibrated to different physiological requirements.
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Blouin S, Lafontaine DA. A loop loop interaction and a K-turn motif located in the lysine aptamer domain are important for the riboswitch gene regulation control. RNA (NEW YORK, N.Y.) 2007; 13:1256-67. [PMID: 17585050 PMCID: PMC1924893 DOI: 10.1261/rna.560307] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The lysine riboswitch is associated to the lysC gene in Bacillus subtilis, and the binding of lysine modulates the RNA structure to allow the formation of an intrinsic terminator presumably involved in transcription attenuation. The complex secondary structure of the lysine riboswitch aptamer is organized around a five-way junction that undergoes structural changes upon ligand binding. Using single-round transcription assays, we show that a loop-loop interaction is important for lysine-induced termination of transcription. Moreover, upon close inspection of the secondary structure, we find that an unconventional kink-turn motif is present in one of the stems participating in the loop-loop interaction. We show that the K-turn adopts a pronounced kink and that it binds the K-turn-binding protein L7Ae of Archaeoglobus fulgidus in the low nanomolar range. The functional importance of this K-turn motif is revealed from single-round transcription assays, which show its importance for efficient transcription termination. This motif is essential for the loop-loop interaction, and consequently, for lysine binding. Taken together, our results depict for the first time the importance of a K-turn-dependent loop-loop interaction for the transcription regulation of a lysine riboswitch.
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Affiliation(s)
- Simon Blouin
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada
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Hayden CA, Jorgensen RA. Identification of novel conserved peptide uORF homology groups in Arabidopsis and rice reveals ancient eukaryotic origin of select groups and preferential association with transcription factor-encoding genes. BMC Biol 2007; 5:32. [PMID: 17663791 PMCID: PMC2075485 DOI: 10.1186/1741-7007-5-32] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Accepted: 07/30/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Upstream open reading frames (uORFs) can mediate translational control over the largest, or major ORF (mORF) in response to starvation, polyamine concentrations, and sucrose concentrations. One plant uORF with conserved peptide sequences has been shown to exert this control in an amino acid sequence-dependent manner but generally it is not clear what kinds of genes are regulated, or how extensively this mechanism is invoked in a given genome. RESULTS By comparing full-length cDNA sequences from Arabidopsis and rice we identified 26 distinct homology groups of conserved peptide uORFs, only three of which have been reported previously. Pairwise Ka/Ks analysis showed that purifying selection had acted on nearly all conserved peptide uORFs and their associated mORFs. Functions of predicted mORF proteins could be inferred for 16 homology groups and many of these proteins appear to have a regulatory function, including 6 transcription factors, 5 signal transduction factors, 3 developmental signal molecules, a homolog of translation initiation factor eIF5, and a RING finger protein. Transcription factors are clearly overrepresented in this data set when compared to the frequency calculated for the entire genome (p = 1.2 x 10(-7)). Duplicate gene pairs arising from a whole genome duplication (ohnologs) with a conserved uORF are much more likely to have been retained in Arabidopsis (Arabidopsis thaliana) than are ohnologs of other genes (39% vs 14% of ancestral genes, p = 5 x 10(-3)). Two uORF groups were found in animals, indicating an ancient origin of these putative regulatory elements. CONCLUSION Conservation of uORF amino acid sequence, association with homologous mORFs over long evolutionary time periods, preferential retention after whole genome duplications, and preferential association with mORFs coding for transcription factors suggest that the conserved peptide uORFs identified in this study are strong candidates for translational controllers of regulatory genes.
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Affiliation(s)
- Celine A Hayden
- Department of Plant Sciences, University of Arizona, Tucson, AZ 85721-0036, USA
| | - Richard A Jorgensen
- Department of Plant Sciences, University of Arizona, Tucson, AZ 85721-0036, USA
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Ng Kwang Loong S, Mishra SK. Unique folding of precursor microRNAs: quantitative evidence and implications for de novo identification. RNA (NEW YORK, N.Y.) 2007; 13:170-87. [PMID: 17194722 PMCID: PMC1781370 DOI: 10.1261/rna.223807] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
MicroRNAs (miRNAs) participate in diverse cellular and physiological processes through the post-transcriptional gene regulatory pathway. Hairpin is a crucial structural feature for the computational identification of precursor miRNAs (pre-miRs), as its formation is critically associated with the early stages of the mature miRNA biogenesis. Our incomplete knowledge about the number of miRNAs present in the genomes of vertebrates, worms, plants, and even viruses necessitates thorough understanding of their sequence motifs, hairpin structural characteristics, and topological descriptors. In this in-depth study, we investigate a comprehensive and heterogeneous collection of 2241 published (nonredundant) pre-miRs across 41 species (miRBase 8.2), 8494 pseudohairpins extracted from the human RefSeq genes, 12,387 (nonredundant) ncRNAs spanning 457 types (Rfam 7.0), 31 full-length mRNAs randomly selected from GenBank, and four sets of synthetically generated genomic background corresponding to each of the native RNA sequence. Our large-scale characterization analysis reveals that pre-miRs are significantly different from other types of ncRNAs, pseudohairpins, mRNAs, and genomic background according to the nonparametric Kruskal-Wallis ANOVA (p<0.001). We examine the intrinsic and global features at the sequence, structural, and topological levels including %G+C content, normalized base-pairing propensity P(S), normalized minimum free energy of folding MFE(s), normalized Shannon entropy Q(s), normalized base-pair distance D(s), and degree of compactness F(S), as well as their corresponding Z scores of P(S), MFE(s), Q(s), D(s), and F(S). The findings will promote more accurate guidelines and distinctive criteria for the prediction of novel pre-miRs with improved performance.
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Anwar M, Nguyen T, Turcotte M. Identification of consensus RNA secondary structures using suffix arrays. BMC Bioinformatics 2006; 7:244. [PMID: 16677380 PMCID: PMC1475642 DOI: 10.1186/1471-2105-7-244] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2005] [Accepted: 05/05/2006] [Indexed: 11/16/2022] Open
Abstract
Background The identification of a consensus RNA motif often consists in finding a conserved secondary structure with minimum free energy in an ensemble of aligned sequences. However, an alignment is often difficult to obtain without prior structural information. Thus the need for tools to automate this process. Results We present an algorithm called Seed to identify all the conserved RNA secondary structure motifs in a set of unaligned sequences. The search space is defined as the set of all the secondary structure motifs inducible from a seed sequence. A general-to-specific search allows finding all the motifs that are conserved. Suffix arrays are used to enumerate efficiently all the biological palindromes as well as for the matching of RNA secondary structure expressions. We assessed the ability of this approach to uncover known structures using four datasets. The enumeration of the motifs relies only on the secondary structure definition and conservation only, therefore allowing for the independent evaluation of scoring schemes. Twelve simple objective functions based on free energy were evaluated for their potential to discriminate native folds from the rest. Conclusion Our evaluation shows that 1) support and exclusion constraints are sufficient to make an exhaustive search of the secondary structure space feasible. 2) The search space induced from a seed sequence contains known motifs. 3) Simple objective functions, consisting of a combination of the free energy of matching sequences, can generally identify motifs with high positive predictive value and sensitivity to known motifs.
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Affiliation(s)
- Mohammad Anwar
- School of Information Technology and Engineering, University of Ottawa, Ottawa, Ontario, Canada
| | - Truong Nguyen
- School of Information Technology and Engineering, University of Ottawa, Ottawa, Ontario, Canada
| | - Marcel Turcotte
- School of Information Technology and Engineering, University of Ottawa, Ottawa, Ontario, Canada
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Banaszynski LA, Wandless TJ. Conditional control of protein function. ACTA ACUST UNITED AC 2006; 13:11-21. [PMID: 16426967 DOI: 10.1016/j.chembiol.2005.10.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2005] [Revised: 10/24/2005] [Accepted: 10/24/2005] [Indexed: 11/22/2022]
Abstract
Deciphering the myriad ways in which proteins interact with each other to give rise to complex behaviors that define living systems is a significant challenge. Using perturbations of DNA, genetic analyses have provided many insights into the functions of proteins encoded by specific genes. However, it can be difficult to study essential genes using these approaches, and many biological processes occur on a fast timescale that precludes study using genetic methods. For these reasons and others, it is often desirable to target proteins directly rather than the genes that encode them. Over the past 20 years, several methods to regulate protein function have been developed. In this review, we discuss the genesis and use of these methods, with particular emphasis on the elements of specificity, speed, and reversibility.
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Abstract
Temperature is an important parameter that free-living cells monitor constantly. The expression of heat-shock, cold-shock and some virulence genes is coordinated in response to temperature changes. Apart from protein-mediated transcriptional control mechanisms, translational control by RNA thermometers is a widely used regulatory strategy. RNA thermometers are complex RNA structures that change their conformation in response to temperature. Most, but not all, RNA thermometers are located in the 5'-untranslated region and mask ribosome-binding sites by base pairing at low temperatures. Melting of the structure at increasing temperature permits ribosome access and translation initiation. Different cis-acting RNA thermometers and a trans-acting thermometer will be presented.
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Affiliation(s)
- Franz Narberhaus
- Lehrstuhl für Biologie der Mikroorganismen, Ruhr-Universität Bochum, Bochum, Germany.
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Velázquez F, Fernández S, de Lorenzo V. The upstream-activating sequences of the sigma54 promoter Pu of Pseudomonas putida filter transcription readthrough from upstream genes. J Biol Chem 2006; 281:11940-8. [PMID: 16510445 DOI: 10.1074/jbc.m511782200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Although the m-xylene-responsive sigma54 promoter Pu of Pseudomonas putida mt-2, borne by the TOL plasmid pWWO, is one of the strongest known promoters in vivo, its base-line level in the absence of its aromatic inducer is below the limit of any detection procedure. This is unusual because regulatory networks (such as the one to which Pu belongs) can hardly escape the noise caused by intrinsic fluctuations in background transcription, including that transmitted from upstream promoters. This study provides genetic evidence that the upstream-activating sequences (UAS), which serve as the binding sites for the pWW0-encoded XylR protein (the m-xylene-responsive sigma54-dependent activator of Pu), isolate expression of the upper TOL genes from any adventitious transcriptional flow originating further upstream. An in vivo test system was developed in which different segments of the Pu promoter were examined for the inhibition of incoming transcription products from an upstream promoter in P. putida and Escherichia coli. Minimal transcription filter ability was located within a 105-bp fragment encompassing the UAS of Pu. Although S1 nuclease assays showed that the UAS prevented the buildup of downstream transcripts, the mechanism seems to diverge from a typical termination system. This was shown by the fact that the UAS did not halt transcription in vitro and that the filter effect could not be relieved by the anti-termination system of lambda phage. Because the Pu promoter lies adjacent to the edge of a transposon in pWW0, the preset transcriptional filter in the UAS may isolate the upper TOL operon from undue expression after random insertion of the mobile genetic element in a new replicon.
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Affiliation(s)
- Francisco Velázquez
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Campus UAM-Cantoblanco, 28049 Madrid, Spain
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Carny O, Gazit E. A model for the role of short self-assembled peptides in the very early stages of the origin of life. FASEB J 2006; 19:1051-5. [PMID: 15985527 DOI: 10.1096/fj.04-3256hyp] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The molecular basis of the origin of life is one of the most fundamental questions in modern biology. While the "RNA world" hypothesis offers a very sensible model for the evolvement of the current biochemical networks, there is a lack of knowledge about the early steps that led to the formation of the first RNA molecules. This issue is essential as it is practically impossible that complex molecules as functional RNA oligonucleotides had evolved spontaneously. It was recently demonstrated that peptide molecules as simple as dipeptides can self-assemble into well-ordered tubular, fibrilar, and closed-cage structures. Other studies have confirmed the ability of dipeptides to act as catalysts and the capability of other peptides, as short as tripeptides, to serve as a template for nucleotide binding and orientation. Unlike complex RNA molecules, the spontaneous formation of functional short peptides in the primordial earth conditions is very likely. We suggest a novel mechanism for the origin of life that is based on the ability of short peptides to form encapsulated structures, catalyst chemical reaction, and serve as highly ordered template for the assembly of nucleotides. This model may explain the early events that led to the formation of the current biochemical machinery that combines the elaborated and coordinated interaction between nucleic acids and proteins to allow the function of living systems.
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Affiliation(s)
- Ohad Carny
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Lim J, Winkler WC, Nakamura S, Scott V, Breaker RR. Molecular-Recognition Characteristics of SAM-Binding Riboswitches. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200503198] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lim J, Winkler WC, Nakamura S, Scott V, Breaker RR. Molecular-Recognition Characteristics of SAM-Binding Riboswitches. Angew Chem Int Ed Engl 2006; 45:964-8. [PMID: 16381055 DOI: 10.1002/anie.200503198] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jinsoo Lim
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA
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Al-Hashimi HM. Dynamics-based amplification of RNA function and its characterization by using NMR spectroscopy. Chembiochem 2006; 6:1506-19. [PMID: 16138302 DOI: 10.1002/cbic.200500002] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The ever-increasing cellular roles ascribed to RNA raise fundamental questions regarding how a biopolymer composed of only four chemically similar building-block nucleotides achieves such functional diversity. Here, I discuss how RNA achieves added mechanistic and chemical complexity by undergoing highly controlled conformational changes in response to a variety of cellular signals. I examine pathways for achieving selectivity in these conformational changes that rely to different extents on the structure and dynamics of RNA. Finally, I review solution-state NMR techniques that can be used to characterize RNA structural dynamics and its relationship to function.
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Affiliation(s)
- Hashim M Al-Hashimi
- Department of Chemistry and Biophysics Research Division, University of Michigan, Ann Arbor, MI 48109, USA.
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Matsumoto S, Akashi H, Taira K. Screening and determination of gene function using randomized ribozyme and siRNA libraries. Handb Exp Pharmacol 2006:197-221. [PMID: 16594617 DOI: 10.1007/3-540-27262-3_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Rapid progress in the sequencing of the genomes of model organisms, such as the mouse, rat, nematode, fly, and Arabidopsis, as well as the human genome, has provided abundant sequence information, but functions of long stretches of these genomes remain to be determined. RNA-based technologies hold promise as tools that allow us to identify the specific functions of portions of these genomes. In particular, catalytic RNAs, known also as ribozymes, can be engineered for optimization of their activities in the intracellular environment. The introduction of a library of active ribozymes into cells, with subsequent screening for phenotypic changes, can be used for the rapid identification ofa gene function. Ribozyme technology complements another RNA-based tool for the determination of gene function, which is based on libraries of small interfering RNAs (siRNAs).
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Affiliation(s)
- S Matsumoto
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1 Hongo, 113-8656 Tokyo, Japan
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Tucker BJ, Breaker RR. Riboswitches as versatile gene control elements. Curr Opin Struct Biol 2005; 15:342-8. [PMID: 15919195 DOI: 10.1016/j.sbi.2005.05.003] [Citation(s) in RCA: 382] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2005] [Revised: 03/16/2005] [Accepted: 05/03/2005] [Indexed: 01/22/2023]
Abstract
Riboswitches are structured elements typically found in the 5' untranslated regions of mRNAs, where they regulate gene expression by binding to small metabolites. In all examples studied to date, these RNA control elements do not require the involvement of protein factors for metabolite binding. Riboswitches appear to be pervasive in eubacteria, suggesting that this form of regulation is an important mechanism by which metabolic genes are controlled. Recently discovered riboswitch classes have surprisingly complex mechanisms for regulating gene expression and new high-resolution structural models of these RNAs provide insight into the molecular details of metabolite recognition by natural RNA aptamers.
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Affiliation(s)
- Brian J Tucker
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
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Ranganath RM. Asymmetric cell divisions in flowering plants - one mother, "two-many" daughters. PLANT BIOLOGY (STUTTGART, GERMANY) 2005; 7:425-48. [PMID: 16163608 DOI: 10.1055/s-2005-865899] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Plant development shows a fascinating range of asymmetric cell divisions. Over the years, however, cellular differentiation has been interpreted mostly in terms of a mother cell dividing mitotically to produce two daughter cells of different fates. This popular view has masked the significance of an entirely different cell fate specification pathway, where the mother cell first becomes a coenocyte and then cellularizes to simultaneously produce more than two specialized daughter cells. The "one mother - two different daughters" pathways rely on spindle-assisted mechanisms, such as translocation of the nucleus/spindle to a specific cellular site and orientation of the spindle, which are coordinated with cell-specific allocation of cell fate determinants and cytokinesis. By contrast, during "coenocyte-cellularization" pathways, the spindle-assisted mechanisms are irrelevant since cell fate specification emerges only after the nuclear divisions are complete, and the number of specialized daughter cells produced depends on the developmental context. The key events, such as the formation of a coenocyte and migration of the nuclei to specific cellular locations, are coordinated with cellularization by unique types of cell wall formation. Both one mother - two different daughters and the coenocyte-cellularization pathways are used by higher plants in precise spatial and time windows during development. In both the pathways, epigenetic regulation of gene expression is crucial not only for cell fate specification but also for its maintenance through cell lineage. In this review, the focus is on the coenocyte-cellularization pathways in the context of our current understanding of the asymmetric cell divisions. Instances where cell differentiation does not involve an asymmetric division are also discussed to provide a comprehensive account of cell differentiation.
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Affiliation(s)
- R M Ranganath
- Cytogenetics and Developmental Biology Laboratory, Department of Botany, Bangalore University, India.
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